There are snakes. How to distinguish a viper from a snake: distinctive features
The lake frog is the largest representative of its species. It is quite wide, so the shape of the color varies depending on the territory. Populations are usually large.
Lake frog: description
It has an elongated body with a slightly pointed snout. The color of the upper part may vary. It is usually green, but sometimes gray and brown frogs. The entire body is covered with large dark spots of uneven shape.
Most representatives of this species have a clearly visible light stripe with small inclusions along the spine and head.
The body below is yellowish or off-white. Almost black spots are often present. The eyes are golden. IN natural environment lives up to 10 years. The lake frog grows up to 17 cm in length. It should be noted that males are slightly fewer females, but they have resonators. During the daytime, it periodically enters the water to increase the moisture content of the skin, but at night, when the air temperature drops, the frog is not in danger of drying out the surface of the body.
Habitat
The amphibian prefers steppes; in the southern part it can be found in deserts; in the north it inhabits some areas of the taiga. Thus, its habitat is Central and Asia, Kazakhstan, Russia, the Caucasus, Iran, and North Africa.
The lake frog lives in bodies of water (more than 20 cm deep). Inhabits ponds, mouths and banks of rivers, lakes. You can also see it within the city limits along the concrete banks of reservoirs, in thickets of willows and reeds. He treats the presence of a person nearby calmly.
The lake frog can adapt to even the most. The habitat of individuals of this species can therefore vary greatly; they are able to survive in places heavily contaminated with waste, but in this case anomalies in development are possible.
It also easily and quickly colonizes artificial dams and reservoirs. When water bodies dry up, they can migrate to a new habitat, covering up to 12 km.
Behavior
The lake frog is a heat-loving species. It is active around the clock at temperatures from +8 to +40 °C. During particularly hot hours, it hides in the shade of plants.
Conducts both on the shore and in the water. On land, it basks in the sun while remaining motionless. However, having excellent hearing and vision, at the slightest danger it jumps into the water. Here the frog finds safe place and hides, often simply hiding in the mud. It can stay in water for quite a long time. And only after he is convinced that there is no danger, he returns to his previous place.
Although she is a good swimmer, she still avoids fast currents, although she is not afraid even of a wave.
The lifestyle of the lake frog allows it to remain over the winter in the same body of water. Sometimes she moves around in search of more deep places or to the springs. Where the water doesn't freeze all year round, the frog remains active constantly. Wintering lasts about 230 days, all this time it is in the silt or at the bottom. It rises to the top by mid-May, when the water warms up enough. In case of frost, a large number of frogs die.
In areas favorable for habitat, the number of amphibians is simply amazing. Often frogs sit on the shore in huge flocks, and the surface of the reservoir is simply teeming with numerous protruding faces.
Diet
What does the lake frog eat? It all depends on age, habitat, gender and time of year. They feed both on land and in water.
Land hunting takes place just a few meters from the shore. This amphibian is a real predator. Due to its impressive size, its potential prey can be a small lizard and snake, a mouse, a chick and even a smaller frog.
Newts become lunch in the water, small fish and their own tadpoles. The main diet includes invertebrates - crustaceans, insects, mollusks, centipedes and worms.
The lake frog can catch its prey even in flight. Usually these are butterflies, flies, dragonflies. During the hunt, she actively uses her tongue, throwing it several centimeters forward. Sticky mucus helps to hold mobile prey. If the victim is on long distance, then the amphibian creeps up to it carefully. The frog can also jump very accurately, landing in the right place.
The main diet of tadpoles is small algae.
How does the lake frog reproduce?
The female reaches puberty at three years of age. Unlike other amphibians, reproduction occurs much later in time. The frog waits until the water temperature rises to +18 °C. Usually this is the end of May or June. It lays eggs in the same body of water in which it lives; it does not make special migrations for this purpose.
From the moment the first frog appears after wintering until the start of spawning, it takes from one week to a month.
They gather to reproduce in large groups. Males during this period are especially vocal and very active. When they croak, resonators swell at the corners of their mouths. Also, during the breeding season, males develop seals on the front leg on the first toe - nuptial calluses.
