Tour to Neocene
Translated by FanboyPhilosopher
After the mass extinction of living creatures
and disappearance of the human species – the most pernicious and the only intelligent
species in history of biosphere – the Earth continued to change gradually. Slow,
but constant movement of continental and oceanic plates has resulted in a non-constant
state of the geography of the planet.
In Neocene Panama land bridge had disappeared under water, and from Atlantic the branch of warm current has penetrated into Pacific Ocean. But in other places, on the contrary, there was a raising of land. Due to it Antilles began larger and have merged to the single island of Great Antigua. This island has risen as a barrier across the way of storms and rains from Atlantic. Because of it the direction of sea currents in the Caribbean Sea had considerably changed – it had turned to one continuous slow whirlpool “spinned” by the Panama current from southern edge. Storms seldom disturb the surface of this sea: southern extremity of North America in the west and islands in the north and the east stop them.
During the ecological crisis of the boundary of Holocene and Neocene the fauna of the Caribbean Sea had undergone significant changes: coral reeves had disappeared, the majority of species of fishes connected to them also had died out, and “plancton accident” had caused extinction of pelagic fishes. Following their prey sharks had abandoned the Caribbean Sea. Species having been earlier absolutely imperceptible creatures densely populating streams, lakes and brackish river estuaries began to occupy the empty sea. The new ichthyofauna of the Caribbean Sea is an empire of descendants of live-bearing tooth-carps (Poeciliidae). There are both small species and two-meter long giants among them.
The largest known fish of the order Cyprinodontiformes was Cuvier’s orestias (Orestias cuvierii) which inhabited the Alpine Titicaca lake in South America and extinct in historical time. The length of its body was no longer than 27 cm. For its relatives from the Neocenic Caribbean sea it is rather insignificant size. Absence of competition and plenty of free ecological niches has enabled small and tiny fish species to turn to giants. The ability of live-bearing fishes of Holocene to live in water with different salinity, or their euryhalinity, was the special feature of them. The cases were known, that it had been possible to meet the same species of fishes both in the river, and at the ocean for tens kilometers far from the coast. Therefore they had succeeded to survive during the ecological accident in rivers, where ecosystems have almost not been damaged, and to occupy the sea later.
Live-bearing fishes have evolved in the Caribbean sea not only to separate genera and species, but also diversified to some families, considerably differing from each other in diet and preferred habitats. Among them there are both herbivorous forms and active predators, not yielding to former sovereigns of the Caribbean Sea in force and ferocity.
In many areas, especially closer to the middle, the surface of the Caribbean Sea looks like the surface of any overgrown pond, differing in scale of overgrowing, of course. Sometimes dense carpets of plants with wide leaves bordered with crystals of salt spread to hundreds of meters on the surface of water. This plant is sea spinach, the descendant of one coastal species of sea grasses of Holocene. Here it has found a nice habitat for itself – plenty of sun and complete absence of competitors. Sometimes, certainly, storm nevertheless tears carpets of this plant to parts, but the damaged greenery quickly grows again, sheltering and feeding many sea animals.
Near to the edge of one such thicket under the surface of water a small living creature is swimming. It has a long head, a mouth armed with small sharp teeth, and a body covered with silvery scales. It is the fry of one fish species inhabiting the Caribbean Sea, the pike live-bearer. Thickets of sea spinach form the good habitat for numerous crustaceans and fry of other species of live-bearing fishes. From time to time the fry rushes in thickets and snatches tiny fry out from dense roots of sea spinach. Smelling blood, neighbours of the preyed one try to hide deeper in thickets – pike live-bearer fry does not like to stay in closeness and tries to not penetrate deep in plant thickets.
However it can not feel like in safety itself though, most likely, it simply does not understand it. Like a silvery arrow the big-eyed fish with long jaws rushes on it, snatches the fry, swallows it, and without stopping its movement, turns around impetuously and joins the big school of neighbors, which is swimming aside thickets of sea spinach.
The fry of the pike live-bearer had fallen a victim to an adult fish of the same species. Cannibalism is not a rarity at these fishes. It can seem severe, but each eaten fry increases chances of survival at its survived neighbors.
The school of pike live-bearers ploughs open areas of the sea. These fishes do not like to come closer to the coast, and they spend their life near the surface of water. Here they pair and give rise to hundreds of young ones, leaving them to the mercy of fate. When fry will grow up, some of them can even find their graves in the stomachs of, maybe, their own parents. But except for them other inhabitants of sea surface get also in stomach of the pike live-bearer.
Silvery shines and bursts of water are the signals, that somewhere nearby a school of dragonfly live-bearers hunts – these ones are the smaller inhabitants of surface of water. These fishes hunt various edible small creatures. They equally greedily eat tiny fry, crustaceans and plankton invertebrates. Sliding under the surface of water, they can gather even insects blown out to the sea by winds from nearby islands.
Pike live-bearers quickly speed up – they have noticed dragonfly live-bearers, and now prepare for an attack. However at dragonfly live-bearers there is one protective trick making them virtually invulnerable even for most high-speed sea inhabitants. Just as from blue haze silhouettes of hunting pike live-bearers appear, dragonfly live-bearers escape in flight. They quickly emerge on the surface of water and their tails start movements at reckless speed. In the beginning their heads appear above the surface of water, and then due to intense movements of tails small fishes emerge out from water almost entirely. And at this moment the indistinct buzzing added to splash: fishes had opened their long pectoral fins transformed into wings. It has allowed them to gather additional speed, and the whole school of dragonfly live-bearers already rushes along the surface of water, having plunged in it only with the bottom edge of pectoral sternum. Flying up on the top of wave, some fishes use it as the springboard, flying some meters in air. The only successful way to prey such fish is to cut off the way to the surface of water to it.
The school of dragonfly live-bearers quickly disperses and disappears from the field of vision of pike live-bearers. And predators are compelled to search for new catch.
