• HAPPY BIRTHDAY, FROG!
• The birth of a frog most often occurs in ponds, lakes and other standing bodies of water, because This is where adult animals lay their 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 this is all true only for our ordinary species, and in tropical rain forests, where the number of species is even higher small area numbers in the dozens, everything is completely different.
• Where frogs are visible or invisible, hunters for frogs, eggs and tadpoles will certainly appear. What to do? How to protect your offspring? To protect eggs from voracious predators, some frogs have adapted to lay eggs on land.
• NATURE'S BEST INVENTIONS.
• The female glass frog places her eggs in the form of a gelatinous mass on the undersurface of a leaf hanging over a pond.
• The male guards the clutch until the tadpoles emerge. Having emerged from the eggs, they slide off the leaf and fall into the water, where a transformation soon occurs - the birth of a frog.

• Glass frog roe

  
  Glass frog roe
• Mother Nature is designed in such a way that no Living being cannot find an absolutely reliable method of protection from predators.
• And yet, eggs laid on leaves or ground are less dangerous than those placed in water.
• To confuse predators, many species of tropical frogs lay their eggs in unexpected places.
• FOAM HOUSE.
• South African frogs make a foam home for their young. When the time comes to lay eggs, they gather on tree branches overhanging any body of water.
• Females secrete a special viscous liquid onto the branch, and males whip it into foam, working with their hind legs. Females lay eggs in such a foam nest to continue their race and give birth to babies. The outer layers of the foam dry out, and the laid eggs are protected from all sorts of troubles.

• Foam house

  
  Foam house
• Despite its apparent unreliability, a foam house is one of the best inventions in the animal world. Firstly, the foam smoothes out changes in temperature and humidity, and secondly, it does not arouse suspicion among predators: there is unlikely to be anything edible hidden inside.
• After a few days, tadpoles hatch from the laid eggs, the nest begins to disintegrate, they come out and fall into the water, where the frog is then born.
• This method of survival is used not only by frogs, but also by many insects - leafhoppers, grasshoppers, etc.
• YOUR OWN POOL.
• And South American poison dart frogs (known for their poisonousness) have adapted to carry their young on their backs. First, they lay eggs on moist soil and jealously guard their future offspring. Then, the hatched tadpoles sit on the back of the parent and the adult frog climbs the tree with its burden.

• Your own pool

  
  Your own pool
• But why? She is looking for a bromeliad - a plant that attaches to a tree, where the leaves at the base form a funnel, into which during rains water is collected, and high in the branches a semblance of a small pond is formed. When the dart frog finds a suitable body of water, the tadpoles detach and fall into the water.
• It is not easy for predators to get into such a shelter, and the tadpoles can develop peacefully.
• LIKE A KANGAROO?
• The dwarf marsupial tree frog has a completely unusual way of giving birth to offspring. The laid eggs develop in a special skin pocket in the protrusions on the female's back. 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 goes down into the water. The water penetrating the bag serves as a signal for the tadpoles to go outside.

• Marsupial tree frog

  
  Marsupial tree frog
• One of the species of marsupial tree frogs also has a skin fold - like a kangaroo's pouch - only located with the entrance at the back. When laying eggs, the mother tree frog uses her hind legs to place them in her pocket, and the hatched tadpoles remain there.
• Only after turning into frogs do they leave their safe shelter.
• MIRACLE CAVIAR.
• The birth of a rain frog occurs in its own way: the female lays eggs on forest floor- in moss, under rotten leaves, near a stream, where there is no danger of drying out.
• The eggs of this frog (compared to others) are enormous in size with a reserve nutrients.

• Miracle caviar

  Miracle caviar
• Therefore, the tadpole can remain in the egg longer than usual - after all, it does not have to worry about its food.
• Without leaving the egg, the tadpole turns into a small, fully formed frog, ready for adult life.
• TOOK IT AND SWALLOWED IT!
• But Darwin's tree frog literally swallows its offspring, but not in order to refresh itself, but in order to protect future frogs.

