Frog breeding: when do frogs lay eggs? The development of a frog from eggs to individuals in an unnatural habitat under different external conditions.

Frogs can breed when they reach four years of age. Waking up after hibernation, mature amphibians immediately rush to spawning ponds, where there is a search for a suitable size partner. 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 boyfriend that she liked, they begin to look for a place for laying eggs and their fertilization.

Courtship games

Vote

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

Courtship

• Appearance and coloring.

Males of many species of frogs, for example, tropical frogs, during mating season change their color, turn black. In males, unlike females, the eyes are larger, the sensory organs are better developed and the brain is enlarged, respectively, and the forelegs are decorated with the so-called mating corns, which are necessary for mating so that the chosen one could not escape.

• Dance

The attention of females can be attracted and various movements. Colostethus trinitatis just jumps rhythmically on a branch, and Colostethus palmatus become in elegant poses when they see a female on the horizon, and other species that live near waterfalls manage to wave their legs to the females.

Males Colostethus collaris perform a dance during courtship. The male creeps to the female and croaks louder and faster, then crawls away, sways and bounces, while freezing on its hind legs in an upright position. If the female is not impressed with 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 to better see the male’s game.

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

In the woodpeckers of gold, on the contrary, females fight for males. Finding a male who croaks, the female claps its hind legs on its body and puts its front paws on it, it can also rub its head on the male's chin. The male with less ardor answers the same, but not always. Many cases have been recorded when this species of amphibians had fights both between females and males for the partner they liked.

Fertilization or how frogs breed

External fertilization

Most often, frogs have this type of fertilization. The smaller male tightly clasps the female with its front paws and fertilizes the female sweeping eggs. The male embraces the female in the position of the amplexus, which there are three options.

1. After the front legs of the female, the male makes a girth (sharp-faced frogs)
2. The male embraces the female in front of the hind limbs (scaphiopus, garlic)
3. There is a girth of the female by the neck (poison frogs).

Fertilization occurring inside

  Few poisonous frogs (for example, Dendrobates granuliferus, Dendrobates auratus) are fertilized in a different way: the female and male turn their heads in opposite directions and connect the cesspools. In the same position, fertilization occurs in amphibians of the species Nectophrynoides, which first carry eggs and then tadpoles in utero until the metamorphosis process is completed and give birth formed completely frog.

Tailed male frogs of the genus Ascaphus truei have a specific organ for reproduction.

During the breeding season in males quite often specific mating calluses form on the forepaws. With the help of these corns, the male rests on the slippery body of the female. Interesting fact: for example, in an ordinary toad (Bufo bufo), a male climbs a female far from a reservoir and rides on it several hundred meters. And some males can ride a female after the pairing process is completed, waiting for the female to form a nest and lay eggs in it.

If the mating process proceeds in water, the male can hold the spawned eggs by the female, pressing her hind legs in time to fertilize the eggs (view - Bufo boreas). Quite often, males can mix up and climb on males who clearly don't like it. The “victim” reproduces a specific sound and vibration of the body, namely the back, and forces you to get off your body. Females also behave at the end of the fertilization process, although sometimes the male can let the female go when she feels that her abdomen has become soft and empty. Quite often, females actively shake off males, which are too lazy to climb off, turning to one side and stretching the hind limbs.

Coitus - Amplexus

Types of Amplexus

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

  For the entire period of carrying tadpoles, and it lasts two months, the frog does not eat anything, while retaining activity. During this period, she uses only the internal reserves of glycogen and fat, which is stored in her liver. After the process of carrying a frog, the liver is reduced three times in size and there is no fat left on the stomach under the skin.

After laying eggs, most females leave their clutch, as well as spawning waters, and go to their usual habitat.

Females usually surround eggs with large gelatinous substance. The egg shell plays a large role, as the egg is protected from drying out, from damage, and most importantly - it protects it from being eaten by predators.

After laying, after some time, the shell of the eggs swells and forms into a transparent gelatinous layer, inside of which the egg is visible. The upper half of the egg is dark, and the lower half, on the contrary, is light. The dark part heats up more, since it uses the rays of the sun more efficiently. In many species of amphibians, clumps of caviar float to the surface of a reservoir, where the water is much warmer.

