I. Akimushkin. The giant salamander and the axolotl that 'plays in the water'. Fire-bellied toads, midwife toads and spadefoot toads. Parachutists. Just frogs. Other foreign relatives of toads. Sea snakes
THE GIANT SALAMANDER AND THE AXOLOTL 'THAT PLAYS IN THE WATER'
Compared to any newt, any frog, a giant salamander is a giant. 1-1.5 m - an excellent size for any amphibian. Moreover, the weight is impressive too - 8-10 kg.
Millions of years ago, such salamanders were plentiful in North America, Europe and Asia. Now, there are only three species: the Japanese giant salamander (the biggest amphibian in the world!), its' Chinese relative (a species or a subspecies?) and the North American hellbender. In all cases, their appearance is significantly infernal: the body is flattened, loose skin forms folds on the sides, the flat 'catfish-like' head are warts and near-sighted eyes, apparently so imperfect, that they distinguish only light from darkness.
A giant salamander, from birth to death, lives in free-flowing streams and rivers that do not freeze in winter. During the day, it aimlessly sleeps under ravines, under rocks, in underwater burrows. At night, it crawls on the river bottom, hunting frogs, crayfish, fish, worms and insects. At the end of the summer, the females find males in their inhabited burrows and lay their eggs there. The males, ceremonilessly having kicked them out, (sometimes the females devour their own eggs!), keep watch over the eggs, ventilating the space, sending fresh water with tail sweeps. In two months, the parental care is over: the larvae hatch.
The meat of these salamanders is tasty, they are being hunted. Few of them are left, especially in Japan. Probably in China too.
'The fairly small family of ambystomas includes 28 species... The overwhelming majority is located in the ambystoma genus, (21 species), widely distributed and well known due to the neotenic larvae, which are locally called 'axolotl' ('player in the water') (Professor A.G. Bannikov).
In nature, the axolotl lives only in the Sochimilko Lake... The name belongs to the Aztecs, when translated it means 'water monster' (Gunther Freytag).
So, the ambystomas. Their homeland is America. They resemble European salamanders, but their eyes are smaller and their life is even more reclusive (in various places underground). This is why the Americans call the ambystomas the mole salamanders. In spring (montane species - in summer), the ambystomas move to ponds and streams and reproduce there. The larvae become adult salamanders in twelve or eighteen months, and some never transform at all! Such, for example, is the now well-known axolotl, a frequent visitor of scientific labs, zoo stores and nature corners in schools. Its' neoteny is inherited. It is passed from generation to generation, even to the hybrids of the axolotl with, say, the tiger salamander. It is an eternal larva (like a caterpillar, which, having not become a butterfly suddenly started to reproduce!). However, you can make it 'grow up', subscribing it several shots of thyreodine or feeding it a thyroid gland. It is these hormones that control the amphibian metamorphosis. In the case of the axolotl, this gland is underdeveloped. After the endocrine 'therapy', the axolotls transformed into Mexican ambystomas, very similar to the tiger salamanders.
The global expansion of the axolotls in the laboratories of the world started small: the natural habitat is miserably puny. The mountain lake Sochimilko is 35 square km. It is approximately twenty miles south-east from Mexico. Actually, it is not even a lake - more of a tangle of channels, ponds and streams that form a single water system. The biggest streams are no more than 20 m wide, and most are so small, that the flat Native American canoes can barely swim through them.
There the axolotls are caught and sold on markets in the nearest villages and in Mexico.
FIRE-BELLIED TOADS, MIDWIFE TOADS AND SPADEFOOT TOADS
A fire-bellied toad resembles an ordinary small toad, grey or black on top, orange on the bottom with black spots. Its' monotonous call has provoked a reaction among the people: 'Listen to the newts hoot!'
Newts are soundless from birth... Why the names were switched is unknown.
The piping, monotonously delicate voices of the fire-bellied toads produce an atmosphere of sadness. A male fire-bellied toad will lie, stretched out, on the surface of a pond. It emits its inviting cry while vibrating its body. A circle will ripple outwards through the surface of the water. The male will jerk forwards - emit its cry once more and the water will ripple. If you get up to look at it from a better angle, the fire-bellied toad will immediately dive. However, from the bottom, its' almost relentless cry will sound, just quieter.
