Frogs - family tailless amphibians, a contemporary of both man and the dinosaur. The frog embodied in itself the longest experience in the history of life on land of the struggle for existence. This led to the universality of its anatomy and physiology, providing a unique adaptability to life in the border zone. Like millions of years ago, a frog begins its life in water. A tadpole develops from eggs laid in water. So far, it is not much different from fish fry. But here begins a series of transformations, consisting of about thirty transitional stages, which helps the frog adapt to life on land, and the tadpole turns from a “fish” into a land animal (metamorphosis).
Very interesting question: what helps the frog to adapt to life on land?
And it helps the frog to adapt to life on land all those devices that appeared during the transformation of the tadpole into a frog. First, the tadpole has hind legs, and then the front. The lungs begin to develop. After a while, it rises to the surface of the water and swallows air, the tail is gradually shortened. The tadpole becomes amphibian, and then comes ashore. And he lives on land adapted as it should.
From this moment, the frog will live on land, more precisely, on the border of land and water. Permanent communication with the aquatic environment imposes on the biology of frogs a number of salient features. Tadpole breathed with gills, and adult frog breathes through the mouth, lungs and skin. Such a large set of respiratory organs is characteristic only of amphibians. While the frog is in the water, it breathes in the skin, and when it is on land - with the mouth and lungs. Universal and circulatory system. Two parts of the heart work in water, and mixed blood flows through the body. On land, the left atrium is connected to the work, and pure arterial oxygenated blood enters the brain. Thus, every time a frog dives, the respiratory system instantly turns off.
While the frog is on the ground, catching her is easy. But in the water you can’t catch her. The hind limbs are long, composed of ten bones - levers. And the forelimbs are a superbly thought-out device for a soft landing. The skin of frogs is naked and covered with mucus, and therefore their activity depends on humidity and air temperature. Going on a hunt in the twilight time, as the coolness increases. In cold and dry weather, the frogs are hidden in shelters.
When it's winter time frog sinks to the bottom.
The body color is affected not only by temperature, but also by the background color, and light, and humidity. Frogs perceive changes in these factors directly by the skin.
One of the most original adaptations to living conditions in the border zone between land and water is frog hearing aid. It turns out she perceives sound signals in three channels. In the air, sound waves are captured by the cells of the inner ear through the eardrum and the ear bone. Sounds propagating through the soil are perceived by the bones and muscles of the limbs and are transmitted through the bones of the skull to the inner ear.
Frog gazes impassively at the world with two large round eyes. They may not be very expressive, but what is unique is certain. When studying frog eyes it turned out that the retina analyzes information using special cells. They were called “detecting” detectors. Each type of detector reacts only to strictly defined properties of objects, for example, the movement of a stimulus in a certain direction. Each type of irritation is transmitted through its own optic nerve fiber to a specific layer of the brain. In the brain, the information received is processed, and the animal perceives the subject as a whole.
Frogs unpretentious and illegible in food, can starve both day and week. Butterflies, bees, wasps and other moving insects are eaten. devours fish fry.
For many decades, physiologists have used frogs in a wide variety of experiments. Observations and experiments with them made it possible to make so many important discoveries that even Paris and Tokyo were erected. frog monuments.
Tree frogs, or woodcuts
A small and very elegant frog; found in Ukraine and the Caucasus, lives on trees and shrubs. She can hold onto the foliage and move on it due to the fact that her fingers are equipped with suction pads at the ends. The tree frog coloring is perfectly adapted to the environment among which she lives: usually it is grassy-green - to the color of the foliage, but in a different setting, the color may change to brown or grayish. Male tree frogs scream very loudly, inflating the resonator. For spawning, tree frogs descend into water bodies, but remain there for a very short time and soon return to the trees again.
Suriname Frog
Bright color surinamese Frog warns predators that an attempt to feast on it will end in death. The Indians of the Amazon basin smeared with frog venom, one of the deadliest arrowheads. The poison strikes nervous system and causes blood coagulation.
Goliath Frog
They live in waterfalls of fast and full-flowing rivers. They need a lot of humidity, so frogs Avoid places heavily lit by the sun. Water should be abundantly saturated with oxygen, not contain tannic acid and be not warmer than 23 degrees and not colder than 16-17 degrees. These giant frogs live secretly, spend most of the day in the water or among the rocks, which are very difficult to get to. Catching a goliath is extremely difficult, it requires great agility and skill. Locals catch them with a net with small cells. The net is thrown from afar so that the frog does not see it.
P align \u003d "justify"\u003e Outwardly Goliath looks like an ordinary frog. His wrinkled skin on the back is greenish-brown, the abdomen and the inside of the paws are yellowish and whitish. Eye diameter can reach 3.3 centimeters, the ear is small, without a shell. These frogs make no sound. Some researchers rate maximum goliath weight six kilograms, and the length, if the hind legs are extended, is 60 centimeters. True, these figures are somewhat overstated, but it is undoubted that goliath is the largest of the existing frogs. There is no noticeable difference between male and female, although the latter is slightly larger.
Goliath Frog Photo
For a long time, the development of goliaths remained unknown; scientists searched in vain for their tadpoles. But somehow, a female in one of the terrariums laid eggs. They were five to six millimeters in diameter. Now scientists knew what the roe of these frogs looked like, and began to look for it everywhere where the goliaths lived. With great difficulty, it was possible to find eggs that were attached to the bush of the plant.
Goliath female begins to lay eggs in the dry season. For 5-6 days, she lays more than 10 thousand eggs. Development from an egg to a frog lasts approximately 70 days. The tadpole at first has a length of 8 millimeters, but at the age of 45 days it reaches a maximum size of 4.8 centimeters. After that, the tail falls off.