Low water temperature delays embryo development. If the weather is warm, the egg divides multiple times and forms into a multicellular embryo. Two weeks later, a tadpole comes out of the eggs - a frog larva.

Tadpole and its development

  After leaving caviar the tadpole falls into the water. After 5 days, having spent the supply of nutrients of eggs, he will be able to swim and eat on his own. He forms a mouth with horny jaws. The tadpole feeds on the simplest algae and other aquatic microorganisms.

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

The head of the tadpole is large, there are no limbs, the tail end of the body plays the role of a fin, a lateral line is also observed, and a suction cup is located near the mouth (the genus of the tadpole can be identified by the suction cup). Two days later, the gap around the edges of the mouth is overgrown with some kind of bird's beak, which acts as a nipper when the tadpole feeds. Tadpoles have gills with gill openings. At the beginning of development, they are external, but in the process of development they are modified and attached to the gill arches, which are located in the pharyngeal region, while functioning as normal internal gills. The tadpole has a two-chamber heart and one circle of blood circulation.

According to the anatomy, the tadpole at the beginning of development is close to fish, and having matured, it already resembles the appearance of reptiles.

After two or three months, the tadpoles grow back and then forepaws, and the tail is first shortened and then falls off. At the same time, lungs also develop.. Having formed for breathing on land, the tadpole begins its rise to the surface of the reservoir in order to swallow air. Change and growth depend largely on hot weather.

Tadpoles at first feed mainly on food of plant origin, but then gradually move on to food of an animal species. The formed frog can go ashore if it is a land species, or it remains to dwell in water if it is an aquatic species. Frogs that climbed onto land are yearlings. Amphibians laying eggs on land sometimes proceed to development without a process of metamorphosis, that is, through direct development. The development process takes about two to three months, from the beginning of laying eggs to the end of the development of the tadpole into a full frog.

Dart frog amphibians  exhibit interesting behavior. After the tadpoles hatch from the eggs, the female on her back, one by one, transfers them to the tops of the trees in flower buds in which water accumulates after rain. Such a peculiar pool is a good children's room where children continue their growth. Unfertilized eggs serve as food for them.

The ability to reproduce in cubs is achieved approximately in the third year of life.

After the breeding process green frogs remain in the water or stay on the shore of a nearby reservoir, while brown go to land from a reservoir. The behavior of amphibians is largely determined by humidity. In hot, dry weather, brown frogs are mostly inconspicuous, as they hide from the sun. But after sunset, they have time to hunt. Since the green frog species lives in or near the water, they also hunt in the daytime.

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

• HAPPY BIRTHDAY, FROG!
• The birth of a frog most often occurs in ponds, lakes and other standing water bodies, as it is here that adult animals lay eggs.

• Happy birthday frog!

  Happy birthday frog!
• Soon tadpoles emerge from the eggs, which after a while will turn into frogs.
• You can read more about this.
• But all this is true only for our ordinary species, and in tropical rainforests, where the number of species even in a small area is in the tens, everything is completely different.
• Where the frogs are visible and invisible, hunters for themselves, caviar and tadpoles will certainly appear. What to do? How to protect your offspring? To protect eggs from voracious predators, some frogs adapted to lay eggs on land.
• BEST INVENTIONS OF NATURE.
• The female "glass" frog places eggs in the form of a gelatinous mass on the lower surface of a leaf hanging over a pond.
• The male guards the masonry until the tadpoles appear. Coming out of the eggs, they slide off the leaf and fall into the water, where the transformation soon takes place - the birth of a frog.

• Glass Frog Caviar

  Glass Frog Caviar
• Mother nature is designed so that no living creature can find an absolutely reliable way to protect against predators.
• And yet, caviar laid on leaves or ground is less at risk than placed in water.
• To confuse predators, many species of tropical frogs lay their eggs in the most unexpected places.
• FOAMY HOUSE.
• South African frogs arrange a foam house for their offspring. When it comes time to lay eggs, they gather on the branches of trees hanging over any body of water.
• A special viscous liquid is secreted on the female branch, and males whip it into foam, working with its hind legs. In such a foamy nest, females lay eggs to continue their kind and the birth of babies. The outer layers of foam dry out, and the laid caviar is protected from all sorts of troubles.