• Darwin's tree frog with newborn

  
  Darwin's tree frog with newborn
• The female lays eggs on the ground, and the male sits down to guard her and, as soon as the tadpoles are about to emerge, he places the eggs in a special pocket in the throat.
• They stay there until they turn into little frogs, and then they get out and begin an independent life.
• So, in completely different ways, the birth of a frog occurs.

Everyone in the world knows what a frog looks like. How is a frog born? Is it true that different species of frogs reproduce and care for their young differently?

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 standing water. After a certain period of time, tadpoles emerge from the laid eggs, then they turn into small frogs... that’s what we used to think when looking at the frogs living in our country, but in reality...

In fact, not all frog species 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 we are talking about is tropical zones exceeds all imaginable ideas. A large number of predators, every now and then wanting to feast on frog eggs, forces these amphibians to invent the most different ways save future offspring.

The Birth of Glass Frogs

Females produce eggs, which look like a 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 emerge from the eggs, they slide off the leaf directly into the pond and further transformation into an adult takes place there.

Birth of the South African frog

Have you heard of “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. Upper layer The foam house hardens, and the eggs can comfortably continue to develop inside without fear of being eaten.

The birth of poison dart frogs

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

Birth of the dwarf marsupial tree frog

Yes, yes, you heard right “marsupial”. By the way, the birth of babies in this frog is similar to the method of reproduction in a kangaroo. The frog has a special pocket made of skin where the laid eggs are placed. Unlike a kangaroo, the tree frog's pocket is on its back. This is how a caring mother carries her future babies until the time comes for them to become tadpoles. Then the tree frog takes the future frogs to the pond and releases them.

Birth of the rain frog

The unusual structure of the eggs of these frogs allows them to be born not as a tadpole, but immediately as a small one. adult. The fact is that the internal composition of the egg is such that it has a sufficient supply of nutrients for the tadpole to feed and survive until it turns into a frog, without leaving the egg shell.

The lesson allows you to repeat and expand children’s ideas about amphibians and their habitats, enrich their knowledge with new information about the life of frogs, teaches them to speak out, and fosters a caring and environmentally literate attitude towards animals.

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Lesson summary for preparatory group children

"HOW A TADPOLE TURNES INTO A FROG"

Main educational field: "Cognition"

Target: To arouse children's interest in objects of living nature, to form their ideas about the stages of development of some animals.

Equipment, materials, tools:Audio recording of frogs croaking, figurines of toy frogs, pictures depicting the stages of frog development (egg embryo - tadpole without legs - tadpole with two legs, tadpole with four legs and a tail - adult frog)

Progress of the lesson:

The teacher asks a riddle:

Shiny, big-eyed,

Lives in the lake, swims on the water.

He sits on the shore, looking at mosquitoes.

Green frog - big-eyed...

Children answer: frog

Educator: Children, do you know how frogs “talk”?

After the children’s answers, the teacher listens to an audio recording with the voices of frogs and shows figurines of toy frogs.

Then he shows a picture of tadpoles and asks the children if they know who is drawn in the picture and explains that this creature is called a tadpole because it has a large head.

The teacher explains that frogs in childhood are not very similar to adult frogs and invites the children to determine how a tadpole is and is not similar to an adult frog.

Then he invites the children to listen to a story about how frogs are born, which is accompanied by showing pictures and depicting the stages of frog development:

In one quiet transparent lake lived a large green frog. She really wanted to have baby frogs. Once spring came, the frog laid small transparent balls - eggs - on the shore of the lake. After some time, creatures with a small body, a large head and a tail emerged from the eggs. At first they didn’t even like the frog, because they weren’t very similar to their mother. After all, the frog itself did not have a tail, and its head was not that big, and most importantly, it had four legs. The tadpoles swam, ate and grew. Some more time passed, and first their hind legs appeared, and then their front legs. Now they had become more like an adult frog, although they still remained tadpoles with tails. Their mother couldn’t wait for the tadpoles to finally turn into real frogs. But the moment has come: the tadpoles have grown and become beautiful, green frogs with four legs and no tails. In the evenings they croaked with their mother, who was very proud of them.

