Giant salamander (gigantic): description, dimensions. The largest salamander

Niramin - Sep 2nd, 2015

There are 2 species of giant salamanders: the Chinese and Japanese giant salamanders, living in the eastern part of China and on the Japanese islands of Shikoku, Honshu and Kyushu. Giant salamanders have not been found anywhere else on Earth.

The Chinese giant salamander has a grayish-brown color of varying intensities, which gives the appearance of spotting. The abdomen is lighter than the rest, with dark spots. The head and body are wide and flattened. The tail is short and resembles an oar. The body is warty, resembling a wet stone sticking out of the water. The eyes are small, widely spaced, there are no eyelids. The front paws have 4 toes, the hind paws have 5 toes. The length of the animal including the tail is up to 180 cm, weighs up to 70 kg. Lives up to 55 years.

Ideal living conditions for a salamander are clean mountain rivers and large streams. During the day she rests on the river bank among the stones, and at night she goes hunting. She has poor eyesight, but a good sense of smell. The giant salamander feeds on fish and other river inhabitants, and can also grab and small mammal. Nature has endowed it with a powerful jaw and small teeth. The jaws are so powerful that the victim, once caught, will not escape.

From the age of 5, the female salamander becomes an adult and is ready to have offspring. After mating, the female lays up to 500 eggs in a hole dug on a steep river bank. The male looks after the eggs, and then the babies. After 2-2 and a half months, the eggs will hatch into larvae, which will live in the water and breathe through gills until they grow up. In adults, the gills disappear.

The Japanese giant salamander is similar to its relative, the Chinese salamander. The only difference is that the resident of the Japanese islands is much smaller (the length including the tail reaches 1.5 m, weighs up to 25 kg) and she has tubercles on her head.

In Japan, salamander meat is eaten; it is considered a delicacy, so an animal as defenseless against humans as the salamander is almost on the verge of extinction. Now these animals have begun to be raised on special farms.

Photo: Giant salamander

Video: Japanese schoolboy found a giant salamander (news)

Tianzishan Geopark, famous for its mountains of amazing beauty, and Soxiu Park, notable, first of all, huge cave Huanglong, whose largest hall can accommodate ten thousand people. In the last five thousand years there have been no significant earthquakes there, so tall openwork-airy stone pillars, overgrown with subtropical vegetation, surrounded by clouds and glorified by James Cameron in his famous film “Avatar,” live and thrive there.

It flows from the mountains there pure water, and salamanders are an indicator of the ecological well-being of the area. Chinese giant salamanders are endemic; they now live in the wild only in Hunan province; these amphibians survived dinosaurs. This is what puzzled biochemists.

People have long been trying to understand how salamanders regenerate severed tails, limbs, and jaws. At the site of injury, after contact with the mucus that constantly covers their skin, they form a protective membrane that protects against blood loss, and subsequently, at the site of the missing limb, a blastema appears - a mass of unspecialized cells that wait for the body’s “order” in order to acquire “specialization.” "and become cells of skin, muscles, bones and blood vessels. It is curious that salamanders are able to regenerate not only limbs, but also individual organs of the body, for example, the eye lens or intestines.

In adult mammals (unlike embryos), such a miracle will not happen - cellular specialization has already ended. But what’s interesting is that humans, like salamanders, have genes necessary for tissue regeneration. But our first defense system does not allow these genes to work. Apparently, during evolution, the immune and regenerative systems became incompatible with each other, and the body had to choose. Salamanders use primitive regenerative, and humans use immune. It protects us from infections, but at the same time blocks “self-repair”. But the ancient “instructions” for growing new organs are stored there somewhere! But how to make it “turn on” when required?

“For reference: the giant salamander is a genus of tailed amphibians of the cryptobranch family and is represented by two species: the Japanese giant salamander (Andrias japonicus) and the Chinese giant salamander (Andrias davidianus), which differ in size, habitat and location of tubercles on the head,” says Pavel Alexandrovich . – Today, it is the largest amphibian, which can reach 2 m in length and weigh up to 100 kg. The officially recorded maximum age of the giant salamander is 100 years. This unique amphibian lived alongside dinosaurs millions of years ago and managed to survive and adapt to new living conditions. Giant salamander leads water image life, active at dusk and at night, prefers cold and clean mountain streams and rivers, damp caves and underground rivers. The dark brown coloring with darker blurry spots makes the salamander invisible against the background of rocky river bottoms. The body and large head of the salamander are flattened, the tail, which makes up almost half of the entire length, is paddle-shaped, the front legs have four fingers and the hind legs have five fingers, the eyelidless eyes are set wide apart, and the nostrils are very close together.

Salamander is different poor eyesight, which is compensated by an excellent sense of smell, with the help of which she finds frogs, fish, crustaceans, insects, slowly moving along the river bottom. The salamander obtains food by hiding at the bottom of the river. With a sharp thrust of the head, it captures and holds the victim with jaws with small teeth. The salamander's metabolism is slow, which allows it long time go without food.