Their “songs” attract the attention of females. Mating occurs before eggs are laid. However, fertilization is external. This happens in almost all amphibians, and the lake frog is no exception.
The description of this process is as follows: the male embraces the female in such a way that his front paws are on the chest. In this way, sperm and eggs are simultaneously released into the water, which promotes fertilization. more eggs Sometimes one female can be “hugged” by two or three males at once.
The breeding period is one month. One female can lay up to 6,000 eggs.
Lake frog tadpoles
Tadpoles appear 3-15 days after fertilization. Immediately after birth, they spread throughout the entire reservoir. During the day they are more active, at night they hide at the bottom. In just 2-3 months they reach a length of 9 cm. However, after metamorphosis, the frogs are only 1.5-2.5 cm.
The most favorable water temperature for them is + 20-28°C, at +5-6°C development stops, and at +1-2°C they die. Not all tadpoles will develop into adult lake frogs. Most of them will become food for various birds.
The pond and lake frog belongs to the class of amphibians. It has a body length of 7-10 centimeters. Her skin is bright green with brown tint. There are dark spots and a white longitudinal stripe on the back, and the belly is white.
The frogs' eyes are bright golden. In spring, near ponds and swamps, their loud mating concerts can be heard. These animals winter in the forest, buried in soft soil or in warm ponds. Already in the second half of April, when the air warms up to 8-10 degrees, frogs begin mating games. The female lays eggs on the bottom of the swamp or on the stems of aquatic plants. One frog can lay 400-1800 eggs. Tadpoles of light olive or green color soon emerge from them. Frogs live up to 12 years.
The pond and lake frog feeds on insects. Its permanent menu consists of dragonfly larvae, mosquitoes, water beetles and mollusks. If there is not enough food, the frogs eat fish fry and even tadpoles. Large frogs of this species sometimes attack small animals (voles, shrews). Small birds, chicks and snakes can also become their prey. The frogs themselves also become objects of hunting for predatory fish, reptiles, birds and mammals.
Frogs of this breed live in southern and central Europe, in Central Asia and in North Africa. They are found in Crimea, the Caucasus and Kazakhstan. This species of amphibian lives in many regions of Russia.
Pond and lake frogs are often used in medicine and for experiments. They are edible, such a delicacy as frog legs are made from this particular type of frog. Also, these animals play a significant role in natural food chain. Their eggs, tadpoles and themselves serve as food for many animals and fish.
Video - breeding of a pond frog.
Video: fight of lake frogs or toad fight.
And another video - tadpoles of a pond frog.
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In addition, on our website you can purchase teaching materials By aquatic ecology and ichthyology:
Pallas, 1771
(= Rana cachinnans Pallas, 1814; Rana caucasica Pallas, 1814; Rana dentex Krynicki, 1837; Rana florinskii Kastschenko et Schipatschev, 1913; Rana esculenta ridibunda - Nikolsky, 1918; Rana ridibunda saharica - Terentyev and Chernov, 1949)
Appearance. Most large species of frogs fauna former USSR; maximum body length 150 mm (outside the former USSR 170 mm). Eardrum large:
1 - eardrum; 2 - slit of the external resonator (the resonator itself is hidden)
Rear limbs(shin and fingers) elongated. The ankle joints, if the limbs are folded perpendicular to the axis of the body, touch or overlap each other:
The length of the hind limbs and the shape of the internal calcaneal tubercle in Europeans green frogs:
A - pond frog, Rana lessonae, B - edible frog, Rana esculenta, C - lake frog.
1 - thigh, 2 - lower leg, 3 - ankle joint, 4 - internal calcaneal tubercle, 5 - first toe of the hind limb, 6 - length of the internal calcaneal tubercle, 7 - length of the first toe
Interior calcaneal tubercle short and low, more than half as long as the first finger:
2 - articular tubercles, 3 - external calcaneal tubercle, 4 - internal calcaneal tubercle
Swimming membranes very well developed. Males are equipped with paired external lateral resonators dark gray, which are located in the corners of the mouth; when inflated they are light gray. On the first digit of the forelimbs of males, a solid nuptial callus dark gray color.
