Futuristic Bestiarium
In this page descriptions of various animals and plants not included to basic chapters are gathered. The wanishing of the description from this part means that you just must search for new chapter in English version of "The incredible world tour to Neocene".

Long-wattled ghost shark (Caecorectolobus cirrhosissimus)
Order: Wobbegongs (Orectolobiformes)
Family: Carpet sharks (Orectolobidae)
Habitat: Pacific Ocean, depth about 1500 – 2000 meters
Sharks are highly adaptive creatures: this group of fishes is known from Devonian, having proved thus the abilities to adapt to various changes of environment. Opinion that sharks do not evolve till their history is deeply wrong. Various species, families and orders of these fishes replaced each other as regularly, as groups of sea mammals, for example. From most ancient times sharks aspired to take a place of supreme predators of ecosystems. It was possible to them for many times, but sharks had reached especial success in Cenozoic when requiem and mackerel sharks, the top of evolution of sharks, had appeared. The place at top of food pyramid is honourable, but too risky – at ecological crisis predators die out at first. At the boundary of Holocene and Neocene “charismatic” pelagic sharks dwelt at ocean had disappeared – schools of pelagic fishes served as food to them and their catch had died out. Their populations undermined by chasing of people gradually degraded. To early Neocene at the planet mainly medium-sized bottom-dwelling sharks survived. And they had given in Neocene a new wave of speciation. The majority of Neocene sharks are descendants of these species.
After ecological crisis and extinction of pelagic organisms sharks descending from shallow-water species developed the oceans anew. Among them there were species had mastered polar waters of Arctic Ocean and Subantarctic. And some sharks had started to storm ocean depths. Deep-water fauna depended on efficiency of ecosystems of top layers of water had suffered huge damage till the time of “plankton accident” at the boundary of epochs, therefore at early Neocene deep-water ecosystems had started to form practically from zero.
Among sharks occupied depths of ocean there is one descendant of carpet sharks, whose ancestors lived in shallow waters earlier. Obviously, ancestors of this fish had “moved down” to depths of ocean along the continental slope (obviously, somewhere in area of Australia or Indonesia). Therefrom this fish had passed to pelagic habit to life already as deep-water animal. Hence of fantastical appearance this fish named ghost shark. The length of this fish is about 2 meters; tail fin with much lengthened top blade located almost horizontally makes about one third of general length.
This fish lives in depths where change of day and night is not felt at all – at the depth over thousand meters. Colouring of skin of ghost shark is unicolor light grey; that’s why fish looks “belongig to the beyond”. As against overwhelming majority of Neocene sharks it is completely blind fish – even a sign of eyes is not remained from outside. Eyes are functionally replaced with another “secret weapon” especially advanced at sharks – instead of them organs of lateral line are used for orientation in water. Ghost shark has flat head, lengthened body and rather short fins. At this fish there are two back fins, on each back fin there is hollow corneous spike connected with poisonous gland. This is the main protective adaptation against deepwater predators: sometimes these sharks are attacked by squids and their own larger congeners.
Similarly to all carpet sharks the ghost shark has many skin outgrowths at the edge of muzzle. This inheritance from carpet sharks of shallow water habitats earlier serving for masking had got other function in gloom of depths, much more important for survival: very much advanced outgrowths on head contain branches of lateral line, and fish orientates with their help. Outgrowths on muzzle reach the length equal to fish’s head. It has determined the specific name of fish: “cirrhosissimus” means “the most whiskered”. Organs of lateral line located on outgrowths of fish’s head permit to trace the slightest changes of electric field surrounding fish, meaning presence of other live creatures.
Besides long-wattled ghost shark there is very keen sense of smell: it has large chinky nostrils.
This shark is slow: the most part of time it passively floats in thickness of water, tracking down other fishes and various pelagic invertebrates – squids and octopuses. Its catch not always differs in speed; therefore it may be easily caught even by such blind and slowly moving predator. Long-wattled ghost shark is able to catch fast catch, making short sharp throws. This fish eats basically fishes and squids having soft and flabby body consistence. Therefore its teeth have not cutting or crushing, but thrusting type – they are rather thin, awl-like and slightly bent. With the help of such teeth it is easy to catch slippery and soft-bodied prey. Having an opportunity, long-wattled ghost shark sometimes eats carrion – corpses of fishes and large sea animals immersed to the bottom. Eating carrion, the fish seizes sticking up parts of carcass and sharply turns, trying to tear off a piece. But more often this shark is interested not in carcass, but in animals coming to feed at it.
In typical case sharks lay large eggs from which the posterity hatches after rather long time. For the pelagic species living above the big depths, such vital strategy is unacceptable: females should make migrations to the continental slope to hatch posterity or to lay eggs right in water where they will fall to depth and can not develop there. The smaller number of sharks is live-bearing species, and long-wattled ghost shark belongs to their number. Pairing at this species occurs at any time of year – in ocean depths seasonal change are not expressed. Male is a little bit smaller than female (its length is about 170 cm), and has advanced copulating organs on abdominal fins. It has keen sense of smell and searches for the female ready to pairing by smell. Having found it, male catches it up and slightly compresses by jaws her back fin, stopping the female and showing to it readiness to copulation. As a rule, deep-water animals differ in small intensity of metabolism processes. For this reason pregnancy at this shark lasts for very long time: about 15 months. Fertility of long-wattled ghost shark is very small: the female gives rise only to two young fishes. But the newborn shark of this species is about 60 cm long at once is able to eat independently and due to the size avoids the fate to be eaten. After birth of posterity the female picks up and eats egg shells. In some days after birth of posterity the female is ready to reproduction again. The young fish reaches length of 1.5 m at the age of 10 – 13 years. In same time it becomes able to breeding. Survival rate at young long-wattled ghost sharks is very high. It partly compensates the low reproduction rate: for all life the female gives birth to no more than two tens of young ones.

Pike shark (Esocisqualus rivularis)
Order: Dog sharks (Squaliformes)
Family: Dog sharks (Squalidae)
Habitat: Asian rivers of Pacific and Arctic Ocean basins.
Shark in the river is more exception, rather than rule. Usually these cartilaginous fishes live in sea, though some species of fossil sharks of Paleozoic era were found in river deposits, and in Holocene some species of sharks were known, able to live and breed normally in rivers. Basically such phenomenon was typical in tropical zone of Earth. However in this case occurrence of freshwater species of sharks in northern rivers was quite natural: approach of glacier from the north forced some sea polar species to recede to rivers. This way in the rivers of Eurasia burbot (Lota lota), the freshwater descendant of sea cod fishes, has appeared.
Ancestor of the pike shark is one of sea dog species of Pacific Ocean. Receding to rivers during ice age, they adapted to long existence in fresh water, and then had made very important step: began to breed in rivers, having torn thus connection with salt water of ocean. At floods of rivers these sharks had settled over far inside of continent - in headstreams of rivers of Arctic Ocean basin. Being isolated from ocean, small sea dogs evolved to separate species – pike shark.
Pike shark is rather large fish: its length is up to 2 meters. Though for sea species it is rather mediocre size (frankly speaking), in fresh water of cool rivers of Northeast Asia only few species, capable to be compared to this shark in size, may be found. Body of this fish is very long and thin: the maximal height of it does not exceed 15 cm. Pike shark crowns feeding chain of northern rivers, being in them the original ecological analogue of crocodile.
The shape of pike shark is characteristic for the majority of sharks: pointed snout, inferior mouth, triangular fins and crescent tail. Colouring of body of this fish is striped: on olive-brown background cross light strips pass, breaking to separate spots on head. Head of pike shark is narrow and flat. Teeth are triangular and sharp: the basic food of this shark is medium-sized fishes and crayfishes. Sometimes pike shark eats small mammals got in water, and waterfowl.
This shark has kept a heritage of ancestors – sharp sense of smell and well advanced circuit of bodies of lateral line on head. These adaptations are especially useful at life in the river when water frequently happens muddy. However sight at pike shark also is well advanced: at it there are large yellow eyes with narrow vertical pupils.
By the habits this fish is typical bottom-dwelling predator. This shark spends the most part of time in thickets of plants, having directed by head against current. So it is easier to it to ventilate gills, and fishes and swimming animals, carrying by current, are visible. Colouring helps pike shark to mask.
In case of necessity this shark can swim from one place to another, bending eel-like by all body. But at attack it develops significant speed: up to 60 km per hour during several tens seconds. However in general it is nevertheless rather bad and lazy swimmer. This fish spends winter in deep holes in river channel, having stopped feeding completely. In winter time pike shark lives due to fat had been accumulated in long liver, stretching along all abdominal cavity.
Appetite at the pike shark awakes in spring when day becomes longer, and water gets warm. During floods of rivers when in river many bodies of drown animals float, pike sharks almost completely pass to feeding by carrion. In summertime when river water strongly gets warm, and the contents of oxygen in it decreases, sharks leave shallow tributaries and keep in places with cooler water: at the bottom of river and near underwater springs. In summer this shark hunts at night.
The basic problem of many sea fishes at transition to life in fresh water is the egg development: their eggs may develop only in salt water. Pike shark had avoided this problem by simple way: it is live-bearing fish. Pairing occurs in the beginning of summer, when fishes grow fat and restore forces after winter catalepsy. Males start to chase females, from time to time cautiously biting them to back edge of back fin. Pairing lasts not for long, and takes place in thickness of water.
In oviducts of the female within 10 months simultaneously 2 cubs develop, growing up to 30 cm. They are born in late spring and at once live quite independently, eating small fishes and crustaceans. Colouring of young fishes is more sated and contrast, than at adults. At the sixth – seventh year of life, when the length of young fishes reaches one and half meters, they become able to breeding.
Pike shark yields to pike in longevity: the age limit of this fish can exceed 100 years.

Zeus's shark (Electroselache zeusii)
Order: Dog sharks (Squaliformes)
Family: Electric sharks (Electroselachidae)
Habitat: Atlantic, depths from 50 up to 300 meters in tropical and subtropical area; at night emerges to water surface.
During the evolution process organs and tissues may considerably change the functions in comparison with their initial applicability. So, at fishes belonging to various systematic groups muscles had changed to electric organs becoming the effective adaptation for orientation and hunting weapon. In Neocene new groups of fishes had got electric organs. Zeus's shark living in Atlantic Ocean is an electric species of sharks. It is an example of parallelism with rays of order Torpediniformes, known even in human epoch as owners of strong electric weapon – hunting and protective adaptation. Zeus's shark has received the name by analogy to skill of antique god Zeus to fulminate, but, as against the mythical person, it makes it in real life.
This species is a pelagic fish of about 2 meters long weighting up to 150 kgs and living in top layers of water in temperate and subtropical zone of Northern hemisphere. Appearance of Zeus's shark is typical for the majority of sharks – it has streamlined body, pointed fins, unequally-lobed tail with the increased top lobe. Pectoral fins of this shark are rather short: it is able to swim quickly only at short distances. Colouring of body of a Zeus's shark is light blue with black spots on tips of pectoral fins. The top lobe of tail from the tip up to middle is colored white.
The anatomy of head of this shark is remarkable. It has wide short snout, and skull is expanded in top part, forming two big crests directed sideways and a little bit upwards. These crests serve as original stabilizers of position of body at swimming. Eyes are shifted downwards under stabilizer crests. The distant relative of this species, huge cachalot shark (Physelache planicephala), has a similar structure of head. Mouth of Zeus's shark is small; jaws are attached to skull and to each other by elastic ligaments. Teeth of this species of sharks are peaked, needle-like, small and weak; they grow on jaws forming six – eight lines. It is impossible to cut half-and-half even the soft body of squid by them; they serve only for keeping of prey. Jaw muscles of this shark are also very weak. It is connected to the fact that the significant part of strong muscle closing the mouth at ancestors had turned to electric organ and had lost the ability of contracting. Besides crests on skull of this fish were also formed for increase of size of electric organs which are attached to their basis. The voltage creating by Zeus's shark may reach 250 volt at force of current up to 2 amperes.
Zeus's shark hunts schooling fishes, pelagic crustaceans and cephalopods. Usually it slowly swims in thickness of water, but, having felt approach of school of prey, makes a throw. Wedging in school of sea animals, shark produces some strong electric pulses one by one. It happens enough to kill or to paralyze several fishes or squids. Usually the most part of school escapes, but this shark always gets some prey animals. It simply swims across the “battlefield” and gathers shocked fishes. This shark swallows prey entirely: jaws can opened widely due to extensible and elastic ligaments. Due to the ability to produce strong electric impulses the present species of sharks does not have any satellite animals of various kinds usually accompanying sharks.
Zeus's shark is a solitary species; only during the pairing some males may court for one female. During the courtship ritual males produce the short weak electric impulses having signal function. Female also replies them with electric impulses. If it is not ready to pairing, it banishes male by stronger electric pulse.
This species is viviparous: after the pregnancy lasting about 7 months the female gives rise to up to 6 large (about 30 cm long) and independent young sharks. Young ones the first days of life can not produce electric impulses – it protects the female at delivery process, but makes young sharks very vulnerable. During the first days of life the electric organ starts to develop, and at young fishes grown up a little electric impulses are already strong enough to frighten off the predators really dangerous to fishes of their size. Sexual maturity at young Zeus's sharks comes at the age of 4 years, and life expectancy reaches 25 years.
In northern part of Pacific Ocean Zeus's shark is substituted by close species – Taranis’s shark (Electroselache taranisii), named after Taranis, the god of lightning of ancient gauls. This species differs from Zeus's shark in larger size – up to 3 meters at weight more than 200 kg. Because in the top layers of water in Pacific Ocean sharkodile (Carcharosuchus deinodontus), ecologically replacing large sharks and being an active predator dominates, in day time this shark keeps at the depths of about 100 – 200 meters. Possible, the settling of an ancestor of these fishes had proceeded through Panama Passage. Taranis’s shark also has electric weapon. Fertility of females of this species reaches to 10 – 15 young fishes.

Meganesian sawfish (Pristis meganesianus)
Order: Sawfishes (Pristiformes)
Family: Sawfishes (Pristidae)
Habitat: rivers of Meganesia.
During Holocene sea ecosystems had suffered not less than land ones, because people polluted ocean and caught many species of food fishes and invertebrates, not reflecting about the future. Besides “planktonic accident” had caused destruction of great number of species of pelagic animals. Species had not died out during the reorganization of ecosystems, should adapt to existing is sharply changed conditions of Neocene. Bentic communities of coastal waters had suffered lesser; more kinds inhabited such areas had kept. Dwarf sawfish (Pristis clavata) was among ones managed to survive in epoch of anthropogenous pressure and biological crisis. Having managed to go through threat from the side of people in Holocene, in Neocene it was compelled to adapt to new neighbours: Neocene saw-nosed crocodile (Pristisuchus serratorostris) had occupied the ecological niche of sawfishees in brackish reservoirs of Meganesia, and other crocodile species, giant sharkodile (Carcharosuchus deinodontus), has risen on top of food pyramid in tropical waters of Pacific Ocean. In such conditions the way of life of sawfish could not remain former. It had adapted to new neighbours and conditions of life by the same way, as well as some other species of cartilaginous fishes. Like pike shark (Esocisqualus rivularis) of Asian rivers and river shark (Neocarcharinus flumineus) of East Africa, dwarf sawfish had passed to life in fresh water. This species lives in Meganesia where there is enough forage and there are no large competitors. Meganesian sawfish inhabits rivers flowing to Eyre Gulf. In Arafura Lake this species of fishes is superseded by saw-nosed crocodile, and submitted by only separate individuals.
Meganesian sawfish is not so large kind of rays: its maximal length is 60 – 80 cm. The largest individuals, sometimes up to one meter long, live in coastal freshened zone and mangrove thickets of Eyre Gulf. Colouring of flattened body is concealing: greenish-brown (at females there is a prevalence of yellow shade). The snout has kept the characteristic sawtooth shape, but became much shorter, than at ancestor – less than one third of total length of fish. On it 9 – 11 pairs of teeth grow; they are sharp enough and quite capable to deliver dangerous laceration to predator or prey. But by its habits Meganesian sawfish is sluggish and inactive fish, preferring to attack from an ambush instead of prey chasing. This ray eats small river fishes and invertebrates, dexterously digging them from silt by snout. The mouth of this fish is located on the bottom side of body, and fish swallows prey, preliminary having pressed it to the bottom by body. At threat of predator attack this fish gets deeper into thickets of aquatic plants, or is simply dug in silt. However the seized fish strikes wounds to the enemy by snout. Male has longer snout, than female; also it is more graceful and smaller a little, than female.
Meganesian sawfish has very small eyes shifted to the basis of snout. Bad sight is quite compensated by a circuit of electroreceptors on skin, especially on bottom part of body. With their help fish easily finds out the prey hidden in sand, in total darkness. This adaptation allows Meganesian sawfish to hunt successfully even during high water, when rivers carry a plenty of dregs.
This is live-bearing species of fishes similarly to its ancestor. The female bears posterity within approximately eight months and gives rise up to four young fishes completely ready to independent life. At newborn sawfishes snout is protected with dense cover of jelly-like mass, which falls down right after birth. To one-year-old age approximately half of young growth stays alive, but further death rate reduces. Female becomes sexually mature at the seventh year of life. Total life expectancy of Meganesian sawfish reaches 40 – 50 years.