• Foam house

  
  Foam house
• Despite the seeming insecurity, the foam house is one of the best inventions in the animal world. Firstly, the foam smooths out changes in temperature and humidity, and secondly, it does not cause suspicion among predators: there is hardly anything edible hidden inside.
• A few days later, tadpoles hatch from the laid eggs, the nest begins to decay, they go outside and fall into the water, where then the frog is born.
• This method of survival is used not only by frogs, but also by many insects - circadian plants, grasshoppers and.
• OWN SWIMMING POOL.
• And South American poison frogs (familiar with their toxicity) have adapted to carry cubs on their backs. First they lay eggs on moist soil and zealously guard future offspring. Then, the hatched tadpoles sit on the back of the parent and the adult frog with its burden climbs the tree.

• Own pool

  
  Own pool
• But why? She searches for bromeliad - a plant that attaches to a tree, where the leaves at the base form a funnel, where water collects during the rains, and high up in the branches a kind of small pond is formed. When the poison frog finds a suitable pond, the tadpoles detach and fall into the water.
• It is not easy for predators to climb into such a shelter, and tadpoles can quietly develop.
• HOW DO KANGAROO?
• Dwarf marsupial tree frog has a completely unusual way of having offspring. Delayed caviar develops in a special skin pocket in the protrusions on the back of the female. Here, future babies are protected from enemies and from drying out.
• When the time comes for the tadpoles to be born, the female finds the same bromeliad and descends into the water. Water entering the bag serves as a signal for tadpoles to exit.

• Marsupial tree frog

  
  Marsupial tree frog
• One of the types of marsupial tree frogs also has a skin fold - like a kangaroo bag - only located backwards. Laying eggs, mother-tree frog with her hind legs places her in her pocket and the hatched tadpoles remain in the same place.
• Only having turned into frogs, they leave a reliable shelter.
• MIRACLE CAVIAR.
• The birth of a rain frog takes place in its own way: the female lays eggs on a forest litter - in moss, under pretty leaves, by a stream where it does not threaten to dry.
• The eggs of this frog (compared to others) are huge in size with a supply of nutrients.

• Miracle Caviar

  Miracle Caviar
• Therefore, the tadpole can remain in the egg longer than usual - because he does not have to take care of his food.
• Without leaving the eggs, the tadpole turns into a small, fully-formed frog, ready for adulthood.
• Took and swallowed!
• But Darwin's tree frog literally swallows its offspring, but not in order to eat, but in order to protect future frogs.

• Tree frog Darwin with a newborn

  
  Tree frog Darwin with a newborn
• The female lays eggs on the ground, and the male sits down to guard her and, as soon as the tadpoles come out, he puts the eggs in a special pocket in his throat.
• They remain there until they turn into little frogs, and then they get out and begin an independent life.
• So, in completely different ways, a frog is born.

Most amphibians are extremely caring parents, trying to give their offspring the best chance of survival. When the frog spawns, it does everything possible to protect its offspring, because the future generation can become a nutritious snack for many species of underwater predators.

When frogs lay eggs, they can follow a variety of strategies to achieve maximum survival of their offspring. It is worth noting that currently more than 500 species of frogs are described, and these animals live almost everywhere. Most species of frogs live in forests, deserts, shrouds and mountains of Africa, but also in the Northern Hemisphere, where the living conditions in water bodies are much more severe, there are many representatives of this order. Given the difference in habitats, different species of frogs choose the most suitable strategies for breeding offspring. In most species of frogs, the reproductive system is based on external fertilization. With this type of fertilization, the female first releases the eggs, and then the male fertilizes her.

It is worth noting that in most species of frogs, males are smaller than females, but it is they who engage in attracting partners during mating. To attract females during the mating season, males use special vocal cords or throat bags that allow them to make loud noises. Mating games in different species of frogs have slight differences. For example, males of the muzzle frog, which lives in marshy areas of the northern hemisphere, during the breeding season change their color to blue, and also emit a very intense croaking. Females of this species are not legible, therefore, the entire surface of the water is soon covered with a layer of caviar.