During warm weather, male fire-bellied toads cry 18-20 times a minute. When a second male will join the first, the first male, falling silent for a moment, will try to echo the second male in harmony, but not in union, and then they 'sing' with intervals, as if there was only one male around. However, if the leading voice will not find the needed tone (it will sing too slowly or too fast), a cacophony will result. Thus, often, an experienced naturalist will break up the harmony of the fire-bellied toads' song, trying to imitate them: they accept him, but the person, not always sufficiently musically gifted, will mess up the centuries-old synchronization of those small-sized choruses.
The eggs are attached at night to plants and other objects found underwater. Approximately, in a week, the tadpoles will hatch. In three months, if the weather is warm enough - even earlier they transform into froglets (in July - August). Then the autumn gets replaced by winter and the fire-bellied toads move into the burrows of mice, voles, into lose shoreline soil, sometimes they winter underwater.
The skin of the fire-bellied toads is poisonous. Not as much as, say, of the poison-arrows frogs, but much more so than in case of most other temperate toads. The fire-bellied toad warns about its' inedibility thus: it turns its black-and-red belly up! When it is frightened, it gets covered with a poisonous foam-like slime. Take care of the eyes, so that the fire-bellied toad's slime will not get into them. Even if you just drop low above the 'foaming' amphibian, the eyes might tear-up and itch.
Only the fire-bellied toads represent the alytid family in the former USSR. However, in Western Europe, there are midwife toads as well. You will not be wrong if you decide that the strange name 'midwife' is directly related to the midwife in question. Scientists have decided upon this more than 200 years ago. However, this is not easy to see. The midwife toad almost does not appear aboveground during the day. Only during nights. Therefore, for many, including rural inhabitants, it is a 'persona incognita', i.e. an unknown creature.
In March - April, as soon as the sun will melt the snow, the midwife toads awake, after spending the winter in burrows, caves and basements. Then, especially in the favored sandy hills and foot-hills, during warm evenings, from sunset and until darkness, the melodical voices of their males will sound. The females cry too, but more quietly and rarely. The mating meetings usually take place 50-100 m away from the nearest body of water.
The eggs are 'packaged' into long slimy cords (up to a meter and longer). The male immediately wraps them onto...its thighs! It grabs a cord with two middle fingers of the left hind leg and wraps a noose onto its right thigh. Then, with its right foot, onto its left thigh. In 10-20 minutes the job is over. The male pushes the heavy load on its back and goes where it is more dump and more out of the way (or cries once more, summoning another girlfriend, to load its eggs on top of the first batch). The male midwife toads hides under roots, in burrows, and does not leave the eggs at night. After 18 (if the weather is warm) or after 30-50 days (if the weather is cold), from the eggs, guarded by the male, the tadpoles should hatch. In addition, the male begins to journey to water. (If you catch and try to take the eggs away, it will piteously cry, try to clumsily fight you off. It will not give the eggs up without a struggle!)
Usually sitting in the shallows thusly, so that only the butt is wet, the male midwife toad, loaded with eggs, patients waits when its offspring, twitching their tails, break through the eggs and swim away. Their nanny, ripping on the algae the remnants of the eggs, will climb to the shore, where it leads a life that is just as private as that of its relative (albeit from another family) - the spadefoot toad.
The latter lives almost everywhere - in the Russian valleys, mixed and broadleaf forests, steppes: from the western border almost to the Irtysh river. In addition, how many people know of this amphibian? It is very reclusive. During the day, you can only accidentally discover it while doing earthworks - in ravines of sandy or clay soil. Alternatively, during the spring - in the water: here the spadefoot toads lay eggs. Without emerging or sitting on hillocks they bubble from some-where in the depths... In addition, later, possibly, the local people there will meet very large tad-poles: 7-10 or even 17.5 cm long.
The spadefoot toads are yellow-brown or grey amphibians (6-8 cm long), with a back with dark spots, smooth and not bumpy as it is in the common toads. Now look at its eyes - if the pupil is vertical, then this is a spadefoot toad for sure. Only in the Caucasus, one can meet two tailless amphibians with a vertical pupil - the Syrian spadefoot toad and the Caucasian parsley frog. (The fire-bellied toads have a more-or-less triangular pupil.)
