Amphibians, amphibians interesting facts. Amphibians are amazing creatures

Let amphibians not be the most attractive and cute creatures. They're not kittens to please everyone. But among them there are also the most interesting rare individuals who are able to conquer anyone with a truly extravagant appearance. Let's get acquainted with this strange class of animals (these are neither on land nor on water - neither yours nor ours) and learn more about the most outstanding representatives.

Signs of amphibians: duplicity as a gift

Amphibians, also known as amphibians (translated from Greek as “one who lives a double life”), are those groups of animals that can live both on land and in water. Therefore, they stand out from all other living beings and have a number of advantages.

Main external sign amphibians - “nakedness” (they are devoid of fur or any other heat-insulating coverings). It is believed that the ancestors of amphibians were lobe-finned fish. But they themselves gave life to reptiles.

Types of amphibians: with or without a tail?

Scientists distinguish three types of amphibians based on the presence and development of the tail and paws.

Tailless amphibians

They have a short body, a poorly defined neck, developed legs (the hind legs are larger and more massive than the front ones: they are used for moving by jumping), and of course they do not have a tail. This species includes toads, frogs, tree frogs, spadefoots, toads and others. This is the largest detachment, which numbers about five thousand different types.

Tailed amphibians

They have a long body that ends in a strong, developed tail, but their legs are short and weak (although there are exceptions). Among the representatives of this order, the most noticeable are newts and salamanders. In total, the group numbers about five hundred species. And just some species of salamanders stand out from the general background - they can run rapidly and even jump.

Legless (aka worms)

They differ in that they have neither a tail nor paws - the animals are unlucky, they seem completely helpless! Moreover, they also look very unattractive - these amphibians look like nasty worms. And from a scientific point of view, they have the most primitive structure of their kind.

Not only hypocrites, but also opportunists

Animals belonging to the class of amphibians are surprisingly tenacious - they live on all continents globe except Antarctica. They are opportunists: very salty waters, arid territories and serious cold - they don’t mind any difficulties! If you climb into the Himalayas, you will meet an amphibian in the mountain heights.

And if you find yourself in the desert or beyond the Arctic Circle (you never know what will happen for fun), then they are here too, just like underground.

True, these are rather exceptional options. The most fertile environment for amphibians is humid, warm and nourishing (where it is easy for amphibian animals to find edible prey) tropical countries.

Amphibians: the immortal snow queen

One of the rarest amphibians is the Siberian salamander. It has a unique cold resistance, which allows this amphibian to exist, in principle, in conditions not typical for the class - on harsh north Russia (territory from the Urals to Kamchatka). And these are temperatures reaching 30-35 degrees below zero, and permafrost...

It is noteworthy that these creatures can survive even in ice for several years at a time. After geologists found such seemingly frozen to death individuals, they thawed, warmed up and returned to vigorous life. How can you return to life after icy death? The fact is that during frost, the water in the cells of this amphibian turns into glycerol, which protects them from certain death.

Rare amphibians: a frog that doesn't croak

But in the lowlands of the British mountains there lives a peculiar frog called the chicken frog. In addition to the fact that it belongs to the largest frog species in the world (reaches 21 centimeters), its meat also has an exceptional taste.

Actually, this is why the green amphibian of peculiar beauty was named that way. True, only criminally wealthy gourmets can now afford such a delicacy, because it is under the protection of the country as a species on the verge of extinction.

Fish that walks

Either a fish or a reptile - a very strange creature! Another unique member of the amphibian class with terrifying names is the water monster, the walking fish, and in science, the axolotl. He, too, can boast of unconventional beauty and strange qualities of survival.

The most remarkable of them is that these amphibians reach sexual maturity without entering the adult stage, but remaining a larva, sometimes even for life. They, as befits amphibians, can live both on land and in water. But often they do not “work” on the development of lungs, like other amphibians, but live in water spaces, but without the scales that fish are supposed to have.

Take it for yourself and tell your friends!