Top thick green, olive, gray or brown colors various shades. On the back of many individuals there are large, much less often small, spots and/or a light longitudinal stripe, sometimes greenish. The underparts are white, gray-white or yellowish in color, often with small dark gray spots.
Spreading. The range of the lake frog is huge and extends from eastern France in the west to eastern Kazakhstan in the east. The northern border runs through Holland, Germany, Poland, Lithuania, Belarus, the central regions of the European part of Russia to the Vyatka and Perm regions, through Bashkiria and southern Urals further southeast to eastern Kazakhstan. In the south, the range covers the Balkans, western Turkey, the entire territory of the former USSR, except for southern Tajikistan and part of Transcaucasia, northern Iran and Afghanistan, and the Ili River region in northwestern China. The species is absent in high mountain areas, as well as in arid deserts. In a number of regions, the boundaries of the range need to be clarified.
More recently, the species' range was considered even more extensive. However, the use of bioacoustic and biochemical methods in systematics showed that frogs in many southern regions, previously classified as Rana ridibunda, actually belong to other, sometimes very similar, 9-10 species. This, from west to east:
- Saharan frog, Rana saharica Boulenger, 1913, found in northwest Africa;
- Pyrenees frog, Rana perezi Seoane, 1883, inhabiting the Iberian Peninsula and southwestern France;
- Albanian frog, Rana shqiperica Hotz, Uzzell, Gunther, Tunner et Heppich, 1987, distributed in Yugoslavia and Albania;
- Hellas frog, Rana epeimtica Schneider, Sofianidou et Kyriakopoulou-Sklavounou, 1984, from Albania and Greece;
- Balkan frog, Rana kurtmuelleeri Gayda, 1940 = Rana balcanica Schneider et Sinsch, 1992, found in Yugoslavia, Albania and Greece;
- Cretan frog, Rana cretensis Beerli, Hotz, Tunner, Heppich et Uzzell, 1994, from the island of Crete;
- South Sporadic frog, Rana cerigensis Beerli, Hotz, Tunner, Heppich et Uzzell, 1994, from Karpathos and possibly Rhodes, Greece;
- Bedriaga's frog, Rana bedriagae Camerano, 1882 = R. levantina Schneider, Sinsch et Nevo, 1992, living in the Middle East from Egypt to Turkey;
- Persian frog, Rana susana Boulenger, 1905, from southern Iran (needs substantiation) and
- Terentievi's frog, Rana terentievi Mezhzherin, 1992, from southern Tajikistan.
The systematic position of frogs in a number of regions, especially in Western Asia, remains unclear. Apparently, the “fragmentation” of the species will continue.
Taxonomy of the species. According to modern ideas, subspecies of the lake frog are not distinguished. The species belongs to the group green frogs(Rana esculenta group).
Apparently, at least 3 species live on the territory of the former USSR: lake frog, Rana ridibunda in the European and Asian parts (there are certain differences between them); Terentievi's frog, Rana terentievi in southern Tajikistan (nomenclatural issues need clarification) and probably Bedriaga's frog, Rana bedriagae in southern Transcaucasia (Armenia and possibly adjacent parts of Georgia and Azerbaijan - special research is needed).
The lake frog is characterized by the ability to resettlement. It easily captures new bodies of water, where it enters on its own or with the help of humans (for example, Yekaterinburg, the outskirts of Riga and St. Petersburg, the southeast of Lake Issyk-Kul, etc.). Therefore, now in a number of cases it is difficult to say definitely where the natural (original) border of the range is, and where resettlement is taking place, as, for example, in the east of Kazakhstan. Artificial populations are also known that existed in reservoirs of thermal power plants, obviously outside the species’ range (for example, in the Middle Urals or Yakutia).