One can also smell their ambiguous catch: often the spadefoot toad reeks off... Of course, of garlic! If this is not enough - take a look at the hind legs: from the inner side there should be a large, with a sharp edge made of hardened skin, bump. This is a shovel for digging, to be able to dig quickly enough (in 2-3 minutes) into soft soil, beneath which the spadefoot toad spends the sunny hours of a day, giving up the surface of the land and of the water for the other tailless amphibians.
PARACHUTISTS
Borneo, Sumatra, Philippines... Forests, shrubs, tall grasses at the water edge... Here lives the famous leopard flying frog. It is also called the Borneose. It looks thusly: green, with sides and stomach in dark spot, (a leopard pattern). The edges of the hind legs and the fingers on the forelegs are orange.
In addition, between the fingers of all legs, are wide webs. The frog unfurls them - and a parachute is made! The frog jumps from a tree - the parachute halts the fall and prolongs the flight! The greater is the height that the amphibious pilot started from, the further it glides. If you measure on the ground the distance from the tree on which the jump started, then it will be approximately equal to the three fifths of the height from which the frog started.
Many leopard parachutists gather at night on trees that grow at the water edge. Males play on 'drums': their cries resemble the sounds of a balloon, drummed by a finger. The females have more important things to worry about. Selecting the lower, overhanging the water, branches, roots, rocks, they make nests on them: foamy at first, and then they get covered with a hardened brown crust. They are made from some froggy liquid that the female frog intently whips with hind legs, just as a housewife whips cream. The foamy hat is located on a leaf or in a 'bundle' - between two or three leaves. The frog hides the eggs in this foam. On top, the foamy cradle soon forms a crust, and inside it remains moist for a long while. The tadpoles will hatch from the eggs and break through the walls of their house, (or rainstorms will wash it down from leaves). They will fall below, into water, where they will live until they become froglets.
The flying frogs are from the Rhacophoridae family: all of them, (it consists of 400 species!) have small bulges, spheres, on their fingertips. When a flying frog puts its legs onto a leaf or onto the bark, the spheres flatten into disks, forming suckers. The suckers keep the frog's legs even on the smooth and sheer surface of leaves and tree trunks, where the Rhacophoridae frogs live. Africa, Madagascar, South-East Asia, (up to Japan in the north) - in this wide space, inhabited by the Rhacophoridae frogs, the flying frogs live only in Asia. The Borneo species was already talked about. Java and Sumatra have the Javanese flying frog, (emerald-green, yellowbellied, the youngsters have blue spots on their webbing!), and one more, with black legs, in the jungles of Borneo, Sumatra, Malaya and Laos. This one, probably is the best glider of all. Having jumped from the top of a five-meter tree it will fly away from it a seven-meter distance!
Certain South American tree frogs can also fly some.
Foam nests are most typical among the Rhacophoridae frogs. Sometimes the males help with the foam too. Some sit at the nests for a week and more, protecting them.
The African grey foam-nest frog works in pairs. Then the female, putting into the foam pile, (the size of a bean), 150 white eggs, sits onto it and firmly hugs it with all four limbs. The time passes; the mother frog sits on eggs and does not leave. Everything around it dries-out from the heat... But then the frog seems to regain its' senses, it twitches its' legs and starts to move. It crawls down the branches - to the water beneath the nest. It dived into a pond, lay a bit, absorbing moisture through its' skin. In addition, it climbs upwards once more. It moistens, (by spraying from its' cloaca) the 'bean' with eggs, and shades it from the sun. If the mother dies, or the strong heat will fully dry out all of the bodies of water in its' immediate surroundings, there will be nothing to water the 'bean', then it becomes as tough as carpentry glue, and the tadpoles cannot escape it...
The foam-nest frogs are also from the Rhacophoridae group - they are the so-called grasping frogs. That is, they do not grasp their prey or anything else, but tree branches. Two internal fingers, moving sideways, oppose, as the biologists say, the other fingers, just as thumbs do on our hands. Branches thus are grasped firmly and the frog climbs them as a primate does. Many Rhacophoridae frogs have tadpoles, (and the tadpoles have their metamorphosis in water, where they fall from their nests). However, in some species the eggs hatch directly into froglets.