After the story, the teacher discusses with the children how to arrange the cards depicting the stage of frog development so that they reflect what happened in the story. In conclusion, he emphasizes that frogs grow from tadpoles, which in turn emerge from eggs.

It is in the spring, in lakes, ponds, puddles, that you can see sticky, transparent balls with a black dot - frog eggs. At the end of the lesson, he invites the children to show how frogs jump and croak, and how tadpoles swim.

Among the many animals, only the so-called invertebrate animals reproduce asexually. Vertebrates - such as mammals, fish, reptiles, birds and amphibians - reproduce sexually: sperm and eggs, carrying hereditary material typical for a given animal species, are united during fertilization. A fertilized egg is called an embryo.

Depending on the species of animal, the embryo can develop both inside and outside the mother's body. Gradually, small cubs develop from fertilized eggs in accordance with the genetic instructions embedded in it. Many, such as frogs, go through one more stage of development before becoming fully grown.

From egg through larva to adult animal

Snails live on land, in running water and in the seas. Sea slugs lay eggs in sea ​​water, which after high tide get stuck between the rocks. From fertilized eggs, larvae (veligers) emerge that can swim. They swim with the current and finally sink to the rocky bottom, where they develop into adult crawling clams.

Fertilized egg

The red spot in the middle of the egg yolk is a three-day-old chicken embryo. After a week, the embryo already takes the shape of a chicken. After a month, the chicken is already fully developed and covered with delicate down. With the egg tooth on his beak, he breaks the egg shell and comes out into the light. The chick hatches and becomes an adult without any additional developmental stage.

From egg to tadpole

During mating season, many frogs gather in large, noisy groups. Females respond to loud calls from males. Only a few species of frogs give birth to live young; most species lay eggs (spawn) in or near water. The number of eggs depends on the type of frog and ranges from one to twenty-five thousand. Typically, the eggs are fertilized outside the frog's body and left to fend for themselves. When the egg matures, a small tadpole hatches from it. Tadpoles live in water and breathe through gills, like fish. In only a few species of frogs, females care for their young.

Frogs and toads

Unlike adult frogs, tadpoles are herbivorous and feed on aquatic plants and algae. After a certain time, an amazing transformation (metamorphosis) occurs in the development of the tadpole: fore and hind limbs appear, the tail disappears, lungs and eyelids develop, and new systems digestion, designed to digest animal food.

The conversion rate is different for different types, the main factor here is water temperature. In some toads and frogs, metamorphosis occurs in a few days or weeks, while in others it takes several months. The tadpole of the North American bullfrog takes a year or more to fully develop.

Frogs and toads belong to the class of amphibians and to the same group of tailless amphibians, but they differ appearance and way of life. Frogs have soft skin and are good jumpers, while toads are covered in warts and tend to crawl. There are more than 3,500 species of frogs and toads on earth. With the exception of Antarctica, they can be found on all continents. They prefer to live in tropical and subtropical zones, where more than 80% of all species live. But no matter where they live, in deserts or mountains, savannas or tropical rain forests, they must return to water to procreate.

What is metamorphosis

In their development, frogs go through three stages: from egg to tadpole, and then to adult frog. This developmental process is called metamorphosis. Many invertebrates also go through the larval stage in their development. However, the most amazing changes occur in the lives of insects: butterflies and beetles, flies and wasps. Their life is divided into four stages, very different from each other in their feeding method and habitat: egg, larva, pupa, adult insect. The larva looks completely different from the adult insect and does not have wings. Her life is completely focused on growth and development, and not on procreation. Only after the larva pupates does it become an adult insect.