Habitats. The lake frog is ecologically very plastic and lives in a variety of forest landscapes (mixed and broadleaf forests), forest-steppe, steppe and even desert zone, found on the plain and in the mountains up to an altitude of 2438 m above sea level (Caucasus). It prefers open areas everywhere and stays in or near water bodies, usually not moving more than 20-50 m (one individual was found 500 m from the water body). It penetrates into forest areas along river beds. Lives in reservoirs of cities and towns. It can be found in very different bodies of water with stagnant, less often flowing water: in pits, large puddles, reed swamps, springs, ponds, oxbow lakes, irrigation canals, lakes, rivers. Most often inhabits large open bodies of water. He tries to avoid fast currents, although he swims well and is not afraid of waves. Frogs are found in brackish water and even in the sea near river mouths and in estuaries. Easily colonizes artificial reservoirs: dams, reservoirs, fish ponds, rice fields etc. In Kalmykia, when water bodies dry up, frogs can migrate long distances, sometimes from 5 to 12 km.
Activity. The activity of individuals is almost 24/7, especially in summer, except during the hottest hours in the south. During cooler times in spring and autumn, animals are active during the day.
Reproduction. Frogs in spring are awakening in February in Kalmykia, March-April in the Caucasus, in April in the Central Black Earth region of Russia, at a temperature not lower than 10°C. The first days the animals are little active. They begin to reproduce at water temperatures of 10-12°C and above. Males appear first and attract females with loud, sometimes deafening sounds. concerts.
Breeding period stretched out and lasts 23-27 days in the forest-steppe of the European part of Russia, from mid-March to August in the Caucasus. Eggs are laid immediately or in portions of 72-300 pieces at a depth of 30 cm to 1 m. Total quantity The eggs spawned by the female range from 1,100 to 16,400. The diameter of the egg is 1.6-1.9 mm.
Embryonic development lasts 3-10 days. The hatched larvae reach a length of 5-8 mm. Larval development covers 40-100 days. Due to the extended spawning period, tadpoles are found until August. Sometimes they are found in the process of metamorphosis late in the fall (in October in the Caucasus); sometimes the larvae overwinter. On the oral disc, the denticles are located 2 rows above the beak and 3 rows below it:
Tadpole (a) and oral disc (b) green frogs
Total length tadpole usually ranges from 40 to 90 mm (with tail). However, there are known cases of developmental delay, including abnormal ones, which lead to rapid growth and gigantism. Some of these tadpoles, reaching a length of up to 165 mm, were mistaken for larvae common spadefoot. No more than 0.4-5.5% of laid eggs undergo metamorphosis. Fledglings appear in Transcaucasia in March, in the Central Black Earth region of Russia in July-September. Their body length is 16-30 mm.
Sexual maturity occurs at the age of two years with a body length of 65-70 mm in males and 70-80 mm in females. The average annual mortality rate is about 46-47%. The maximum life expectancy in nature is at least 11 years.
Nutrition. The composition of feed depends on the season, area, sex and age of the frogs. Insects predominate, usually terrestrial, and are found both during the day and at night. Mostly these are beetles, Hymenoptera, Diptera, aphids, especially in young frogs, and less often butterflies. In addition, frogs consume arachnids, crustaceans, and earthworms. Large individuals can grab small birds and mammals. Cannibalism is often observed. In the literature, especially in the fisheries literature, one can find the statement that the lake frog causes serious harm by eating fish. In fact, this type of feed constitutes a minor component diet. Tadpoles eat various algae, as well as small aquatic invertebrates.
The frogs themselves, as well as the tadpoles, are booty for many vertebrates (some fish, snakes, many birds and mammals), as well as invertebrate animals (predatory aquatic beetles, dragonfly larvae, leeches, etc.).
Wintering. Frogs for the winter leaving at the end of September - October in the European part, in the second half of October - November in the Caucasus, at soil, water and air temperatures of 6°, 7° and 11°C, respectively. Fingerlings disappear later than adults. In general, the period of seasonal activity in the Volga-Kama region is 136-145 days. They overwinter at the bottom of deep, usually non-freezing reservoirs, burrowing into the silt, preferring, if possible, places with running water. Wintering reservoirs may not coincide with spawning ones. There are known cases of gerbils wintering in burrows. In case of death at the end of winter, a large number of frogs die. In warm cooling ponds of power plants, where the water temperature in winter does not fall below 13°C, animals are active all winter. In the Caucasus they are found in warm winters in January and February.