Small fishes and shrimps frequently hide from large predators under various floating objects. Sometimes winds fell large trees in woods of Great Antigua and southern part of North America, and rivers carry them to the sea. In branches of such trees there is the true Noah’s ark for set of living creatures.
The huge tree is floating in the sea. Roots of this forest giant were washed away by the river flooded its banks during heavy rains. And one hard blast of wind had been enough for tree to fall in the river, tearing off lianas and breaking saplings and bushes.
Above the water some branches of tree are still alive due to internal stocks of water in tree trunk. On them various lizards and insects creep, and against the bark some snails have stuck. If all of them will be lucky, the tree can be cast ashore of one of numerous small islands, and its passengers will begin new life. The branches appeared under water are already dead. Among scraps of leaves and bark dozens of fishes and shrimps hide. Some of them find plentiful food and shelter against large sea predators here. But in branches one of predators also hides. Under water in shadow of trunk the lancemouth keeps; it is the relative of the pike live-bearer, but it prefers to hunt from the ambush.
When one small fish swims near to the head of the hidden predator, the lightning throw follows – and it already twitches convulsively in narrow, tweezers-like jaws of the predator. However not any fish can be afraid of the lancemouth – the young sea swift, the small fish with deep body and long fins, swims absolutely near to the hidden lancemouth, searching for hidden shrimps and dead insects in branches. The lancemouth will not to have eaten it: the sea swift is obviously uneatable for the predator. But among carnivorous fishes there are not only “strict experts”, but also “universal predators”; and many inhabitants of the sea had to afraid of them. One of them is the pike live-bearer, swimming rather inappropriately to the tree trunk, involved with silvery shine of scales of the hidden fishes.
To be on the safe side the lancemouth hides from its large-toothed and gluttonous relative in thicket of branches closer to the trunk. Its long body nestles against the bark densely and it is quite impossible to take it from branches. And the sea swift seems to have problems – it can’t hide close to the trunk because of deep body. Adult fishes of this species live in thickets of sea spinach, hiding among its roots. But here there is no habitual shelter around, and the fish almost at once falls a prey to the pike live-bearer.
Not all species of fishes like to live in the high sea, preferring to disappear in shelters of any kind. But in the Caribbean Sea there are also some species which have chosen open sea spaces as the habitual residence. In top layers of water the huge amount of phytoplancton develops; it is devoured by thousands of transparent microscopic representatives of zooplancton – tiny crustaceans, larvae of various sea invertebrates and fishes. This rich, almost inexhaustible fodder resource had been mastered by the largest representatives of live-bearing fishes.
From muddy greenish veil silhouettes of these monsters appear: in the beginning they look like dark spots in a cloud of plancton, but then they come nearer and their size appears really huge.
Their mouths, every day passing through gills hundreds of liters of water, are widely opened, huge fins slowly move, and from time to time any of giants accelerates movement, having lazily waved their mighty tail. These two-meter monsters are whale-headed phytopoecilii, the largest species among live-bearing fishes. In their school there are young growth and fry, but it is so hard to name the half meter long fish as “fry”. Nevertheless, they are born being of such size. Young phytopoecilius at once can swim and eat plancton, therefore it stays in parental school and freely follows adult fishes. At the majority of live-bearing fishes of Holocene epoch, and also at carnivorous live-bearers of Neocene cannibalism is a common phenomenon, therefore a fry staying in group of adult fishes risks its own life. But at phytopoecilii it is not present because of their food specialization: the adult fish simply can’t have eaten large catch, including their posterity, because of its anatomy. Therefore young phytopoecilii feel like in safety in school of adult neighbours. It is a strategy very favorable to the survival, because in the Caribbean Sea there are fishes capable to overcome easily the half-meter long catch.
From depth predators, rise to huge phytopoecilii – the half-dozen of pike live-bearers. Their movement and smell cause anxiety in sea giants, and phytopoecilii rise to the surface of water, as if the squadron of dirigible balloons. Alone the pike live-bearer cannot overcome the phytopoecilius, much more surpassing it by weight even at equal length. But in school of phytopoecilii there are young fishes, which have the reason to be afraid for their lives. They try to hide from predators swimming around the school, keeping behind the bodies of adult neighbors. Some of them are almost ready to climb out from water on backs of adult fishes. But this is only the regular beginning of hunting.
Pike live-bearers start to frighten the adult phytopoecilii, trying to disperse them in sides and to deprive young fishes with shelter. They rush to huge fishes, biting their fins and striking at full speed impacts to their stomachs and gills. And after some attacks school of phytopoecilii wavered. One by one the huge fishes have started to rush to sides at approach of pike live-bearers, and large-toothed jaws of predators chatter closer and closer to young fishes. At last the event, waited by predatory fishes, has been happened: one of young fishes panics and tries to rescue itself by flight. It swims out from-behind backs of adult fishes and tries to cover in rich cloud of plankton. But phytopoecilius is bad swimmer. The pike live-bearers swim much faster, and literally in some seconds this fish is already caught and exterminated by strong bites.
The pike live-bearers tear catch similarly to crocodiles: seizing teeth in body of prey, they try to pull out piece of meat, “scrolling” around the body axis. Gradually only inedible for the pike live-bearers a huge head is left from killed phytopoecilius, and it sinks slowly.
Phytopoecilii try to leave the place of fight: the smell of blood can involve other predators. But they do not get to anywhere from it – wounds are put to several adult fishes. And another predator starts to pursue huge fishes along their bloody trail. From the greenish haze a strange creature appears: it carries a shell coiled to a flat spiral. From the shell a strange mushroom-looking sucker and proboscis jut out, and from sides muscled “wings” flap; they are transparent on the edges, and due to them the animal gathers significant speed. It is a special predator – astarotus, the pelagic mollusc combining angelic appearance and devilish habits.