Frogs are the most well-known tailless amphibians. They occupy an intermediate place between terrestrial and aquatic vertebrates.
The life of amphibians deserves attention, primarily because they occupy a special place in the history of the development of terrestrial vertebrates, being the first and most primitive inhabitants of land. Assess the importance of amphibians in nature and economic activity human beings is possible with further study of amphibians, the biology of which has been developed only extremely superficially. The use of this animal to study biological issues gave recognition to the frog's enormous merits in medicine.

Firstly, the lake frog is a destroyer of harmful animals. This representative of the amphibian order as an adult feeds exclusively on animal food and, living in a wide variety of places, brings benefits by eating harmful insects. The importance of amphibians also increases because they eat insects in greater numbers than birds. unpleasant smell and taste, as well as insects with a protective coloring. Special attention deserves the fact that land species Amphibians are hunted at night, when the vast majority of insectivorous birds are asleep.

Secondly, amphibian frogs are a food source for some fur-bearing animals. Frogs make up more than one third of all mink food, a valuable fur-bearing animal confined to water bodies. The otter also readily eats amphibians. Amphibians are relatively often found in the stomachs of badgers and black polecats. Finally, many commercial fish In lakes and rivers in winter, frogs are eaten in large quantities, which turn out to be quite accessible mass food.

Of course, there are also negative aspects when frogs destroy young fish in large quantities. Attracted by clusters of fry, numerous lake frogs turn out to be their main enemies here.

In some cases, frog tadpoles can compete with fish for food. Behind Lately indications have appeared of the negative significance of amphibians in nature as guardians of dangerous infectious diseases, such as tularemia.

Third, amphibians are valued as laboratory animals. The ease of dissection of the frog, its suitable size and vitality have made it a favorite experimental subject for a long time. Most devices in experimental medicine and biology are designed for this animal. The technique of physiological experiment is constantly being developed on the frog. A huge number of experiments and observations have been and are being carried out on these “martyrs of science.” Laboratories of large educational and scientific institutions consume tens of thousands of frogs per year. This expense can be so great that it becomes necessary to take measures so as not to destroy all the animals. Thus, in England, frogs are now protected by law, and catching them is prohibited.

Thus, the question arises about the relevance of raising frogs in an artificial environment.

All this made it possible to determine the topic of scientific work.

Purpose of the study: find out under what different, artificially created conditions, the frog larva will go through all stages of metamorphosis faster.

Research objectives:
1. Study scientific literature on biology;
2. Identify the reasons for positive and negative influences environment for development;
3. Conduct research work.

Object of study: caviar of a common frog.

Hypothesis: Various external conditions affect the development of a frog from egg to individual in an unnatural habitat. If you create all the necessary conditions, you can achieve the maximum percentage of tadpole survival.

Reliability of results is ensured by the personal participation of the author in the research process.

Lake frog

Description

Lake frog- a species of tailless amphibians of the family of true frogs. The lake frog is the largest species of amphibian fauna in Russia: its body length can reach up to 150 mm.

Anurans are the largest order of amphibians, numbering about 6,000 modern and 84 fossil species. Representatives of the order are often called frogs, but the use of this term is complicated by the fact that frogs in in the narrow sense only representatives of the family of true frogs are named. The larvae of tailless amphibians are tadpoles.

Class - Amphibians, order - Tailless, family - Frogs, Genus - Frogs.

Size 6-10 cm. Average weight 22.7 gr. The muzzle is blunt, the body is squat. The eyes are brown with black horizontal pupils. The inner eyelid is transparent, protecting the eyes in water. A dark brown triangle is clearly visible near the eardrum. The skin of a frog is slimy and smooth to the touch; its epidermis does not keratinize. There is a marble-like pattern on the dark belly. The internal calcaneal tubercle is low.

