Reproduction of different types of frogs, how amphibians breed

Mating season in frogs

Frogs can reproduce when they reach the age of four. Waking up after hibernation, amphibians of mature age immediately rush to spawning reservoirs, where they search for a partner of a suitable size. The male has to perform various types of tricks in front of the female in order to attract her attention, such as songs and dances, to show off with might and main. After the female chooses a suitor that she liked, they begin to look for a place to lay eggs and fertilize them.

Mating games

Vote

Most male toads and frogs attract females of their own species with a voice, namely croaking, which is different in different species: in one species it looks like a "trill" of a cricket, and in the other - on the usual "kva-kva" ... You can easily find male voices on the Internet. The loud voice in the pond belongs to males, while in females the voice is very quiet or absent altogether.

Courtship

Males of many species of frogs, for example, tropical poison dart frogs, change their color during mating season, become black. In males, unlike females, the eyes are larger, the sense organs are better developed and the brain is enlarged, respectively, and the front paws are decorated with so-called mating calluses, which are necessary for mating so that the chosen one cannot escape.

The attention of females can be attracted and different movements ... Colostethus trinitatis simply jump rhythmically on a branch, and Colostethus palmatus take exquisite poses when they see a female on the horizon, and other species that live near waterfalls manage to wave their paws to the females.

Males of Colostethus collaris perform a dance during courtship. The male creeps up to the female and croaks louder and faster, then crawls away, sways and jumps, while freezing on its hind legs in an upright position. If the female is not impressed by the performance, she raises her head, showing her bright yellow throat, this dares the male. If the female liked the male's dance, then she observes the beautiful dance, crawling to different places in order to better see the male's play.

Mating dances of frogs

Sometimes a large audience can gather: once scientists, observing Colostethus collaris, counted eighteen females who stared at one male and moved synchronously to another position. After dancing, the male slowly leaves, while often turning around to make sure that the lady of the heart is following him.

In the case of golden tree frogs, on the contrary, females fight for males ... Having found a male who croaks, the female slaps her hind legs on his body and puts her front paws on him, she can also rub her head against the male's chin. The male responds in the same way with less fervor, but not always. Many cases have been recorded when this species of amphibians had fights both between females and males for a partner they liked.

Fertilization or how frogs breed

Fertilization taking place externally

This type of fertilization occurs most often in frogs. The smaller male tightly grasps the female with its forepaws and fertilizes the eggs spawning by the female. The male embraces the female in the amplexus pose, which there are three options .

  1. Behind the front paws of the female, the male makes a girth (sharp-faced frogs)
  2. The male grasps the female in front of the hind limbs (scaphiopus, garlic)
  3. The female is grasped by the neck (dendrops).

Fertilization taking place inside

The period of courting a partner

Few poison dart frogs (for example, Dendrobates granuliferus, Dendrobates auratus) are fertilized in a different way: the female and the male turn their heads in opposite directions and connect the cloaca. In the same position, fertilization occurs in amphibians of the species Nectophrynoides, which first hatch eggs, and then tadpoles in utero until the completion of the process of metamorphosis and give birth to fully formed frogs .

The tailed male frogs of the genus Ascaphus truei have a specific reproductive organ.

During the breeding season, males quite often develop specific mating rough calluses on their front paws. With the help of these calluses, the male is kept on the slippery body of the female. An interesting fact: for example, in the common toad (Bufo bufo), the male climbs onto the female far from the reservoir and rides on her for several hundred meters. And some males can ride the female after completing the mating process, waiting for the female to form a nest and will lay eggs in it .

If the mating process takes place in water, the male can hold the spawned eggs by the female, tucking his hind legs in order to have time to fertilize the eggs (species - Bufo boreas). Quite often, males can confuse and climb on males who clearly do not like it. The “victim” reproduces a specific sound and vibration of the body, namely the back, and forces you to get off yourself. Females also behave at the end of the fertilization process, although sometimes the male can release the female himself when he feels that her abdomen has become soft and empty. Quite often, females actively shake off males who are too lazy to climb off, turning over to one side and stretching their hind limbs.