On the tentacles decorating its head extended to proboscis, plenty of receptors have developed, allowing it to catch millions of various smells. And the most desired of them is the smell of fish blood. The astarotus attacks small fishes and kills them by a strong sting, and then slowly eats catch, floating at the surface of water. Mollusc holds it by strong sucker, and wags slightly with wide “wings” to prevent submerging into the depth.
Having founded the bloody trace, mollusc swims in circles for some time, trying to define the direction to the source of smell. Gradually it passes to purposeful search and pursuit. The astarotus swims very quickly, and some minutes later the source of attractive blood smell – some huge phytopoecilii – is already shown in the distance. Certainly, it is not any small fish which can be killed by one sting in head and can be eaten quietly, but the mollusc is very hungry and consequently does not refuse pursuing.
The skin at the side of one huge phytopoecilius is injured by the razor-sharp teeth of the pike live-bearer. Blood gradually oozes out from the wound, and in the water an odorous trace is formed, detectable by the keen sense of smell of the astarotus. Some powerful waves wings have done – and the astarotus has already overtaken the school of phytopoecilii. This mollusc seems tiny against giant fishes, therefore it does not cause the anxiety in giants – such a tiny one does not cause fear even in half meter long “fry” of this species. But, probably, phytopoecilii had not face yet this predator closely.
Having found the source of tempting smell, the astarotus falls on skin of one of fishes. Having attached by powerful creeping sole sucker, it folds “wing” fins, covering its shell by them from sides. After that the mollusc extends long oral proboscis and chomps into in flesh of huge fish.
A sharp pain has pierced the side of huge phytopoecilius: the astarotus started to tear the living flesh of the fish by a sharp radula, emitting out in wound the meat-lysing saliva. The attacked fish began attempts to escape from the predator tiny compared to its own size. At first it began stirring up by whole body, and then it had made sharp jerk forward and had sharply stopped. However the sucker of the astarotus had endured these trials, and the mollusc has continued its meal, having put out from shell. But the fish has one more way to remove it: many massive neighbours swim around, and the attacked fish simply rubs itself against one of them. It is rather dangerous to the astarotus, and the predator leaves fish: collision of two sizeable massive bodies would simply crush it into a flat mass. It can be too dangerous to eat live catch, and the small predator departs, flapping by fins.
But its further way appeared too short: there are other predators in the sea, for which the astarotus is only one of many kinds of prey. The huge grayish-blue body of the fish not yielding in the size to phytopoecilius, has appeared from depths. Sharp crescent fins indicate in this animal the fine swimmer, and speed and quickness shows the active predator. Almost not paying attention to huge phytopoecilii, the fish directs after the astarotus, overtakes and snaps it. The slight crunch of the shell says that hunting has passed successfully. The murderer of the astarotus appeared one more predator of the Caribbean Sea – large shark catfish. Certainly, catfishes too seldom live in the sea though in Holocene representatives of at least two families of these fishes lived at oceans. But after mass extinction of sea fishes catfishes were among those ones which had successfully occupied the exempted ecological niches. The shark catfish is a large representative of ariid catfishes (Ariidae). Due to poisonous spikes in back and pectoral fins it is reliably protected from attacks of other predatory fishes, and leads the serene life of the lonely hunter. Usually shark catfishes do not leave far from coast – they like to have a rest in underwater caves. But among them there are also such individuals which spend a significant part of life in thickness of water above depths, coming to coastal shallow waters only for spawning. Probably, after some millions years the species uniform earlier will diverge into two species, one of which will inhabit coastal shallow waters, and another will live in the high sea.
There are some kilometers up to the coast, and the nearness of it is clearly felt: in water fruits, parts of plants, and sometimes whole trunks of trees float. All these rests attract set of sea inhabitants, sheltering and feeding them.
In branches under the tree trunk the whole school of silvery fishes swims – these ones are young sea swifts. They have already started to change monotonous juvenile coloring to striped adult pattern, and now they instinctively tend to hide under any floating object. When their temporary refuge will float near to thickets of sea spinach, they necessarily will move there, but while such opportunity was not presented to them. Branches of tree reliably hide these fishes from large predators: when near to the trunk the shark catfish swims, moving by tail lazily, sea swifts hide in the dense branches of the dead tree. The wattles of the shark catfish, supplied with chemoreceptors, suggest to it, that in branches possible catch is hidden, but the fish does not react to this signal – this catfish has already to had eaten a large pike live-bearer, and now it does not begin to hunt in vain, yet will digest this plentiful dinner.
And other predator, the gluttonous astarotus gastropod, will not give up to capture the sea swift. Certainly, it is rather difficult for it to make the way through branches, but it is able to make it. Having crept up to their refuge imperceptibly for fishes, this mollusc presses “wings” to sides of body almost completely, and swims, flapping only by their tips. The abdominal sucker of animal extends forward, attaches to the tree bark, and the mollusc is dragged forward with its contraction. It stops for rather long time, when not yet suspecting sea swifts come nearer to it. But when fishes swim out a little, the mollusc makes one more jerk. Having crept up to the fishes closely enough, the astarotus waits for an opportunity for attack. And, when the sea swift swims by closely to it, the long proboscis with a sharp radula pierces in its side – the attack lasts within fractions of second.
The sea swift twitches convulsively, seized by ruthless mollusc, and its scared neighbors rush away from place of tragedy, gradually gathering in roots of floating tree.
When the catch has ceased to resist and went limp lifelessly, the predatory mollusc began getting out from the branches slowly. Here is not its world obviously – this mollusc has got used to live at open space. Some jerks are made – and the astarotus gets out of the weave of branches, keeping the killed fish. Having reached open water, the mollusc opens its wing-looking fins and swims, flapping with them. Thus the sucker keeps the body of fish, and the mouth on the tip of proboscis tears off pieces of meat greedily.