In males, external resonators of a dark gray color are located in the corners of the mouth. On the first (inner) finger of the forelimbs of males there is a skin thickening - a callus, which grows during mating.

The class of amphibians requires oxygen to live. The frog can obtain it on land and partially underwater through the skin. The respiratory organs of amphibians, which include frogs, are lungs, skin and gills. Unlike tadpoles, which lead an aquatic lifestyle, adult frogs do not have gills. Oxygen dissolved in water enters the blood of these creatures through the skin. This method of breathing can provide the body with the necessary gas only if the frog is in a state of hibernation.

Frog can long time be under water, because she has very large lungs. Before diving, the animal takes in full lungs of air. Under water, oxygen is absorbed very slowly through the blood arteries, which helps the frog stay under water for a long time. As soon as the air reserves run out, the animal quickly surfaces and holds its head above the surface of the water for some time in order to regain full lungs of air.

Frogs never drink. Liquid enters their body through the skin.

The adult breeds in water, but prefers to spend most of its life on land, choosing very damp and shaded places to live.

On land, frogs hunt by catching insects, which are their main diet. In vegetable gardens located in lowlands near water bodies, fruit trees, shrubs and vegetable crops are almost never affected by pests, since frogs are cleaning animals. Just a few frogs can destroy hordes of insect pests.

Breeding season is April - early May. Reproduction occurs in puddles, ponds, lakes, canals, and in any shallow body of water. Spawning begins 3-5 days after waking up. Males appear on reservoirs earlier; they sing mating songs, inviting females. Having spawned, grass frog does not linger in the reservoir and disperses to summer habitats. The eggs are light yellow in color, surrounded by a thick layer of gelatinous substance. This shell has great importance for the embryo, since in this way the egg is protected from drying out, from mechanical damage, and most importantly, it protects them from being eaten by other animals. They are connected into clusters of quite significant size, and sometimes into cords; a lot of them are put aside. One female lays 670-1400 small eggs.

Use in science

“And how many frogs are countless,
They can be counted and counted endlessly, -
They gave frog legs to science,
They gave their hearts for the benefit of science.”
L. Gainulina

Lake frogs are often captured as laboratory animals for scientific, medical and educational institutions.
For example, students of the Orenburg State Pedagogical University use up to 3,000 individuals of the lake frog to conduct workshops on physiology and zoology during one year of study.

Quite a lot of biologically active substances have been discovered in frogs, but they have been studied much less than those in toads.

It has long been known that if you put a frog in milk, it will not turn sour for a very long time. Modern research The antimicrobial properties of the mucus covering the skin of the frog have been confirmed. This prevents the proliferation of fermented milk bacillus.

A number of substances with biological activity have been extracted from the skin of different species of frogs.

Some of these substances effectively kill bacteria, others have vasodilating properties. A substance with a choleretic effect and also stimulating the secretion of gastric juice was isolated from the skin of the white Australian tree frog. From this substance it is possible to make a drug for the treatment of certain mental illnesses.

Dermorphins were found in the skin of one species of frog, which have an analgesic effect 11 times greater than morphine.

Frog neurotoxins are some of the most powerful. Batrachotoxin, isolated from the Colombian frog, locally called "cocoi", is the most potent of the non-protein poisons, stronger than potassium cyanide. Its action is similar to that of curare.

Substances isolated from some South American tree frogs act on the transmission of nerve impulses in skeletal muscles. Some block smooth muscle receptors, while others cause skeletal and respiratory muscle spasms.

Currently, these substances are not used in medicine; the possibility of including them in clinical practice is being explored.

The antimicrobial and wound-healing properties of frog caviar have been scientifically confirmed - the substance ranidone, which has high bactericidal activity, has been isolated from the shell of the caviar.

No matter how we feel about frogs, they are one of the most common, frequently used laboratory animals, along with rats and mice. For example, the clawed frog was the first animal to be cloned, and not Dolly the sheep, as we used to think. In the 1960s, English embryologist Gurdon cloned tadpoles and adult frogs.