Coition - amplexus

Types of amplexus

Frogs lay eggs , like fish, since eggs (eggs) and embryos lack adaptations for development on land (anamnia). Different types of amphibians lay eggs in amazing places:

  • Fertilization of frogsinto holes, the slope of which descends into the water. When a tadpole hatches, it rolls into the water, where its further development takes place;
  • the female, with the collected mucus from her skin, forms nests or lumps, then attaches the nest to the leaves that hang over the pond;
  • some wrap each egg in a separate leaf of a tree or reed hanging above the water;
  • female of the species Hylambates brevirostris in general bears eggs in her mouth ... Males of the Darwin's rinoderma species have special sacs in the throat, where they carry the eggs laid by the female;
  • in arid areas, narrow-mouthed frogs live, which lay eggs in moist soil, where then the tadpole develops, and a formed amphibian crawls out onto land;
  • females of the genus pipa carry eggs on themselves. After fertilization of the eggs, the male presses them into the back of the female with his abdomen, laying the eggs in rows. Eggs that have adhered to plants or to the bottom of the reservoir cannot develop and die. They survive only on the back of the female. A couple of hours after laying, a porous gray mass is formed on the back of the female, into which the eggs are sunk, then the female molts;
  • some types of females form annular shafts from their own mucus;
  • in some species of frogs, a so-called brood bag is formed in the folds of the skin on the back, where the amphibian carries eggs;
  • some Australian frog species eggs hatch in the stomach and tadpoles. For the period of gestation in the stomach with the help of prostaglandin, the function of producing gastric juice is turned off.

The frog laid its eggs

For the entire period of gestation of tadpoles, and it lasts two months, the frog does not eat anything, while remaining active. During this period, she uses only the internal stores of glycogen and fat, which are stored in her liver. After the gestation process in the frog, the liver is three times reduced in size and there is no fat left on the belly under the skin.

After laying eggs, most females leave their masonry, as well as spawning waters, and go to their places of normal habitat.

Eggs usually surround big Layer of a centered substance . The shell for eggs plays a big role, since the egg is protected from drying, from damage, and most importantly, it protects it from eating predators.

After the tab, after some time, the shell at the icon swells and is formed into a transparent cushy layer, inside which the egg is peeled. The upper half of the eggs is dark, and the bottom is the turn, light. The dark part is stronger thanks, as the rays of the sun use more efficient. In many types of amphibians, the lumps of caviar float to the surface of the reservoir, where the water is much warmer.

Low water temperature detains the development of the embryo. If the weather is warm, the egg is divided repeatedly and is formed into a multicellular embryo. Two weeks later, Golovastik goes from Ikrinka - Larva Frog.

Golovastic and its development

Small tadpoles

After exiting caviar Golovastic falls into the water . Already in 5 days, having spent the supply of nutrients Ikrinka, he will be able to swim and eat independently. He has a mouth with horny jaws. Golovascular feed on the simplest algae and other water microorganisms.

By this time, the tadpoles are already visible to the body, head, tail.

Talker's head There are no limbs, the tail ending the body plays the role of the fin, the side line is also observed, and the suction cup is located near the mouth (the suction cup can be identified by the nickname). Two days later, the gap across the edges of the mouth is becoming some kind of bird beak, which performs the function of the bustard when the headasting produces feeding. Golobastikov has gills with gill holes. At the beginning of development, they are external, but in the development process are modified and attached to the gill arcs, which are in the field of pharynx, while functioning already as ordinary inner gills. Urban is a two-chamber heart and one circle circulation.

According to the anatomy, the tadpole at the beginning of development is close to the fish, and he has matured, it already has similarities with the species of reptiles.

After two or three months, the tadpoles are growing with the rear, and then the front paws, and the tail is first crushed, and then disappears. Develop and light . Formed for breathing on land, the headasting begins its rise to the surface of the water branch to block the air. Changes and growth depends largely from hot weather.

Tasps first feed on predominantly vegetable origin, but then gradually go to the food of the animal species. The formed frog can be selected by the shore, if it is a kind of land, or then remains to dwell in water, if it is a water view. Footing on the drying of the frog - these are flying. Amphibians that postpone on land of caviar sometimes go to development without the process of metamorphosis, that is, through direct development. The development process takes about two to three months, from the beginning of the posting of iconic until the end of the development of the headastrics in a full-fledged frog.

Monument to the frog in Paris

Amphibians-tree Show interesting behavior. After the tadpoles hatch from the cheek, the female on their back, one after another transfers them to the tops of the trees in the flowering buds, in which water accumulates after the rain. Such a kind of pool is a good children's room, where children continue their height. Eat for them is uninterrupted eggs.