One sharp-mouthed frog can lay about 3 thousand eggs, but only 2-3% of them have reached adulthood. In the northern hemisphere, where the boundaries of the seasons are clearly visible, frogs, as a rule, start throwing eggs only when the water temperature reaches 5-7 ° C. For some freshwater frogs, the optimal temperature for laying eggs is more than 10-12 ° C. In ordinary pond frogs, after 7 days, tadpoles are removed from the eggs, which require at least 3-4 months to turn into adults. Frogs in the northern hemisphere have to carefully check their masonry time, since only in this case the eggs will not die during spring freezing, but the tadpoles will have time to become adults before they hibernate.

Many frogs try to lay eggs at the same time as other members of their family, including tree frogs and toads. The simultaneous appearance in the water of a large amount of caviar allows the survival of more tadpoles, since predators are simply not able to eat them all at once.

Many species of frogs lead a land lifestyle, but at the same time return to water bodies only for the breeding season. However, not all frogs lay their eggs directly in the pond. For example, many species of tropical frog-frogs spend their whole lives in trees, so finding a pond would be too difficult for them. All at the same time rainforests  characterized by high humidity. It rains so often that there is no need to find a reservoir.

Dart frogs solve the reproduction problem in different ways. Some species during the breeding season gather in tall grass and shrubs, where males try to take the highest place so that they can be heard at a greater distance. Females appear much later than males and try to find the largest partner, located on top of a bush or grass. After the female finds a suitable partner, he climbs onto her back, after which she jumps onto a vertically hanging leaf. When the frog lays eggs, the male fertilizes it and at the same time, with its hind legs, on which there are special glands secreting sticky mucus, fastens the edges of the leaf. Thus, the tree frog roe ripens in a special hammock.

After heavy rains begin, the sticky mucus is washed off the leaf and the hatched tadpoles slide down, falling into a vast puddle or swamp. This is not the only tree frog protection strategy for offspring. Some species of these amphibians behave completely differently. For example, some frog frogs after fertilization move their eggs in a kind of nursery, which are located in the axils of the leaves of plants filled with water. Often, frogs choose lilies and heliconiums as such nurseries. In such a small pond, located between the stem of the plant and the leaf, the frog places only one egg.

The female can travel long distances, first distributing her eggs over different plants, and then, bringing food to the tadpoles that were born. Such a strategy reduces the risk of predators attacking both spawn and tadpoles, providing high productivity for the whole species. Another remedy for caviar produced by tree frogs is poisonous mucus, which scares away predators of any kind.

Frogs are among the most ancient amphibians, since they appeared about 300 million years ago. The success of these living creatures is largely due to their high productivity, because a large number of caviar produced leads to the fact that at least part of the tadpoles survive and become adults.

The method of propagation of frogs is extremely primitive, but at the same time it is so effective that in the process of evolution it underwent almost no changes. That is why the loud croaking of male frogs during breeding spills over almost all the water bodies on the planet.

What does a frog look like - everyone knows. And how is the birth of a frog? Is it true that different types of frogs reproduce and care for their offspring in different ways?

In this article we will talk about how nature arranged the process of the birth of the most. Typically, these amphibians are born in a pond or lake. The female frog leaves eggs only in stagnant water. After a certain period of time, tadpoles appear from the laid eggs, then they turn into small frogs ... so we used to think when looking at the frogs that live in our country, but in reality ...

In fact, not all species of frogs reproduce equally. The main "innovators" in the reproductive sphere are those frogs that live in the tropics. Firstly, the number of species of tailless amphibians that we are talking about in tropical areas  exceeds all conceivable ideas. A large number of predators, every now and again wanting to eat frog eggs, makes these amphibians invent various ways to save future offspring.

The birth of glass frogs

Females produce eggs that look like gelatinous mass. This "mass" is attached to the back of the sheet (it is important that the sheet is located directly above the water). The father of the family becomes a guard for future offspring. When the tadpoles come out of the eggs, they slide off the leaf directly into the pond and there is already a further transformation into an adult.

The birth of a South African frog

Have you heard of the “foam houses”? This is not just an unusual substance, but a real shelter in which South African frogs hide their eggs. How is foam formed? In order to create such a "house", the female frog secretes a special substance, and the hardworking male whips it into foam. The top layer of the foam house hardens, and the eggs can comfortably continue to develop inside without fear of being eaten.