For his services in the field of medicine, monuments were erected to the frog in Paris, Tokyo and Boston, as a tribute to and recognition of the truly invaluable services of these animals in the development of science. This is how scientists thanked their unwitting assistants in many important scientific research and discoveries. Experiments of Italian physicists XVIII century Luigi Galvani and Alessandro Volta's research on frogs led to the discovery of galvanic current. Physiologist Ivan Sechenov conducted a huge number of experiments on frogs. In particular, he used them in studying the nervous activity of animals. And the frog’s heart turned out to be an interesting object for studying cardiac activity. The French physiologist Claude Bernard, to whom frogs also helped make a number of discoveries, expressed the idea of ​​erecting a monument to them. And in late XIX century, the first monument to frogs was unveiled at the Sorbonne (University of Paris). And the second was erected by medical students in Tokyo in the 60s of the 20th century, when the number of frogs they used for science reached 100 thousand.

In addition to scientific value, these amphibians have practical value. Thus, in many countries, the meat of certain types of frogs is considered a delicacy. There are even special farms where frogs are bred for meat.

Practical work

So, let's get started:

05/07/15 The eggs were taken from a pond surrounded by bushes and aquatic plants.

The shell of each egg is swollen, similar to a gelatinous transparent layer, inside of which the egg is visible. Its upper half is dark and the lower half is light.

In nature, the rate of egg development depends on the water temperature. The higher the temperature, the faster the development. In deep, shaded reservoirs, eggs develop approximately four times slower than in well-warmed reservoirs. Caviar easily withstands low temperatures.

We create optimal conditions for the development of eggs: room temperature, warm.

After 8-10 days, tadpoles hatch from the eggs, more like fish fry. Passive, do not feed. Apparently there is enough nutritional supply of eggs. There are gill openings and gills.

05/23/15 Metamorphosis is noticeable. The tadpoles began to feed independently, move actively, and stay closely together. They scurry in different directions, but do not swim far, and the entire flock moves almost simultaneously. The average size of tadpoles is approximately 7-8 mm.

By this time, the head, body, and tail are already visible. The head is large, there are no limbs, the caudal section of the body is a fin, a lateral line is also present, and the oral cavity is similar to a suction cup. The gills are initially external, attached to the gill arches located in the pharynx area, and function as real internal gills.

The suction cup is located at the bottom near the mouth (you can use it to determine the type of tadpole); after a few days, the gap in the mouth along the edges becomes overgrown with some semblance of a beak, which works like nippers when the tadpole feeds. The tadpole has one circulation and a two-chambered heart.

In terms of body structure, amphibian larvae are close to fish, and adults are similar to reptiles.

In nature, tadpoles sometimes form huge aggregations - up to 10,000 in one cubic meter of water. It is not for nothing that among the ancient Egyptians the image of a tadpole meant the number 100,000, i.e. “very many.” But not all of them survive. The frog larva serves as food for fish, birds, swimming beetles and other inhabitants of the reservoir.

We place the tadpoles in different containers:

We place an absolutely transparent plastic container (10 l) in a well-lit area, in a warm place Not in an area of ​​direct sunlight (balcony) – 25 pcs.

We place an absolutely transparent glass container (3 l) in a well-lit area, in a warm place in an area of ​​direct sunlight (balcony) - 10 pcs.

Place a dark, opaque container (5 liters) in a warm place, slightly shaded, but with sufficient light. No direct sunlight (room) – 30 pcs.

We place an opaque container (2 l) in a poorly lit, cool place (garage) - 10 pcs.

All containers are filled with water taken from the place where the eggs were collected, i.e. closest to the breeding conditions, as well as algae and grass. Microorganisms are observed in water.