Abundance and conservation status. The lake frog is a very numerous species and is a background species almost everywhere it lives. Found in many nature reserves. There is no threat to the existence of the species yet. Previously (there is no information now) in a number of places, frogs were prepared for export, and were also caught for sale to scientific, medical and educational organizations, which could lead to a serious decline in the number of local populations. In such cases, control measures are necessary.
As rare species on the periphery of its range, the lake frog is listed in the Red Book of Estonia, in the territory of which, however, no reliable finds are known (confusion with the hybrid form is possible - see edible frog). Not listed in the Red Data Books of the former USSR and other republics. In Europe it is protected by the Berne Convention (Annex III).
Similar species. It differs from the pond frog in its longer hind limbs, the shape and size of the internal calcaneal tubercle, and the color of the body and resonators in males. The differences from the edible frog are less pronounced, and for reliable identification it is advisable to use biochemical methods. The lake frog coexists with these species only in forest and forest-steppe zones European part of the former USSR. It differs from the black-spotted frog, brought to southern Turkmenistan, by its longer shin and the shape of its heel puff. It differs from brown frogs in the absence of a dark temporal spot, the nature of the spots on the back, and the presence of external resonators in males.
The lake frog is a representative of another group of frogs - green, or water frogs.
They spend almost their entire lives in water, are predominantly green in color and do not have a dark temporal spot. The lake frog is the largest, most abundant and widespread species of this group.
The lake frog is the largest in Russia
This frog is the largest one found in our country. Its length can reach 15 cm. The color of the upper side of the body is very diverse, most often it is all kinds of shades of green, but there are also gray and brown frogs. Large, uneven dark spots are scattered throughout the body. Often there is a light stripe along the back. Abdominal side light, usually with dark specks or spots. Males are somewhat smaller than females, and they have resonators.
Range of the lake frog
It is widespread east of Central Europe to Iran and Eastern Kazakhstan. In Russia it is common up to southern borders European part, to the east reaches the Urals, in Southern Siberia- to Baikal; There are isolated populations in the upper reaches of the Irtysh and Ob. In the north of the European part of Russia, the border of its range lies in the middle reaches Western Dvina and the upper reaches of the Kama.
The lake frog inhabits a variety of water bodies in almost any biotopes (from northern forests to the deserts). It also occurs in small ponds, and in large lakes and rivers. It can even be found in mountain streams and cave lakes. She prefers open, well-lit bodies of water with abundant aquatic and semi-aquatic vegetation. It also inhabits artificially created reservoirs - canals, reservoirs. Not afraid of human proximity and meets even in major cities. In favorable habitats, the number of lake frogs can be stunning: sometimes on the shore they sit side by side in whole clusters, and the water surface is simply strewn with big-eyed faces sticking out of the water.
The lake frog is a heat-loving species. It can be active at ambient temperatures up to +40°C; it has been found in hot springs with water temperatures from +35 to +40°C. Lower temperature limits of activity: air up to +14°C and water up to +8°C. With more low temperatures frog activity stops.
Lifestyle
Active lake frogs are usually found during the day, but their activity continues at dusk and at night. During the day they can be spotted in the water or on the shore, although this can be quite difficult. In water, frogs are almost invisible, since they are usually hidden under plants floating on the surface and only protrude their nostrils and eyes. They sit on the shore, basking in the sun, completely motionless; spotted or brown coloring perfectly camouflages them on the ground and among plants. Possessing perfectly developed vision and hearing, the frog carefully monitors all movements around and reacts to the slightest shaking of water or soil. In case of any danger, it dives with lightning speed, swims a considerable distance underwater and hides in the silt or under objects lying at the bottom. Like a good diver, she can stay under water for quite a long time, and then carefully emerges in a completely different place. In this case, the tip of the muzzle and eyes appear first, and only after making sure that there is no danger, the frog returns to its original place.
What does the lake frog eat?