The Rhacophoridae make nests for their eggs in bent leaves and hang the eggs on leaves and stems that are located above water, and bury them not far from water into the soil or into fallen leaves. In addition, the Sri Lankan Rhacophorus frog carries its eggs on its' own body, pressed into a tight disk on the frog's stomach! In short, the wide family of the Rhacophoridae frogs take care of their young in very different ways. The same goes for the ecological habits of these frogs. Many live high in the leaves. To see and catch them is hard work for biologists. Others jump and climb among shrubs and grasses, and some live in dry savannas, and hide, as spadefoot toads do, from the heat underground. These earth-digging relatives of the 'pilots' have atrophied webs ad sticky suckers. However, the Japanese singing frog kept them. It lives in rapid mountain streams: a firm adherence to sticky stones is most necessary here. The cries of the singing frogs are pleasant, just as the bird calls are.
'In Japan, these singers are sold in the markets, and the best of them are expensive'. (M.N. Denisov).
JUST FROGS
Their mismatched choruses are a necessary accompaniment to all of the sounds that feel the summer nights, of course, in sufficiently damp places. 'Worr... worr... worr... kruu!' - methodically, loudly, huskily. Suddenly, a sharp - 'kre-kre-kre... nek-nek-nek' - a croaking solo of one or another male, bursts out like a loud crescendo from the monotonously sounding cry. These are green marsh frogs.
In small, usually stagnant bodies of water, in ponds, forest pits, in simple puddles and ditches live smaller, but also green frogs - the pool frogs. They are brighter, more emerald, and their cries are not as loud and rough: 'Koax, koax, koax...'
Suddenly, a loud, vibrating cry: 'Rekkekkekke!', and once more: 'Koax... koax... koax...' They inflate sound-amplifying, white or yellowish resonators - spheres in the corners of their mouths.
The marsh frogs have grey, or even black, resonators. When the resonators are not inflated, they can be seen from below and behind the corners of the mouths, looking as thin, long, dark spots. The marsh frog is bleaker in color than the pool frog is; it is often olive in color, sometimes even brown, with black and dark green spots and a bright stripe running through the middle of the back. It is the biggest Russian frog - from nose to the end of the tail it is 9-15 cm, and sometimes even 17. In addition, the most carnivorous: the marsh frog attacks even vertebrates! Not big ones, of course. Fish fry, tadpoles, adult tree frogs and moor frogs, even young grass snakes, shrews, young voles and small birds! However, such cases are rare.
The male pool frogs are smaller than the females are (the average lengths is 7.5 cm in males, 9 - in the females). The marsh frogs' females are not much larger than the males are. The pool frogs, as it was said already, are usually elegantly emerald, like the vibrant pool plants are. However, there are also yellowish-, or grey-green, and very rarely - bronze-brown, even bluish in color. Their Latin name 'esculenta' in translation means 'edible': the people, which eat frogs, prefer the pool frogs to the others. Their meat is indeed very tender, like a young chicken's. However, according to the experts, the ordinary, common frogs that we meet in field and forest are even tastier!
They are brown, in various shades. Below, on the bottom - a marbled mottled design, with the basic color being dirty white (for the males) or brownish-yellow, reddish-brown (for the females). A monotonously light belly (without any spots) is very rare.
If a frog with such belly is caught, then it is usually the moor frog. It is also brown in color; in size, it is smaller than the common frog is. It is usually found in copses, meadows, swamps, steppes and scrub-land, in gardens too, as is the common frog, actually.
Both frogs also in the boreal forests beyond the Arctic circle, but the common frog in places goes further north that the moor frog does, for example on the Kola Peninsula, (the moor frog isn't found there), and throughout the entire Scandinavia, up to the North Cape. However, the moor frogs are prevalent in the steppes. They more easily endure the heat and the dryness.
The common frog is the most northern of all the frogs, and, probably, the quietest one. Its' quiet purring croaking can be heard, (often from beneath the water), in spring, when the common frogs breed. There is still ice in places on lakes and pools, but they have already woken up from hibernation be-neath the waters and are busy laying eggs. (The moor frogs usually winter on land. Some western scientists believe that the sexually immature common and pool frogs, as well as possibly some others, also winter on land.)