This species of fishes was discovered by Bhut, the forum member.

Bunyip (Teratoceratodus bunyip)
Order Australian lungfishes (Ceratodiformes)
Family Barramundas (Ceratodidae)
Habitat: rivers of Eastern Australia to the north up to Carpentaria Lake.
The bunyip is a mythical predatory water monster from Australian rivers. In Neocene the legend about this creature had been unexpectedly embodied in reality. Crocodiles had died out in an ice age, but to change them in their ecological niche the new predator had come, quite suitable by its habits to the image of legendary monster.
Ancestor of this creature is not a reptile, but fish, the amazing Australian barramunda (Neoceratodus forsteri). As it is paradoxical, this creature had got advantage in survival because of human activity: in XX century of human epoch this fish had been widely settled by people at the continent for the purpose of preservation of this species. It was successful act, and the small population of barramunda had survived in lakes at bottom of Great Dividing Ridge. To survive, these fishes had starting to master other food sources, than were at their ancestors. Rather large animals, mainly vertebrates, are including to ration of Neocenic bunyip. This fish had replaced the extinct crocodiles at top of food pyramid.
It is strictly freshwater fish. Bunyip does not come to Carpentaria Lake far from coast because of residual salinity of depths (this lake represents a former sea gulf), moving only along coast and is settling in swamps surrounding this lake. Bunyip does not live in Arafura Lake at all: it is even more salt, and here one of relic species of crocodiles replaces it. But bunyips live in the rivers running into these lakes, and in circuit of channels and bogs of tropical rainforest.
Bunyip not so strongly differs from the ancestor: it had kept features of structure characteristic for the barramunda – flipper-like fins, large scale and one lung. But it had appreciably increased its size: it is a huge predatory fish up to 4 meters long and weighting over 400 kg. The female is larger and paler than male, but at the male head is larger. The tail of bunyip is short, rounded and expanded in comparison with the lengthened peaked tail of barramunda. It is used only for sharp throws for catch, and not hunting fish swims with the help of movements of wide flipper-like paired fins.
The head of bunyip had turned to true ram: the cartilaginous skull is considerably strengthened by shell scutes. Corneous plates, with which help fish grasps and dismembers catch, have peaked cutting outgrowths. They can split half-and-half seized catch: fish, lizard, bird or mammal. Bunyip avoids only attacks on the adult turtles protected by firm carapace, but this fish swallows the young growth of turtles entirely and exterminates it in plenty.
At the bunyip there are small eyes and bad sense of sight, but sharp sense of smell and sensitive lateral line. Even in darkness this fish can easily find and seize small frog swimming several meters far from predator.
Bunyip is bad swimmer, but it is the master of camouflage: its colouring – brown with dark speckles – makes it badly seen among river dust: driftwood, trunks of trees and layer of fallen leaves. Having masked, the fish passively expects catch, attacking it by fast throw. About two - three times at hour bunyip emerges for air, though in case of necessity and in fresh water, rich in oxygen, it can make it only once per hour, and even less often. At breath the fish utters loud groaning sound especially far heard in silent night. Each fish protects territory from neighbours, and this sound distributing under water, warns neighbours of territorial claims of bunyip.
The bunyip tolerantly concerns to life in pond with muddy stinky slush to which water turns during a drought: it respires by air, and the zero contents of oxygen in such water is indifferent to it. However this fish does not live in completely drying up reservoirs, because it has no special mechanisms promoting preservation of water in body. When the drought begins, bunyips leave inundated reservoirs and migrate to the central channel of river, or stay in deepest ponds. When in river channel many fishes of this species swim together at once, between them there are fights and many borders of territories are reconsidered. Though in inundated reservoirs there are young and weaker fishes, and in the main channel the strongest individuals live, some young applicants had “grown up” till the rain season, more often succeed to win at older individuals a place to themselves. Fight is accompanied by demonstration of forces, pushes by sides and impacts by head. When forces are equal and any contender does not concede, jaws are used for fight. Some old individuals have characteristic traces of stings on back and sides – four deep V-shaped small holes placed in corners of rectangular, staying from the pointed ends of cutting plates.
The spawning of bunyips occurs once a year in rain season: at this time many fishes leave the basic channel, and the competition is reduced. The unitary fast spawning is a consequence of very short period favorable for spawning at ancestors of bunyip during the ice age (at the barramunda spawning is portional and dragged out to some months). For spawning the male chooses underwater small-leaved plants, clears them of silt by movements of fins, carries off stones and dust, and starts to invite the female to the prepared breeding bottom. It pushes the female by head, swims around of chosen bush of water plants, emerges and specially “sings”, exhaling air with all its might.
In clutch of bunyips there is up to thousand of very large grains of roe (their diameter is about 2 cm). Fishes spawn eggs in plants prepared by male, and he stays to protect territory around of clutch, not caring special way about eggs.
Egg incubation lasts about 2 weeks, and then approximately equal time the larva passively lives at the bottom, hiding from enemies, not eating and digesting the rests of contents of yolk sac. Later it passes to feeding by small water invertebrates and fry of fishes. At one-year-old age the bunyip reaches length about 10 cm. Further, having transited to feeding by fish, fish strongly accelerates the growth rate, and at ten years' age, at length about two meters, the fish already can take part in spawning. The maximal life expectancy of bunyips may exceed 150 years.

River boltergiller (Potamocetus balaenognathus)
Order: Osteoglossoids (Osteoglossiformes)
Family: Aravanas (Osteoglossidae)
Habitat: rivers of South America, central part of channel.
After the ice age had marked border of Holocene and Neocene, climate began considerably more humid: seas have filled coastal sites of land, and areas of water evaporation had increased. Rains had returned again to equatorial areas of Earth, having filled with water great rivers. Amazon and Hyppolite, flowing in parallel to it, are two rivers gathering water from significant part of South-American continent. Each of these rivers differs in large width, overflowing at tens kilometers and flooding riverbank woods.
Waters of these rivers gather organic substances from huge woody area, and current of the rivers is slow enough. Due to it in central part of river channel in upper layer of water plankton (algae, small crustaceans and worms) plentifully develops. Shoals of fishes serving as food to some predatory reptiles, mastered channels of big rivers, eat river plankton. But these predators respectfully make way for one of inhabitants of channel – huge four-meter fish slowly swimming near the surface. This fish inspires respect in size, but it is not furious predator. It is the river boltergiller, the descendant of aravana (Osteoglossum). This fish does not represent danger for animals longer than 3 – 4 centimeters: it eats plankton, tiny schooling fishes and fry.
Due to abundance of food this river giant easily increases weight up to about 300 kgs. Body of the boltergiller is compressed from sides, especially in tail part, right after abdominal fins. Back, head and top part of tail make practically straight line: it is an attribute of top-skimmer fish spending the most part of time at water surface. Boltergiller swims rather slowly, bending by all body like eel. The tail fin at it is small and narrow, grown together with anal. Wide band-like anal fin stretching from middle of body up to the end, is the main organ of movement of fish. The back fin is reduced up to the several fin rays not connected by membrane.
The head of boltergiller is high, and mouth can open widely. Thus jaws draw downwards and in sides, forming wide funnel. Gills of fish had changed to effective filter device: branchial stamens have turned to similarity of dense grid, detaining even smallest zooplankton. Eyes of boltergiller are rather large, orange-colored. In spawning season eyes of males get ruby-red color. On chin pair of characteristic wattles directed forward stick.
The body of fish is covered with large rounded scale. Colouring of body is silvery with blue shine and grey back. The anal fin is bordered by black strip.
The boltergiller spends all adult life far from river coast. It is solitary fish, only at “pastures” rich in river plankton it is possible to meet at once several fishes. They do not pay attention against each other.
The spawning season at these fishes lasts within all year, but fishes show especial activity after rain season when water in the rivers is rich in plankton. Male ready to spawning declares itself by high jumps from water. At times fish takes off from water vertically at three - four meters upwards, and plops down on side, splashing a cloud of splashes. The booming sound lets females know, that the male is ready to take part in courtship. This fish is monodin. Spawning proceeds in thickness of water. Female spawns large egg in portions, male fertilizes them, and then female picks them up by mouth. Such acts repeat, while all eggs will be spawned.
At this species not only the female, but also the male, shows care of posterity: when all eggs are spawned, female delivers a part of clutch to the male from mouth in mouth. Term of egg incubating is about one week. All this time fish, bearing posterity, does not eat. But it does not harm to its organism: fishes are able to fast for very long time. Fry spend first days in mouth of the parent, but starting to swim, they leave it and further live independently. When the fish bearing posterity, feels, that fry are ready to leave the refuge, it approaches to riverbank and comes into small rivers. Here parent opens mouth, and fry swim out in searches of food.
Larvae of river boltergillers feed in coastal waters, occasionally remaining in lakes after river floods. Here, far from the majority of predators, fishes grow fat, and at the following floods leave temporary refuge and swim to the basic channel of river. They become sexual matured at the fifth year of life at length about two meters.
The boltergiller differs in significant longevity: this fish can live up to 60 - 70 years.
In shallow rivers of Amazon and Hyppolite basins there are close species: green boltergiller (Potamocetus viridis) smaller fish reaching only two-meter length. It differs in richer branchial stamens allowing filtering from water phytoplankton – the main food of this species. The body of this fish is higher and also has greenish colouring.

Deadly phyllomormyrus (Phyllomormyrus lethalis)
Order: Elephantfishes (Mormyriformes)
Family: Elephantfishes (Mormyridae)
Habitat: Zinj Land, steady flowing rivers and lakes.
Till the evolution process the role of adaptations produced by ancestors of any species of live organisms can vary strongly. For example, leaves of plants may turn to spikes, and stalk fulfills the function of leaves. When any plant loses petals, but later comes back to pollination with the help of insects again, floral bracts become bright like petals. Such phenomenon of function change is not a rarity in nature.
At African elephant fishes till the evolution the adaptation was developed for orientation in space in conditions of bad visibility – fishes had got ability to develop faint electric field, and began to define the presence of other objects near to themselves by its changes. Such attribute during the evolution process appeared repeatedly at various species of fishes, therefore the development of electric bodies at elephantfishes does not look something oustanding. When the East African subcontinent (Zinj Land) had separated from the continent, these fishes began to evolve independently of continental species. In reservoirs of Zinj Land the special ecosystem had formed, where the original species of elephantfishes became one of top predators. It has developed special hunting tactics getting food – small schooling fishes and tadpoles.
These species of elephantfishes is named phyllomormyrus (“leaf-like Mormyrus”) for the special body shape and coloring. This fish has cryptic coloring and shape which simulates rotting leaves very precisely. High rhomb-like body of fish is compressed from sides; it is about 20 cm long and colored brown with yellowish spots. Along the side rough light strip stretches. On back and anal fins there are rough dark brown borders similar to rotten edges of leaves of any tree. The edge of back fin, pectoral fins and tail of fish are completely transparent. Eyes of phyllomormyrus are also disguised – iris of eyes is brown with grey “marble” pattern masking the eye at the background of body colouring. The snout of phyllomormyrus has the lengthened shape characteristic for these fishes, and simulates a leaf petiole. It is very long, and also makes about one third of general length of fish. On the tip of snout there is small mouth with short appendage on lower lip. The male of this species does not differ from the female in colouring; it is only smaller a little than the female.
The hunting tactics of phyllomormyrus combines tactics of South-American fishes of Holocene epoch known to people: leaf fish (Monocirrhus polyacanthus) and electric eel (Electrophorus electricus). This species of elephantfishes eats small animals, preferring tiny schooling vertebrates. This predator creeps to fry or tadpole school using cryptic colouring. The shape of fish simulates leaves of a tree beginning to rot so well that it misleads even the most cautious fishes. Hunting phyllomormyrus is slowly swimming to planned prey, moving by transparent fins. For most persuasiveness fish can swim in any position, keeping body obliquely or even laying on the side. Appearing among fry or tadpole school the fish suddenly strikes them by electric impulse. Stunning prey, fish can emit one by one up to four electric impulses in succession. After that fish simply gathers paralysed catch by proboscis from the bottom. If necessary the phyllomormyrus gives additional electric impulses, paralyzing animals trying to escape from it. Phyllomormyrus also eats larvae of insects, searching for them in thickets of underwater plants.
This fish is a single predator. Each individual occupies the certain site in shallow waters overgrown with plants. Large driftwood and bushes of water plants serve as marks of territory borders. When two fishes meet at the border of territory, they exchange series of faint electric pulses, distinguishing each other and estimating physical condition of the contender. Usually young fishes live at boundaries of sites of adult fishes, avoiding an opportunity of meeting the adult individuals. These fishes can not injure each other by stings - mouth at them is too small for it. But the adult fish can paralyze and even kill young individual of this species by electric impulse.
The spawning of phyllomormyruses begins with approach of rainseason. Pairs at this species are formed of adult individuals living at next sites. Before the spawning male and female exchange electric pulses in special rhythm which is analogue of courtship dance. For this purpose partners rise under floating plants in parallel to each other, and emit a series of electric impulses. First male and female do it alternately, and then pulses become simultaneous. Such feature of behavior synchronizes processes of roe ripening. Prespawning games proceed till approximately day and night. For spawning fishes build a nest of floating long-steme plants. They weave plants to dense tangle among thickets, and get into it together to spawn large eggs.
In clutch of phyllomormyruses it may be totally more than three hundred large eggs. The male protects nest against possible predators with the help of electric impulses. At this time it eats almost nothing, and only occasionally catches prey had casually appeared near the nest. The egg incubating lasts about three days, and two more weeks larvae not able to swim sit in nest. When fry starts to swim and leaves the nest, male ceases to protect the posterity. Young fishes usually keep in rich thickets of plants where adult fishes of this species can not make the way. To the end of first year of life young fishes reach the length 4 – 5 cm, and at the third year of life at length about 15 cm they already start to breed.

New Zealand eversmolt (Salmini novazealandiae)
Order: Salmons (Salmoniformes)
Family: Salmons (Salmonidae)
Habitat: mountain rivers of New Zealand.
In human epoch the ichthyofauna of New Zealand differed in certain poverty and high degree of endemism. This archipelago had separated from continents in Mesozoic era when typical groups of freshwater fishes had not evolved yet. In Holocene freshwater fishes of New Zealand were presented by descendants of sea and euryhaline species. But later the situation had sharply changed. People had introduced to New Zealand various freshwater fishes descended from other continents, and had caused irreparable damage to local fauna by this action. After extinction of mankind newcomer species had quickly developed new habitats, having superseded the majority of survived native species, and development of ecosystems of archipelago had proceeded in absolutely another direction.
Climate of New Zealand in Neocene is typical subtropical, and in the south it is warm-temperate. But the significant part of archipelago is presented by mountain areas where the cool climate dominates. And at high tops of mountains the most part of year snow and ice lays. Short cool rivers of islands originate here. In upper courses of rivers, in crystal-clear and ice-cold water the small fish keeping by large schools on current is found. From time to time these fishes jump from water, trying to seize any insect flying above water. It is one of fishes appeared due to activity of human had missed for millions of years before epoch of Neocene. This fish is New Zealand eversmolt, dwarf descendant of trout introduced to New Zealand. Actually it is simply dwarf variety of trout quickly maturing, keeping in adult condition juvenile attributes, and living not for long.
New Zealand eversmolt has kept characteristic for trouts propensity to live in cool and rich in oxygen water. The torpedo-like shape of body with pointed snout helps this fish to resist to current successfully. Fins of New Zealand eversmolt are peaked; tail fin is high and crescent. These are attributes of quickly swimming fish: actually, these fishes all the day struggle with current only to remain at the same place – near the chosen stone or bush of aquatic moss. Body length of New Zealand eversmolt is about 12 cm; the female is larger and approximately 25 % heavier, than male.
Colouring of this fish in details is similar to coloring of its ancestor, brook trout (the river form of Salmo trutta). Out of spawning season male and female are coloured similarly: black and red spots on the body form marble pattern on silvery-green background. At this fish there are large silvery eyes: New Zealand eversmolt hunts mainly with the help of sight.
The mouth of fish opens widely; on tips of jaws well advanced sharp teeth grow. Usually this fish keeps in schools in current near water surface. New Zealand eversmolt eats basically flying insects – dragonflies and May flies. Hunting fish waits for insects, keeping near stones or leaves of water plants fluttering in current in order to be not too appreciable at sight from above. When above surface of water an insect flies, fish catches it right in air in well-aimed jump. Planning jump, fish instinctively makes the amendment to refraction of water, and on average each third jump appears successful. Occasionally fish gathers insects from surface of water and catches aquatic larvae of dragonflies and May flies between stones.
The courtship season at New Zealand eversmolt begins in spring (in Southern hemisphere it is October – November) when mountain snows thaw. At this time males get more saturated colouring: they turn velvety-black with silvery eyes and red spots on the body. Only on stomach and near anal fin they keep sites of silvery background colouring. Females, on the contrary, brighten, and their colouring becomes almost completely silvery with dark grey back and speckled anal fin. Similarly to salmons of Holocene epoch, New Zealand eversmolt spawns on current, on sites of bottom covered with fine pebblestone. On spawning places these fishes gather to schools numbering up to hundred individuals and stay there within several days. These fishes dig eggs in pebble where clutch is reliably kept from the majority of predators.
Spawning act of New Zealand eversmolt takes place in the morning. At this time schools of fishes approach to riverbank, and keep in shallow water. From water fins of males behaving rather aggressively relatively to each other stick up. Males combat with each other for place more convenient for spawning, and gradually the school breaks up to separate groups. The appearing of females at spawning place results in excitation at males. Their colouring turns brighter, and they by two or three chase females when they swim near to male groups. Gradually each female chooses the certain site of bottom, and males surround her. During the spawning female digs a hole for eggs by lateral movements of stomach and tail, and after it one or two males throw ground in sides. At the following attempt female throws up eggs in made furrow, and males immediately fertilize them. After that fishes dig eggs in ground and do not care of it more. Spawned individuals are very weak, and at this time various aquatic and ground predators actively hunt for them. Fishes keep on sites of rivers with slower current, and sometimes hide in cracks between stones and have a long rest there. The most part of fishes spawns eggs no more than three times per life.
Eggs develop among pebblestone within approximately three weeks. For this time part of it perishes from various predators – mainly from worms and larvae of insects. Fry hatch translucent and helpless, and start to swim at week age. Up to this moment the significant part of fry perishes, but the number of survived ones is enough to keep the stable populations of species. The maturity of New Zealand eversmolt comes at 2-nd year of life, and life expectancy makes up to 5 – 6 years.