The ability to reproduce in young is achieved around the third year of life.

After the breeding process green frogs stay in water or they keep on the shore near the reservoir, while the brown ones go to land from the reservoir. The behavior of amphibians is largely determined by humidity. In hot dry weather, brown frogs are mostly invisible, as they hide from the rays of the sun. But after sunset it is time for them to hunt. Since the green frog species lives in or near water, they hunt in the daytime.

With the onset of the cold season, brown frogs move to the reservoir. When the water temperature rises above the air temperature, brown and green frogs sink to the bottom of the reservoir for the entire period of winter cold.

  • Breeding frogs
  • Frog: description, structure, characteristics. What does a frog look like?
  • Frog lifestyle
  • Frog eyes
  • Where do frogs live?
  • How long do frogs live?
  • What do frogs eat?
  • The benefits of frogs
  • Interesting facts about frogs
  • Recommended reading and useful links
  • Frogs monsters video
  • Millions of years have passed since the appearance of vertebrates on land. The continents were filled with a variety of animals adapted to the most varied living conditions, but amphibians remained the only vertebrates that belong to both water and land. The frog - a modern representative of the amphibian class - captured the longest experience of the struggle for existence in the history of life on land. This led to the versatility of her anatomy and physiology, providing a unique adaptability to life in the border zone.

    Breeding frogs

    Like millions of years ago, a frog begins its life in water. Each spring, you can observe in an abbreviated form the process that once led to the transformation of fish-like ancestors into land animals.

    A tadpole develops from an egg laid in water. So far, it differs little from fish fry. But then a series of transformations begins, consisting of about thirty transitional stages. The last one is the main one. A week - and radical changes occur in all organs. A week - and the tadpole turns from a "fish" into a land animal. From this moment on, the frog will live on land, more precisely, on the border of land and water.

    Лягушка

    Frog: description, structure, characteristics. What does a frog look like?

    The constant connection with the aquatic environment imposes a number of characteristic features on the biology of frogs. The tadpole breathed with gills, and the adult frog breathes through the mouth, lungs and skin. Such a large set of respiratory organs is characteristic only of amphibians. While the frog is in the water, it breathes with its skin, and when it is on land - with its mouth and lungs. The circulatory system is also universal. Two parts of the heart work in the water, and mixed blood flows through the body, like in fish. On land, the left atrium is connected to work, and purely arterial blood, saturated with oxygen, is supplied to the brain. Thus, with each dive, the frog's respiratory organs are instantly switched.

    Лягушка

    When wintering time comes, the frog sinks to the bottom. While the frog is on the ground, it is not difficult to catch it. And try to hunt for her near the water. It is unlikely that you will succeed. The entire skeleton of the frog is remarkably adapted for jumping. The hind limbs are long, consisting of ten bones-levers. Ten levers that are simultaneously activated by very strong muscles. And the belt of the forelimbs is a superbly "thought out" device for a "soft landing".

    лягушка в прыжке

    Although common frogs and frogs spend most of their time on land, they seem to continue to exist in a humid environment. Their skin is bare and covered with mucus, and therefore the activity of the frog is determined not like in other animals - by the time of day, but above all by the humidity and temperature of the air. The frog can go hunting at any time. And if most often this happens at night, it is only because it is usually more humid at night. During the day, she prefers warm mushroom rain to any weather.

    Frog lifestyle

    Frogs love to jump on grass wet with dew. During this time, they replenish their water supply and breathe through the skin. But in cold and dry weather, they hide in shelters, which can serve as small Christmas trees, rotten stumps, driftwood, heaps of brushwood. If there is no suitable shelter nearby, frogs will bury themselves in the leafy mat.

    Лягушка

    Despite its excellent jumping ability, the grass frog is far from being a runner. For a whole week, she sometimes makes a path only thirty meters long. And only in the most hunting, wet weeks, the range increases to half a kilometer. Running away from the enemy is not easy at this speed. Therefore, the frog prefers not to catch his eye. It achieves this goal due to the ability to change color, adapting to the color of the surrounding soil.