In Kiev's suburbs the first frogs appear at the end of February, (if the spring is early), in Moscow's - in March-April, and in northern France - in January. They will lay in the water their viscous knots of eggs and will soon leave to travel on land (the green-skinned frogs, the marsh and the pool frog, live all summer long in water and near it).
In April - in the beginning of May the moor frogs are plentiful - they lounge in crowds in the shallows of sylvan swamps, in forest clearings and lowlands, flooded with spring waters. The males of the species at that time are celestial blue in color! The beautiful sky shade of the frogs' skin is produced by lymph, which fills the skin. Have you seen blue frogs in spring?
Day and night, the supposedly quite voices of the moor frogs can be heard from afar, filling the Russian forests. They endlessly cry 'Ko-ko-ko'. You listen and you think: 'When will they take a rest, quiet down at least for some time?..' You move further away - it is as if gamebirds were crying on their lek.
The family of true frogs has more than 400 species. Among them the prominent ones are:
In size and weights - the bullfrog (southeast USA) and the goliath frog from Western Africa (Cameroon, Angola). The first species is already sizeable (20 cm), but the second... The second is the biggest among all the frogs and toads - 33 cm. Moreover, one of them, caught in Angola, was 40 cm long, 24 wide. It weighted 5 kg. The eyes were only slightly smaller than a human's, and the thighs were as thick as a human's wrist!
In unusual hirsuteness! In Western Africa (from Guinea to Cameroon) the males of some frogs... grow hair when the mating season comes. Quite long ones, in fact - one to one and a half cm. It is truly a beard! However, not where we are used to seeing it, but on thighs and sides. Why does a frog need 'hair'?
Most likely: the 'hairs' are extra organs to breathe through skin. They are not real hairs, of course, but thin, hair-like, outgrowths of skin, densely penetrated with blood vessels. However, how are they useful to a frog that lives and breeds in oxygen-rich, freely flowing water? In bodies of water so freely flowing, that only eggs glued to rocks, are not taken downstream. The tadpoles, hatched from these eggs, are excellent swimmers, but without powerful sucker-mouths, they too would not last among the rocks. Therefore, says the famous specialist of amphibians, the Swiss scientist Hans Hoiser, until their true designation in life won't be proven, these 'hairs' should be treated as decorations.
In exceptional toxicity! These are the poison dart frogs. They are smallish, but brightly and powerfully colored frogs of Central and South America. Their skin secretions are so toxic, that the birds and monkeys, struck with poisoned darts, immediately fall out of trees, paralyzed.
The arming of the darts begins with when the poison dart frogs are caught, the Native Americans first warm them up: hold them above a fire stuck on a stick. The poison drips from the skin of the wretched animals into the vessel held below. It is a neurotoxin. It is dangerous for people too.
For the scientists, who study animal behavior, the poison dart frogs are some of the most interesting members of the amphibians. All inhabited territory is firmly divided into individual zones. 'A border pillar' and the main HQ is usually some object that dominates the neighborhood. A big stone or a rotting trunk of a cast-down tree. Usually it is guarded by the female. The male takes care of the young.
When some relative approaches, the frog on watch warns it to stay away with a special signal: standing upwards, it shows its' yellow chest. Ignoring the warning leads to a face-off. A jump forwards, and... an interesting wrestling begins. The frogs stand on their hind legs, stretching fully out, and with the front legs, grappling each other as if they were amateur wrestlers, they try to topple their opponent. The loser flees.
In some species, this sort of fighting is replaced by a more playful action. Males, females, and even sexually immature youngsters 'amuse' themselves, constantly fighting, while standing up on their hind legs.
Just like the Seychelles' frogs, the male poison dart frogs carry tadpoles on their backs (as far as we currently know, the females too, in one species). Fully ready to execute their parental duties, they keep watch over eggs, laid in a quiet and dark spot on the ground.
In a couple of weeks, the tadpoles hatch. Striking with their powerful tails, they move forwards and upwards, over their father's legs and sides. Their flat stomachs firmly stick to his slimy, bumpy back. Some males carry for a long time this 'first edition' of youngsters. The tadpoles that ride them, while feeding only on their store of yolk, grow up some.