Ice galaxia (Antarctogalaxia cryoresista)
Order: Galaxiiforms (Galaxiiformes)
Family: Galaxias (Galaxiidae)
Habitat: fresh waters of Antarctica.
Antarctica is a continent which nature had gone through catastrophic changes in late Cenozoic. The severe congelation had held down continent for millions years by ice layer of more, than one kilometers thick, having completely deprived this ground of vegetation and fresh water. In Holocene the nature of this continent was presented only by sea animals dependent on efficiency of ocean, and several species of tiny terrestrial invertebrates.
In Neocene, due to climate warming, glaciers of Antarctica had started to thaw. The significant part of continent had exempted from ice, but in polar area still there is a glacial cover. But the edges of continent directed to Indian Ocean and Australia, are covered with meadows of graminoids and sedges. In spring, when snow thaws, meadows become covered by circuit of lakes and bogs. Besides on central glacier short rivers spring. In them an interesting ecosystem had formed – the primal freshwater fauna of fishes was destroyed by a congelation, and various larvae of dragonflies have partly replaced small fishes live in the majority of temporary and constant reservoirs. Sea fishes come into lower reaches of Antarctic rivers, but they do not live in fresh water constantly. However some descendants of sea fishes passed to life in fresh water. It is rather difficult step – in Antarctica extreme conditions of an inhabiting dominate. In frosty winter rivers of Antarctica become covered by thick layer of ice, and shallow standing reservoirs may freeze up to the bottom. But all the same, as soon as ice thaws, in the rivers of Antarctica it is possible to see fishes.
Long-bodied fishes about 20 – 30 cm long slide in ice-cold water among stones. At them there is rounded in section eel-like body supplied with short fins. The skin of fish is lack of scales, covered with layer of slippery slime due to what fish freely rummages in stones, not being afraid, that it may be pressed down. Colouring of this fish is brown with numerous green speckles. This inhabitant of Antarctica is named ice galaxia, and it belongs to group of fishes very characteristic for southern hemisphere. In prehistoric times galaxias, obviously, lived in Antarctica before the continent was buried under ice cover. In Neocene descendants of one species of these fishes (possible, South-American or Tasmanian one) had conquered the continent “fishless” earlier.
Ice galaxia almost constantly lives in fresh waters of Antarctica - in rivers, lakes and bogs. It eats larvae of numerous Antarctic species of dragonflies. This fish can catch swimming larvae in thickness of water, but prefers to dig ground by flattened head in searches of sluggish creeping larvae of large species of dragonflies.
For Antarctica the seasonal climate with sharp difference between winter and summer temperatures is characteristic. Though Neocene is rather warm epoch, Antarctica still is near South Pole, and it is only slightly warmed with sea currents from equator. Therefore in winter ice galaxias put on trail on durability – they should resist to all-permeating rigorous cold. These fishes do not try to escape in warmer places (for example, in sea). They continue to live in the same place where they lived before colds. When frosts lock the surface of reservoir, fishes dig in silt, plaiting in tangle of several tens individuals and plentifully secreting slime. Such tangle of fishes is surrounded with viscous mucous mass which has two important qualities – antifreeze and antiseptic. It interferes the freezing of integuments of fishes, and does not enable parasites to attack hibernating fishes. In winter at weakened fishes in collective hibernation wounds heal easier, and individuals struck by ectoparazites recover. In deep whirlpools fishes do not dig in ground, but also surround itself with slime. This way fishes hibernate more successfully – even if ice is formed on the surface of common mucous cover, fishes will not be injured. And even if the tangle of fishes will freeze in thickness of ice, inside it all the same semi-liquid slime remains.
Ice galaxia spawns in lower reaches of rivers and at the sea shallows. In spring till the high water time fishes had survived in wintering, migrate to lower reaches of rivers by large shoals. If fishes hibernated in standing reservoir, they all the same aspire to reach the sea. While night replaces day, fish creeps out of water and creeps by ground to the nearest river, being guided by smell of river water. Males arrive to breeding bottoms the first. Having felt brackish water, they get courtship dress. In breeding-dress at the male green speckles in forward part of body turn golden, and iris of eyes brightens. Males begin courtship demonstrations in places well protected from local fish-eating birds – yellow-headed divesparrow and large penguigulls: among brown algae where birds do not swim. They gather schools, and while there are no fish-eating birds around, demonstrate themselves in shallow water. At the slightest sign of danger they hide among seaweed and turn dull.
When females come, males change. Any care is lost, and rough spawning begins. Schools of males and females join, and leave a trace of pale soft roe and small translucent eggs. At this time they are not afraid neither birds, nor predatory fishes, absorbed by the purpose of breeding. Fishes scatter eggs at the bottom, and it is the limit of their care of posterity. After spawning schools of ice galaxias remain in lower reaches of rivers till some days, restoring forces. Strongest individuals spawn once again, though a repeated spawning is not as active, as main one.
Young fishes spend first two years in river estuaries which do not freeze – they are too small to resist to cold. It is easier to hibernate to large fishes, and small fishes often freeze in ice and freeze through, that results in their death. Having reached approximately 2/3 of the size of adult individual, ice galaxias rise upstream and settled from river mouth to fresh waters of continent. Young fishes rise against the current in common with adult individuals coming back from spawning. It will pass about 2 – 3 years, and they will mature and can take part in spawning.
Long growth of ice galaxia is compensated by enviable longevity – cold winters as if brake ageing of fish organism, “preserving” it approximately for half-year. For this small species of fishes the age of 40 years is usual term of life, and occasionally even 50 – 60-years old “patriarchs” are found.

Hornet catfish (Toxiglanis crabro)
Order: Catfishes (Siluriformes)
Family: Bagrid catfishes (Bagridae)
Habitat: Zinj Land, medium course of Indian Ocean basin rivers.
Zinj Land is huge subcontinent which broken away from Africa approximately 15 MY after the mankind extinction. It is separated from the basic continent with Tanganyica Passage which has passed just along the chain of Great African lakes. Salt water became an absolute obstacle for freshwater fishes, and species of Zinj Land began to evolve independently of African species. For 10 million years of isolation they had not formed any new family, but between Zinj Land and Africa there is no one common genus of freshwater fishes. Only representatives of migrating fishes may freely cross Tanganyica Passage and meet both in rivers of Africa and Zinj Land.
The rivers of Zinj Land are much shorter, rather than African ones, but conditions of life in them are more various: Zinj Land “had got” highest mountains of Africa. For freshwater fishes the communication between rivers of subcontinent flowing to the east (to Indian Ocean) and to the west (to Tanganyica Passage) is complicated, therefore in rivers of subcontinent the per cent of endemic fish species is rather high. But in any ecosystems struggle for survival is very sharp. Evolution process resulted in formation of diverse protective adaptations at fishes.
One of fishes living in rivers of eastern part of Zinj Land uses for self-defense poison – it is the reliable and repeatedly time-tested means. It belongs to bagrid catfishes for which sharp poisonous spikes in fins are characteristic. Poisonness and characteristic striped colouring have served as an occasion for the name: this fish is named hornet catfish. It is small fish (its length is about 12 – 15 cm) of contrast warning colouring. Out of spawning season these fishes have striped colouring – yellow with brown cross strips and white belly. Males differ from females in larger size and wider head.
At hornet catfish there is flat head with large shining eyes. On the top jaw of fish two long wattles in corners of mouth grow and two shorter ones stick up near nostrils. On the bottom jaw four short wattles grow. Fins of fish are pointed: it is preciously fast swimmer.
The hornet catfish differs in features of biology from many species of catfishes: it is diurnal fish hunting in schools in thickness of water to small fishes, tadpoles and water insects. At night hornet catfishes hide under floating leaves of water plants. At this time their colouring turns pale, and cross strips become narrow and faltering.
Poison is one of the basic means of protection at hornet catfishes. In back and pectoral fins of these fishes sharp spikes grow, in which basis advanced poisonous glands are located. Besides one more feature of this fish makes it similar to wasp: at this species the effective group protection is developed. Having noticed a predator, the fish of this species utters warning signal – it makes sharp scratching sound with the help of spikes of pectoral fins. At the alarm signal all fishes gather to spherical school (as at marine catfishes (Plotosus) of Holocene epoch). Angry fishes lift spikes, and their colouring becomes much more contrast. Hornet catfishes do not hide from the enemy – they entirely rely on efficiency of group demonstration. The sting of spikes of this catfish is dangerous to predatory fishes. The seized catfish spreads fins wide and sticks spikes in gullet walls of predator attacking him. The predatory fish can even die, having choked with such catfish. Therefore after attack on these catfishes predators had survived do not attack them any more.
When hornet catfishes are quiet, their school swims in river, having stretched to long rank. Fishes exchange sound signals and keep up movements of congeners, keeping a distance.
The spawning of these fishes takes place at night. After plentiful rains which serve as stimulus to spawning males of hornet catfishes gather to separate schools and “sing a chorus” involving females. Their colouring changes: in courtship dress male has black head and white lips, the body color stays like former one. Male ready to spawning shows to the female widely opened mouth, and thus with the help of pectoral fin spikes utters sounds similar to grasshopper chirring.
Demonstration of mouth till courtship display is not casual: it is connected to way of care of posterity at hornet catfish. Males bear eggs in mouth – such way of care of posterity appeared independently at fishes of various families and orders including catfishes of other families. Fertility of this species amounts about 100 large orange eggs incubated within one week. Males bearing eggs gather to dense school and keep in common: it helps them to protect against predators. Such school may total over hundred of fishes, and sometimes in one school it happens up to half thousand of males incubating eggs. At this time they have characteristic colouring – they are white with narrow vertical black strips on body and black top part of head. The forward part of back fin where the large poisonous spike is located gets reddish-brown color and is well appreciable from afar. When the predator comes nearer, fishes gather to spherical shoal and utter warning sounds in common. Loudness of alarm signal is proportional to the size of predator – all flight of fishes reacts to occurrence of large predator.
Helpless larvae hatch from eggs; they lay in mouth of the male motionlessly, yet yolk sac will resorb. At the fourth day of life when it occurs, larva turns to fry. First days of life fry have badly advanced spikes, but at this time they are reliably protected from enemies by care of the male. Fry distinguish the parent male by smell and keep nearby from it swimming out from its mouth. They start to feed, eating slime emitting on the body of the parent. About one week after larvae had turned to fry male hides them in mouth in case of danger (like fishes of cichlids (Cichlidae) family known to people acted). At this time schools of males with posterity move to shallows overgrown with plants where fry have an opportunity to feed on small animals.
Every day fry swim out of parental mouth for a longer time and depart from the male farther. Sooner or later they leave loving father absolutely and start to lead independent life. When the male will have no fry to keep, it starts to eat. For one year the male can bring up to three hatches of fry.
When fry become independent, at them spikes quickly develop, and young fishes become protected from predators. Passing to independent life, fry become cross-striped and group to schools. Schools may unite or broken depending on amount of forage. Main enemies of young hornet catfishes are larvae of water beetles and water bugs. They do not swallow small catfishes entirely, but exhaust avoiding poisonous spikes. But adult fishes have almost no enemies.

Electric synodontis (Synodontocephalus electrophorus)
Order: Catfishes (Siluriformes)
Family: Upside-down catfishes (Mochcidae)
Habitat: rivers of Central Africa.
Natural accident of the end of Holocene has affected mostly ecosystems of open ocean and large seas. Natural communities of rivers had not suffered almost, though the river ichthyofauna had lost only some species of large fishes, mainly predators. But when conditions were stabilized, and also climate gradually began to improve, new species of fishes have borrowed become empty ecological niches. One of the most original predators of rivers of Western Africa is electric synodontis.
It is very large fish - the length of body reaches one and half meters, and weight exceeds 20 kgs (females are a little bit larger than males). The body of the electric synodontis is flat: it is the bottom-dwelling fish, preferring to spend time in ambush, hiding among driftwood and water plants. Head is wide, with long wattles - length of wattles at the top jaw is up to 1 meter; on chin there are 4 feather-like barbs about 10 cm long. Eyes are small, shifted to sides of head. In wide mouth there is set of very small teeth - they do not allow to crack catch half-and-half (as at sharks), but help to keep it.
Fins of this fish are rather short and rounded. In back and pectoral fins ahead there are sharp poisonous spikes – the protection against large predators. Tail fin is wide and two-lobed: this fish is lazy swimmer, preferring to hunt from an ambush.
Smaller relatives of this river giant, catfishes of Synodontis genus differ in various coloring: spotty and striped, sometimes contrast bicolor. Electric synodontis during evolution had developed cryptic colouring of black and brown spots on grayish-green background. The bottom part of body of this catfish is yellowish-white.
The main hunting weapon of the electric synodontis is latent under skin. It is a layer of modified muscles, able to generate strong electric charge with which help fish stuns catch: smaller fishes and frogs. This fish also uses electric charges for protection against enemies: large predatory water turtles and lizards. In due time people had found at small African synodontis catfishes ability emit very weak electric charges. Obviously, one of numerous species of these catfishes during evolution had turned this ability for its own benefit, having strengthened power of electric batteries in many times. It had allowed it to occupy ecological niche in ecosystems of African rivers, earlier occupied by electric catfish (Malapterurus).
This catfish spends the most part of time at the river bottom. This fish inhabits shallow wood rivers and coastal area of large reservoirs. Electric synodontis keeps in places where small fishes and frogs - the basic forage of this predator – live in large number. Usually this fish hides in thickets of water plants or among driftwood, but at lack of shelters catfish simply can dig in layer of fallen leaves at the bottom. When in field of action of electric charge of this fish catch (fish up to 20 - 30 cm long, or frog) appears, catfish actuates the weapon, and after some seconds prey already fall on bottom, convulsively pulling. For a short time the catfish shows itself from shelter, grasps the paralyzed catch, and quickly swallows it. After hunting it needs time to have a rest and restore charge in electric organ.
But in spawning season these fishes do not hide at all, making courtship rituals. Males actively care for females, driving them by two – three ones. At this time cryptic colouring gives up the place to bright colors: throat and chest of the male become bright red, the body background brightens, and stains appear on it with the greater intensity. During caring males utter series of clicks and scratches with the help of spikes in pectoral fins. To the moment of spawning at females sides turn pale and become rounded from roe. More clearly female shows the readiness to spawning, more strongly the competition between males for the right to spawn with it proceeds. Males push away each other, sometimes put to the contender bites or grip its wattle. Eventually only one male will stay with the female, fertilizing spawned eggs.
At synodontises of Holocene epoch fishes more often simply dropped eggs at the bottom and did not care of it any more. In Great African lakes some species of synodontises simply put eggs stealthily for incubating to other species of fishes. Electric synodontises care of own posterity independently: female digs fertilized eggs in sand at the river bottom and protects a place of clutch within approximately week. All this time it eats of nothing. Being attacked by predators (more often it is large turtle or lizard), it protects future posterity with the help of impulses of an electric current.
Development of eggs proceeds about three days. But after hatching larvae sit in sandy nest approximately equal time, yet their yolk sac is resorbing. At hatching time the female by strong jet of water from mouth washes away the top layer of sand, accurately gathering by mouth and putting to the nest casually dropped out helpless larvae. After yolk sac resorbing larvae abandon nest for ever. They hide in thickets and eat small invertebrates. First some months of life their electric organ is not advanced, and they perish in great number from every possible predators, including from adult individuals of the same species. But at length about 6 – 8 cm they are already able to stun by charge fry of other fishes at the distance up to 10 cm. And special “signal of identification”, submitted by them at a meeting with neighbours, helps to avoid attack from the side of adult fishes. If the young fish succeed to survive, to the end of third year of life its length will reach one meter, and it’ll take part in spawning.