In August-September, salamanders begin their breeding season. The female lays eggs in horizontal burrows under water at a depth of up to three meters, which is absolutely not typical for amphibians.

Caviar matures in 60-70 days at a water temperature of about 12°C. In this case, as a rule, the male constantly provides aeration of the eggs, creating a flow of water with his tail. The larvae are about 30 mm long, have three pairs of external gills, limb buds and a long tail with a wide fin fold. Small salamanders are constantly in the water for up to a year and a half, until their lungs are finally formed and they can go to land. But the salamander can also breathe through its skin. At the same time comes puberty giant salamander. The meat of the giant salamander is quite tasty and edible, which has led to a reduction in the animal’s population and its inclusion in the Red Book as a species threatened with extinction.

The Legend of the Dinosaur

According to local old-timers, this impressive-sized specimen seems like a mere tadpole compared to the salamanders that were once found in the area around the city.

A 17th-century legend tells of a salamander, or, in local terms, khanzaki, 10 meters long, which ruled the roads and ate horses and cows.

Then a hero named Mitsui Hikoshiro was found, who allowed the dragon to swallow himself along with his faithful sword, which he used, killing the monster.

But it turned out that the dragon had cast a spell on the city. There was a crop failure, people began to die strange death, the hero himself died.

Very soon, the townspeople realized that the spirit of the dragon was roaming the country, and they erected a temple in the city, in which the Khanzaks began to make sacrifices.

However, scientists have their own interest in amphibians. Firstly, this is a surprisingly archaic creature that rightfully claims to be a living fossil. Moreover, this salamander turned out to be surprisingly resistant to the effects of the chytrid fungus, which has killed many amphibians from Australia to the Andes.

IN science Center in the city of Maniwa, 800 km west of Tokyo, people flock to see the unique amphibian.

We are talking about a giant salamander, which is almost 1.7 meters long.

Japanese giant salamander (lat. Andrias japonicus) in appearance it resembles another species - the Chinese giant salamander (lat. Andras davidianus), and differs only in the location of the tubercles on the head. Average length body - more than 1 meter, can reach a length of up to 1.44 meters and a weight of up to 25 kg.

Gigantic salamanders have a large flattened head with eyes devoid of eyelids, a body with a noticeable glenoacetobular (between the limbs of one side of the body) skin fold and tuberculate skin, a paddle-shaped tail compressed from the sides, short and thick limbs with four toes on the front paws and five on the rear

The size and appearance of the skeleton of a gigantic salamander from the Miocene deposits of Germany so captivated the imagination of the Viennese physician A. Scheichzer that in 1724 he described it as Homo diluvitestis (“man-witness” global flood"), having apparently decided that skeletal materials are all that remains of the biblical hero who failed to escape on Noah's Ark. Only Georges Cuvier, the famous zoologist at the turn of the XYII and XYIII centuries, classified this “man” as an amphibian.

The Japanese giant salamander lives in cold mountain rivers and streams with fast current, spending the day under washed-out shores or large rocks in the western part of the island of Honshu (north of Gifu Prefecture) and on the islands of Shikoku and Kyushu (Oita Prefecture), choosing altitudes from 300 to 1000 m above sea level. Adults tolerate relatively well low temperatures. For example, a case is described when a gigantic salamander calmly survived the drop in water temperature to zero in January 1838. In the aquarium of the Moscow Zoo, even a crust of ice appeared on the water surface during cold nights.
The giant salamander is active at dusk and at night, when it crawls out to hunt. It feeds on small fish and amphibians, crustaceans and insects. It is also capable of long-term fasting - there are cases when in captivity salamanders did not feed for two months without visible harm to themselves.
The gigantic salamander can both seek out prey, navigating by sense of smell, and lie in wait for it, hiding, and grab it with a sharp movement of its head to the side. In captivity, cases of cannibalism (eating their own kind) have been reported.

IN natural conditions at a depth of 1 - 3 m in a coastal underwater burrow in August - September, the female lays several hundred eggs with a diameter of 6 - 7 mm in the form of clear-shaped cords or beads. The male, showing care for the offspring in a specific way, protects the clutch and, with movements of his tail, creates a flow of water around it, thus increasing the aeration of the eggs. At a water temperature of 12 - 13 ° C, egg development lasts 2 - 2.5 months.