    The spectrum of the grass frog is much richer than that of the pond frog. This is due to the fact that the first one spends most of his life on land, where the palette is very diverse. The pond frog usually lives in the water, but hides among thickets of green plants. Therefore, her palette is more modest: from dark green to yellowish green. The color change depends on the regulation of body temperature in accordance with a well-known physical law: dark objects absorb heat, and light ones reflect. However, the color is influenced not only by the temperature, but also by the background color, and illumination, and humidity. The frogs perceive changes in these factors directly with their skin, as evidenced by experiments on blind animals.

    Frogs

    There are special colored cells in the frog's skin - black, orange, white. They can expand and contract. The color change is also carried out by the movement of special colored particles. Such a variety of sensing elements allows one to perceive such optical properties of light as decomposition, refraction, reflection, scattering. This entire complex mechanism that controls the color of the skin is regulated by the nervous system and the endocrine glands - the pituitary gland and the pineal gland.

    One of the most original adaptations to living conditions in the border zone between land and water is the frog's hearing aid. It turns out that she perceives sound signals through three channels. In the air, sound waves are captured by the sensitive cells of the inner ear through the eardrum and ear bone. Sounds propagating through the soil are perceived by the bones and muscles of the limbs and are transmitted through the bones of the skull to the inner ear. And, finally, sounds in water, as suggested by zoologists, are captured by the skin, and enter the inner ear through the circulatory system. In the latter case, the sound passes through a homogeneous medium: water - blood - fluid of the inner ear.

    лягушка

    That is how simply and ingeniously these animals coped with difficult habitat conditions, how they managed to take advantage of even the difficulties caused by the need to adapt to life on the border of two environments.

    Frog eyes

    The unusual sensitivity, diminutiveness, and reliability of the design of the frog's orientation organs are increasingly attracting engineers. They have already built an "electronic eye" - a device based on the principle of the frog's eye.

    Frog eyes

    As you know, the most important part of the eye is the retina, which consists of a layer of photoreceptors, several layers of bipolar cells and one layer of ganglion cells. Photoreceptors - rods and cones - perceive light, transform it into biocurrents, amplify and transmit it to bipolar cells. The bipolar process the information received and transmit it to the ganglia. Branches of the optic nerve are already leaving the ganglia, along which biocurrents go to the brain. But it turned out that the various groups of ganglia are strictly specialized. Some of them perceive only the contrast, others - the moving edge, the third - the curved edge, the fourth - different illumination.

    Each type of stimulus is transmitted along its own fiber of the optic nerve to a specific layer of the brain. In the brain, the information received is processed, and the animal perceives the object as a whole.

    Глаз лягушки

    Where do frogs live?

    Frogs live almost everywhere, they can be found on all earthly continents, with the exception of Antarctica. Since frogs are still not very fond of the cold, they are not often found in the cold Arctic latitudes (although there are several species that live there as well). But many species of frogs perfectly tolerate our temperate climate. As we wrote above, frogs sink to the bottom of reservoirs in winter, that is, they pass into the water element, so that with the onset of spring they rise to the surface again.

    Also, many species of frogs live in the tropical latitudes of Africa, Asia and South America.

    How long do frogs live?

    The lifespan of frogs depends on their species. On average, they live for 10-20 years. Of course, in natural conditions, frogs have many enemies, so they often do not live to old age. But if nothing threatens them, then, for example, pond frogs living in terrariums calmly live up to 20 years, and once there was even a case when one toad lived as much as 32 years, by frog standards it turned out to be a true long-liver.

    лягушки в пруду

    What do frogs eat?

    A long history of development has developed in a frog such a valuable quality as unpretentiousness and indiscriminate food. Little food - the frog will starve for a day and a week.

    A lot - he eats everything, everything that is in a given place at a given time. The menu turns out to be very varied. Caterpillars and butterflies, bees and wasps, ants and beetles, dragonflies and mayflies, various larvae and snails, spiders and millipedes, slugs and worms, etc. Moreover, the tastes are the same for almost all frogs, with the exception of the lake frogs.

    лягушка охотится

    The latter clearly suffers from aggressive inclinations - it devours fish fry and even its own tadpoles. There are cases when these frogs ate chicks.

    And how many harmful insects can frogs really destroy? Herpetologist B. A. Krasavtsev counted that on an area of ​​24 thousand square meters of meadows and fields, on average, 720 grass frogs. If one frog eats about seven insects per day, then during wakefulness (six months: from half of April to half of October), it exterminates 7 X 180 = 1,260 copies. Multiplying this number by the number of frogs on the site, we get an impressive figure: 907 200. Almost a million insects!