Root turtle catfish (Cystobiichthys radicans)
Order: Catfishes (Siluriformes)
Family: Pencil catfishes (Trichomycteridae)
Habitat: large rivers of South America – Amazon and Hyppolite.
Some groups of invertebrates are submitted exclusively by parasitic forms – for example, classes of tape worms and trematodes among flat worms, orders of fleas and lice among insects. In other groups representatives of few separate genera or species in the group submitted by free-living forms are parasites. Among vertebrate animals parasitic forms are rare exceptions. In Neocene only some mammals and birds turned to haematophags. In fresh waters of South America there is a blood-sucking species of neotenical tadpoles. But parasitism is most typical for fishes among vertebrates. Some catfishes of pencil catfish family are blood-sucking parasites, and among them in Neocene absolutely fantastic forms had evolved.
In cloacal bladder of elasmosaurine hydromedusa and other large turtles of South America one species of these catfishes parasitizes – the root turtle catfish, worm-like creature about 8 cm long. This fish lives in cloacal bladder and in adult condition leads sedentary habit of life. The parasitic way of life had leaved an imprint to anatomy of this catfish. It is blind depigmentated fish with transparent body through which walls interiors are visible. On stomach of fish the longitudinal plica of skin forms a line of suckers. This species eats exclusively blood of turtle – fish bites through epithelium of cloacal bladder and sucks blood, having densely attached by lips to wound.
One attribute gives out the presence of this parasite in turtle’s body: the long and strong shoot of tail fin formed by elongated fin rays and extending at the tip as a blade is put out from cloaca of reptile. It is penetrated with blood vessels, and through its surface gas exchange proceeds. The additional source of oxygen is blood of the turtle. This catfish has the special adaptation, permitting to extract oxygen. On the bottom side of body of the fish a plenty of fibers is developed; they take root into the epithelium of turtle (hence the specific name “radicans” meaning “taking roots”). Through them oxygen diffuses from blood of turtle. Due to uselessness gills of this species are greatly reduced, and branchial apertures are tightened by skin and are reduced up to two small holes above the bases of pectoral fins.
Pectoral fins of root turtle catfish have muscled bases, and the membrane between fin rays is reduced. Rays represent structures like claws with which help fish attaches to walls of cloacal bladder. Due to inhabiting inside turtle body this fish easily endures the necessity of turtle to go to the riverbank for egg laying. Therefore such catfishes parasitize in turtles of both genders.
Gender of root turtle catfish is not fixed genetically and may easily change in any direction depending on circumstances. Two any fishes appeared near each other in the same host animal turn to individuals of different genders and produce normal posterity. In connection with motionless way of life this species does not have courtship ritual and internal fertilization had developed. The cloaca of this catfish has ability to turn out and to extend as a tube. It forms similarity of penis at male and long extensible ovipositor at female. Male makes internal fertilization, and in ovoducts of female eggs start to develop. The female puts the ovipositor outside and lays fertilized eggs in water. At this time the embryo has already passed early stages of development. At absence of breeding partner fish develops as a hermaphrodite and lays normal fertilized eggs alone.
The fertility of root turtle catfish is rather big for such tiny fishes – within one week the female lays up to one hundred large eggs. Egg laying lasts some weeks in succession after one fertilization, and then female restores the physical condition, and male fertilizes it again. The young ones of this species lead strictly another way of life, rather than adult fishes: they are active planktonic predators eating fry of other fishes and also larvae of insects.
This species of fishes may exist as free-living stage for rather long time, reaching the length of 4 – 5 cm. At young individual in such condition eyes are well advanced; it is translucent and leads mobile mode of life for a long time, but at this time puberty is delayed. Frequently fish even dies “eternally young”, having not searched for host turtle and having not reached sexual maturity. Having found out a host turtle, catfish penetrates into its cloacal bladder and attaches to its wall. After the attachment the fast degeneration of unnecessary organs – eyes and fins – proceeds. On the belly side of body suckers and “roots” quickly develop, and then on tail additional respiring organ grows. For some weeks fish turns to true parasite, and then normally continues development and reaches sexual maturity. Too old individuals, however, can not go through such radical reorganization of an organism, and perish in body of host turtle.
Life expectancy of this catfish reaches 4 – 5 years.

Antiguan phoboclarias (Phoboclarias antiguae)
Order: Catfishes (Siluriformes)
Family: Airbreathing catfishes (Clariidae)
Habitat: fresh waters of Great Antigua – lakes and swamps.
In human epoch borders of faunistic and floristic areas appeared broken. People introduced various species of animals and plants to territory where these species could never appear by natural way. Frequently such activity resulted in degrading of ecosystems. Some of newcomer species had died out in epoch of global ecological crisis, but the part of species had survived, and their descendants had taken the place in ecosystems of Neocene.
In swamps and other freshwater reservoirs of Great Antigua Island one of descendants of animals introduced by people lives. It is the large catfish Antiguan phoboclarias, the descendant of clarias (Clarias batrachus) introduced from Asia to Florida. In human epoch clarias had got out of human control and had widely settled in freshwater reservoirs of Florida. In ice age this fish had got from Florida to Cuba, and then by temporary land bridges over small islets had reached islands formed Great Antigua in Neocene.
Antiguan phoboclarias is very large predatory fish (hence the name meaning “awful clarias”). The length of adult fish may reach two meters and even more (male is smaller and more graceful, than female). Body is very much lengthened, flexible and cylindrical. Low back fin lasts at all its length. Tail fin of fish merges with anal one. The skin of phoboclarias without scale is covered with plentiful slime. Colouring of this catfish usually is sandy yellow with small spots; stomach is white. Depending on color of environment this catfish can change colouring – on dark ground it turns dark brown with black spots. Change of colouring proceeds within several days after resettlement of catfish to other place.
Head of phoboclarias is flattened and wide. If necessary it may be used as a weapon – by impact of head the catfish is able to cripple animal swimming in water which it wants to eat. Due to wide mouth phoboclarias easily swallows chicken-sized animals.
This fish has badly developed sense of sight; small eyes are located on edges of head and are slightly shifted upwards. Bad sight at fish is filled with chemical sense – around of mouth of phoboclarias eight wattles about one meter long grow, and their surface is covered with set of receptors.
In pectoral fins of catfish spikes with poisonous slime grow. One prick of such spikes is enough to kill large dog-sized animal; therefore adult phoboclarias does not have enemies.
Phoboclarias, similarly to the majority of catfishes, does not like to swim long. It is a passive ambuscader trapping prey, having buried in ground almost completely. At the hidden fish only long wattles and a part of head with eyes is out of ground, therefore it is difficult to notice it among plants. When the fish or other prey of suitable size swims near, catfish rushes out from sand and catches it. Usually phoboclarias eats small fishes, aquatic insects and their larvae, frogs and tadpoles. But at an opportunity this fish eats animals got in water during flooding or crossing the reservoir. Also phoboclarias hunts ducks and other waterfowl. Hunting birds, it hides under leaves of water lilies and waits while the careless bird will move nearer to it. At this species cannibalism is advanced, and a significant part of posterity passed to independent life may be eaten by own relatives.
Phoboclarias is able to live almost in any freshwater reservoir with water of any quality. If in water there is no oxygen, approximately once per twenty minutes fish emerges to water surface and takes in mouth an air bubble – from it oxygen for breath is taken. It is especially important, if the fish lives in poor in oxygen water of swamp, in which there is plenty of rotten plants. From the ancestor, the clarias, phoboclarias had inherited the adaptation for breath by air – specially modified gills.
In rain season at fishes the courtship season begins. Its beginning is audible even at the coast of reservoir: male involves female, uttering melodious sounds – chirping trills. In shallow water it digs a nest – a hole about two meters in diameter and about half meter depth. Having cleared ground from dust, male begins courtship “songs”. It is very cautious at the presence of the female, and constantly keeps at some distance, always directing by head to her.
Fertility of the female makes up to 200 thousand of small eggs. After spawning male stays near the nest and protects eggs till five days, while fry will hatch. When fry will start to swim, male stays with them and protects the hatch during approximately two next weeks. At this fish the care of posterity is very strongly advanced: in case of danger male takes away eggs and fry in mouth. Also it acts so, if the reservoir where the nest is arranged dries up, or water level decreases. But it is only a part of that the adult fish can make for posterity. Clarid catfishes are able to creep overland, and phoboclarias can leave a reservoir, carrying away posterity. Keeping the posterity the adult catfish can creep overland till some days in searches of new habitats. During overland travel the body of fish becomes covered by viscous slime, helping to keep moisture; and in mouth eggs or fry become covered by liquid slime which slows the evaporation of water. The catfish feels a smell of water, and easily finds new reservoirs. If it had to move with eggs, in new residence it continues to incubate it in the mouth.
Young phoboclariases grow quickly, and at the age of about five years become sexually mature. Young fishes live in rich thickets of marsh vegetation where adult fishes can not eat them.

Branchial suckermouth (Branchiolorica molligaster)
Order: Catfishes (Siluriformes)
Family: Suckermouth catfishes (Loricariidae)
Habitat: basin of Amazon and Hyppolite; the blood-sucking parasite on fish gills.
Parasitic species are very common among invertebrates – some large groups of these animals are present only by parasites. Parasitic vertebrates are rather the rare exception, than a rule. Among fishes representatives of various orders passed to partial parasitism, but most deeply specialized parasites were pencil catfishes (Trichomycteridae) known in human epoch. In Neocene some other kinds of sanguivorous vertebrates added to their number. The original branchial tadpole (Branchiosuga nosferatu), neotenical species of amphibians became the parasite. And among fishes one more parasitic catfish, the close relative of leechcatfish (Hirudistomus cataphractus), branchial suckermouth had evolved. It is small species of fishes – general body length of adult individual is about 5 cm. It eats exclusively blood of fishes.
Branchial suckermouth lives on gills of large fishes (for example, boltergillers (Potamocetus spp.)). It is kept on gills of host fish with the help of hooks growing on rays of pectoral fins. The mouth of all loricariid catfishes is transformed to sucker, and only few changes had been required for transformation of scraping mouth to sucking one. In mouth of branchial suckermouth sharp corneous plates grow. With their help catfish bites through an epithelium of gills of host fish, and sticks to the wound by lips.
The body of branchial suckermouth has lengthened shape and is flattened from above. It had undergone strong changes in connection with the adaptation to parasitism. The armour of fish is strongly reduced and represents very thin transparent plates which do not adjoin to each other on the back part of the body. The skin on stomach of fish is depigmentated, and through belly wall interiors and intestines filled with semidigested blood are visible. The top side of body is grey with cross black strokes. Strangely enough, at this parasite there are rather large shining eyes: it has good sight. Besides on front edge of head of this fish the set of the fleecy outgrowths covered with chemoreceptors grows.
Abdominal fins are rather small, but pectoral ones are strongly advanced – they are principal organs of attachment to body of the host fish. Front rays of pectoral fins are thick, covered with set of tiny corneous thorns, and the tip of fin ray is bent like a hook. Branchial suckermouth clings to gills of host fish by it. Unpaired fins are rather small; on bottom lobe of narrow tail fin there is long threadlike outgrowth.
This catfish does not live on the same fish constantly. It is able to swim and prefers to move from one fish to another at night when fishes are less active. If this catfish does not find suitable host, it may appear completely defenseless surrounded by various predators. Therefore branchial suckermouth having no host behaves very cautiously and secretively. In the morning it is dug in layer of fallen leaves at the bottom of river, or hides in long roots of floating plants, and keeps a full immovability, not giving out itself until the last second, or … yet will find out the host fish. Then catfish promptly attacks it and clings to its body behind the operculum. Having chosen a right moment, branchial suckermouth cautiously slips under the operculum of host fish, and attaches to its branchial arches.
These catfishes spawn during all year. When sexually mature fishes ready to spawning meet, they begin simple courtship ritual. Male cautiously sticks to the body of female, unfastens some seconds later and moves forward a little. It moves this way along the body of the female from tail to head, yet will reach her nape. Then he cautiously starts to slip to side of the female (because at this moment the female is attached to branchial arch of host fish, male actually slips downwards and appears turned the stomach upwards), and touches by abdominal fin the skin on her stomach. The female lays on stomach of the male about 20 – 30 eggs which stick to skin of the male. Male fertilizes eggs and cautiously moves them to its head. He bears eggs on fleecy outgrowths on edges of head.
Fry hatch after 6 – 7 days of incubation. The first days of life they keep on stomach of male, and he protects them from the current of water moving through gills of host fish. Within several days young fishes gradually leave him. They hide among underwater plants and eat algal scurf. Since the second month of life, at the length of about 1 cm young branchial suckermouths start to attack medium-sized fishes.

Cave suckermouth (Spealeoloricaria setosa)
Order: Catfishes (Siluriformes)
Family: Suckermouth catfishes (Loricariidae)
Habitat: caves of Yucatan, fresh water.
The family to which this species of fishes belongs is the most numerous in order and simultaneously looks the exception by food predilections among other families of predatory catfishes. Loricariid catfishes are very characteristic fishes of New World. After break of Panama Isthmus the part of species had remained in Central America where evolved independently from the majority of species had stayed in South America. Some species of loricariid catfishes had adapted to unusual habit of life: the parasitic species of these fishes is found in South America, and there is a sanitary species. But one species of Central American loricariid catfishes had settled under ground, in extensive calcareous caves of Yucatan, and had successfully adapted to unusual way of life.
Cave suckermouth prefers quickly flowing rivers and is especially numerous in places where the river current on ground surface hides in caves. In these places cave suckermouth finds enough food, being in habitual environment.
The shape of this fish shows the long history of settlement under the ground. Eyes of cave suckermouth are strongly reduced and are visible under skin only as dark spots. They are completely covered by skin and thin armour plates, and do not perceive light at all. In shape of fish presence of set of corneous bristles (hence the specific epithet “setosa”, meaning “bristly”) on lateral faces of head is remarkable. The armour at this catfish is kept: water in caves is strongly mineralized, and problem of armour construction does not arise. Neighbours of this species are crayfishes and crabs living in various caves, therefore additional protection is vital.
Body of cave suckermouth is strongly extended; it is about 15 cm long at the maximal width no more than 1 cm. At back edge of back fin at males the long string grows – it is strongly extended back ray of back fin. The same threadlike outgrowth is present at the bottom lobe of tail fin. Therefore catfish seems little bit larger, than actually is. The body of fish is colored pinkish white.
Pectoral fins at males and females are advanced equally well. At them there is a firm forward ray covered from the bottom side with set of frieze-like prickles. The bases of pectoral fins are shifted downwards. They are extended, lack of armour plates, and turned to strong suckers which keep this fish in rough underground streams.
Cave suckermouth has characteristic for loricariid catfishes scraping inferior mouth modified to sucker. This catfish eats bacteria and larvae of insects settling on stones. If in cave dead bodies of animals get from the surface, cave suckermouth willingly feeds on carrion. Also it eats bats had sunk in water which frequently drop from the ceiling of caves in which this species lives.
Caves differ in poor food resources, therefore populations of cave fishes are not numerous, and rate of breeding is very slow. But it is compensated by absence of large active predators; therefore the survival rate of posterity at cave fishes is rather great. Seasonal prevalence in spawning of cave suckermouth is absent, but breeding may repeat up to four times per year. Courtship games of these fishes differ in simplicity. Courting at the female, male keeps in parallel to her and by strong lateral movements of body turns waves to her body. The female estimates physical condition of the male by force of waves which it makes. Male broods a small amount of eggs (about 20 ones) in the mouth within several weeks; all this time it does not eat.
Young cave suckermouths become sexually mature at the age of about 10 months. Life expectancy of these fishes is no more than 6 years.