About half an hour later from the sea swift only head and part of backbone, and also rags of inedible fins remain. The gluttonous mollusc leaves them, and swims in search for new prey. Astarotus is successful predator. Due to the abundance of fishes in the Caribbean Sea this species prospers. Food of the astarotus includes many species of fishes, even the young pike live-bearer can easily turn to its prey.
From time to time during the hot tropical summer astarotuses give one of the most interesting performances in the world of nature – the breeding ritual. Rituals of molluscs take place in the afternoon. At this time animals gather in the big schools near to floating thickets of sea spinach. They get the special coloring, signaling to neighbors about the intention to give posterity. Each mollusc swims near to surface of water, having extended upwards the respiratory tube on which the contrast pattern of black cross-strips on a white background appears. Such long tube becomes well appreciable against the background of sea blue, and besides the astarotus makes wavy movements by it. This species does not have difficulties in search of partners for pairing: astarotuses are hermaphrodites, therefore any two animals can theoretically have common posterity easily. The only difficulty which arises here, is that not at all molluscs eggs ripen simultaneously by virtue of the various reasons. But even here a nature has found a very simple way out: during the process of egg forming in organism of mollusc the special repugnatorial gland starts to work. In the beginning its smell is very slight, but soon the mollusc starts to “fume” rather appreciably, leaving the precise odorous trace in water. When hundreds of molluscs gather near surface of the sea, they correctly find the mate with the same degree of egg forming by the intensity of smell. Having found a mate for itself, molluscs keep together – such behaviour synchronizes and accelerates forming of their eggs. Frequently one of molluscs attaches to the shell of another one, and both animals slowly swim at the surface, almost simultaneously flapping fins. Also there comes the moment when both animals are ready to pairing. They approach mouths of shells to each other, having attached by sucker to the shell of the partner. Thus one fin closes a part of shell of the partner, and another makes slow waves, that’s why pairing animals spin on the spot. The set of such pairs “dancing” the original “waltz”, looks very strange and unusually. Pairing lasts for some minutes, but after it pair swims together for the some time, and it repeats up to three-five times.
The fertilized mollusc starts to express a sharpened interest in the subjects floating on the surface of water – it searches for the place where it is possible to leave the clutch of transparent eggs. One of such astarotuses swims to the large tree trunk which, judging from the shabby branches and peeled off bark, serves as a toy to waves and wind for many days. But it seems that this trunk is already kept: under it some astarotuses swim, and here and there on the trunk flat clutches of eggs in mucous capsules are visible. It is no need to stay here for a long: the larvae which have left eggs will have many competitors. And moreover, neighbors ready to egg laying already behave tensely enough: between them constantly there are short-term skirmishes and remaining here means only heating of conditions which can develop in severe thrashing. Therefore the lonely mollusc does not hasten to win a place under this tree trunk to itself and searches for another place for egg laying.
The coconut rolling by sea waves like the water polo ball, could serve as the ideal place for egg laying, but near to it an undesirable neighbor swims – the young pike live-bearer. Certainly, it easily can be caught and be eaten, but from time of pairing up to laying eggs astarotuses eat completely nothing. Therefore the coconut is rejected, and the mollusc disappears in blue haze. It does not swim aimlessly: keen sense of smell indicates to it, that there is something suitable nearby from here.
On the waves thickets of sea spinach bob – it is a large islet of floating plants about ten meters in diameter. Long roots covered with hair hang down to one-and-a-half-meter depth. And from several leaves, injured by fishes, the sap flows to the water – its smell has involved the astarotus. As if a bird, the mollusc hovers near thickets, checking, whether there are no competitors. However, it seems, that it is alone here, at least now. Having convinced, that anybody will not prevent it, the astarotus comes nearer to plant and, having extended the sucker forward, clings to the root. Scared by unexpected movement of this root, tiny fry turn tail and disappear in thicket of plants. And the mollusc does not pay attention to them: it is preoccupied by cares of future posterity. Having clung to the root, the mollusc extends the tubule of ovipositor and leaves the clutch on the root of sea spinach. With several powerful waves of wing-shaped fins the animal swims out from thickets, turns back, and leaves the future posterity. Its parental cares come to end here, but appetite wakes up, and the hunter swims out in search of food.
Thickets of sea spinach rock on waves. This plant expands very quickly, therefore even after the most furious storm the biomass of this species in the sea stays almost constant. Every week storms cast ashore the great banks of this plant together with its inhabitants to various islets of the Caribbean Sea, but for some days sea spinach can restore losses, inflicted to it by storm.
Under the leaves of these plants decorated on edges by border of salt crystals, thousands of fry of various live-bearing fishes of the Caribbean Sea hide. Here it is possible to find youngs of pike live-bearer, lancemouth and other species of fishes. At the edge of thickets large fry of the dragonfly live-bearer keep. They are too large to maneuver among roots and sprouts of this plant, but patrol attentively edges of thickets, eating careless young growth of other fishes. Tiny fry of the pike live-bearer especially suffer from them. At this species the mortality of larvae is compensated exclusively by a plenty of posterity in hatch.
Some tiny young pike live-bearers hide under the surface of water in roots of sea spinach when beside them the young dragonfly live-bearer swims. Its pectoral fins are still little and short, therefore it can not fly up above water, as adult fishes of this species do. But its mouth is already turned upwards, letting it gathering prey from under the surface of water. Therefore, having noticed delicious fry of pike live-bearer, it directs to the rosette of sea spinach, and attacks its prey. Involved with shine of its sides, other young dragonfly live-bearers direct to the plant, and arrange hazardous hunting for fry of pike live-bearer. Eventually from the whole school one fish has escaped only. Only by chance it can survive, and in some years, on contrary, the school of dragonfly live-bearers will search for rescue in flight when this fish will hunt them, surrounded by the school of neighbors. But now this young fish has escaped by a miracle.