1. Amphibians live near water

The word "amphibian" means " double life", which pretty much sums up the peculiarity of these vertebrates: they lay eggs in water, and also require constant access to moisture in order to survive. Only a few species of amphibians are located in the middle of the evolutionary tree between fishes, leading completely water image life, as well as terrestrial reptiles and mammals.

2. There are three main types of amphibians

Scientists divide amphibians into three main orders: tailless (frogs and toads), tailed (newts and salamanders) and legless (caecilians). Currently, science knows about 6,000 species of frogs and toads, about 500 species of newts and salamanders, and less than 100 species of caecilians. All amphibians are technically classified as unshelled, but there are also two extinct groups of amphibians: the slender-vertebrates and the temnospondyls, some of which reached gigantic sizes during the late Paleozoic period.

3. Most amphibians undergo metamorphosis

True to their evolutionary position (halfway between fish and fully terrestrial vertebrates), most amphibians are born from eggs laid in water and short period lives are spent in aquatic environment equipped with external gills. Then, the larvae undergo metamorphosis, during which they lose their tails, grow gills, grow strong legs and develop primitive lungs in order to eventually get out onto land. The most famous larval stage is the tadpole of frogs, but the process of metamorphosis that occurs in them is less striking than in newts and salamanders.

4. Millions of years ago, amphibians dominated the Earth

For about 60 million years, from the beginning of the Carboniferous to the end of the Permian, amphibians were the dominant land animals on the planet until they gave way to reptiles, which evolved from isolated populations of amphibians, including archosaurs (the ancestors of dinosaurs) and therapsids (the ancestors of mammals). The classic representative of temnospondyl amphibians was the large-headed Eryops, which had a body length of up to 2 meters.

5. Amphibians have permeable skin

One reason amphibians must stay near bodies of water is that they have thin, permeable skin. If they move too far from the water, they literally dry out and die. To help keep their skin moist, amphibians constantly secrete mucus (hence frogs' reputation for being "slippery" creatures), and their dermis is littered with glands that produce toxic substances designed to protect against predators. In most species, these toxins are barely noticeable, but some frogs are so poisonous that they can kill an adult.

6. Amphibians evolved from lobe-finned fish

During the Devonian period, about 400 million years ago, lobe-finned fish ventured onto land. They developed several key features: a musculoskeletal framework to support their body weight on land, as well as nostrils and leg bones, which became the impetus for subsequent evolution that, over the course of several million years, produced the first primitive amphibians such as Eucritus and crassigyrinus.

7. Like reptiles, amphibians are cold-blooded

Warm-blooded metabolism is typically characteristic of more “advanced” vertebrates, so it is not surprising that amphibians are cold-blooded animals, heating up and cooling down in accordance with the ambient temperature. The advantage of being cold-blooded is that warm-blooded animals need much more food to maintain their core body temperature, but main drawback- they are limited in the ecosystem in which they can develop. Just a few degrees hotter or colder than their limit means certain death.

8. Amphibians swallow prey whole

Unlike reptiles and mammals, amphibians do not have the ability to chew their food. They have only a few teeth on the front upper part of their jaws, allowing them to hold squirming prey. To compensate for this disadvantage, most amphibians have long, sticky tongues, which they shoot out at lightning speed to capture prey.

9. Amphibians have extremely primitive lungs

Much of the progress in vertebrate evolution goes hand in hand with the development of lung efficiency. Amphibian lungs have a relatively low internal volume, and are not able to process as much air as the lungs of reptiles and mammals. Fortunately, amphibians can be absorbed a small amount of oxygen through permeable skin, which allows them to maintain metabolic needs.

10. Amphibians are among the most endangered animal species in the world.

Their small size, permeable skin and dependence on water make amphibians more vulnerable than most other animals and pose a threat of extinction. It is estimated that half of the planet's amphibian species are directly threatened by pollution and habitat destruction. invasive species, and even destruction of the ozone layer. Perhaps the biggest threat to frogs, salamanders and caecilians is the chytridiomycete fungus, the spread of which some experts link to global warming.