Within two days no differences in behavior are observed. All tadpoles are mobile, hide in mud and grass, and actively respond to sound and movement. They feed on plant foods during the day, as if biting them off, and also scrape off plaque from surfaces. They periodically rise to the surface of the water and swallow air. The growth rate is not striking; as is known, it averages 0.6 mm per day.

05/25/15 In a glass container located in an area of ​​direct sunlight, all the tadpoles died by evening. At the same time, without preserving the contours of the body, it almost completely decomposed and disappeared. Externally, the surface of the water in the container looked like it was bubbling, as if it had turned sour.

Conclusion: tadpoles, despite the statement that complete metamorphosis occurs faster with more high temperatures(21-26 C), and on average it lasts 50-90 days, they do not tolerate direct sunlight.

Cover the completely transparent plastic container with paper, protecting it from the sun.

05/28/15 In a plastic container, even though it is not directly sun rays, tadpoles are passive, practically motionless. The water is very hot. Several died. We remove it to a more shaded place.

In the remaining containers, the tadpoles are still active. They are in almost constant motion and feeding.

The growth of tadpoles is already more noticeable. The average is approximately 10 mm.

We add fresh water and algae from the reservoir, but not from the laying site, to all containers with tadpoles.

06/01/15 In a transparent container that allows daylight to pass through, placed in the shade, the tadpoles increased in growth. There was a sharp difference between larger and smaller tadpoles. Large ones are approximately 13-15 mm. They eat all the time, stick to the walls, grab air. The eyes and marble body pattern are clearly visible.

In an opaque container that practically does not allow daylight to pass through, but is located in a warm place, the growth of tadpoles is practically unnoticeable, as is the case in a container located in a cool, dark place. Several died despite the presence of food and the absence of direct sunlight.

Conclusion: There is high mortality during development, even in the absence of external predators feeding on the tadpoles.

For 3 weeks with constant feeding and changing water in containers, because Products of food processing by tadpoles accumulated at the bottom, the death of some specimens and the growth of stronger ones were observed. The average size is already approximately 20-25 mm.

The highest mortality rate was in a transparent container located in a warm place. Possibly from a constant change in water temperature: from very warm, heated by the sun to daytime, until it cools down very much at night.

06/27/15 The tadpole in the garage has undergone visible metamorphosis: hind legs have appeared.

07/03/15 Over a short period of time, the tadpole takes the form of a small frog. The front legs have grown, the tail has shortened. At the same time, the young frog appears to be smaller in size, what was the tadpole from which it was just formed.

Thus, as in nature, from the moment the eggs are laid to the end of the transformation of the tadpole into a frog, about 2-3 months pass.

Metamorphosis of a frog: 1 - eggs (spawn), 2 - tadpole with external gills, 3 - without gills, 4 - with hind legs, 5 - with all legs and a tail, 6 - frog.

The luckiest of the tadpoles survive to the stage of metamorphosis and turn into a young frog. Fingerlings are very voracious. The volume of their stomach when full exceeds one fifth total weight. There is one interesting detail: if there is not enough animal food in the reservoir, the herbivorous tadpole overwinters in the larval stage, postponing the transformation from vegetarian to predator until spring. They become fully carnivorous once their hind legs develop, feeding on small aquatic animals or even other tadpoles when food is scarce.

07/05/15 As is known in nature, tadpoles feed on algae, plant matter, and larvae of small microorganisms. In captivity, perhaps due to a lack of plant food (despite its presence in the container), the tadpoles ate the newly formed frog, and not vice versa.

Conclusion

Thus, we conclude that tadpoles are very fragile organisms. Our hypothesis was confirmed.

1. Mortality of eggs and tadpoles reaches 80.4 - 96.8%.

Of enough large quantity hatched tadpoles, 11 survived. Moreover, 5 out of 30 are in a dark, opaque container (5 l), located in a slightly shaded room, without direct sunlight.

3 out of 10 - in a light, opaque container (2 l), located in a poorly lit, cool place, in the garage. At the same time, a frog formed ahead of everyone else.