The birth of poisonous poison frogs

Poisonous South American frogs also give their offspring life in an unusual way. They, like their other relatives, lay eggs (placing it on moist soil). Then they carefully and very zealously guard the eggs. Well, when the tadpoles emerge from the eggs, they immediately climb onto the back to their parent. What for? To move from earth to tree. Having found the leaves of the bromeliad plant (which winds around the trees), the mother frog places the tadpoles in the funnel located at the base of the bromeliad leaf (where water always accumulates after rains). Here the tadpoles find temporary shelter until their parent finds a nearby body of water and transfers them into it for subsequent maturation.

The birth of dwarf marsupial tree frog

Yes, yes, you didn’t hear exactly “marsupial”. By the way, the birth of cubs in this frog is similar to the method of reproduction in a kangaroo. The frog has a special leather pocket, where the laid eggs are placed. Unlike a kangaroo, a tree frog pocket is on the back. So a caring mother carries her future babies until the time comes for them to become tadpoles. Then tree frog carries future frogs to the reservoir and releases them.

The birth of a rain frog

The unusual arrangement of the eggs of these frogs allows you to be born not as a tadpole, but immediately as a small adult. The fact is that the internal composition of the egg is such that it has a sufficient supply of nutrients so that the tadpole feeds and survives until it turns into a frog, without leaving the egg shell.

This spring, I looked at the frog’s caviar in a ditch on the plot and thought how to show Masha how the frogs emerge from the eggs. But she was afraid that I would destroy the future "princes" and "princes")).

But now, thanks to this article, I am theoretically savvy, and I’ll definitely arrange a frog incubator in the country next spring. We will observe how frogs are made from eggs.

Grass frog is the most common amphibian of the middle strip of our country. She is painted in a greenish-brown color with all kinds of stains. It usually lives in river floodplains, in forests, and quite far from water bodies. She is most active at dusk and at night, and spends the day in forest litter. During rain and cloudy weather it can be found during the day. The grass frog eats all sorts of insects, mollusks, and worms, and those inedible species that birds avoid are also eaten. They are happy to catch mosquitoes who are trying to drink her blood.

They are associated with water bodies only in early spring (during the breeding season) and in winter. At the end of September, they move to their native pond for wintering. They climb under the snag at the bottom of the pond and fall asleep until next spring. There was a time when there were a lot of grass frogs in Moscow, especially in the floodplains of the rivers. Now they have become much less. The reason is commonplace - environmental degradation.

Frogs are food for many animals and birds. They enjoy eating foxes, badgers, martens, storks, owls and ... even hedgehogs. Thus, the energy stored in small animals (insects, mollusks, bugs, worms), through frogs enters a higher trophic level.

***
  Frogs are an interesting object of observation of the development of the body - from eggs to adult animals. This is a fascinating sight when a small frog is obtained from the eggs in a fairly short time. If a child is fond of biology at home, he can be invited to conduct such an experiment with nature. Moreover, this biological "show" can be said to be free. It will "take" the child for several months. For this, frog caviar is used, which is collected in ponds, small lakes, and rivers.

Grass frog lays eggs in late April (in central Russia) in shallow areas of ponds, ditches and puddles. In the southern regions - a little earlier. The masonry is usually in the form of a mucous lump containing up to 1000 or more eggs. Tadpoles develop from eggs, and then small frogs develop.

Specialists noticed that twenty years ago, hatching tadpoles from eggs in the city was almost one hundred percent. All the tadpoles were like picks. Recently, the hatching percentage has sharply decreased, among the tadpoles freaks (one-eyed, with two tails, with one external gill, etc.) began to appear, which, in the end, died. Many tadpoles die without completing their development - turning into a small frog. All this is associated with severe pollution of urban water bodies. However, for the sake of the child, you can go somewhere further away from the city, where in any pond you can collect decent frog caviar.

Frogs are interesting in that any person (even a schoolboy) can bring frogs out of their eggs at home, and then release them into a pond. There is nothing complicated, just need to know some basic rules.

The spawning period in frogs begins in April and lasts about a week, after which adults leave the pond and settle. And caviar, accordingly, remains. Frogs return to the reservoir only in autumn.