Others immediately hurry to water, dive into it, and their children swim away to transform there into their second 'edition' (significantly reworked by metamorphosis). Some species of poison dart from, for example, the golden dart frog, the male carries on its back into waterlogged tree hollows and branches only one tadpole. There the tadpole swims for six more weeks before it becomes a frog.
THE OTHER FOREIGN RELATIVES OF TOADS
The toad side of the family tree has six subfamilies. We already met three of them. Three more remain: the harlequin frogs, the stubfoot toads, and the glass frogs.
Stubfoot toads number two South American genera. The most interesting among them is the par-adoxical frog (Pseudis genus). The paradox is that its' children are larger than their parents are!
The maximal proportions are thus: 7.5 cm (the adults) and 25-28 cm (the tadpoles). Before undergoing metamorphosis, the giant tadpoles seem to wither, shrinking to 1/5 of their former length. Such 'diminutive transformation', says the German scientist Gunther Freytag, 'is unusual in amphibians, but is more common with fish'.
However, for the amphibians such giant larvae are not exceptional either. Other species of the Pseudis genus, the saddleback toads, the common tree frog, and some other frog species, have something similar, though the 'diminution' (shrinking) is expressed here to a considerably lesser degree.
The paradoxical frog lives in the Amazon and on the Trinidad Island, only in water.
The saddleback toad lives in eastern Brazil and Guyana, in foliage, close to the ground. In rain, numerous bright yellow, tiny saddleback toads, twinkling with black eyes, jump and run on the ground. However, they avoid sunny spots. Their tadpoles are also orange. And large-up to 4.8 cm. The adult amphibians - only 1.5-2 cm. They are called saddleback due to stiff skin covering their backs as shields or saddles.
The harlequin frogs are small yellow-black-red-mottled frogs. Their bright warning coloration is similar to that of the poison dart frogs, and their skin is just as toxic. Their homeland are Central and South America, (they number about 30 species). Ditto, from Mexico to Paraguay, live the glass frogs, (more than 30 species). They are small, rarely larger than 3 cm in length, green, similar to tree frogs in appearance and habits. Down below, their skin is so transparent, that people can see their beating heart, pulsing blood vessels, stomach, full of mosquitoes, and the looping guts. They live in trees.
SEA SNAKES
They live in the tropics and the subtropics of two oceans - the Indian and the Pacific, from Japan in the north to Tasmania and New Zealand in the south, from Africa to the state of California and to Peru in the west. In the Atlantic Ocean, there are no sea snakes. The coastlines of continents and islands, sea-grass and seaweed, the coral labyrinths - here pass the lives of snakes who abandoned the land. Sometimes you can find hundreds and thousands of them in a small space of an aquatic forest. They lie in comfortable nooks of reefs, curling into knots. Some species of sea snakes also live in lakes: in a brackish one in the Solomon Islands, even in a freshwater one in the Philippines. They go upriver for hundreds of kilometers, but always return to the seas. How-ever, they do not go too far from the shoreline either, staying within a few km of it.
Only one sea snake, the yellow-belied sea snake, is different. It is the only pelagic snake in the world! They are often seen hundreds of km away from the nearest land. Both solitary and in packs of hundreds and thousands of snakes, floating and swimming on the surface of a calm sea. In the ocean, far from the coastlines where it is easy to launch an ambush, where it is impossible to sneak up 'from behind a corner' (a coral), and the yellow-belied sea snakes catch fish with cunning. People know: all sorts of floating objects attract many fishes. They swim up to an immobile snake too. Here the snake does not waste time, it launches its dexterous body, strikes, and once venom has killed it, the snake swallows its prey.
When they are frightened by anything, the yellow-belied sea snakes dive. They will not emerge soon; they can stay underwater for an hour. They are colored beautifully, in all sorts of style, but usually they are black above, yellow below, both colors on the sides are joined abruptly, in contrast. The habitat is wide, as it is for the rest of the family - from Africa eastwards to America, and to Japan in the north. Even in the Russian Far East, in the Posyet bay, a dead yellow-bellied sea snake was encountered.