The gills disappear in the larvae probably after a year (according to other sources, in the third year of life), when their body length reaches 20 cm. In summer, adults molt almost monthly.
The meat of giant salamanders has gastronomic significance. At the beginning and middle of the last century, in the markets of the cities of Osako and Kyoto, local residents sold average size salamanders for 12 - 24 guilders. At the same time, Chinese and Japanese doctors advised the use of boiled meat and broth from giant salamanders as an anti-infective agent in the treatment of consumption and diseases of the digestive system. However, due to the rarity of the animal, even then “medicines” from it cost a lot of money. As a result of overfishing, giant salamanders are now protected: they are included in the Red List of the International Union for Conservation of Nature (IUCN) and in Appendix II International Convention on trade in wild flora and fauna (CITEC). The catch of the Japanese salamander from nature is extremely limited, although it is quite successfully bred on Japanese farms.

A stuffed Japanese giant salamander in an open-air museum.

Salamanders have poor eyesight; they rely on other senses to determine their position in space and the position of other objects.

The maximum recorded lifespan of the giant salamander is 55 years.

This type of salamander is also capable of regenerating, which is often noted in this genus of amphibians.

Living fossils

"The skeleton of this creature is almost identical to fossil remains that are 30 million years old," says Takeyoshi Tohimoto, director of the Hanzaki Institute near Hyogo.

Hanzaki salamander (Andriasjaponicus) has only two modern related species- This Chinese giant salamander (A. Davidianus ) , which is so close to the Japanese that it can interbreed with it, and the much smaller salamander Cryptobranchus alleganiensis , native to the southeastern United States.

Chinese giant salamander (A. Davidianus)

Salamander (Cryptobranchus alleganiensis)

"They are considered very primitive creatures, partly because they are the only salamanders that reproduce through external fertilization, like fish," says Don Church, an amphibian specialist at Conservation International.

Typically, these salamanders sit quietly under the river bank or hide in the leaves, waiting for prey to appear, which they grab with their powerful jaws.

A feat worthy of a great warrior

When the chytrid fungus appeared in Asia ten years ago, no one could have imagined that Japanese salamanders were to blame.

But last year a group of researchers from the Institute environmental problems Japan, headed by Koichi Goka, published an article from which it followed that this fungus settled exclusively on the skin of giant salamanders, which did not suffer from it in any way.

This discovery could help study the biology of this fungus, which kills millions of amphibians around the world.

It turned out that on the skin Japanese salamanders bacteria live that can resist the peptides secreted by the fungus.

If, on this basis, it is possible to isolate substances that can reproduce this effect, scientists will be able to obtain a universal antifungal agent that will save millions of frogs and toads.

And this will be a feat worthy of heroism Japanese warrior Mitsui Hikoshiro.

Scientific classification
Kingdom: Animals
Type: Chordates
Class: Amphibians
Squad: Tailed amphibians
Family: Cryptobranchidae (lat. Cryptobranchidae)
Genus: Andrias
View

Externally, the salamander resembles a huge lizard, being its “relative”. This is a classic endemic to the Japanese islands, that is, in wildlife lives only there. This type is one of the largest salamanders on Earth.

Description of the species

This species of salamander was discovered in the 18th century. In 1820, it was first discovered and described by a German scientist named Siebold during his scientific activity in Japan. The length of the animal's body reaches one and a half meters including the tail. The weight of an adult salamander is about 35 kilograms.

The shape of the animal's body is not distinguished by grace, as, for example, in lizards. It is slightly flattened, distinguished by a large head and a tail compressed in a vertical plane. Small and juvenile salamanders have gills that disappear when they reach sexual maturity.

The salamander has a very slow metabolism. This circumstance allows her for a long time do without food, and also survive in conditions of insufficient food supply. Poor vision has led to an increase in other senses. Giant salamanders have acute hearing and a good sense of smell.

Another one interesting feature salamanders - the ability to regenerate tissue. This term refers to the restoration of tissues and even entire organs, if they were lost for any reason. The most striking and familiar example to many is the growth of a new tail in lizards to replace what they easily and voluntarily leave behind when trying to catch them.

Lifestyle

This type of salamander lives exclusively in water and is active at night. For a comfortable living, the animal needs a current, so salamanders often settle in fast mountain streams and rivers. The water temperature is also important - the lower the better.

The salamander's diet consists of fish and various crustaceans. In addition, it quite often eats small amphibians and aquatic insects.

The giant salamander lays small eggs, up to 7 millimeters in diameter. A special hole dug at a depth of 1-3 meters is used as a “nest”. In one clutch, as a rule, there are several hundred eggs, which require constant renewal of the environment. aquatic environment. The male is responsible for creating an artificial current, using his tail to periodically disperse the water in the area of ​​the clutch.

Eggs mature for almost a month and a half. The small salamanders that are born are larvae no more than 30 millimeters long. They breathe through gills and are able to move independently.

Salamander and man

Despite the unsightly appearance, this species of salamander has nutritional value. Salamander meat is tender and has a pleasant taste. It is actively consumed by the inhabitants of Japan, considered a delicacy.