Mountain suckermouth (Platyhypostomus frigophilus)
Order: Catfishes (Siluriformes)
Family: Suckermouth catfishes (Loricariidae)
Habitat: Andes, mountain streams and cool rivers.
South America differs in large variety of catfishes; some families of these fishes are endemics of this continent. In Neocene when the climate became warm and damp, catfishes as many other freshwater fishes had started to evolve roughly and to develop new habitats. Andes, the high mountain ridge stretched along the whole Pacific coast of continent, became the house for some new species of fishes, including catfishes.
In cold quickly flowing water of mountain rivers, clean and rich in oxygen, large loricariid catfish – mountain suckermouth – lives. Length of this fish is about 40 cm – it is one of the largest representatives of family in Neocene epoch. This fish is perfectly adapted to life in fast current. The body of mountain suckermouth is strongly flattened; therefore when fish lays at the bottom, resistance to current is minimal. The shape of this catfish forces the current to press fish to the bottom.
Mountain suckermouth has wide head of rounded outlines with blunt snout. Small yellow eyes are shifted to edges of head and protected by bone “eyebrows”. Operculums are shifted to the bottom side of head. On the body of fish there are well advanced armour plates (it is the common feature of family), providing good protection against enemies and casual traumas against the stones moved by current. Colouring of body of mountain suckermouth serves for camouflage – it is grey with olive shade; on top side of the body there is “marble” pattern of cross irregular-shaped strips. When fish lays motionlessly on stones, it is almost not visible among patches of light at the bottom. Passive protection is the main vital strategy of this harmless fish. In case of danger mountain suckermouth prefers to hide at the bottom, and seeks safety in flight only at direct threat of life.
Unpaired fins of mountain suckermouth are wide and fanlike, with rounded tips. Tail fin of these fishes has colouring appreciable from apart: on dark grey background “trout” oculate spots, red with white border, are scattered. At large males this pattern is supplemented with white border on external edge of fin. These marks serve for warning of competitors and for courtship display. Also at males on bottom lobe of tail the long string formed by two strongly lengthened rays of tail fin grows. One more attribute of sexual dimorphism is characteristic for many representatives of loricariid catfishes, and mountain suckermouth is not exception here: at the male on edge of head long outgrowths grow; at this species they are appreciably corneous, firm and bristle-like. On forward part of head they are short; on each side of head they are much longer and grow in two lines, forming rich “whiskers”.
Pectoral fins of these catfishes are rigid and strong, with powerful front rays: they help fish to cling to stones. Fromt rays can be fixed in opened position, resting against stones, as an anchor.
The sucker-like mouth of this species of fishes is very strong; it helps to keep in current. Mountain suckermouth eats various kinds of food. This catfish scratches out from stones water mosses growing as pellicles, plants of Podostemaceae family, and also microscopic algae. Besides of plants mountain suckermouth eats larvae of insects – two-winged flies, dragonflies and caddis flies. Using wide head, catfish is able to overturn stones, searching for invertebrates. At an opportunity this fish eats dead bodies of animals had got in the river.
At the bases of abdominal fins of mountain suckermouth skin plica forms an additional sucker of semilunar shape. Using oral and belly suckers alternately and clinging by pectoral fins, this catfish is able to creep on stones, rising upwards in mountain rivers and even in low falls.
Mountain suckermouths spawn in places with weaker current, near stones, in underwater caves. Courtship games at them proceed not for long. Male displays to the female stretched back and tail fins, swimming in front of her head and from time to time pushing the female by side. Before spawning fishes keep in parallel to each other, and touch each other by tips of fins. The female lays eggs on bottom; male fertilizes them and at once gathers from stones, rowing up by outgrowths on head. In first minutes after fertilization jelly-like sticky layer starts to produce on the surface of eggs; with its help eggs stick to head of the male. Male broods eggs pasted to bristles from the bottom side of head till 8 – 9 days. Such speed of development of eggs is connected to low temperature of water in habitats of these fishes. Mountain suckermouths living in better warmed lower reaches of rivers rise upstream for spawning: at high temperature fry hatch weak. In first days of life fry keep on head of the male and sometimes escape from danger in its mouth. Till all brooding time male eats of nothing.
Young fishes become able to spawning at the age of two years, but active growth proceeds within first ten years of life.

Arafura mangrove catfish (Batrachoplotosus mangrophilus)
Order: Catfishes (Siluriformes)
Family: Stinging catfishes (Plotosidae)
Habitat: mangrove swamps of Arafura Lake.
Movement of lithosperic plate on which Australia and New Guinea are located, had caused rising of its northern edge. Arafura Sea had shoaled and gradually turned to extensive brackish lake separated from the ocean by multikilometer circuit of mangrove swamps and shallow channels. Salinity of water in them varies from slightly brackish during tropical downpours up to almost equal to oceanic one. In such conditions only few species of aquatic animals may exist normally – the majority of sea inhabitants does not endure fresh water, and freshwater animals do not suffer presence of salt in water. Nevertheless, there are fishes in mangrove channels. One of their representatives is Arafura mangrove catfish, the descendant of one species of sea stinging catfishes (Plotosus). When sea water began to turn fresh, the ancesor of this fish had not left it, and had adapted to life at coastal shallows, and then had moved to mangrove channels.
This species of catfishes is large eel-looking fish up to one meter long. The trunk of this catfish is compressed from sides, and the tail is bordered with merged back, tail and anal fins. With the help of strong tail fish can be dug in sand at outflow, and survive outside of water due to it till many hours. Head of this catfish is flat, with small eyes shifted to the sides. Wide mouth is surrounded with eight short wattles. This catfish has changeable colouring: in rest this fish is grey with numerous black spots on the top part of body, merging in twisting marble pattern on back and tail. Stomach and the bottom part of head at this catfish are white. At fright or at night black spots turn pale grey. In courtship dress male and female strongly differ from each other: female turns monotonously grey, and male has black back and sides, and white belly. On the background of black colouring its silvery eyes, surrounded with white spot, look especially impressively.
It is a predatory fish eating any prey, which it is able to seize and to swallow – smaller fishes, crabs and shrimps. Catfishes also eat animals fallen in water – mammals, reptiles and nestlings of small birds.
For protection against numerous predators living in mangrove forests, this catfish is armored with poisonous spikes growing in fins. This is a heritage got from ancestral species, which had been remarkable by their poisonness in human epoch. But in any case this species prefers to be imperceptible, and at danger is quickly dug in sand. Young fishes use this way of protection especially frequently.
As against to far ancestors lived at sea reeves in numerous schools, Arafura mangrove catfish is a solitary species, though it does not avoid the presence of congeners. It gathers to schools only for migrations connected to spawning. The adult fish lives in water of any salinity – from fresh up to oceanic water. But it spawns only in salt water, because too freshened water kills an embryo. For spawning catfishes wait for a time of the highest inflow in the month. With a tidal wave, filling channels of mangrove forest, adult fishes gather to schools and migrate to the depths of lake. At the depth of about 10 meters catfishes gather to shoals numbering many thousands of fishes, including individuals of both sexes. Within night fishes find each other, and courtship games begin in the morning. With the first rays of sun males turn black and white, and start to court after females. Competing for the female, males shove each other aside from her, pushing by sides. At this time their spikes are pressed to the body and are not used – their prick may be dangerous to congeners. During the courtship ritual male bites fins of the female and keeps near to her. The pair of fishes swims so till several hours, synchronizing ripening of eggs and soft roe. Directly to the moment of spawning the shoal is broken to the set of pairs.
Male and female throw up sexual products simultaneously, and male picks up by mouth large eggs – in clutch it may be up to 200 pea-sized eggs. Having spawned all eggs, females at once return to mangrove thickets, and males remain at spawning place. Male looks after posterity, brooding eggs in mouth. At this time males gather to schools and keep together at the distance from lake coast. They do not eat, and between them there is no competition, therefore in male school there are no fights.
The incubation lasts till about 50 hours, and some more days male carries helpless fry in mouth. In one week after spawning males swim up to the coast and let out posterity in thickets of aquatic plants. After that they return to rendered habitable places and do not care any more of posterity. At the age of 3 years young fishes become sexually mature. Life expectancy of this species makes over 30 years.

Usambara characid trout (Alestotrutta ussambarica)
Order: Characids (Characiformes) (or order Cyprinoid fishes (Cypriniformes) suborder Characids)
Family: African tetras (Alestidae)
Habitat: mountain regions at the east of Zinj Land, mountain rivers.
When African continent had broken up along the Great Rift Valley line, all highest mountains of continent had stopped to belong to it. They had remained at the subcontinent named Zinj Land. Because of global ecological accident many ecosystems appeared destroyed, but it almost had not affected terrestrial and fresh-water ecosystems. Flora and fauna of Zinj Land developed completely separately from Africa till at least approximately ten millions years, from the moment of separating of subcontinent from continent. The variety of freshwater species of animals had kept almost at former level. Characid fishes are very characteristic for continental reservoirs of Africa to the south of Sahara and for New World (South America and the south of North America). They inhabit various reservoirs – from stagnant swamps up to cold mountain streams. They avoid only brackish water.
Significant spaces of Zinj Land are occupied by mountain landscapes. One of characteristic species of fishes lives in streams with quickly flowing clean and cold water – large trout-looking characid named Usambara characid trout. It is a fish about 60 – 70 cm long with torpedo-like body and pointed muzzle. It swims quickly and can “stand” in fast current near stones or bushes of water plants for a long, similarly to trout.
The basic colouring of body of characid trout is silvery blue. Fish has narrow black longitudinal strip on body, stretching from tip of muzzle through an eye up to the basis of tail fin. Also at characid trout there is darker back making fish imperceptible on the background of bottom at sight from above. Back fin of fish has pointed tip. At the male the height of fin exceeds height of body. Tail fin is high and crescent; it also has rigid rays.
Characid trout is insectivorous predator. This fish hunts down insects flying low above water, and jumps to catch them at height up to one meter. Characid trout has large eyes – sight plays a leading role in air hunting. Also fish searches for larvae of dragonflies and caddis flies at the bottom of streams. Occasionally characid trout hunts down small fishes, including its younger congeners. The mouth of characid trout is wide – its cut lasts up to level of front edge of eye. Jaws are armed with numerous thin pointed teeth.
Characid trouts spawn in current, spawning very large amount of eggs – up to 200 thousand small eggs. Male at these fishes is larger, but more graceful, than female. Its colouring differs in more intensive blue shade which is amplified on head, passing to dark blue on tip of muzzle. On this background at the male silvery “ear-ring” spots at operculums are clearly visible. In courtship season (during the thawing of mountain snows) male actively chases females, pressing them by body to the bottom. If the female is ready to breeding, she swims near the male within several hours. At this time at fishes sexual products intensively develop. At night or in early morning spawning begins. Fishes splash in stream, jumping out of water, and male chases the female, biting her tail. Just before the dawn time fishes spawn eggs, scattering them in current. This species of fishes does not care of posterity, and as required adult characid trouts can be cannibals. The young ones differ in habit of life from adult fishes. Young characid trouts keep in thickets of water plants. At them bottom jaw is short, and mouth is inferior. They scrape off larvae of insects and bacterial cover from stones. The young ones also differ in cross-striped colouring. As they grow, the middle part of strips stays dark, edges turn pale and fishes gradually get “adult” longitudinal-striped colouring.
The first spawning of young fishes takes place at the age of three years at length of body about 30 – 35 cm. This species reaches the usual size to the age of six years, and then growth of fish slows down. At the age of 20 years some fishes reach length of 80 cm, but it is the extreme rarity. Usually life expectancy of characid trout does not exceed 15 years.

Tyrannocharax (Tyrannocharax deinodontus)
Order: Characids (Characiformes) (or order Cyprinoid fishes (Cypriniformes), suborder Characids)
Family: Trahiras (Etythrinidae)
Habitat: shallow fresh reservoirs in tropical zone of South America.
After climatic accidents of the end of Holocene and the beginning of Neocene many of earlier prospering groups of animals have died out. Such destiny has comprehended almost all crocodiles existing on Earth still from Triassic period of Mesozoic era. Only few representatives of this group live on Earth in Neocene epoch, and in many places where they had lived before, in ecological niche of large water predator absolutely other animals have replaced them. More often they are various turtles and lizards, but in South America where the forked chain of rivers and lakes was kept, the role of terrible water predator was undertaken by fishes. In Holocene epoch in basins of tropical South-American rivers trahiras, large and unaccommodating predatory fishes, reached sometimes one meter length, were settled. They trapped catch, having hidden in ambush among plants. Same tactics is successfully used by their descendant – huge tyrannocharax.
The length of almost cylindrical body of tyrannocharax reaches four and half meters: it is one of largest osseous fishes of Neocenic Earth. Huge head with extended snout and sharp teeth similar to recurved nails accounts about meter from this length. Weight of this monstrous fish can reach 300 - 350 kgs. The head is covered with dense armour of skin osteoscutes, that give to it additional durability and protect from casual damages which large catch can put to this predator. In the top part of head small black eyes and approximately in middle between eyes and tip of muzzle sensitive nostrils are located.
The constitution gives out in this fish the typical ambuscading predator not swimming long and far. Practically all time tyrannocharax spends having hidden among plentiful water vegetation at the depth about 1 – 1.5 meters. The pattern on its scales helps to remain unnoticed even to such enormous fish. On sides of tyrannocharax there is non-uniform mesh figure: on greenish-grey background there are black spots merging in vertical strips. Back of this fish is brown-black with small number of light spots.
Tail fin of tyrannocharax is short and rounded, and tail stalk is high and muscled. Such proportions are characteristic for fishes able to make sharp throw. The back fin lasts approximately from middle of back almost to the beginning of tail stalk; fatty fin is very small and rounded. Pectoral and abdominal fins of fish are advanced well and shifted downwards.
Living in shallow, strongly warmed up reservoirs, the large fish faces with one problem: the organism demands a lot of oxygen, and its contents in water is insignificant. Tyrannocharax solves this problem with the help of one adaptation inherited by it from ancestors. Swimming bladder of this fish is opened – it has turned to original lung. From time to time the huge fish cautiously emerges to the surface of water and breathes. After that the tyrannocharax can lay in ambush up to half an hour, giving itself out by nothing to possible victims. Lung helps fish to survive in conditions of drought: when reservoirs dry up, tyrannocharax can move from reservoir to another, bending by all body and helping itself by pectoral and abdominal fins. Thus the fish keeps branchial covers close, preserving gills from drying, and breathes exclusively with the help of lung.
Female is paler and fuller than male, and besides it is longer than male approximately at half-meter and heavier at 20 – 30 kgs. At such arrangement of forces, taking into account rather unaccommodating and aggressive character of fishes, the maximum of care is required from the male at relations with the female during spawning. Ritual of caring at tyrannocharaxes is rather long; male gradually accustoms female to his presence, keeping on edge of her territory. He is ready to recede any minute to respectful distance, when female shows attributes of displeasure from his presence. But in due course female gets used to the male, and he can come nearer to her cautiously. During caring the male becomes brighter: his body gets bright green color with velvet black strips, and the bottom part of head becomes bright red. Looking after the female, male swims near to her, having opened fins and uttering series of clicks heard from under water, especially at night.
The tyrannocharax belongs to phytophyls: this fish spawns eggs on leaves of small-leaved plants. Before spawning pair of fishes chooses thickets of any water plant with small leaves, and tears out all vegetation at the distance of two meters around it. After that courtship ritual begins; during it the male drives female in thickets and nestles against her side. After several trial attempts pair spawns eggs – about 20 thousand of rather large grains of roe.
The female practically at once leaves breeding bottom, and male stays to protect posterity. At this time he becomes almost entirely black, only on sides some green spots are appreciable. His aggression at this time increases so, that even female surpassing him by size, is compelled to recede away from clutch.
The incubating of eggs lasts about one week, and then male leaves clutch to the mercy of fate. First days larvae hide among plants, at three-day age start to swim and to eat small crustaceans. They quickly grow, and at length about 1 centimeter already can attack fry of other fishes. Cannibalism is typical to this species at any stage of development, therefore only few fishes live up to adult condition. Sexual maturity at young fishes comes at the age of about seven years; life expectancy reaches 50 years and more.
Tyrannocharax hunts large mammals, waterfowl and large fishes. Jaw might at this predator is those, that it can easily punch by teeth even carapace of small turtle. Usually fish hides near favorite watering places of large animals, and waits, while any animal will come in water too far. Then sharp throw follows, and prey disappears under water. At tyrannocharax there is iron jaw bite. But even if animal can escape, it most likely will die from loss of blood: sharp teeth of tyrannocharax put deep wounds. This fish catches waterfowl, seizing it from under water. Also tyrannocharax is not squeamish to eat small catch: nestlings of small birds fallen in water and small mammals, escaping from flood, can easily finish life in its teeth. The full fish swims to depth and lays for some days in deep whirlpool, digesting food.