Although lake frogs spend most of their time in the water, they often collect food on land. When hunting on land, they do not move further than a few meters from the water. These rather large frogs with a huge mouth are real voracious predators. They can swallow another smaller frog, a small lizard or snake, a chick, or a mouse. In the water, the lake frog will, on occasion, certainly grab a fish, a newt or its own tadpole. However, the basis of nutrition for this species, like other amphibians, is made up of various invertebrates: worms, mollusks, millipedes, crustaceans and numerous insects. The lake frog often captures flying insects - flies, butterflies, dragonflies, when they land somewhere nearby. The sticky tongue, “thrown out” a few centimeters, helps the frog to grab such mobile and cautious prey. If a dragonfly or fly lands at a greater distance, then the hunter slowly creeps up to it. The lake frog is also an excellent jumper and can catch a flying insect in a jump, or can very accurately “land” on the place where the victim is sitting and grab it with lightning speed.
Reproduction of lake frogs
Heat-loving lake frogs begin breeding much later than other species of amphibians, when the water temperature rises to +12+18°C. Eggs are laid in the same reservoirs where frogs live constantly, so they do not make special migrations to breeding sites. But they are still removed from their “home” places, since they gather in groups to reproduce. Males form quite large clusters and “sing” in chorus. Unlike brown frogs and many other tailless amphibians, the loud calling “singing” of lake frogs is heard during the daytime. Males make sharp short signals like “uh-uh”. Like males of other species, they are not very picky and can embrace not only their female, but also any animate or inanimate object floating nearby. It happens that two or four males grab one female with their front paws at once. This is no longer a marriage couple, but a whole “marriage ball” floating slowly and randomly in the water. Large female can lay up to 12 thousand eggs, up to 10 in one lump or several portions.
Tadpoles are born after 3-18 days. They are lighter than the tadpoles of brown frogs and do not form clusters; soon after hatching they spread throughout the entire reservoir. Like adult frogs, tadpoles are active mainly during the day, and at night they lie down on the bottom, hiding under stones and among plants. They feed mainly on algae, and to a lesser extent on the smallest aquatic animals (protozoa, rotifers), as well as blue-green algae. The population density of lake frog tadpoles can be impressive: in the lower reaches of the Volga they numbered up to nine thousand per cubic meter. The tadpoles of the lake frog grow faster than the larvae of other amphibians. Two to three months after hatching, before metamorphosis, their length reaches 7-9 centimeters. The baby frogs that appear after metamorphosis are much smaller - their body length is 1.5-2.5 centimeters. Sometimes tadpoles that have not had time to undergo metamorphosis remain in the reservoir for the winter and next year can reach huge size- up to 18.5 centimeters. Perhaps the phenomenon of such gigantism is associated with hormonal disorders in their body.
Young frogs can reach sexual maturity already in the year following metamorphosis, but more often this occurs in more late age- at two to four years. In nature, lake frogs live up to eleven years.
Where do lake frogs spend the winter?
Animals usually hibernate underwater, burying themselves in silt and bottom debris. Sometimes they get hidden under the banks overhanging the water, or accumulate in depressions in the ground. In some places, frogs overwinter in rodent burrows, for example, in the deep (up to 180 centimeters) gerbil burrows built in wet sand. In the south of their range, in non-freezing and relatively warm water bodies, they are active all year round.
As already noted, the lake frog is an indiscriminate predator, but it, in turn, has a lot of enemies. And these are not only such obvious predators as fish, snakes or water birds, but also gray monitor lizards, And freshwater crabs. In addition, it, like all green frogs, is used for food by humans. Frog legs (hind legs) are considered a delicacy; they taste like poultry. Large sizes and high numbers make the lake frog a real commercial species.
lake frog (Rana ridibunda)
Class – Amphibians
Squad – Tailless
Family – True frogs
Genus – Pelophylax
Appearance
A large frog, body length up to 18 cm, weight up to 200 g. The body is oblong, the muzzle is slightly pointed, generally oval. The eardrum is round. The body color is brownish-greenish, with dark spots. The belly is dirty white or slightly yellowish with small dark spots. A light, yellowish or greenish-yellow stripe runs along the back (zigzag in some specimens). Males develop nuptial calluses on their fingers. The eyes are bright golden in color.
Basic distinctive features: if the shins of the legs are pressed to the thighs and placed perpendicular to the longitudinal axis of the body, then the ankle joints overlap one another; the internal calcaneal tubercle is low, usually more than 2 times shorter than the first toe; The resonators (balls in the corners of the mouth that inflate) in males are gray, sometimes completely black. The larva, or tadpole, is light olive in color and pear-shaped. The distance between the eyes is more than 2 times wider than the distance between the nostrils. On upper lip 2-3 oral discs, 3 rows of teeth on the lower one.