    лягушка прыгает

    The benefits of frogs

    But where the frog's merit is truly tremendous is, of course, in biology and medicine. For many decades, physiologists have been using frogs in a wide variety of experiments and preferring them to other animals. The frog received this honor due to its phenomenal endurance and vitality, acquired over a long period of struggle for existence.

    лягушка в лаборатории

    Such "love" by the researchers is expensive to be frogs. They are caught by hundreds of thousands. A person for his economic needs takes away all new extensive territories from nature. And if the forests, meadows and rivers still protect, the wetlands and temporary reservoirs are the main habitats of frogs - are considered useless landscapes. They are mastered first. In addition, the progressive reduction in the number of frogs contributes to the peculiarity of their physiology: they slowly grow. A frog capable of reproduction becomes only for the third year and the same time reaches sizes sufficient to conduct experiments. Therefore, any sabotage of a person against nature (stock of crude waters, flooding of land, landfills) affects the frogs very painfully. They are accustomed to fighting the most different natural phenomena, but they do not resist people against human ingenuity.

    The merits of the frog in front of biological science, medicine and agriculture are indisputable. No wonder in some countries, monuments have already been delivered in her honor.

    Памятник лягушке в Париже

    Monument to the frog in Paris.

    So we will hope that our current and future monuments of the frog will be a tribute to her merit, and not an apology for the destruction of another representative of the animal of the world, who could not withstand the competition with the pace of civilization.

    Interesting facts about frogs

    • The frog Goliath, inhabiting Cameroon, is the largest in the world. Its weight reaches three and a half kilograms, and the length of the body is 32 centimeters. The garlic with the Seychelles is considered the smallest frog in the world. Adult animals do not exceed 1.8 - 1.9 centimeters.
    • Creek frog-bull founding in the east of North America is heard at a distance of several kilometers and reminds the roar of the bull.
    • Flying frogs live on Indonesia Islands. Parachute they serve me with a membrane between your fingers. A flying frog from the island of Borneo the area of ​​the membrane reaches 19 square centimeters.
    • Poison frog-tree is the same strong as the coarara. South American hunters use it on the hunt for jaguars and deer, lubricating the poison of the arrows.
    • Three-peerwood (Brazil, Peru, Guiana) originally cares about his children. When the puddle dries up, the tadpoles are embarrassed to the body of the parent, and he transports them to a new reservoir.
    • Male rinoderma living in Chile, swallows developing eggs and lays them out in their voice bag.
    • The female of Pipov (Brazil, Guiana) with the help of a protruding rectum (egg-owned) postpones 40 - 114 eggs on his back. Then around eggs are formed cells with lids. All the development and transformation (82 days) occurs in these cells, from where you have already formed frogs.
    Лягушка

    Recommended reading and useful links

    • Maslova I.V. The influence of the climate on the individual aspects of the vital activity of amphibians and reptiles (Rus.): Collection / Sost. A. O. Kokorin. - Moscow: WWF Russia, 2006. - P. 111. - ISBN 5895640370. - BIBCode: 26.23B58.
    • Ananyeva N. B., Borkin L. Ya., Darevsky I. S., Orlov N. L. Pyatifying dictionary of animal names. Amphibians and reptiles. Latin, Russian, English, German, French. / Under the general editors of Acad.
    • Ferrell, Vance. Geographical Distribution. Evolution ENCYCLOPEDIA, Volume 3. Evolution Facts (March 4, 2012). Dahl, Chris; Novotny, Vojtech; Moravec, Jiri; Richards, Stephen J. Beta Diversity of Frogs in The Forests of New Guinea, Amazonia and Europe: Contrasting Tropical and Temperate Communities (English) // Journal of Biogeography (English) Russian. : journal. - 2009. - Vol. 36, no. 5. - P. 896? 904. - DOI: 10.1111 / J.1365-2699.2008.02042.x.
    • Shabanov D. A., Litvinchuk S. N. Green frogs: life without rules or a special way of evolution? (rus.) // Nature: magazine. - Science, 2010. - No. 3. - P. 29-36.
    • Kartashev N.N., Sokolov V.E., Shilov I.A. Workshop on Vertebrate Zoology.

    Frogs monsters video

    And finally, an interesting documentary about monster frogs.