In thickets of plants it is quite possible to hide from gluttonous young dragonfly live-bearers. But it will never be absolute safety here – here there are local predators. Sometimes it seems that roots of some plants start as if “to double”. But it is not an optical illusion at all – simply fishes move among them. Their deep short body permits free maneuvering between roots of plants, and striped coloring reliably hides from the extraneous look. These ones are the adult sea swifts. The young growth of this species spends the childhood in the high sea that helps this species to expand, but in the course of maturing fishes start to express the interest to various shelters, eventually settling in thickets of sea spinach. And nothing can expel them from their shelter. Even in storm fishes do not leave the habitual refuge: their pectoral fins have jaggies at one edge. When the storm begins, the fish simply clamps tightly the root of sea spinach between body and pectoral fin, and now even the most furious storm can not tear it off from plant. The grip of this fish and its attachment to shelter are so great, that on the coast in heaps of the sea spinach, cast ashore by waves, it is possible to find dead sea swifts, which still grip the root of plant.
In thickets of sea spinach sea swifts search for food – fry and larvae of various sea inhabitants. The tubular mouth of the sea swift does not give chance to rescue to any tiny edible sea inhabitants. Attentively inspecting roots of sea spinach, these fishes exterminate fry in plenty.
The clutch of astarotus is ready to larvae hatching: it is visible through transparent slime, how the larvae looking absolutely unsimilar to adult animal, turn in egg shells. Larvae produce together the substance gradually diluting the shells of eggs. And at this moment the sea swift finds the clutch of the mollusc. This fish seems a giant compared to astarotus larvae. Having extended the mouth as if a tubule, it begins “pecking” larvae orderly. Some of them succeed to escape and to disappear among roots of sea spinach. The fact, that their siblings were lost, will facilitate their life in certain degree, having lowered a competition between them … to the hundredth part of one per cent. But during the feeding of sea swifts and other inhabitants of thickets more than half of number of astarotus clutches, made on sea spinach, perishes. But survived larvae immediately receive plentiful food – infusorians and microscopic worms abounding among plants.
Larvae of astarotus represent a delicious dish for fry of some fishes, for example, of dragonfly live-bearers. Young fishes of this species are in relative safety from the majority of small predators: they are born very large and advanced, therefore even sea swifts, exterminating huge numbers of fry of other species, are not damgerous for them. Swimming past sea swift does not pay attention to them because of two reasons: first, they are rather large for its mouth, and second, it is the female, going to give birth. Its body from time to time quivers convulsively, and the area near its cloaca is pigmented intensively now. Having seized roots of sea spinach by pectoral fin, the female bends and sharply pulls body, and in water big-bellied small fish – its fry – already whirls. After it one more fry appears, and short time later the female gives rise to all others, one by one. In total for once it has spawned ten youngs absolutely not similar to their mother neither in shape, nor in color. Fry of sea swift try to leave thickets of sea spinach, gathering in small schools. They will spend in the ocean for about ten weeks, feeding on plankton, and then they will begin to turn to small copies of parents and to search for the shelter to themselves. In high sea great number of dangers waits of them: dragonfly live-bearers, astarotuses and pike live-bearers. Even slow whale-headed phytopoecilius can eat young sea swifts, if they appear insufficiently quick. And when they will grow up, they will be afraid of shark catfishes and their deadly jaws.
But this predator comes to the high sea not so often, preferring to keep closer to shallows, where rocks and bottom are indented with caves, in which it likes to have a rest.
The coastal waters of the Caribbean Sea are also populated with live-bearing fishes. In thickets of seaweed waving near the coast it is possible to see completely unusual representatives of this group. Among green and brown thalli, undoubtedly, fishes flash, but they behave very strange: almost all their time they keep body in vertical position, as if “head-standing”. They are named as acrobat live-bearers because of it. The tail of these fishes is weak, but anal fin is very well-advanced: it lets fish to maneuver among seaweed, keeping head directed down. These fishes scratch algal coating, and also eat various tiny animals creeping on stones. Striated coloring makes them completely invsible for predators, which are not less numerous here, rather than in the high sea. The top predator here is the shark catfish. When the shadow of this fish with pointed fins slides on the bottom, acrobat live-bearers hide into the thicket of seaweed and literally merge with them: they seize by lips to stones and make wavy movements in rhythm to seaweed surrounding them. However the catfish does not pay attention to them at all. And the reason of it is not only the masking skill of fishes: when above the bottom young pike live-bearer swims, the catfish also does not react to it at all. It is the male, and it is busy with the important and crucial occupation: in its mouth some tens of large eggs roll. For two weeks it keeps eggs in the mouth, and in addition for one and a half month it will not eat even a morsel, until the posterity will hatch. Fishes in general can fast very easily: their metabolism is less intensive, rather than mammalian and avian one, for example.
The happy daddy-to-be swims among schools of tiny fishes and hides in one coastal cave. Its parental cares will finish one day, and it will turn to the menace for local inhabitants again.
Enclosed in a ring of islands and continents, the Caribbean Sea of the Neocene epoch represents the world inhabited by amazing living beings. It is impossible to tell precisely how would it look if events in nature would develop another way. But it is doubtless, that live beings would to find here a convenient place for life, and in any case this place of paradise would be populated.
Order: Xenopteropods (Xenopteropoda)
Family: Fin snails (Pterohelicidae)
Habitat: Caribbean Sea, upper layers of water.
This sea animal is named after mythical fallen angel absolutely
not vainly. In it really demonic habits of predator are combined with “angelic”
appearance. It is the swimming gastropod living constantly in thickness of water.
In Holocene some species of snails passed to such habit of life – pteropod molluscs
(Pteropoda), for example. At times their number is so great, that on sea bottom
layers of their shells are deposited. But in the time of “plancton accident”
at the boundary of Holocene and Neocene all of them have died out, as they completely
depended on other plankton animals.