Females are usually larger than males.
Habitat
Found in Southern and Central Europe, South and Central Asia, North Africa, the south of the Asian part of Russia. IN Western Europe spread up to 60 degrees northern latitude, found in Crimea, the Caucasus, Kazakhstan and Central Asia, in the east to Lake Balkhash. Beyond the Urals - in Tomsk, Novosibirsk regions and Krasnoyarsk region. The lake frog lives in permanent, fairly deep (at least 20 cm) reservoirs. Most often these are oxbow lakes, lakes, ponds, ditches, but it can often be found along the banks of large and small rivers.
In nature
Active almost around the clock. The lake frog spends most of its time in water, swims and dives well. It is careful, and in case of danger it quickly goes into the depths and hides. The frog has a rather loud voice. It hunts mainly on land, along the banks of reservoirs, here it can most often be found at the most warm time days - from 12 to 17 hours.
Like all frogs, the lake frog feeds various insects(68–95% of the diet), of which 27% are flying forms, dragonfly larvae, water bugs and their larvae, mollusks. When ground food is insufficient, lake frogs large quantities They eat tadpoles of their own species, they are even able to feed on fish fry in places where they are concentrated in fish ponds. However, in natural reservoirs the role of fish in feeding lake frogs is minimal. This large frog sometimes attacks small mammals(voles, shrews), small birds, chicks, young snakes (most often snakes are not enough).
Reproduction
Heat-loving lake frogs begin breeding much later than other species of amphibians, when the water temperature rises to +12+18°C. Eggs are laid in the same reservoirs where frogs live constantly, so they do not make special migrations to breeding sites. But they are still removed from their “home” places, since they gather in groups to reproduce. Males form quite large clusters and “sing” in chorus. Unlike brown frogs and many other tailless amphibians, the loud calling “singing” of lake frogs is heard during the daytime. Males make sharp short signals like “uh-uh”. Like males of other species, they are not very picky and can embrace not only their female, but also any animate or inanimate object floating nearby. It happens that two or four males grab one female with their front paws at once. This is no longer a marriage couple, but a whole “marriage ball” floating slowly and randomly in the water. A large female can lay up to 12 thousand eggs, up to 10 in one clump or several portions.
Tadpoles are born after 3-18 days. They are lighter than the tadpoles of brown frogs and do not form clusters; soon after hatching they spread throughout the entire reservoir. Like adult frogs, tadpoles are active mainly during the day, and at night they lie down on the bottom, hiding under stones and among plants. They feed mainly on algae, and to a lesser extent on the smallest aquatic animals (protozoa, rotifers), as well as blue-green algae. The population density of lake frog tadpoles can be impressive: in the lower reaches of the Volga they numbered up to nine thousand per cubic meter. The tadpoles of the lake frog grow faster than the larvae of other amphibians. Two to three months after hatching, before metamorphosis, their length reaches 7-9 centimeters. The baby frogs that appear after metamorphosis are much smaller - their body length is 1.5-2.5 centimeters. Sometimes tadpoles that have not had time to undergo metamorphosis remain in the reservoir for the winter and the next year can reach enormous sizes - up to 18.5 centimeters. Perhaps the phenomenon of such gigantism is associated with hormonal disorders in their body.
Young frogs can reach sexual maturity in the year following metamorphosis, but more often this occurs at a later age - at two to four years.
In nature, lake frogs live up to 11 years.
To keep a lake frog at home, it is recommended to use a 30-40 liter aquarium filled with water, but with pieces of wood or foam floating on its surface, so that your pet can spend the necessary part of the time out of water. It is best to throw the stem and leaves of some kind onto this improvised “land”. aquatic plant so that the lake frog can hide from the light in them. Plants growing directly in water are naturally welcome in every possible way. The lake frog is not picky about living conditions in natural conditions, so if you decide to keep it at home, you can change the water only once a week by one third, and once a month - entirely. Additional lighting and heating are not required.