    Author: Pavel Chaika, editor-in-chief of Poznavayka magazine

    When writing the article, I tried to make it as interesting, useful and high-quality as possible. I would be grateful for any feedback and constructive criticism in the form of comments to the article. Also, your wish / question / suggestion can be written to my mail [email protected] or Facebook, sincerely the author.

    Frogs Is a common and widespread name that unites a whole group of animals that belong to the order Tailless amphibians. In a broad sense, this term is applicable to any representatives belonging to the order Tailless, and in a narrow sense, the name applies only to the family True frogs.

    Description of frogs

    Absolutely any representatives of frogs are distinguished by the absence of a pronounced neck, and the head of such amphibian animals seems to grow together with a short and fairly wide body. The complete absence of a tail in frogs is reflected directly in the name of the order, which unites all amphibians. It should be noted that frogs have simply unique vision, therefore they do not close their eyes during sleep, and are also able to look forward, up and to the side at the same time.

    Appearance

    The frog has a large and flat head, on the side of which protruding eyes are located. ... Along with other terrestrial vertebrates, frogs have upper and lower eyelids. A blinking membrane is found under the lower eyelid of an amphibian, which is called the "third eyelid". Behind the eyes of an amphibian there is a special area covered with a thin skin, called the eardrum. Two nostrils with special valves are located above a huge mouth with small teeth.

    The frog's forepaws are characterized by the presence of four rather short toes. The hind legs of the animal are strong and well developed, equipped with five toes, the space between which is specially tightened by a leathery membrane. There are no claws on the fingers of the animal. The only outlet part is located in the posterior region of the frog's body and is represented by the so-called cloacal opening. The frog's body is covered with bare skin, quite thickly smeared with special mucus, which is abundantly secreted by numerous special subcutaneous glands of the animal.

    It is interesting! The sizes of frogs depend on the species, therefore, European frogs most often do not exceed one decimeter, and African goliath frogs are a kind of record holders in terms of dimensions, therefore, when they are half a meter, they have a weight of several kilograms.

    The size of an adult frog varies markedly depending on the species characteristics, but most often it varies between 0.8-32 cm. The color of the skin is also very diverse and can be represented by brownish, yellow, green or unusual variegated coloration. Many members of the family prefer to disguise themselves as grassy vegetation, foliage or branches, therefore they have a skin of a characteristic green, gray and grayish-green color.

    The battle coloration, as a rule, indicates the poisonousness of the frog, which is explained by the presence of special glands on the skin that produce substances that are toxic and harmful to human or animal health. Some frogs easily mimic, imitating dangerous amphibians to escape from enemies.

    Varieties of frogs

    There are over 500 species of frogs in the modern world. To simplify the perception, representatives of amphibians were conditionally divided into the following subfamilies:

    • toad-like;
    • shield-toed;
    • real;
    • African forestry;
    • dwarf;
    • discopal.

    The most amazing and unusual frogs in the world are the following:

    • transparent (glass) - individuals grow up to only 2 cm, have colorless skin through which all internal organs are enlightened;
    • poisonous kokoy frogs - miniature amphibians that produce a strong toxic poison in their skin, surpassing the most dangerous snakes in the world;
    • hairy - unusual amphibians, in which hair grows on the back and is a kind of respiratory system;
    • goliath frogs are one of the largest tailless, growing up to 40 cm and weighing up to 3.5 kg;
    • sharp-nosed woody - have an extraordinary nose;
    • bull frogs - large individuals emitting a deafening croak;
    • flying frogs - small amphibians, famous for their long jumps; they can jump up to 12 meters.

    Researchers claim that a large number of frog species are still unknown to mankind. Therefore, scientists are happy to continue to study the animal world in anticipation of new finds.

    Differences between toads and frogs

    Toads, unlike frogs, have no teeth, their whole body is covered with small tubercles, and the skin is much drier. In addition, toads like to spend most of their life on solid ground, migrating to water only during breeding seasons.

    Why do frogs grow extra paws?

    The absence of one paw from the symbol of wealth can be explained in any way (according to legend, the fourth was taken away by the Buddha for sins), but individuals with extra paws for a long time caused bewilderment among scientists, and they sinned on chemical waste. It turned out that amphibians become victims of chemicals that did not get into water bodies, in the parasites of Ribeiroia, which have a complex life cycle that begins in snails. Growing up, they look for a new host, which becomes a fish or a tadpole. And since the tadpole is just growing its paws, the process of reproduction of new molecules is disrupted and spreads to other parts of the body, causing the growth of new limbs. The maximum number of paws seen on a frog by humans was 10 on each side.