The astarotus represents an original “second attempt” of gastropods to occupy ecological niche became empty. This species have perfectly adapted to the new inhabitancy. Its flat lens-shaped shell is about 15 cm in diameter and 4-5 cm thick; it became very thin for not being a burden at swimming. The float bag formed by pallium of mollusc, the original “swimming bladder”, functioning also as the additional breath organ, is placed inside it. Its mouth is capable to turn off as a tube and to extend to the water surface. The creeping sole, initially intended for slow creeping, is divided into three lobes. The right and left lobes are wing-shaped and muscled, adapted to the active swimming by means of flaps (like bird wings); the back lobe has turned to a kind of extending sucker, helping to seize and to keep prey and also to attach to the mate at the copulation. The head of this mollusc is well appreciable. It can extend to long proboscis with the advanced radula on the tip. It is the adaptation for capture and killing of fishes representing its basic prey. On the head there are well advanced large (cherry pit-sized) eyes and long sensitive tentacles supplied with organs of chemical feeling.
The shell is colored light blue with large dark blue and grey spots – it is the camouflage hiding it from prey and possible predators. Body of mollusc is semi-transparent; epithelium is colored greyish-caesious color with yellow speckles on “wings”.
This species is hermaphroditic, laying eggs in jellylike capsules on roots of floating sea spinach plants and on branches of floating trees. Before the mating molluscs gather near the sea surface and emit the special odorous substance for mate attraction. To make the animal more appreciable, its respiratory tube becomes cross-striped, black-and-white in color. For mate attraction respiratory tube also makes wavy movements. At the copulation both animals simultaneously mutually fertilize each other, keeping each other by creeping sole sucker.
The larva hatches one week after egg laying. It looks absolutely different rather than the adult animal: it has the “sail”, allowing it drifting in water, and it has no fins and shell. At first it feeds on planktonic unicellular organisms, later begins to eat worms and larvae of fishes. At the age of one month it starts to turn to young animal of characteristic shape.
live-bearer (Sphyraenesia ferox)
Order: Toothcarps (Cyprinodontiformes)
Family: Predatory live-bearers (Rapaciliidae)
Habitat: the Caribbean Sea, high sea far from the coast.
After the extinction of the most part of predatory fishes
their place in ecosystems turned to be occupied by those creatures, which sometimes
served them as prey. In the Caribbean Sea, rather isolated from Atlantic, the
role of numerous predatory fishes is played by descendants of small and tiny
live-bearers (Gambusiidae). Remarkable in ability to live both in sea, and in
fresh water, they have successfully survived in “plancton accident” and later
have formed the significant number of large and small species strikingly differing
from their ancestors.
The pike live-bearer is the representative of predatory live-bearer family, including basically sea carnivorous species. It is very large fish: length of its body is up to 1.5-1.7 meters. It frequently keeps in small schools of 5-10 fishes though in places, rather poor in catch, it frequently lives alone. It is a fish having large head (approximately 20% of body length), wide mouth and big eyes. In mouth of this fish long recurved teeth are seen. Body is long, rather deep, compressed from sides. Caudal peduncle is tetrahedral in section – on each side of body the well-expressed keel stretch and there are strong muscles, letting the fish to swim fast and to make sharp throws. The back fin is approximately at the middle of total length of fish. Tail fin is high and crescent – it is the feature of a fast and tireless swimmer. Coloring of this fish is characteristic for sea pelagic species – body is silvery-blue, covered with small black speckles. On sides speckles are sparse, but on the back their number is larger.
At this species the male is a little bit smaller than the female. Fertilization, like at ancestral live-bearing fishes, is performed with the help of first rays of anal fin, which are very long at the male of this species – at the fish swimming they reach the tail edge. The basis of these rays is covered with small scales, and fin rays form the tube intended for injection of soft roe into the female’s oviducts. Pregnancy lasts about two weeks. The fish is remarkable in great fertility – up to 300 young fishes in one litter. But they are tiny and ver vulnerable to predators, therefore the significant part of them perishes already during the first month of life. But being one-year-old, this fish already grows to 60 cm long, and two years old one already gives birth to its first pack. Life expectancy seldom happens more than 10 years.
Order: Toothcarps (Cyprinodontiformes)
Family: Predatory live-bearers (Rapaciliidae)
Habitat: the Caribbean Sea, thickets of floating plants.
As opposed to the pike live-bearer keeping in the high sea,
this long predatory fish with narrow jaws lives in thickets of floating plants.
However it is the relative of pike live-bearer and the representative of predatory
live-bearers family. This species also likes to keep under the floating trees
born in the sea by the river.
The shape of fish of this species is characteristic for the sprinter and ambuscader, unable to long time chasing of catch, rather than for the fast swimmer. Body of this fish is long and slightly compressed from sides – by appearance the fish is similar to needlefish (Belone). Length of its body is about 1 meter. Unpaired fins are shifted to back third of body, to the tail. Caudal peduncle is short and muscled. The body of fish by the anatomy has the wedge-shaped form – head has straight thin jaws, body depth gradually extends to the end, and then abruptly narrows at the caudal peduncle. Eyes of fish are very large and mobile: being in an ambush, the fish can look around freely.
Coloring of body at this species is cryptic: on blue background cross-stripes of irregular shape stretch. This fish eats small fishes, shrimps and other crustaceans. Because of narrow long jaws this species can eat only rather long-bodied catch.
The male is approximately three quarters as long as the female, but it has very long forward rays of anal fin, sometimes growing over the edge of tail fin. Pregnancy of the female lasts about 3 weeks, then it gives rise to only 7-10 very large young fishes (up to 5 cm long). Coloring of fry is contrast – forward half of body is grayish-white, back one is almost black with transparent fins. At the moment of birth the fry is coiled, but in the first second of life it stretches the body, sheds the rests of membranes and swims away quickly. Sometimes adult fishes eat their own posterity.