Amphibians lived on land, but had to return to the water to lay eggs. The first animals to live full time on land were the early reptiles. They are the ancestors of dinosaurs.

The first creatures on land were called scaly fin fish. They developed lungs for inhaling air and propelled themselves out of the water with strong, leg-like fins.

Ichthyostega was one of the first amphibians. Her belly was covered with scales, she had a tail like a fish, but walked on four legs. This amphibian lived in Greenland, which was hot and humid 370 million years ago.

Amphibians are the first creatures capable of throwing out their tongues to catch insects.

One of the earliest strangest amphibians is the diplocolus. Her head was shaped like a boomerang. It must have been very difficult for her enemies to swallow.

The first animals to appear on land were fish. About 370 million years ago, a group of them left their homes in bodies of water and made their way onto land. They evolved into amphibians, a family of animals that includes frogs and toads.

Amphibians can recover... the heart. During experiments, one or another section of the heart muscle was literally cut off from newts, and it almost always regenerated.

Amphibians or amphibians (Amphibia)- class of vertebrates.

íbios - live twofold lives. The Latin name comes from the Greek amph íbios - living a double life.

When witches brewed their potions hundreds of years ago, tradition dictated that frogs were always the key ingredient in any witchcraft potion. The strong poison of some amphibians, for example, the golden frog, has long been used as a weapon; the Choco Indians lubricated the tips of their arrows with it. Frogs are a traditional symbol of injury, rejection and rejection. In 16th century England, a woman who found a frog in her house was tried for witchcraft. But why a frog? Is it because of their skin, the shape of their body, or does it still contain dark forces? Since ancient times, there have been many stories of stones that suddenly split open, releasing the frog that lived inside. Witchcraft, magic? No. This is hibernation. To avoid freezing in winter, frogs fall asleep in dark and warm places.- this is a proven fact.

Males attract females by singing.

The call of the coca frog consists of two tones.

But females hear only a high sound - calling, and other males only hear a low sound - threatening.

For male American bullfrogs, good hearing is very important.

They are aggressive and constantly listen for rivals nearby.

Their ears are almost twice the size of their eyes. The vision of amphibians depends on their habitat. The teeth serve only to grasp and hold prey. Frogs have no teeth at all. Herbivores among amphibians have an extremely sluggish metabolism. Amphibians feed on small animals (mainly insects and invertebrates) and are prone to cannibalism. IN aquatic species The diet may include juvenile fish, and the largest ones prey on chicks of waterfowl and small rodents that fall into the water.

IN life cycle amphibians clearly stand out four stages of development: egg, larva (tadpole), period of metamorphosis, adult.

For the development of the egg (spawn), it needs constant moisture.

The vast majority of amphibians lay their eggs in fresh water bodies, but there are exceptions:

giant salamanders , amphium frogs and some other amphibians lay eggs on land. Even in these cases, eggs need high humidity environment, the provision of which falls on the parents.

Species are known that carry eggs on their bodies: male midwife frogs wrap a cord-like clutch around their hind legs, and a female reticulated copepod frog attaches the eggs to her stomach. The fertilized eggs in the Surinamese pipa are pressed by the male into the back of the female and the latter carries it on herself until young pipas hatch from the eggs. horror. Average length amphibians of those times were about 2 meters, and the largest representatives had bodies up to 15 meters in length. Despite their enormous size, they were extremely vulnerable, so with the appearance of the first natural enemies they began to disappear catastrophically. Until now, they remain the class that is disappearing from the face of the Earth the fastest.

This species of amphibian - Rheobatrachus or Caring Frogs - was discovered only in 1973. While observing them, zoologists were faced with an amazing discovery: rheobatrachus bears their offspring in the stomach. This one amazing fact explains the name of the species.