It is necessary to take 1-2 lumps and place them in a small vessel (cup, basin) with a depth of about 10 cm. After 1-2 days, embryos begin to develop from the eggs. In the beginning, these will be small black dots inside the eggs (see the picture), then something similar to a fish, and then you can already see inside the eggs a creature that looks like a small tadpole.

After about 7-10 days (depending on the temperature of the water) small tadpoles come out of the eggs. On the sides of the head they have branched external gills with which they breathe. The first days of the tadpole rest on aquatic plants, attaching to them with a suction cup. Soon their mouth cuts out, surrounded by horny jaws, with which they scrape off leaves of fouling and pieces of the plants themselves.

I recall a case. We lived at a biostation, cooked food in the kitchen, and washed dishes in the lake. There were a lot of tadpoles that year that “helped” us wash dirty dishes. They stuck around plates, pans, pots and ate the remnants of food. At such nutritious food, they quickly grew and left the pond much earlier (as it seemed to us) than the frogs from neighboring plots that were not fed.

There must be a bush in the vessel water plantfor example, elodea, from which tadpoles scrap off algae and bacteria. In laboratory conditions, tadpoles are fed with boiled egg, dried milk, nettle broth (small leaves are steamed with boiling water), bread. At this stern they grow rapidly. However, it must be borne in mind that such food quickly rots, so it must be given little by little and periodically removed.

You can observe daily how the further development of tadpoles proceeds. External gills do not last long. Then the tadpoles develop gill slits with internal gills, like fish. He himself and outwardly becomes like a small fish. This kind of tadpole lasts about a month. Then he develops the hind limbs, and then the forelimbs.

The lungs begin to develop, and the tadpole periodically rises to the surface to breathe them. At this time, it is necessary to put green leaves floating on the surface of the water in the vessel so that the tadpoles can comfortably get out on them. His tail gradually decreases, and his mouth, on the contrary, expands. Now the tadpole already resembles a frog in appearance. The frogs must be transferred to a vessel with high sides so that they do not run away. A similar incident happened at our place, they overlooked and the frogs ran around the apartment. I had to get them from all angles and crevices.

At this time, frogs do not eat anything. The size of such frogs reaches 2 cm, only a small tail reminds that it is a former tadpole. At this age, they can be released into the reservoir, because having problems with feeding. At this time, they switch to animal feed - eat insects. But, if it is possible to grow small Drosophila flies, you can continue the process of observing small frogs. In our laboratory, there were several large frogs that we fed crickets (bought at a pet store).

Full development - from eggs to frogs - takes 2.5-3 months and depends on water temperature and feed quality. Next, frogs begin a life full of dangers. They become adults only in the third year.

Immediately I want to ask a question, but what fairy-tale princess frog was of what kind? Most likely, it was a grass frog. Tsars in Russia have always lived in the middle lane, and only lake, pond, muzzle and grass frogs live here. The first two - they spend their whole lives in water and do not go far from water bodies. And the princess frog, as you know, moved to the royal chambers. The sharp-mouthed frog is one and a half times smaller than the grassy one, and it could hardly cope with the arrow, and its number is much smaller than the grassy one.

***
  Observing the development of frogs is an amazing sight. It allows you to understand how the development of a living creature occurs from an egg. In your eyes (in front of the eyes of a child), a living being develops. Mammals, including humans, develop in approximately the same way. After all, they all swim in the water until they exit the womb of the mother. These observations help to understand the origin of terrestrial vertebrates, which include amphibians.

Amphibians live on land, and breed in water. Here live their tadpoles, similar to fish (both in appearance and in internal structure). This similarity leads to the conclusion about the kinship of amphibians and fish. The transitional form between fish and amphibians is the brush-headed fish, which were believed to have died out over 100 million years ago. However, in 1938, the first specimen of such a fish, which was called coelacanth, was caught in the Atlantic Ocean off the southern coast of Africa.

***
  So, dear parents, get your children a live "toy", frog caviar, which will captivate the children for several months, and maybe for life.

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  When implementing the project, state support funds allocated as a grant in accordance with the order of the President were used Russian Federation  dated March 29, 2013 No. 115-rp ") and based on a competition held by the Knowledge Society of Russia