Young fish grows quickly and becomes sexual matured in the age of one and half years.
live-bearer (Thoracilia volans)
Order: Toothcarps (Cyprinodontiformes)
Family: Jumping live-bearers (Salticiliidae)
Habitat: the Caribbean Sea, edges of thickets of floating plants.
Surface of Caribbean Sea is the ideal place for development
of an every possible kinds of tiny edible creatures. The island chain of large
Antilles, especially Great Antigua, slows down and weaken furious storms from
Atlantic, therefore in top layers of waters lots of rather large plankton beings
live. It also has caused evolution of some live-bearing fishes to form a separate
family – of jumping live-bearers. Characteristic feature of behavior of these
fishes is their inclination to keep near to the surface of water. In fact all
species of this family are good swimmers and jumpers, but the present species
is especially remarkable among them.
As against flying fishes of Holocene epoch, this fish is a true flyer: its pectoral fins are long, and strong pectoral muscles are attached to them. Due to these features fish can glide along the surface of water for some tens meters and fly up to 20 meters in air, actively flapping by wing-shaped fins. Body of this fish is about 30-40 cm long; it is similar to axe in appearance: the chest is very deep, and, in contrast, tail is rather narrow. Back fin is shifted to back third of body, tail fin is wide, its bottom part is appreciably larger than top one. Fish has silvery color with expressed iridescent shine. This shine is given to its body by plentiful slime facilitating sliding in water. Pectoral fins are transparent with white somactids and black border on the tip. Back of fish is dark blue.
This fish is active predator, eating small fishes and crustaceans. After storm fishes of this species gather on the surface of water insects carried from Great Antigua by wind having overcome this barrier between the Caribbean Sea and Atlantic. Sometimes dragonfly live-bearer even catches low-flying insects via high jumps. The mouth of this fish is shifted upwards and supplied with long pointed teeth in front part of jaws.
Mobility of this fish has had an effect on features of its breeding: it gives birth to only one or two very large young fishes once in one and a half month. But the fry of this fish in one week after birth is as good in speed as parents, though can not fly yet.
live-bearer (Algopoecilia acrobata)
Order: Toothcarps (Cyprinodontiformes)
Family: Head-standing live-bearers (Verticalichtchydae)
Habitat: the Caribbean Sea, shallow-water habitats, thickets of submerged macrophytes.
This species is herbivorous fish belonging to family of odd-looking
vertical, or head-standing live-bearers. The anatomy of this species is very
remarkable: back fin has turned to longitudinal crest of short and wide fin
rays connected by fleshy membrane, similar to crest of fairy tale dragon. Tail
fin is short, but has wide base. Anal fin is very big and stretches from chest
up to tail fin. The cloaca of fishes is shifted forward in great degree; it
is almost between pectoral fins. Such body shape is connected to features of
behavior of fish: it spends the most part of time in thickets of seaweed in
vertical position. Thus the strong anal fin serves as the basic moving organ
of its body. However in case of danger the fish easily turns to horizontal position
and swims off head on, like all other fishes. Body of fish is narrow and lengthened;
length of the female is about 15-17 cm, the male is smaller (up to 12-14 cm).
Coloring of fish quite corresponds to unusual position of body: it represents slightly wavy longitudinal green strips on grayish-blue background. The eye of fish is camouflaged by strip stretching across it, and at back edge of the anal fin there is bright yellow false “eye” with black center, distracting predator from the real head.
It eats algae, scrapes them from stones, but can add sedentary animals (even polyps with poisonous tentacles) to its diet. Due to such diet the terminal mouth of fish has turned to scraping sucker (similarly to mouth of “kissing gourami” (Helostoma temminkii)).
Pairing of fishes occurs in vertical position by heads downwards. After one month long pregnancy female gives rise to 50-80 thin young fishes eating the same food as adults.
phytopoecilius (Phytopoecilius ceticephalus)
Order: Toothcarps (Cyprinodontiformes)
Family: Phytopoecilii (Phytopoeciliidae)
Habitat: the Caribbean Sea, pelagic habitats far from coasts.
The huge species of live-bearing fishes distinguished by very
massive constitution, the representative of the separate phytopoecilii family,
related to jumping live-bearers. As against to fast carnivorous relatives, this
fish is slowly moving vegetarian and plankton feeder. Length of the adult female
is up to 2 meters, the male is about 1.5 m long. As a rule, males are less numerous
– 1 male to 2-4 females; it takes place due to higher mortality rate of males
caused by slower growth. Fishes of this species keep in schools numbering 20-30
The body of this fish is thick and cylindrical. It is directly connected to features of feeding – intestines of this species are very long (up to 20 meters), letting to acquire nutrients of plankton maximally completely. The forward part of body and top of head make almost straight line, stomach is strongly bulged. The body is colored greenish-blue with small white and black speckles. Fins are wide; tail fin is fan-shaped. As the fish does not belong to predators, its eyesight is very weak, and small eyes are located near to angles of mouth, as at whale shark.
The mouth of fish is very wide; gills have turned to the effective filtering device letting to filter phytoplankton and small zooplankton from water. Mouth of phytopoecilius can stretch wide, containing large quantity of water. Feeding fishes slowly move in schools near to surface of water. When fish is not feeding, it closes mouth, and its head becomes wedge-shaped in profile.