The yellow-bellied sea snake is from the Hydrophiinae subfamily (it has over 36 species - more than ? of all the sea snakes). The Hydrophiinae never go ashore, (only some, according to certain date, do breed on dry land). The sea is their entire life. If they are thrown out by the tide, they can even choke on land. They have lost the firm muscles, necessary for moving on land. Bound by their own weight, they can barely able to move their chest, to utilize lungs for breathing.
The Hydrophiinae give birth in the water, to 2-6 large, half their mother's length, offspring, who immediately can swim. Some - only one or two. The fertility is miserable. However, why are these snakes so plentiful in the seas? Especially around the islands of Indonesia? One must suppose that because their enemies are few and sexual maturity comes quickly: in a year, and some in just six months, can breed themselves.
The sea snakes of the second, more primitive subfamily, the Laticaudinae, (12 species), have not lost the skills to live on land. During the day they often hide under roots of trees, in sea refuse, in cracks of cliffs, under anglers' huts, built in the shallows, they even crawl into them. One or two, or even eight eggs are laid by Laticaudinae females on shore, in piles of rotten sea grass, into sand, moist earth.
Much in the sea snakes' anatomy connects them to the asps, especially the Laticaudinae. Therefore, herpetologists believe that the latter are part of the Elapidae family. However, the life in the sea has left its own particular mark: tail, pressed from the sides, flat, as an oar; nostrils, moved upwards, to breathe, not raising the head above water. The nostrils are closed with muscular flaps when submerged. The mouth tissues are rich in capillaries that draw oxygen straight from the water. In the eyes - salt-removing glands, (just as in case of marine iguanas, turtles, crocodiles, tube-nose birds and other animals, who have to swallow plenty of sea water with their meals).
The venomous teeth are small. The venom is very powerful, though not in every species: 12 times deadlier than a cobra's. Sea snakes do not attack bathers, but those caught by anglers' nets and traps sometimes bite. If there is not a proper antivenin around, a person usually will die. The sea snakes are not aggressive, but patient. Children of Fiji and Samoa often play with them, as if they were harmless.
Their length is 1 or 1.5 m; the record is 2.75 m (the yellow sea snake). Some have sexual dimorphism: the males are very rough (they have spikes on their scales). The coloring is varied and bright. Some species are monotonous.
Now imagine an endless multitude of red-black snake bodies, stretching in an endless ribbon beyond the horizon, where the sea meets the sky. Such gatherings of sea snakes do occur. Weddings? Perhaps.
Sea snakes feed on fish (some, apparently, only on fish eggs). Sea species of eels are their favored prey. In aquariums, various fishes often live alongside a sea snake for months. It does not touch the fishes. If there are no eels, the sea snake fasts. However, as soon as the sea snake just smells their scent - say, when it is given the water from a pool that has eels - the sea snake immediately acquires an appetite and an instinct to hunt and seek out.
Some sea snakes are strangely disproportionate: the head is tiny, the neck and the body behind it are thin, and the hind half is five times wide. This oddity has two explanations: first, the massive hindquarters serve the snake as something of an advantage point in the unstable aquatic element. The thin and dexterous front half acquires, in such body, a better maneuverability. Secondly, it is supposed that this 'elongated' neck can allow the sea snake to successfully hunt the moray eel. They hunt in burrows in the sea floor - so, the snake gotten squeezed by nature precisely to the diameter of that burrow, so that, once the sea snake got into the eel's hide-out, the sea snake could pull the eel out.
In addition, sea snakes are eaten too! In Indonesia, in the Philippines, they are being caught specifically for that and are being exported live to Japan. On the islands of the Rising Sun, roasted and smoked snakes are a treat.
There is a banded water cobra, many non-venomous water snakes. An entire subfamily of colubrid snakes (around 30 species) has adapted to live in fresh, brackish and even in sea water - in the zone of ebbs and tides: in India, and in the entire South-East Asia up to north-eastern Australia.
There, just not in Australia, in the coastal seas, in the mouths of rivers, in mangrove swamps live the wart snakes (three species in a separate family, related to the colubrids). Their scales got keels, it is rough and warty. On land, they are helpless. However, in the water, they are slow too, often lying on the bottom. Now, these water snakes, just like the real sea snakes, often swim far out into the sea. The little wart snake, externally, especially with its bright striped coloring, resembles a sea snake. But its' tail isn't pressed into a wide, oar-like limb.