    Why throw frogs in milk?

    Many people know that it was customary to do this in the old days. It was believed that a cold amphibian prevents the product from heating up, which means it slows down its souring. In the absence of refrigerators, this was fully justified. A similar sanitary and hygienic rite was practiced not only in Russia, but also in many other European and Middle Eastern countries.

    For a long time it was considered a superstition, but the milk really did not turn sour and biologists became interested in the phenomenon. It turned out that the skin of the amphibian has special cells capable of producing natural antibiotics, without which existence in a humid environment, especially in the tropics, would be impossible. Due to fungal and bacterial infections, for which such conditions are paradise on earth, amphibians would not have time to look around as they would become covered with mold. Natural antibiotics also change depending on the habitat. In amphibians galloping along our native shores, they are not so strong, but the peptides produced by the skin have sufficient antimicrobial effect to prevent several liters of milk from souring.

    You can eat, but you can't touch

    One of the strongest (and according to some sources, the strongest) poisons of animal origin is the mucus of the tiny Colombian cocoa frog, whose weight does not exceed 1 g, and the height is 3 cm.But one such individual is enough to kill 1,500 people. At the same time, its poison is harmless when eaten, but the slightest amount of it that gets on the wound causes immediate paralysis and death. There is no antidote for it. By the way, the body of an amphibian does not know how to produce poison, it enters it with food.

    The local Choco Indians with great difficulty get several specimens of cocoi in the jungle and hold them over the fire so that the poison appears on the skin, after which they smear arrows with them. When dried, it retains its properties for up to 15 years.

    Habitat, habitats

    Vertebrates have spread to almost all countries and continents, and are also found even in the Arctic snow. But frogs give preference to tropical forest zones, where there is simply a huge variety of species and subspecies of such amphibians. Frogs predominantly inhabit fresh water bodies.

    True frogs are members of the Tailless Amphibian (Anura) family, which are almost ubiquitous, with the exception of South America, southern Australia and New Zealand. Our country is dominated by the grass frog (Rana temporaria) and the pond frog (Rana esculenta).

    It should be remembered that the distribution of some subspecies and species of frogs may well be limited by natural causes, including rivers, mountain ranges and deserts, as well as by man-made factors such as highways and canals.

    In tropical conditions, the diversity of amphibian species is much greater than in zones characterized by cold or temperate climates. Certain species and subspecies of frogs are able to live even in salt waters or beyond the Arctic Circle. .

    Frog diet

    Insectivorous frogs belong to the category of predatory animals ... Such amphibians eat with great pleasure a large number of mosquitoes, as well as all kinds of butterflies and small invertebrates. Especially large adult insectivores do not disdain even more impressive prey in size, which can be represented by some species of animal frogs and relatively small relatives of their own.

    It is interesting! Frogs of many species are of great benefit to humans. They actively destroy and eat many worms, bugs and insects harmful and dangerous to humans and plants.

    Hunting for their victims is carried out by frogs using a sticky and sufficiently long tongue, which deftly catches midges, dragonflies, moths and other winged animals directly on the fly. Among the currently existing species and subspecies of frogs, omnivorous amphibians are also known, which gladly use fruits or berries for food.

    Character and lifestyle

    Frogs are able to perfectly move on land, as well as make just huge jumps, climb the crowns of tall trees and dig underground holes. Some species are characterized by the ability not only to swim perfectly, but also to run, walk, quickly climb trees and even glide easily from a height.

    A very interesting feature of frogs is the absorption of oxygen through the skin. This process is quite successfully carried out on land or in water, due to which the animal belongs to the category of amphibians. Nevertheless, European herbal frogs, very widely known in our country, approach water bodies only during the period of active reproduction.

    It is interesting! The activity indicators for different species and subspecies are very different, so one of these amphibians prefers to hunt exclusively at night, but there are bright representatives who remain tireless all twenty-four hours a day.

    An interesting fact is that the lungs are necessary for frogs in order to make rather loud and peculiar sounds called croaking. ... Sound bubbles and resonators help the amphibian produce the widest range of sounds, which is most often used to attract the opposite sex during the breeding season.