As usual, uncontrolled hunting of these animals has led to a sharp reduction in their numbers and today salamanders are raised “for food” on special farms. In the wild, the population is cause for concern. The International Union for Conservation of Nature has classified the species as Near Threatened. This means that in the absence of measures to support and create optimal conditions to live, salamanders may begin to die out.

Today, the number of salamanders is not large, but quite stable. They live off the coast Japanese island Honshu, as well as off the islands of Shikoku and Kyushu.

Destruction of natural habitats during economic activity Humans, hunting and poaching, the spread of diseases and environmental pollution together lead to the extinction of many species of living beings. A striking example an endangered species - the Chinese giant salamander ( Andrias davidianus). Long-term study large group Scientists have shown that this species is actually split into several closely related species and that hybridization of wild and artificially bred salamanders leads to the displacement of wild genotypes from the population. This means that attempts to breed salamanders on special farms have a rather negative impact on the conservation of the species, since the uncontrolled release of salamanders into the wild leads to an impoverishment of the gene pool.

Chinese giant salamanders ( Andrias davidianus) is a species of amphibian endemic to China, part of the cryptobranch family (Cryptobrachidae). Representatives of this family are considered the most primitive of modern tailed amphibians: they separated from other amphibians back in the Jurassic period. And the Chinese giant salamanders, growing up to two meters in length, are also the largest of all living amphibians.

The Chinese giant salamander was once widespread in China, but its numbers began to decline rapidly since the mid-20th century. This happens, firstly, due to human invasion into the usual habitats of salamanders: rivers and streams in which these amphibians prefer to live are actively dammed for the needs of Agriculture, become silted and polluted industrial waste. Secondly, for a long time these salamanders were exterminated by hunters: they are valued in Chinese folk medicine, and their meat is used for food.

Now this species is listed in the Red Book and has been assigned the status of being on the verge of complete extinction. Around the 1980s, it was realized that Chinese giant salamanders could become extinct by the end of the 20th century if urgent measures were not taken to save them. In places where these amphibians used to live, reserves were organized, but the number of salamanders still continued to decline. Then they began to use artificial reproduction. Salamanders are bred on specialized commercial farms: some of the bred amphibians are transferred for scientific purposes, some are sold to aquarists, some are slaughtered for meat and for drugs traditional medicine, and some more are released in local rivers as part of a species conservation program - without any genetic testing or medical examination.

Research on Chinese giant salamanders has been ongoing for many years. In 2000, a population from Huangshan County in Anhui Province was shown to diverge in mitochondrial DNA (mtDNA) from other populations (R. W. Murphy et al., 2000. Genetic variability among endangered Chinese giant salamanders, Andrias davidianus). Taking into account limited opportunity The territorial distribution of salamanders and their long evolutionary history, scientists suspected that in fact the Chinese giant salamander is not one species, but several (see Cryptic species - cryptic, or hidden, species). If this is so, then the methods used to preserve salamanders may cause the extinction of species that have not even yet been properly identified as independent taxonomic units.

A group of Chinese zoologists led by Jing Che () from the Kunming Zoological Institute of the Chinese Academy of Sciences, with the participation of colleagues from the USA, Canada and Great Britain, published in the journal last week Current Biology two articles with the results of a ten-year study of the Chinese giant salamander. They collected tissue samples from 70 wild individuals and 1,034 farmed individuals. Wild salamanders were caught until 2010 in areas where artificially bred amphibians were not released. Most of their tissue samples are pieces of exfoliated skin; liver and muscle samples were taken from dead salamanders. Salamanders from the farms had oral swabs taken from 35 farms between 2014 and 2016.

Genetic analysis of wild salamanders, based on comparisons of more than 23,000 single nucleotide polymorphisms and mtDNA, showed that the population splits into at least five genetic clusters (see Cluster analysis), which diverged between 4.71 and 10.25 million years ago. This clustering fits well with geographical location populations: division takes place along river basins. Two more haplotypes were found only in artificially bred salamanders. All this indicates that the Chinese giant salamander is several closely related species of amphibians (or, at least, this was the case before, before the onset of active human activities).

Despite genetic divergence dating back millions of years, Chinese giant salamanders from different clusters can hybridize. This is confirmed by their previously established ability to interbreed with a close, but still different species - the Japanese giant salamander (J. Wang, 2015. Current status of Japanese giant salamander and the enlightenment on the conservation of Chinese giant salamander). This means that uncontrolled breeding of salamanders on farms can lead to the depletion of their gene pool and put the entire population at risk.

Over the past 10 years, more than 72,000 amphibians have been released into the wild. Scientists believe this has already led to a reduction in genetic diversity. As an illustration, they cite the following fact: individuals recently caught in tributaries of the Pearl and Yangtze Rivers possessed mitochondrial haplotypes of the species living in the Yellow River, while they did not have haplotypes of the indigenous forms.