Gestation of cubs lasts about 2 months, and this period becomes a difficult test for females: the amphibian completely stops feeding and lives off existing reserves nutrients. During such a “fast”, about 40 eggs develop in the female’s stomach, from which tadpoles emerge. To prevent the babies from dissolving in the gastric juice, the secretion of the glands completely stops, and instead of digestive enzymes, prostaglandin E2 is produced - a substance in which the young animals feel cozy and comfortable.

After babies develop skin, it also begins to produce prostaglandin, helping the mother. The restless offspring in the stomach behaves extremely actively, so from the outside the rheobatrachus looks strange: its body shakes, it protrudes into different sides. This picture is worthy of any horror movie.

When the tadpoles become fully formed frogs, the mother gently pushes them outside, where they finally become independent.

Incredible Regeneration

The class of amphibians is known for its ability to renew lost organs and quickly restore tissue. But even compared to all other representatives of the class, the crested newt stands out far ahead thanks to its amazing regeneration abilities.

IN surrounding nature it has many enemies, so injuries and body damage are not uncommon for this amphibian. Scientists have noticed that healing occurs at a speed that is simply amazing. After this, numerous laboratory studies began, during which it was possible to establish that the crested newt can regrow almost any organ. After complete loss of paws or tail, they recover in 3-4 months. Even after both eyes were completely removed, they grew in 10 months and were in no way inferior to those that were before: the amphibian could see with them the same way.

And even on this amazing properties crested newt did not end. If in the reservoir where it lives, the water freezes and the animal turns into ice, then after thawing it continues to live as if nothing had happened. If a severe drought occurs, the newt turns into a dried mummy, which, it would seem, will never come to life again. But after the first rain, it restores all tissues of the body and continues to live and reproduce.

Honeycomb on the back

Pipa Toad doesn't trust environment in the responsible business of raising offspring, preferring to ensure the safety of her children herself. While the male lays eggs, the female exposes her back to the flow of eggs, and the male carefully presses them directly into the female’s skin. After a few hours, her back looks like a honeycomb, in which from 40 to 144 eggs are securely hidden.

Pipa bears its children for 80 days. During this time, they manage to hatch from eggs, turn into tadpoles and become fully formed individuals. Mom's back swells more and more, and it becomes very difficult for her to move, as her weight increases almost 3 times. Nutrition and oxygen to the cubs come from the mother's body, so during the months of gestation the pipa becomes very depleted.

After the babies become sufficiently formed, they break through the film and actively get out, crawling in different directions. This is how their long independent life begins, in which they will be able to acquire their own offspring only after 6 years of age.

Spiked monsters

Crested newts, native to China, lead a predominantly aquatic lifestyle. Their females are no different from most newts, but the males look different: on their backs they have a crest with spikes that grows to an impressive size during the mating season.

The body length of this amazing amphibian is from 11 to 20 cm, and the spiked crest reaches 2 cm. When do these animals begin mating season, they often crawl onto the banks of reservoirs, straightening their crest, which becomes brighter in color than usual.

It was during this period that these terrifying appearance amphibians can be encountered by people who often experience mystical horror, because crested newts resemble small dragons and look terrifying. Several centuries ago, for this reason, they were exterminated en masse, taking them for manifestations evil spirits, which affected their numbers.

Higher and further

The Javan flying frog is one of the few amphibians that can soar like a bird. Of course, this is not the full-fledged flight characteristic of birds, but with the help of its adaptations the amphibian can glide perfectly.

Having a size of only 10-12 cm, the Javan flying frog can soar at a distance of as much as 12 m. To do this, during a jump, it spreads the membranes on the toes of all four paws, catching air currents. total area The interdigital membranes of this small amphibian are 19 cm 2. Thanks to this amazing ability, she can catch up with any insect that is of interest to her, so the flying hunter is not in danger of starvation.