Comb-jawed duckweed-hackler (Exodolabrus lemnivorus)
Order: Characids (Characiformes) (or order Cyprinoid fishes (Cypriniformes), suborder Characids)
Family: Comb-lipped characids (Ctenolabiidae)
Habitat: Congo basin, lakes, bays and cutoff meanders.
Characids are one of groups of fishes common for Africa and South America. Though at these two continents even common families of these fishes had not remained, the relationship of African and South-American characids indicates former connection of Old and New World. In Africa the majority of characids is presented with predatory or omnivorous species, but representatives of citarinids family (Citarinidae) are exclusively vegetarians, despite of competition from the side of numerous cyprinid fishes. Till the ice age in equatorial zone of Africa many representatives of aborigial tropical fauna had been kept, and life in this place had always differed in variety. Therefore narrow food specialization had become the best solution in stable environment at rigid competition. In such conditions some African characids had turned to stenophagous species.
One of narrowest food specialists among herbivorous fishes of Africa is the comb-jawed duckweed-hackler. It is rather large fish reaching length about 30 cm. Duckweed-hackler constantly keeps near to surface of water; in this connection its body has got rather characteristic shape. The top part of body of this fish is flattened; head and back make practically straight line. The bottom part of body of duckweed-hackler, on the contrary, has rounded outlines. The body of fish is strongly compressed from sides due to what duckweed-hackler easily squeezes among roots of floating plants hanging down in thickness of water.
Tail of this fish is short and wide: duckweed-hackler does not like to swim far, but in case of necessity it can accelerate large speed, escaping from predators or arranging courtship display. Back fin of fish is short and triangular; flesh fin is low. Wide anal fin of this species has the important role in displays: having stretched and colored it brightly, male involves females, swimming near the surface of water.
The body of fish is colored yellowish with brown irregular-shaped spots and pale “leaf nerves”. In case of danger fish skilfully simulates rotten leaves, rushing on bottom and quickly digging in dust. When silt and settle sediment, the hidden fish becomes invisible. Duckweed-hackler can hide in bottom dust for some minutes. As a rule, it is enough, that predatory fish ceases to search for it.
Duckweed-hackler eats exclusively one kind of food: duckweed covering like continuous carpet the surface of tropical reservoirs. The mouth of this fish is perfectly adapted to such diet: it is shifted and oblique upwards. Top jaw of duckweed-hackler has a remarkable structure: teeth on it are very thin and numerous, forming true “palings”. They stick up on the internal surface of upper lip, and when the mouth is opened their edges are directed upwards and a little forward. Bottom jaw with thick fringy lip at the opened mouth is directed in parallel to water surface. Eating fish “draws” water surface by upper lip, gathering duckweed by thin teeth, as if like net. From time to time it closes mouth, and lower lip rakes gathered duckweed from top jaw and fish swallows it. Duckweed is rich in protein, but fish also eats tiny animals settling on duckweed.
Duckweed-hacklers protect the fodder site actively, and support it in cleanliness: they tear off leaves of water lilies and take away large floating plants, releasing living place for growth of duckweed. Each fish owns the certain site on water surface (approximately some tens square meters). It drives off congeners from site, showing itself in ray of sun light. However, at edges of fodder territories at these fishes necessarily there is secluded nook in which duckweed-hackler hides from predators.
In spawning season duckweed-hackler does not show strict intolerance to congeners. Females have a right to swim to another's territories, and males do not hide their location – they highly jump out of water, ploping down back loudly splashing. At duckweed-hacklers males are smaller than females, but they have larger head and are colored brighter. Courting after the female, male spreads anal fin on which the border of red color appears, and shows itself in sun rays. Preliminary it scatters plants floating on water surface to make the place of display lighter.
As against to the majority of citarinids and their relatives, duckweed-hacklers spawn in pairs. Male drives female above the bottom, and from time to time presses it to underwater objects. Sires spawn transparent not sticky eggs in water, and it sediments on bottom. Fertility of one female may reach 30 thousands of eggs. Adult fishes may eat a part of eggs, picking them up during the spawning act, but after spawning male banishes female and swims up to the surface of water. Therefore the significant part of eggs has an opportunity to develop at the bottom among dust.
Incubating lasts about two days, and about day larvae motionlessly hang on plants. Then they turn to fry and start to eat phytoplankton and protozoans. Till the first year of life young fishes reach length of 4 – 5 cm and win to themselves small fodder territories, usually in shallow water where adult fishes do not swim. Approximately to the third year of life duckweed-hackler reaches the usual size of adult fish and becomes able to spawning.

Barracuda phago (Necrophago sphyraenoides)
Order: Characids (Characiformes) (or order Cyprinoid fishes (Cypriniformes), suborder Characids)
Family: Citarinids (Citarinidae)
Habitat: Congo, middle part of river channel.
Among inhabitants of African rivers characid fishes are very typical. They are less various, than species in South America, and occupy slightly other ecological niches. Among them there are many predatory species, and omnivorous and herbivorous ones frequently differ in large size. Small predatory fishes of genus Phago had occupied the special place among African characids. These creatures distinguished by furious and predatory behavior, had survived in mass extinction – being small fishes, they could keep rather numerous population till the falling of biological efficiency of reservoirs. Large river predators died out till the ice age – this process had completely exterminated crocodiles, for example. But after stabilization of environment conditions at small fishes the tremendous chance to force the way into large-sized class and to be among succeeding predators of Equatorial Africa rivers, competing with predatory turtles and lizards, had appeared.
Length of Phago and most part of its congeners of Holocene epoch did not exceed 20 – 30 cm. But their descendant, huge barracuda phago, became frightening inhabitant of Congo. It is the predatory fish reaching length up to 2 meters. Body of this predator is lengthened and streamline-shaped. Barracuda phago may accelerate large speed and easily resists to strong current. On sides of this fish body is covered with armour of thick scales – barracuda phagos are rather aggressive relatively to each other, and this adaptation for protection in intraspecific skirmishes is not superfluous for them. Scales form set of slanting cross lines on sides, and the body keeps sufficient flexibility and mobility.
Fins of barracuda phago are short and peaked, and fatty fin is very small. Unpaired fins are shifted to the back part of body – such feature is characteristic for fishes making fast throws. Tail fin of barracuda phago is high and rigid, adapted to accelerating of fast speed.
Barracuda phago has kept a diet, characteristic for ancestors: it is active predator. At it there is big head with long jaws on which numerous pointed teeth stick up. Due to the size this fish eats any animals which it may find in the river and swallow: fishes, shrimps, waterfowl and small ground animals had got in water. For this species cannibalism is very characteristic, therefore young fishes avoid meetings with adults: they keep in shallow rivers, mastering main channel till the process of growth.
Young and adult fishes have different ways of life and thereof at them the various colouring varying in process of growth was developed. Young fishes are more secretive, than adults: they spend a lot of time, hiding among roots of floating plants near the water surface. Therefore their colouring is cross-striped: on silvery background rough vertical strips stretch, hiding fishes among roots of plants. Adult fishes keep in river channel where there are not enough bushes of floating plants. Their body has monotonous silvery colouring.
Being a predator, barracuda phago is solitary fish. Each individual has extensive fodder territory in river channel and actively protects it from neighbours. Threatening the neighbour, the fish utters series of loud creaking sounds well heard from under water. If the contender does not abandon the occupied territory, fishes enter fight: they put bites to each other, drag each other by jaw and tear contender’s fins. Sometimes one of fishes may even kill the contender.
The loneliness of barracuda phago is broken in spawning season. Spawning at this species is schooling, as at many others characids: at this time all borders of individual possession are broken, and predators gather in large shoals numbering up to fifty adult fishes. Unique rescue for river inhabitants at this time is that during spawning the food behaviour at barracuda phago is suppressed. Therefore in shoals of adult fishes it is possible to find young fishes not yet completely left striped colouring.
During courtship games males pursue female by small group, uttering abrupt single clicks. At the culmination moment they densely nestle against the female from different sides, literally squeezing eggs out from it. Small transparent eggs are spawned in water, at once are fertilized, and males lose interest to the female. They abandon it, and start to drive other females, yet not spawned eggs. Having spawned eggs, females try to get rid of chasing from the side of males: they leave the common shoal and hide in thickets of floating plants, as if young growth.
Eggs develop in thickness of water, being gathered at coast or among small bushes of floating vegetation. The incubating lasts about 2 days. Larvae passively soar in thickness of water, becoming prey of various plankton crustaceans and small fishes. But part of them turns to fry a day after. Fry actively swims and hides among plants floating on water surface. Part of them perishes, when the watercourse carries away thickets of floating plants to the ocean. But some of them succeed to survive among thickets, washed to river banks. Growing up, young barracuda phagos migrate in rivers then to return to main channel as one of main predators of the river. They become sexual mature at the fifth year of life, at length about one meter. But at this time at them striped colouring is still kept. They completely develop and lose juvenile colouring up to seven years. Life expectancy of barracuda phago may reach 30 – 35 years.

Rainbow silverscaler (Argentopleura iridescens)
Order Cyprinoids (Cypriniformes)
Family Cyprinids (Cyprinidae)
Habitat: deep part of Fourseas.
Cyprinoids are mainly freshwater fishes, though separate representatives of order can live any time in sea water. And some freshwater species regularly come to sea water for feeding. Earlier such species of cyprinoids lived in Black, Caspian and Aral seas. And, when Fourseas had appeared in Neocene at the territory of Southern Europe, some species of cyprinid fishes survived during mass extinction, had mastered this new environment.
One of main pelagic species of Fourseas belongs to cyprinids. It is silverscaler, the descendant of roach (Rutilus rutilus). This fish appreciably differs from the ancestor, first of all by size and habit of life.
Silverscaler is schooling fish about one meter long, weighting about 15 kg. At it there are muscled body and wide two-lobed tail fin. It is a fish of silvery colouring with bluish shade and strong iridescent shine on sides. Back is appreciably darker than sides, and iridescent shine is swept less up on it. Back fin is short, high and transparent; on it there is a coal-black cross strip – with the help of this natural label fishes of present species distinguish congeners at the large distance. To be less appreciable for predators, fishes simply lower back fin, and become imperceptible on the background of blue water. The mouth is rather small, but it can extend forward as a tube. This fish is mainly zoophagous – it eats invertebrates and fry of fishes (primarily gobies). As at all cyprinids, at silverscaler there are no teeth, but on branchial arches sharp pharyngeal teeth permitting crushing of armors of crustaceans and to keep small fishes are advanced.
Silverscalers keep in huge schools numbering up to hundred of fishes and more. Schools usually include fishes of approximately equal size and age. The expressed leader is not present in them. The school synchronously moves in thickness of water, and scatters in sides as if dissolving in blue haze of water at approach of predator (for example, the tsarfish, the largest inhabitant of Fourseas). When danger is over, fishes gather, signaling to neighbours by movements of back fins.
The spawning of silverscalers takes place in the spring in reeds among thickets of pondweed and eel grass. Fertility of the adult female is up to 100 thousand eggs. The spawning proceeds very roughly: fishes jump out from water, plop down with loud splash; males in schools of four - five individuals chase females ready to spawning. In spawning season males have elements of spawning dress: on their operculums “pearl rash” appears, and the tail fin has red colouring. In spawning season fishes become easily excitable and any sharp burst results to their active jumping out from water in great number. Fishes prefer to spawn approximately in the beginning of spring while water plants only have started to grow, and water is cold and rich in oxygen. There is one more reason in it: in cold water appetite of predators is reduced, and the larvae will be in relatively safety.
Similarly to the majority of cyprinids, these fishes do not care of eggs, and the part of eggs may be had simply eaten by congeners.
The incubating lasts about two weeks. For this time the significant part of eggs is eaten by various animals. The larva hangs on plants two more days, and then turns to fry. Schools of fry of silverscaler leave the coastal zone and pass to life in high sea. To the age of five years fishes reach the length 50 – 60 cm and become sexual mature. Life expectancy at this species may be up to 35 – 40 years.

Potamolabeo (Potamolabeo platycephalus)
Order: Cyprinoid fishes (Cypriniformes)
Family: Cyprinids (Cyprinidae)
Habitat: Zinj Land, fast-flowing mountain rivers and streams.
Zinj Land had separated from Africa by break line marked even in prehistoric time by Great Rift Valley. This enormous land mass, separated from the main continent, includes territories on which in human epoch eastern part of Ethiopia, Somalia, Kenya, Tanzania and the north of Mozambique were placed. In human epoch it was the district including mountainous areas and savanna with additions of woods. Having separated from the continent, Zinj Land had carried away Kilimanjaro, the highest mountain of continent. Rivers of this huge island are short, but flow in warm district favorable to development of diverse life forms. Because of isolation rivers of island are rich in endemic species of fishes. Many interesting species of fishes live in cool mountain rivers. One of these species shows excellent fitness to life in rough current. It is potamolabeo, “stream labeo”, the descendant of cyprinid fishes of genus Labeo, lived in African rivers in Holocene.
Potamolabeo is rather large fish: length of adult individual is up to 30 cm. At this fish sexual dimorphism is well expressed – it is the unusual phenomenon in cyprinid family. The female is larger than male, but at the male head is relatively bigger. Also on operculums of the male the several lines of small spikes increasing in courtship season grow.
Potamolabeo looks very clumsily: the fish seems made of two parts of completely different fishes. At this fish there are massive flat head, slightly convex eyes and constantly opened mouth looking like sucker. On lips of fish some numbers of corneous denticles develop – similarly to all cyprinids, potamolabeo has no true teeth. Operculums of this fish are shifted downwards, and gills are protected from below from sand by additional skin valves.
Body of fish is thin and low. Wide pectoral fins serve potamolabeo as rudders of depth. This fish lives in fast flowing water; therefore, having slightly turned fins, it can emerge or nestle against the bottom easily, not spending superfluous efforts. The first ray of pectoral and abdominal fins at fishes of both sexes is thick, strong, and saw-like jagged, having a spike on the tip. At males spike is thicker, rather than at females.
Back fin of potamolabeo is very bright – red with black speckles. Its basis is short, and fin rays are long. This fin has the function of warning signal, equally important both for the male, and for the female. Therefore back fin is equally bright at representatives of both sexes.
Strong current is a factor of environment difficult to struggle with it. In current fishes develop two basic tactics of behaviour: they either become fast swimmers to move against the stream, staying on place, or avoid the current. Potamolabeo had chosen the second way: this massive fish swims hardly and does not emerge without special necessities. All efforts of fish are directed on being kept at the bottom and to not be carried away by rough current. This fish keeps by spikes of fins for stones, and the counter stream presses fish to stones. Swimming bladder at potamolabeo is lack.
This fish keeps on stony areas of rivers. Potamolabeo eats algae, water mosses and larvae of insects attaching to stones. Also it can clean off microscopic seaweed growing on leaves of underwater plants living in flowing water. Except for corneous denticles, on bottom jaw the corneous edges develop, assisting to scrape off algae. For digestion of such poorly nutritious food at fish the long intestines had developed – its length fifteen times exceeds length of fish body. Being filled with food, intestines also raise density of fish and facilitate resistance to current.
Feeding by so specific kind of forage had caused the certain changes in habit of life of potamolabeo. Potamolabeo is territorial and aggressive. Each fish has territory the area about 10 square meters; the fish knows borders of territory and furiously protects them from neighbours. Bushes of plants and large stones serve as boundary marks. If the stranger interferes in limits of territory of fish, the owner of territory quickly lifts and lowers back fin some times. It is a signal, that the stranger is noticed, and simultaneously it is the requirement to leave the territory which is already occupied. If the stranger does not leave territory, the fish owning a site, swims towards to the contender, having opened back fin. This is the warning of opportunity to fight. Fights at potamolabeo are very severe: fish accelerates speed and puts to the opponent ramming impacts by a head. Such impact, if it is put to the operculum area, may even kill the contender. There is one more, more harmless reception of struggle – the fish picks up the opponent by head, lifts it above the bottom and by strong impact of snout throws upwards. Current picks up the infringer of territory and carries it to some distance from the site occupied by with a fish.
In spawning season male leaves its territory and spawns with the female in her territory. As a rule, the male chooses the female living in the neighbourhood. Courtship at these fishes is simple and even a little bit formal: the male simply drives the female, trying to swim forward and to touch its head by spikes growing on operculums. Accepting the courting, the female trembles by pectoral fins and presses back fin to the back. Pair of fishes simply scatters eggs at the bottom and does not care of them. For one spawning the pair spawns more than 200 thousands eggs. Eggs fail between stones and are incubating in conditions of good supply by oxygen till about two weeks. The first some minutes after fertilization the shell of eggs is not sticky, but further it swells and on its surface slime appears, which pastes eggs to stones and driftwood. Larvae of potamolabeo are inactive. They hide in cracks between stones and eat bacterial slime and particles of organic substances. Larger fry keep secretively under stones or in bushes of water plants. Young fishes migrate in shallow streams where there are no adult fishes, and gradually grow there. At this stage of life many fishes become victims of various water predators. As they grow, they settle in deeper sites of river channel and occupy individual sites. Young fishes take part in spawning at one-year-old age.

Indugenous labiocyprinus (Labiocyprinus indigenus)
Order: Cyprinoid fishes (Cypriniformes)
Family: Cyprinids (Cyprinidae)
Habitat: rivers of New Zealand.
Before the people colonization of New Zealand the freshwater ichthyofauna of this archipelago was very poor. People had changed the direction of evolution, when they had introduced to New Zealand various freshwater fishes from other continents, and carp, the domestic species of fishes, among them. After the human disappearance descendants of carp had settled widely in fresh waters of islands, having formed a lot of vital forms – from small up to large ones, from inhabitants of bogs up to inhabitants of crystal clear ice-cold water of mountain rivers.
Labiocyprinus lives in rivers of New Zealand, preferring moderate current and clean water. These fishes are especially numerous in foothills where rivers are not so fast, but have not grown turbid yet from soil suspension. The length of labiocyprinus reaches 40 cm, but usually these fishes are smaller.
Labiocyprinus belongs to omnivorous fishes, and eats algal covers and sedentary animals living on stones. The mouth of this fish had changed to sucker and had moved downwards. Bottom jaw is shorter, than top one, and consequently the mouth of fish is constantly opened. Thick lips of labiocyprinus (the name literally means “thick-lipped carp”) are covered with fleecy corneous outgrowths, which help more effectively scrape out incrustations from stones. The upper lip is divided into two mobile halves, which can move independently one from another. The front edge of muzzle of this fish is covered with corneous “callouses” assisting in case of need to dig ground in searches of forage. The mouth of fish is surrounded with eight short barbs – two of them stick up forward, two ones are directed in sides, and four barbs are turned back. Barbs are covered with various receptors, including flavouring and tactile ones. They give a fish the adequate information about the world around. Eyes of labiocyprinus are turned upwards and in sides.
Labiocyprinus is convergent similar to Labeo and other fishes living in current. Body of this fish is triangular in section, with wide flat stomach. The back of fish is colored brown; sides are greenish, and stomach and bottom side of head are white. Fins of fish are grey with dark spots in basis. Out of spawning season male and female of this fish species are practically indiscernible by colouring. The fish spends the most part of time at the bottom, therefore the swimming bladder at labiocyprinus is reduced, and represents tissue band filled with fat. Tail stalk is short; tail is strong, with wide two-lobed fin. On top blade of tail fin of the male there is long “tress” – some very much lengthened flexible fin rays connected by a membrane. “Tress” has a pattern of cross black strips.
All fishes living in strong current face with one problem – the necessity to keep on place. Labiocyprinus has left difficulty, having got “clawed” fins: tips of thickened forward rays of pectoral and abdominal fins jut out from fin membrane and are slightly bent downwards. They permit the fish to cling to smooth stones and to keep strongly even in strong current. Usually each fish has some favourite places of rest – small holes at the bottom of river where it is almost not necessary to hold by fins.
By the habit of life labiocyprinus is a solitary territorial fish. Each individual occupies territory about twenty square meters, extended along a watercourse. At places poor in nutrition territories of these fishes may be even larger. Borders of territory are well-known to each individual, and it is ready to die in the last ditch, protecting the possession from congeners.
In courtship season male gets very bright colouring – its body turns emerald-green with iridescent shine, and fins get red colouring. “Tress” on its tail fin turns more contrast and well appreciable. Male ready to spawning starts “singing” – with the help of pharyngeal “teeth” it utters loud clicks. This way it warns other males that the territory is occupied, and involves females to the place of spawning.
These fishes spawn in pair, and spawn eggs in simple small hole which is dug out at the bottom of the river near to riverbank. After spawning male digs the hole in and protects territory, where the nest is located, from congeners and even from other rather sizable fishes. It aggressively attacks newcomers, striking them by impacts of strong snout. But at the same time it practically does not pay attention to tiny animals, therefore water invertebrates – insects and river crabs – cause the big damage to posterity of this fish.
The young growth of labiocyprinuses since the first days of life is leaved to the mercy of fate. The mortality among young fishes of this species is very great, and at times only 1 – 2 % from all hatch survives up to second year of life. But life expectancy of these fishes can reach 100 years and more. From 4-years age young labiocyprinuses can take part in spawning, and to 8 – 9 years grow to the size characteristic for adult fish of this species.