    Periodically, adult frogs shed their skin, which is not an organ necessary for the life of an amphibian animal, and then eat it in anticipation of regrowth of new skin integuments. By way of life, all real frogs are sedentary solitary, prone to short-term migration over short distances only during the breeding season. Species that live in the temperate zone go into hibernation with the onset of winter.

    Breeding frogs

    Frogs reproduce with the help of external fertilization of the eggs laid by the female. There are species that lay more than 20,000 eggs into the water in one throw. 10 days after fertilization, tadpoles are born, which breathe with gills. As they develop, their tail disappears and paws grow. After four months, small frogs are born. Three years later, they become sexually mature individuals, fully ready to reproduce offspring and continue the "frog genus".

    Natural enemies

    Natural enemies of frogs are represented by leeches, larvae of swimming beetles and dragonflies, as well as predatory fish, including pike perch, perch, bream, pike and catfish. Also, frogs are actively hunted by some species of reptiles, including snakes and vipers. Amphibians very often become easy prey for an adult stork and heron, crows and waterfowl ducks, some mammals, which include desman, rats and muskrats, shrews and representatives of mustelids.

    Population and status of the species

    Research shows a significant decline in the total number of frogs ... More than a third of all known species are currently under threat of complete extinction. The most common causes of this disastrous situation are habitat destruction, noticeable climatic changes and alien predators.

    Particularly destructive and dangerous for the frog population are infectious diseases represented by chytridiomycosis and ranavirus. Among other things, amphibians in general and some frogs in particular are highly sensitive to severe environmental pollution, which is due to too permeable skin and life cycle features.

    Other curious facts about frogs

    • On the shores of the Amazon, there is a species in which males are born 10 times more often than females. Therefore, in the mating season, they do not have to choose, and they try to fertilize not only live, but also dead females. In scientific language, this phenomenon is called "functional necrophilia".
    • There is a variety in which the cubs do not grow with age, but shrink. While the parents of a tadpole do not exceed 6 cm in length, he himself can have a "height" of up to 25 cm.
    • The transformation from an egg to an adult has about 30 stages, allowing it to fully adapt to life in a different environment.
    • The frogs perceive changes in lighting and background not with their eyes, but with their skin. Some varieties are able to adapt to these factors with their color.
    • When an enemy approaches, different types of amphibians behave differently. For example, the lichen copepod (mossy frog) curls up and disguises itself. But this is not at all how the 13-centimeter scutellum meets the enemy. She stretches her legs to the sides, inflates her belly, opens her mouth and begins to yell, rushing at the enemy.
    • The hairy African frog is not actually hairy, but grows strips of skin during the mating season (males). But the most surprising is the fact that, being born without claws, they easily make them for themselves on their own. To do this, they simply break their fingers and pierce the skin with fragments of bones. Now they are perfectly armed! Unfortunately, not from the local Cameroonians, who love to eat them fried, which is considered a delicacy in these parts.
    • The purple frog, despite its very diffuse shape, perfectly digs holes and quickly goes to a depth of 3 m or more. There she finds the moisture she needs. At the same time, representatives of the species are very unimportant parents. Having laid eggs, the female again goes underground, completely not caring what will happen to the offspring. However, like my father.
    • A somewhat different picture is observed in a pair of Darwin's frogs. The female behaves in a similar way, but the father remains near the clutch until the tadpoles appear from the eggs. Having licked them with his tongue, he transfers them all to his own throat bag, where he bears at the expense of his own resources until complete formation.
    • In a different environment, an amphibian hears with different organs - the cells and bones of the inner ear, as well as the bones and muscles of the limbs through soil vibrations.
    • Frogs have teeth, but toads, unlike them, do not. However, they need teeth only to lock the prey in the mouth until the eyeballs push it inside.
    • Tree frogs have special membranes on their feet that help them fly. This can be called a flight, of course, conditionally, but they can glide over decent distances.
    • Of the 5 thousand amphibians described by biologists, 88% are frogs.
    • They were used in 11% of the revolutionary works of Nobel laureates in the field of medicine and biology.
    • A well-known folk recipe for angina says that you need to catch a very large toad, bring it to your mouth and actively breathe on it. According to legends, the animal will soon die, and the patient will recover. It is not known how true this recipe is, but it has lived for more than a century.

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