Breeding rate of this species is very slow – once in 2 months female gives rise to one very large fry of about a quarter of parent length in size. At the young fish filtering device is already advanced, and in some seconds after birth it is able to swim near to adult fishes. Low fertility is considerably compensated by high survival rate of posterity – young fish already has almost no enemies, and the life in school partly protects young ones against large predators. Due to high level of mortality in males at this species spontaneous transformation of the female (even of the fish already gave birth for some times) to the male, and after that the reverse transformation can take place easily.
swift (Priapophyllum apodipterus)
Order: Toothcarps (Cyprinodontiformes)
Family: Deep-bodied live-bearers (Altipoeciliidae)
Habitat: thikets of floating marine plants far from the coast.
It is a small fish developed the convergent similarity to
batfishes (Monodactylus) and angelfishes (Pterophyllum). The length of body
is only 10 cm, but height (including unpaired fins) can reach up to 25 cm. It
lives in thickets of floating plants and eats invertebrates and fry of fishes
Body is very deep; its bottom part and anal fin is greatly extended downwards. Colouring of adult fishes is cross-striped, silvery with black marks. Young fishes of this species live in high sea; therefore their coloring is grayish-blue, characteristic for the majority of pelagic fishes. Back and anal fins are extended; therefore the fish has the characteristic form of half moon. Caudal peduncle is short and high, tail fin is fan-shaped: this fish is the bad swimmer for long distances, but is able to maneuver dexterously in thicket of sea spinach roots. At adult fish on front rays of pectoral fins numerous spikes develop, assisting to cling to roots of sea spinach or to bark of floating tree – during storm this fish prefers to stay in shelter as in open water it can not resist to waves, and after storm – to escape from quickly swimming predators.
The mouth at this fish is able to extend, forming the tube to get tiny animals from thickets of plants.
Because of special body shape pairing according the common type for live-bearers is complicated at this species: the male can not bend gonopodium in order to reach oviducts of the female. Therefore during pairing fishes turn to the position fantastical in comparison with their relatives: male and female “lay down” on one side, turn stomachs to each other and approach cautiously to the mate. Pregnancy of the female lasts about 2 weeks. Fry are not so similar to parents: their body has no characteristic rhomboid shape and long fins, because of what young and adult fishes may be classified mistakenly to different genera. Only at the age of 3 month the young fish becomes similar to parents. Then it leaves the high sea and searches for thickets of sea spinach where it will spend the whole further life.
catfish (Arioselache carcharinomorphus)
Order: Catfishes (Siluriformes)
Family: Sea catfishes (Ariidae)
Habitat: the Caribbean Sea, sea bottom in coastal zone and pelagic habitats.
When in the Caribbean Sea predatory fishes, including the
most part of sharks, have died out, not only live-bearing fishes have occupied
their place, though we have to assume that live-bearers form the most numerous
group among fishes of this region. But among large fishes catfishes represent
their strong contenders.
Shark catfish is very large species of sea-dwelling ariid catfishes, occupying the ecological niche of small sharks. Growing to almost two-meter length, this fish has successfully developed hunting large inhabitants of the Caribbean Sea, mainly fishes. As against sharks – eternal “tramps” of ocean – in spawning season these fishes live in shallow waters, zealously defending them from neighbors. But out of spawning season fishes freely move along seacoasts, however preferring not to come far into the high sea.
The body shape of this catfish is very similar to recent shark’s one: its body is streamlined; it also has sharp triangular fins and wide mouth with numerous teeth. The body of shark catfish is colored grey-blue, edges of fins are dark, and belly is light grey. Back and pectoral fins of this fish are supplied with pointed poisonous spikes on front edge. As against sharks, these catfishes have very large eyes. In darkness eyes of these fishes shine, as at cats: at this fish behind a retina there is a layer of cells containing guanine. It improves visual acuity: catfish prefers to hunt in twilight and at night, hiding in the afternoon in grottoes and among stones, or simply in depth. In search of prey wattles supplied with chemoreceptors help this catfish – there are two long ones on top jaw and “barb” formed by 4 growing near each other short wattles on bottom jaw.
Male broods large eggs (up to 20-30 one of about 2 cm in diameter) in mouth within 2 months, thus it does not feed. In case of danger it can swallow eggs for the greater safety, but then moves them to the mouth again. Thus not fertilized and dead eggs are separated from live ones and are digested. After the fry hatching male protects them from enemies for the first time: the young growth keeps near the head of the male.
spinach (Thalassolatucca crystallophylla)
Order: Alismatales (Alismatales)
Family: Tape grasses (Hydrocharitaceae)
Habitat: the Caribbean Sea, surface of water.
Floating sea plant, the descendant of a coastal sea flowering plant Halophyla. As against an ancestor dwelt in coastal shallow waters, the present species leads a floating habit of life, resembling plants like water hyacinth (Eichornia), water letucce (Pistia) and floating fern Salvinia.
Main shoots of sea spinach are short; leaves are alternate and gathered to round rosettes. Diameter of the rosette of this plant does not exceed 25-30 cm. In axils of leaves long lateral sprouts – tendrils on which secondary crowns grow – develop. Being bound with each other, these sprouts form rather dense structure resisting impacts of storm waves. During storm dense “carpet” of sea spinach may be torn, but after storm each thicket forms set of shoots.
At the plant there are long roots (the length of them sometimes reaches 2 meters), covered with well advanced numerous lateral roots. Their primary goal is not as much the absorbing of water and mineral substances like at ground plants, as filtration of surplus of salt and keeping the plant steady: roots serve as if a floating anchor, slowing down drift of plant. In places where sea spinach grows, the sea surface is quieter, and roots of this plant serve as a refuge for fry of fishes.
The surface of leaves is covered with a wax cover protecting from superfluous wetting by salt water. On leaf edge there is a plenty of salt glands, removing the surplus of salts as concentrated brine, drying up on edge of the leaf blade like crystals.
Sea spinach blooms very unpresentably – its flowers have no petals and stamens, and are pollinated with the help of water: plentiful pollen is washed away by water and is freely carried to stigmae of pistillate flowers. Seeds are also carrying by water and sprout quickly.