Mudsleeper (Dormicyprinus robustus)
Order: Cyprinoid fishes (Cypriniformes)
Family: Cyprinids (Cyprinidae)
Habitat: Meganesia, savanna areas to the west from Eyre Gulf; temporary reservoirs.
Not all species of animals and plants introduced by people to various places of the Earth had died out during global ecological crisis at the boundary of Holocene and Neocene. At various continents in Neocene flora and fauna it is possible to meet species descended from species introduced to these regions by people millions years ago. Ecosystems of islands and Australia, continent, for long time being in isolation, suffered from introducing of alien species especially strongly. In Neocene at the territory of Meganesia (continent united Australia and New Guinea) many species being descendants of non-native species live. In ichthyofauna of Meganesia one of their representatives is the large cyprinoid fish named mudsleeper. It is the descendant of of carp (Cyprinus carpio) introduced by people, which had exellently adapted to extreme conditions of new motherland.
Freshwater reservoirs in Meganesia are concentrated at the north and at the east, along Great Dividing Ridge. Farther at the west there is wide brackish-water Eyre Gulf; from the west only temporary rivers which may dry up completely for some months run into this gulf. In such reservoirs this fish is dominant species of ichthyofauna.
Body length of mudsleeper is about 40 cm. Body of this fish is prolonged; head is flattened and rather small. The fin shape of this species is characteristic for slowly swimming omnivorous cyprinids – all its fins are rounded and have soft rays. Only in back fin some forward rays have grown together to one strong prickle on which front edge small denticles develop. Colouring of body of mudsleeper is beautiful: there is golden-brown background with vertical greenish-black strips, one of which stretches across the eye. Fins are transparent with reddish-orange shade.
This species of fishes is omnivorous, and equally willingly eats insects, aquatic vegetation and even dead animals had sunk during rains.
The remarkable skill of its ancestor, the ability to go through temporary drying of reservoir, had received the further development at this species. Mudsleeper can survive till about 15 months, having dug in ground of the dried up reservoir to the depth of about one meter. At this time in organism of fish significant physiological changes proceed. Shortly before complete drying of reservoir muscles of fish as if impregnate with water and become slightly watery. It is the stock of water necessary for successful surviving in drought. When water level falls so, that it does not provide the survival of fish, it starts to dig in ground the vertical shaft to the depth up to one meter. Usually the individuals living in droughter conditions hide deeper, than ones from populations of the coast of Eyre Gulf. Having reached the needed depth, fish forms the small chamber, in which falls into anabiosis, by movements of body. In chamber fish is turned as a ring, having covered operculums by tail fin from below. The body of fish starts to produce slime plentifully. Thus water is gradually “squeezed out” of muscles. Slime is produced in small amount up to the end of term of anabiosis, therefore to the end of dry season fish seems dried alive. At this time fish grows thin strongly; even its eyes fall in, but blood in any case is kept liquid. During anabiosis the body is covered with “cocoon” in which there is only one small aperture which opens to the mouth. External surface of cocoon represents the hardened crust of sand and clay stuck to strong cover by protein fractions of slime. During the rain when the ground is impregnated with water enough, the cocoon becomes soggy quickly, and fish absorbs water through skin of stomach and gills. When muscles restore approximately 50% of the lost moisture, fish starts to get out of ground captivity.
Right after filling of reservoirs by water mudsleepers arrange noisy courtship games. In day time they are slow and hide among quickly growing plants, but in the evening males one by one or in small groups jump from water and loudly splash back, involving females. At night males start to chase females and to drive them to thickets of underwater plants. Nestling to females, males force them to spawn eggs. Fertility of these fishes makes over 50 thousand eggs.
At the majority of cyprinoid fishes the care of posterity is limited only by spawning of plenty of eggs in place favorable for its incubation. Mudsleeper had not departed this “tradition”. The young ones hatch after 3 – 4 days and start to develop very quickly. Young fishes are mainly zoophagous - they had to grow up as much as possible while the reservoir is not dried up. They eat larvae of insects, small crustaceans (their eggs go through drought in dried up silt), and larger ones devour their own congeners. Having such diet some individuals grow to the length of 13 – 15 cm to the time of drying of reservoir. At such size they have a great chance to survive in drought in anabiosis. Small individuals also have chance to survive: many of them successfully live the first years of life in not drying up ponds in lower reaches of rivers. These fishes do not endure salt water and do not live in Eyre Gulf.
At the third year of life mudsleeper reaches a sexual maturity. Life expectancy of this species may reach 40 years and more – ageing of a fish is sharply slowed down while it falls into anabiosis.

Manatee fish (Ichthyomanatus crassilabrus)
Order: Cyprinoid fish (Cypriniformes)
Family: Suckerfishes (Catostomidae)
Habitat: lakes and rivers of southern part of North America.
In Eurasia and Africa cyprinoid fishes were characteristic component of Holocene ichthyofauna. In North America fishes of this family had also lived, but they had been represented only by small species. And the place occupied by cyprinids in ecosystems of Eurasia had been occupied in New World by representatives of suckerfishes – representatives of other family of fishes.
Suckerfishes are fishes of clean rivers and lakes. In human epoch number of many of their species had sharply decreased because of pollution of reservoirs, and some species had been destroyed completely. During the ice age few survived species prospered in cool lakes, and till the global warming they had widely settled in all North America. When the climate began to change, descendants of northern suckerfishes had to maintain an impact of heat-loving fishes from the south. Some suckerfish species had died out or had receded to the north in such conditions, but anothers managed to survive and to occupy various ecological niches in new ecosystems.
In subtropical and tropical waters of North America to the east from Great Plains extensive river systems stretch; earlier the Mississipi basin was here. Here and in smaller river systems of Gulf of Mexico basin, one species of suckerfishes lives, having no analogues in ichthyofauna of North America. Presence of this fish can be defined by moving of leaves and stalks of plants: when this fish eats plants, stalks of reed move and fall in water, and from bottom clubs of silt rise. Occasionally in sun light wide scaly back with large fin shines, or wide-foreheaded head is shown. By behaviour mode and the role in ecosystems this fish resembles the manatee (Trichechus manatus), herbivorous water mammal, rare in Holocene and extinct completely to Neocene. This water inhabitant is named manatee fish.
The length of manatee fish is over 4 meters, and weight reaches one and half tons: it is largest freshwater fish of North America of Neocene epoch, and it is possible, the largest freshwater fish of the world. This is peaceful sluggish creature and the exclusive vegetarian. Manatee fish has massive body covered with large scales. This species of fishes is not able to swim quickly, but it is not necessary for adult fish: manatee fish had reached the size characteristic for these fishes, has practically no enemies. Tail fin is short, two-lobed with rounded blades. Tail is thick and high. Pectoral and abdominal fins of this fish have strong bases and very thick beams - they help the manatee fish to make the way through thickets of reed and among roots of trees. Manatee fish has bad sight and small eyes are located near to corners of mouth. This fish orientates with the help of sense of smell.
Body of this fish is colored dark green, and stomach is grey. On back and sides small brown spots are scattered. On back they are more numerous and merge, forming “marble” pattern. All fins are grayish. Male does not differ from the female in colouring; it is only smaller and slender a little.
One more feature which makes manatee fish a little similar to the mammal prototype is its mouth. At manatee fish there are fleshy mobile lips covered with numerous fleecy outgrowths. With their help the fish pulls out water plants with roots, and then swallows it entirely. Vegetative forage is poorly nutritious, therefore to increase the efficiency of digestion fish has got very long intestines – the length of bowels is about 30 meters. In it vegetative food is digested as if on the conveyor. The stomach at this fish is not expressed. Manatee fish eats practically till all day, consuming up to 30 kg of water plants per day. Using its dung infusorians and bacteria breed; they are eaten by plankton crustaceans and larvae of fishes serving as forage for various predatory fishes and water insects. Therefore reservoirs where the manatee fish lives differ in large productivity.
In reservoirs where heaten water contains not enough oxygen or in silty water manatee fish uses air breath. The mechanism of it is extremely imperfect, but effective. Having felt an asphyxia, fish emerges to water surface and ventilates gills actively: it simply swallows air from surface and blows it through gills as strong jet. Such activity of set of manatee fishes living in the same reservoir helps to avoid asphyxia in hot season and benefits to other inhabitants of reservoirs. One more advantage to inhabitants of lakes and slowly flowing rivers is that manatee fishes eat floating water plants. For this purpose the huge fish is overturned upside down and gathers plants, sucking them by mouth. From time to time the fish strongly compresses operculums, noisily throwing out from mouth casually swallowed air. Floating plants evaporate a lot of water, therefore, controlling their growth, manatee fishes slow down turning of reservoir to swamp.
At large species there is very slow cycle of reproduction, and manatee fish is not exception here. First time the female of this species spawns only at the age of about 12 years. Despite of the adaptation to life in warm and slowly flowing reservoirs, manatee fish has kept characteristic for suckerfishes attachment to the cool clean rivers which is shown during the spawning. To spawn eggs fish leave inundated lakes and coastal shallows during the river flood, gather in main channel and swim in schools to upper flows of rivers to pebble shallows. In these places there is a simultaneous and rough spawning. Males involving females jump out of water and loudly slap tails. They gather small groups and drive females ready to spawning. But usually one of males drives off other ones and spawns with the female alone. This species of fishes spawns a lot of roe – the adult female spawns more than 10 million eggs. Breeding fishes dig eggs in pebble and do not come back to it any more. The most part of spawned eggs perishes of different kind of water animals: crayfishes, small fish and snails. Fry hatch in one week. Young fishes swim to places with slow current where spend first months of life. At first they eat algal films and their mouth has the sucker shape. Growing up, young fishes start to eat filamentous algae and leaflets of water plants. The most part of young fishes perishes of various predators, but few individuals had reached 4 – 5-years age and length about 40 cm already have an every prospect to reach sexual maturity. At the age of 8 years young manatee fish reaches length of 1 meter and from above one and half meters to maturity approach. This species differs in enviable longevity: the average fish of this species may live till 150 years and more.

Disk rainbow fish (Discotaenia multicolor)
Order: Aterinoids (Ateriniformes)
Family: Rainbow fishes (Melanotaeniidae)
Habitat: freshwater reservoirs of Northern Australia, thickets of aquatic plants.
Movement of Australian continent to the north and its collision with New Guinea had caused active processes of mountain forming which had divided Arafura Sea and Gulf of Carpentaria to some isolated lakes, separated from each other and from ocean by mountain ridges. Gradually rains and rivers had filled these reservoirs with fresh water, and salt sea water had filtered out from them in ocean through cracks in rocks. Only lowermost layers of water in these large lakes have slightly brackish water, as if in memory of that once they were a part of sea.
In reservoirs of Neocenic Australian-New Guinean continent fishes, being descendants of species that inhabited it in far Holocene, prosper. Basically they are representatives of order Aterinoid fishes - various descendants of rainbow fishes (Melanotaenia) and forms related to them (however, among ichthyologists there was also an opinion, that rainbow fishes belong to other order – Mullets (Mugiliformes)). Similarly to cichlids in Africa (in Holocene epoch) and to Neocenic live-bearing fishes of Caribbean Sea, rainbow fishes had evolved to plenty of various species, mainly predators or omnivorous species.
Disk rainbow fish is some kind of “angelfish” among rainbow fishes. It is an omnivorous fish about 10 - 15 cm long, living in thickets of plants. Here this fish hides from enemies and searches for food – larvae of insects and freshwater shrimps. Body of disk rainbow fish is short, but very high: fish at a sight from side seems almost round, only head and tail break disk-like shape a little. Such body shape is characteristic for fishes living among stalks of water plants – having such constitution it is impossible to swim fast, but it is possible to maneuver easily in rich thickets. The body of disk rainbow fish is colored very brightly: scales on body have green metal shine, on operculum there is red “neon” spot, allowing to identify neighbours (at males it is brighter, than at females), and unpaired fins are transparent green with blue border on edge of tail. Body is covered with narrow and twisting cross strips of black color: it helps to mask among vertical stalks of plants.
The mouth of disk rainbow fish is small; it can extend to small tube: by such mouth it is more conveniently to gather attaching larvae of midges and mosquitoes making a basis of diet of this species from plant stalks.
Disk rainbow fishes breed, dropping eggs above thickets of small-leaved plants. For spawning they gather to big shoals (up to 200 fishes and more). Males begin school formation, gathering to groups and appealingly swimming above thickets of water plants. Gradually new males and females join them. The school swims above plants, from time to time quickening, synchronously turning and twirling. Movements of school of fishes ready to spawning resemble fantastic bewitching dance. Vital processes of separate individuals are synchronized so, and females begin ready to spawn practically simultaneously. Each female in time of “common dance” is surrounded by two - three males (usually there are more males than females in school). Then at the culmination moment “dance” interrupts and prompt race begins. Females spawn eggs, and males following them, fertilize them. Eggs fall in thickets of plants, and fishes do not worry any more about their destiny. Having spawned a portion of eggs, female has a rest any time, having replaced race to “dance”, and then spawning repeats. Usually female has exhausted egg stock, leaves school, hiding in thickets. But it does not worry males: from vicinities new males and females swim to school. Such “dancing madness” proceeds some days in succession, and then fishes gradually calm down and again live reticent life in plants.
If eggs will not be eaten with numerous predators and simply foddies loving gratuitous entertainment, in day from them tiny larvae will hatch. They hang on plants about day (yet a yolk sac will resorb), and then turn to active gluttonous fry. At the age of half-year young fish has length about 5 cm and colouring, characteristic for adult fishes (only without red spots on operculums), and at seven-month age it already can breed.