The beauty and the Beast

An amazing amphibian called the American proteus is both a beauty and a beast. Among salamanders, it ranks second in size: the body of this amazing amphibian is about 40 cm. The salamander does not look particularly attractive, since it has very small eyes located on a large grayish head. But on the cheeks there are gill outgrowths, painted bright red. It is these beautiful outgrowths that unmistakably indicate belonging to the species.

For a long time, scientists considered the American protea to be the larval form of another species of amphibian, but then it was found that it is an independent biological unit. Unlike other salamanders, the American Proteus does not have a skin surface containing toxic substances, helping to scare away predators, so he is often forced to hide from birds or predatory fish.

Another interesting fact is known about the American protea: it is the only salamander capable of making quite loud sounds. They resemble the barking of a small dog, for which in America this amphibian is called a “squealing puppy.”

Blind worker

The purple frog was discovered as recently as 2003. The reason that it went unnoticed for so long was its special lifestyle, in which the amphibian spends most of its life in burrows and holes.

The appearance and shape of the body does not particularly resemble ordinary frogs, since the head is very small with a pointed muzzle, and the body looks like a shapeless jelly mass. It looks like a very clumsy amphibian, but in reality this is not at all the case. With a body size of up to 9 cm, this amphibian is capable of digging a hole 3.7 m deep in just a couple of minutes. To do this, it works very actively with its front and hind legs. The purple frog crawls to the surface from holes and pits extremely rarely, since its small eyes see almost nothing. She can only be forced to leave her home by the need to reproduce, since their mating season takes place on the surface of the earth. After the reproductive instinct is satisfied, the amazing animal again hides at a safe depth, where there is enough dampness and coolness.

Vanishing Giant

The largest creature among amphibians is the gigantic salamander. Its length can reach 160 cm, while its tail is not long, so most of this length falls on the body and head. Due to such enormous size, the amphibian’s weight is impressive - about 180 kg. Its lifespan most often lasts from 55 to 60 years.

Exactly these amazing amphibians appeared many millions of years ago and were able to survive the heyday of the era of reptiles and the death of dinosaurs, successfully adapting to changing living conditions. But now it hangs over them new threat, which this species copes with less successfully. The point is that meat giant salamanders very gentle and soft, which became the reason for the mass destruction of the population in Japan and China, where these amphibians live. So far, the situation cannot be changed by the fact that the gigantic salamander was included in the international Red Book and taken under legal protection.

In addition to the barbaric attitude on the part of people, the population of the species was seriously affected by the deterioration of the condition of natural reservoirs, since these amphibians can only live in clean water free of industrial pollutants. In order to somehow rectify the situation, a huge nursery for breeding giant salamanders was created in China, where they are kept in ideal conditions and reproduce successfully.

Dangerous Kid

The Zimmerman dart frog is a frog that is considered one of the most poisonous on the planet. Its body size is only 2 cm, but this amphibian is easy to spot in nature thanks to its bright colors. The beautiful blue and lime color, as well as large spots on the back, look like the creature came straight out of the pages of a children's coloring book, but the amphibian is by no means harmless.

The surface of her skin contains a strong poison, batrachotoxin, which can cause a spasm of the heart muscles in a person and cause rapid respiratory arrest. This fact was discovered by the Indians of Peru, who learned to use it to their advantage: they passed an arrow along the body of a poison dart frog, after which it became deadly to enemies and capable of killing the enemy in a few seconds.

There are amphibians that only zoologists know about - caecilians. What sets them apart from the rest of the class is complete absence limbs, so in appearance they more closely resemble something between snakes and earthworms. The largest representative is 1.55 m long and looks creepy.

Such amphibians can live in the soil, inside anthills or termite mounds. The eyes of caecilians almost do not see, but these animals have an excellent sense of smell, which allows them to find worms that serve as food for them.

In many species of caecilians, the hatched babies eat for the first time skin covering mothers, which is the best food for them. At the same time, they do not cause harm to their parent, since they only eat upper layer, rejuvenating her skin.

The study of amphibians does not stop, so every year scientists discover new amazing views, preserved to this day far from human eyes.