Wide-mouthed rainbow pike (Esocitaenia angustistoma)
Order: Aterinoid fishes (Ateriniformes)
Family: Rainbow fishes (Melanotaeniidae)
Habitat: freshwater reservoirs of Northern Australia, thickets of underwater plants.
Being out of competition in various conditions of inhabiting, species of live organisms quickly divides to some new forms, occupying various habitats, weakening thus a competition among themselves. Such process is named “adaptive radiation”. In Australian-New Guinean region such phenomenon is shown by fishes: representatives of family of rainbow fishes. Among them species had mastered most various habitats and habit of life have appeared. One of species of this family, the wide-mouthed rainbow pike, had turned to active predator of brackish lake formed at the place of Gulf of Carpentaria.
This solitary species of fishes had occupied ecological niche of pikes and other ambush predators. In this connection at the rainbow pike the characteristic shape was formed. Body of fish is oblong and almost cylindrical; length is up to 60 - 80 m. Tail fin is two-lobed, wide and short. Unpaired fins are shifted in back half of body, prickly and soft back fins are connected. Abdominal fins are very short, located approximately under pectoral ones. Rainbow pike swims reluctantly, but can stand per many hours in ambush at the bottom, waiting while catch itself will approach to it close enough to prey it.
Head at this fish is large with wide mouth, extending to short tube. On jawsthere are about hundred small needle-like teeth permitting to keep easily slippery fish or firm shrimp (they make a basis of food of rainbow pike).
The body of this fish is colored with “marble” pattern imitating stones overgrown by seaweed and solar patches of light on them: the basic background is sandy-yellow with cross green and white irregular-shaped “dabs”. At each individual they form unique individual pattern. Besides the shade of coloring can vary depending on color of environmental site of bottom: from almost entirely green color with white and yellowish-green spots up to almost monochromic sandy-yellow color with white “dabs”. At night the fish as if appreciates ancestral colouring: it turns pale, and along the middle line of body the clear black longitudinal strip appears: ancestors of rainbow pike were australian and New Giunean rainbow fishes (Melanotaenia), named so for this feature (“Melanotaenia” in Latin means “black-striped”: many species have longitudinal black strip in colouring).
Each fish occupies at the bottom the certain territory, preserving it against neighbours. As borders of territories various underwater objects, and simple sites of the bottom, not overgrown by plants, serve. If on border the neighbour appears, the owner of territory swims up from thickets, uttering series of clicks. Usually such signal happens enough to drive the stranger off. The fish banishes especially persistent newcomers by sharp throw, braking and turning off aside near to stranger. If the stranger is not going to leave, the turn and ramming impact by snout in area of operculum follows.
During spawning borders of territories as if cease to exist: rainbow pikes earlier were selfish and bilious singles, gather to schools of some tens fishes. Spawning is stimulated with rains freshened the top layer of lake water, and also with bright sunlight. Males shine with bright red fins and golden spots on sides. Fishes spawn in groups, spreading eggs above leaves of aquatic plants near coast. Spawning passes roughly: fishes keen on pursuit one after another jump out from water at meter height and plop down back with loud splash. Each female can spawn approximately 500 - 600 grains of roe for one breeding cycle. After the ending of spawning fishes swim out to their sites, and each of them precisely remembers borders of the possession and ruthlessly expels strangers, which had time to lodge at this site of bottom, from the territory. Approximately month later spawning repeats. But, despite of such fertility, fry of rainbow pikes meet among plants in shallow waters of Carpentaria Lake much less often, than fry of other species of fishes.
Eggs develop within approximately two weeks. Because fishes do not care of posterity, for this time the most part of eggs appear had eaten by various inhabitants of lake. Larvae grow disjointedly, and among fry of rainbow pike cannibalism is not a rarity, and fry frequently become preys of adult fishes. If the young fish managed to reach half-year age and length about 20 cm, it has quite good chances to live up to 10 - 12 years – it is the age limit of wide-mouthed rainbow pikes.

Long-termed archontobranchius (Archontobranchius longaevus)
Order: Cyprinodontiformes (Cyprinodontiformes)
Family: Killyfishes (Cyprinodontidae)
Habitat: north of Zinj Land, shallow rivers and lakes.
For tropical zone of the Earth so-called “annual” fishes are very characteristic. It is the large group of small species of cyprinodontiform fishes living till only one season, and surviving in drought as dormant eggs. In Old and New World there was a set of species of these fishes. Sometimes they could be met even in pools, existing only few weeks in rain season. The part of species of “annual” fishes had successfully gone through climatic changes of the boundary of Neocene and Holocene. In Neocene the active speciation of this group connected to expansion of area of tropical climate and split of African continent began. One species had gone on the unusual way of evolution - it turned to “perennial” species again, and had considerably increased in size. The ancestor of this fish belonged to number of small fishes of genus Notobranchius. Its descendant looks hereby Methuselah in comparison with ancestral forms: duration of its life makes about 15 years. For this feature the fish is named archontobranchius.
Archontobranchius lives in rivers of northern part of Zinj Land having slow current, strongly overgrown with water plants and well warmed by sun. It is a solitary fish aggressive to congeners out of spawning season.
The length of body of archontobranchius reaches 30 – 35 cm. This fish is a little similar to the goby: at archontobranchius there is massive body slightly compressed from sides, and large head with wide mouth turned upwards. Unpaired fins are rounded and shifted to back half of body. Tail fin is two-lobed, with small cut at back edge. Pectoral fins of males are wide and fan-shaped. The body of fish is covered with very small scales.
At archontobranchius the sexual dimorphism in size and colouring of body is well expressed. The male is larger and more aggressive, than the female, and it is painted much brighter, than the female. The back of fishes of both sexes is brown with black speckles – fish is less appreciable so for air predators. At male sides are blue with slanting faltering red strips. Eyes of male are bright blue and shining. On its pectoral fins there is a pattern of
small black spots on red background, forming faltering cross lines.
Female is colored more modest, rather than male – at it there is “marble” brown colouring with grayish-green irregular-shaped spots; eyes are grey with slight shine. In populations the number of males is less, than the number of females – the significant part of males perishes because of bright colouring in beaks of fish-eating birds.
Archontobranchius is carnivorous fish; its food is made by water insects and their larvae, and also shrimps and fry of fishes. This fish hunts catch, which keeps near the surface of water.
The spawning of this fish passes very originally: in it features, characteristic for ancestors of archontobranchius were kept and had received the surprising continuation. This fish breeds at flood of the rivers, during the peak of rain season. Archontobranchiuses spawn in pairs, digging eggs in silt in shallow water. Fishes spawn in the morning, while fish-eating birds have not woken up yet. At this time shallow water literally boil from pairs of spawning fishes which hasten to lay eggs while sun is not rose high enough. Spawning pair jumps out from depth of reservoir to the shallow water, and is literally twisted in layer of coastal mud. At this moment male covers the female by the body, snapping her by pectoral fin or operculum. The female digs out in silt the furrow by sharp movements of head and breast and immediately lays in it small eggs (in clutch it may be up to 500 eggs). The male on the spot fertilizes eggs, and pair of fishes, spinning in silt, buries eggs. For one act of spawning fishes make in mud some furrows and lay in them all caviar which is produced by female. After spawning adult fishes slip from shallow water and swim out to depth. They hide under floating leaves of water plants and restore forces after tiresome spawning. The female spawns only once for a rain season; and one male can repeat spawning with different females some times having breaks approximately in two days. Right after spawning fishes feed more actively, and at females the forming of new portion of eggs begins, but its development stops up to new rain season. Rain water serves as stimulus for the further egg ripening.
Eggs of archontobranchius are small, but the period of their incubating stretches almost to one year. Conditions of egg incubating of this species of fishes are original: in some days after spawning shallows dry up, and eggs appears in layer of liquid mud, or even simply on land. It does not kill them: egg of this fish easily tolerates drying due to dense shell. This feature inherited from ancestors, allows archontobranchius to settle actively. Eggs can be transferred in dry season by wind or on legs of animals to long distances. Sometimes water birds carry eggs on paws over sea passages, and archontobranchiuses may be met even at Madagascar, in Arabia and at the African coast of Tanganyica Passage. But there constant populations of this fish are not formed – practically all immigrants fall victims of local species of fishes and fish-eating birds. But in conditions of seasonal climate at the north of Zinj Land, when the rain season is replaced by drought, archontobranchius is out of competition.
Adult archontobranchiuses live in rivers and lakes which in drought may turn to stinking ponds with dirty water. These fishes are steady against lack of oxygen dissolved in water. They can respire, grasping an air bubble from the surface of water. When the fish holds air bubble in mouth, oxygen from it gets in blood through gills. When the reservoir dries up strongly, archontobranchius digs itself in silt and rotten plants, and respires with the help of skin. This fish has the certain abilities to forecasting a drought: having a presentiment of rough drought, fishes dig in silt deeper, and fall into catalepsy.
When the rain season comes, adult fishes leave the refuges. They at once start to hunt various insects flying to water, and even try to catch butterflies and dragonflies flying above water. During the rain season from eggs fry hatch. The part of them may appear in temporary reservoirs unsuitable for life, but some ones may get in other rivers and lakes where there are good conditions for life. Fry is very tiny – the length of just hatched fry does not exceed 2 – 3 mm. But they grow quickly, and to the end of the second month of life reach the length of 4 – 5 cm. At the age of about half-year young fish already can take part in spawning.

Tiny snail cleaner (Helicichthys hygeius)
Order: Cyprinodontiformes (Cyprinodontiformes)
Family: Live-bearers (Poeciliidae)
Habitat: Great Antigua, slowly flowing rivers, ponds and bogs.
Sometimes health of animal may depend on other species of live beings, and sometimes the connection may look too strange. Vertebrates are hosts of various helminths. Life cycle of these parasitic worms is connected to change of various hosts at different stages of development of worm. Frequently larvae of helminths parasitize in freshwater snails during any time, and then pass from them to the final host.
At Great Antigua many species of animals live, and some their parasites pass the part of life cycle in large freshwater snails of families Ampullariidae, Viviparidae and others. But the evolution had given to snails the unexpected assistant – one local fishes.
Small translucent fish about 25 millimeters long constantly keeps near large snails. The body of this fish has only some dark spots on back, and on side thin longitudinal silver strip stretching from eye up to the basis of tail fin is visible. It is a symbiote of snails, tiny snail cleaner. The body of snail cleaner is prolonged and thin due to what fish can penetrate into pallial cavity of snail, not causing it of anxiety. The pointed head of snail cleaner permits this fish to clear delicate snail gills of parasites accurately. Fish constantly keeps near the snail, not departuring from it more, than to 10 – 15 centimeters. Only at extreme danger snail cleaner can leave a snail “cared” by it, but after that it necessarily searches to itself for the new host mollusc. If danger threatens to the fish, it hides in shell of snail. Sometimes it even squeezes into shell of snail when mollusk retracts into it, and waits danger, having covered in pallial cavity of snail. Enemies of tiny snail cleaner are water beetles, bugs and leeches.
Tiny snail cleaner eats various invertebrates found near snails and on its body. It eats rotifers and smallest larvae of midges and mosquitoes. This fish is able to eat planarias, harming to snails strongly, without harm for itself. Other fishes do not eat planarias because of their poisonous slime. But the biggest benefit of this fish is received not only by snails cleared by it, but also by various species of vertebrates of Great Antigua. Tiny snail cleaner, in addition, eats swimming larvae of helminths searching for snails to pass the next stage of life cycle. Therefore contamination by helminths of vertebrats of Great Antigua in habitats of tiny snail cleaner is much lower, than in similar areas where this fish is not present at the same number of snails.
Tiny snail cleaner belongs to viviparous species. The complex ritual previous to pairing is lack at this species. Male and female are coupled at the meeting of their host snails. The sperm received by female, keeps viability for a long time, therefore female is able to bring posterity within several months after the only pairing. Embryos in ovoducts of female do not lose connection with it up to last moment before birth. Stimulus for their birth is the presence of large snail having no symbiote fish. When such snail comes nearer to closer distance, the female of tiny snail cleaner leaves its own host snail and quickly gives rise to one well developed young fish for other snail. The anal fin of female of tiny snail cleaner has lengthened front edge and resembles the male gonopodium a little. At the birth moment the edge of fin turns off in tube like an ovipositor. With its help the female places newborn fry right in pallial cavity of snail. After the fry birth it quickly swims back to its own host snail. Fertility of the female can make up to fifty young fishes for three months of life. Sometimes within one day the female gives rise up to three young ones in shells of different snails. Right after the last birth in her organism next embryo starts to develop.
Transparent young tiny snail cleaners are completely independent and very active. They clear host snail of parasites, and the first weeks of life hide in its shell. At bi-monthly age young tiny snail cleaner reaches sexual maturity. Life expectancy of this fish seldom exceeds 20 months.

Barbed cave live-bearer (Caecopoecilichthys barbatus)
Order: Cyprinodontiformes (Cyprinodontiformes)
Family: Live-bearers (Poeciliidae)
Habitat: caves of Central America (Yucatan).
In Neocene viviparous fishes of Poeciliidae family have a true evolutionary blossoming. Among them many freshwater species had evolved, and the significant number of these fishes had developed sea inhabitancy. Among poeciliids in human epoch there were some species of low-specialized troglobionts – cave species made only first steps in development of gloomy world of caves.
From human epoch millions years had passed. In Neocene among live-bearers the true cave species deeply specialized to such habit of life, barbed cave live-bearer, had evolved. It lives in underground waters of Yucatan Peninsula and was widely settled in various caves due to unpretentiousness and endurance.
It is rather large species of fishes at which the sexual dimorphism is clearly expressed: the female is much larger, than male. Length of female is about 15 sm, male is only about 10 cm long. Female and male very strongly differ from each other not only in size, but also in shape, and also in features of behaviour. Female is massive and has deep body. It swoms slower and eats larger prey. Male is faster and has prolonged body. It has smaller mouth and eats small aquatic animals.
The shape of barbed cave live-bearer is the evidence of millions years of evolution in underground habitats. It is completely blind fish at which even rudiments of eyes was not kept. Only two holes on head indicate former presence of eyes at far ancestors of this species. Instead of lost sight this species has well advanced organs of lateral line and set of receptors located on head. Related to barbed cave live-bearer fishes living in rivers and sea have no wattles, but at cave live-bearer around of mouth the outgrowths similar to short wattles are developed. They are especially numerous on bottom jaw, because of what this species has received the specific epithet “barbatus” – “barbed”. The length of these outgrowths reaches 20 – 25 mm; they are plentifully covered with sensory cells.
The body of barbed cave live-bearer is lack of pigmentation and has pinkish-white color. The skin of fish is covered with thin transparent scale. Fins are wide; back and anal fins are shifted back, to tail. At males anal fin is turned to long mobile gonopodium which basis is covered with small scales. The length of gonopodium makes about half of length of male’s body. Tail fin is trapezoid; at its back edge there is small cutting dividing it to lobes. Pectoral fins are fan-shaped and mobile.
This species of fishes is widely settled in underground waters of Yucatan and adjoining areas of Central America. It is connected with the fact that barbed cave live-bearer can live in water of various salinity – from fresh up to oceanic. Using sea caves, it settles from one underground river into another one.
Barbed cave live-bearer represents strongly expressed predator. At this one wide mouth able to extend to tube and literally to suck prey is developed. This fish eats larvae of insects and other water animals living in caves. If from vaults of cave bat drops and falls in water, bearded cave live-bearer willingly eats them, especially representatives of small species or cubs. It swallows prey entirely – in conditions of caves as in ocean depths it is practically impossible to have strict diet or to eat more or less regularly, therefore the present species of fishes uses poor food resources of cave to the full. Jaw bones are connected by mobile ligaments, and gullet and stomach can stretch strongly.
Similarly to all relatives, this fish is viviparous. However, breeding rate at barbed cave live-bearer is much slower, than at fishes living in open reservoirs. The female of this species gives rise only to one young fish at once. But fry is very big – its length reaches one third of length of female, and it has all chances to survive. Nevertheless, females of barbed cave live-bearer frequently attack young fishes of its species. Within one year the female bears posterity no more than four times, but it is enough of it to provide reproduction of species in conditions of rather isolated reservoir with poor food resources. Right after birth male and female do not differ from each other in size, but further male finishes growth earlier and matures faster. However, in connection to cannibalism of females, the number of males in population is insignificant – it mounts about a quarter of the whole population. Young fishes mature at the age of 1 year, and life expectancy makes not less than 8 years.

River needle-jawed live-bearer (Potamobelone acutirostris)
Order: Cyprinodontiformes (Cyprinodontiformes)
Family: Predatory live-bearers (Rapaciliidae)
Habitat: rivers of Great Antigua.
At the boundary of Holocene and Neocene the most productive communities of ocean, coral reeves and plankton, had suffered irreparable damage as a result of catastrophic processes happened in biosphere. With their disappearance in crisis period the biological variety of oceans had sharply decreased. When conditions acceptable to life had started to restore, survived species had started to evolve actively. Caribbean Sea and Antilles became the center of active speciation of live-bearing fishes. Their ability to live in fresh and sea water, and also high survival rate of posterity were the features determined their evolutionary success.
In shallow waters of Caribbean Sea, in rivers and estuaries live-bearing fishes make an appreciable part of the variety of ichthyofauna. In rivers of Antilles species of fishes of other families were kept, but live-bearers make a considerable part of ichthyofauna there. Some river live-bearers have related species in Caribbean sea. The needle-jawed live-bearer living in lower reaches of rivers of Great Antigua is the close relative of sea lancemouth. This fish lives in deep parts of river channel and occasionally leaves in brackish water of rivers mouth.
The body length of river needle-jawed live-bearer reaches half meter at weight about 400 gramms. Colouring of sides of this fish is silvery with slanting cross strips; back is dark green. Eyes at fishes of both genders are red. River needle-jawed live-bearer keeps in shadow of plants floating on the water surface, or under tree trunks floating in the river. When fish leaves shelter, its colouring becomes uniform silvery.
The most remarkable feature in appearance of this species is the structure of jaws: they are extended and pointed at tips; the bottom jaw is longer than top one and has triangular section. On its bottom side sharp keel stretches. The bottom jaw serves as the hunting weapon: fish pins catch up with the help of this adaptation. Protecting itself against predator, river needle-jawed live-bearer puts to aggressor deep stab and slash wounds by jaws. This tactics of defense makes it very dangerous species: this fish is very excitable and sometimes attacks ground animals swimming in water, taking it for aggressor. By this feature river needle-jawed live-bearer is similar to swordfish of Holocene epoch, which had also attacked objects had not represented any danger for it.
Similarly to many predators, river needle-jawed live-bearer is solitary species. But it is not aggressive relatively to congeners and does not avoid their neighbourhood. At places rich in food this species forms small congestions changeable by structure without any hierarchy. The social behaviour at this species is not advanced; therefore this fish does not form true schools and does not pay attention