Studies of the contents of the stomach of goliaths have shown that they feed mainly on insects, but do not disdain crayfish, mollusks, amphibians and spiders. In their stomachs even the remains of small rodents were found.
At first, the main enemies of frogs are birds and, possibly, some fish. Goliaths later become prey for crocodiles.
Locals in Cameroon and Rio Muni, where these frogs live, consider their meat excellent. It is white and delicate, and the front legs are a special delicacy ...
So far, you can be sure of the safety of these representatives of the animal world. It is very difficult to catch goliaths, and they live in places almost inaccessible to humans. But since it concerns a species that can hardly adapt to other conditions of life, everything must be done to preserve goliath frogs.
Goliath Frog - video
The amphibian world is amazing and diverse. Some evidence of this interesting Facts about frogscreatures, most of which do not cause a surge of positive emotions.
Do you know why in ancient times it was customary to throw a frog into a bucket of milk?
The fact is that there were no refrigerators at that time, and the frog’s wet skin has bactericidal properties, which is why milk with the frog has never turned sour.
Frogs have a very interesting vision - they can simultaneously look up, forward and sideways
Also, frog eyes play an important role in ... digestion. It is through the eyes that the frog helps push food in the mouth further down the digestive tract. Therefore, capturing the prey, these representatives of the amphibian world must blink. And frogs close their eyes only for a short period of time, even when they are sleeping.
Frogs have a unique breathing system, because these amphibians breathe both with their lungs and their mouths and the entire surface of the skin
While in the water, frogs breathe skin, on land, their lungs and mouth are responsible for their breathing. The frogs organism is arranged in such a way that each time immersing in water, the animal provokes a trip respiratory system. The circulatory system of frogs is also quite interesting: their heart consists of 2 sections, and mixed venous-arterial blood runs in the body.
The hearing of frogs is designed so that when they are on land they pick up sound vibrations with the help of their inner ear, and while sitting on the ground they feel audio vibrations from their skin and bones.
Frogs are the best jumpers in the animal kingdom
Representatives of some species (the frog Litoria nasuta, living in Australia) can overcome 50 times the distance in the jump and achieve acceleration up to 20 meters per second. Others ( Rhacophorus Nigropalmatus - Wallace's Flying Frogliving in the humid jungle of Malaysia and Borneo) can not only jump superbly, but even plan, “flying” distances of 15 m.
The size range of these amphibians is quite wide. So, the smallest frog in the world is only 8.5 mm long, and she lives in Cuba.
And here is a closeup photo of the smallest frog.
Giant Goliath Frog is the largest representative of its species.
- its length is 90 cm, and weight can exceed 3 kilograms. The goliath has very strong legs, thanks to which the average jump of this frog exceeds 3 meters.
Do not think that frogs are harmless creatures. In fact, it is the frog that is the most poisonous land animal in the world.
The breed of this frog is “ cocoa", She lives only in South America. Kokoi poison is thirty-five times more dangerous than cobra poison.
In Japan, frogs have a very revered role - there they are a symbol of luck.
And in ancient Egypt, these creatures were also a symbol - but personified the resurrection, and they were mummified simultaneously with the deceased person. Scientists suggest that this is most likely due to the following. In temperate and cold latitudes, frogs "freeze" every year, falling into hibernation, and come back to life only in the spring.
This is due to the fact that the frog produces glucose. In frost, all the liquid with glucose takes on the consistency of a syrup, without the formation of crystals. That is why, after a short winter sleep, the frog is able to survive.
At the moment, scientists have described 5 thousand species of amphibians, with 88% of these five thousand being frogs
Objectives of the lesson:
To expand and clarify children's knowledge of frogs. Dictionary: amphibian, molting, molting. To acquaint with riddles, a saying about a frog and idiom "tongue untied". Exercise children in onomatopoeia. To develop fine musculature of the hands. To educate children in interest and humane attitude to nature.
Equipment:
Pictures and photographs of frogs, cards with the image of eggs, tadpole, fry, frog, colored paper, equipment for paper construction.
Frog
Frog
Course progress:
Today we will learn a lot of new and interesting information about the well-known inhabitant of our Crimea. About whom the speech will prompt you a riddle.
The riddle of a frog
Not a beast, not a bird
Total afraid.
Catch flies -
And into the water - a splash!
(Answers of children). What in the riddle made you think of a frog? What can you tell about the life of frogs? (Answers of children).
Frogs settled throughout our peninsula. They live in rivers, lakes, ponds.
Frogs hibernate in companies at the bottom of ponds or somewhere under stones, in rotten stumps, in rodent burrows. It happens that in winter the frogs freeze in ice, and in the spring they still wake up alive and healthy.
Tell me, do you know how we breathe? (Answers of children). Inhale the air through the nose, draw it into the lungs and exhale. So the frogs also breathe, but not in the winter. In a state of winter rest, they breathe not in the lungs, but in the skin. This is what helps them survive the difficult and cold times. Well, if the winter in Crimea turned out to be warm, then the frogs may not fall into hibernation at all.
In early spring, all the sleeping frogs wake up and begin to feed. As soon as they feed and gain weight, they begin to prepare for weddings. Frog weddings and songs begin most often after the first spring thunderstorm and proverb notes: "The first thunder unleashed the tongue of frogs and cuckoos." How do you understand this saying? What does the expression “untied the tongue” mean? (Answers of children). “Unleashed the tongue” is when, after silence, they begin to talk a lot, or, like frogs, sing. What do we call frog singing? (Answers of children). Croaking.
Listen to our frogs sing: “aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaOnly males sing and conscientiously, loudly and diligently. Let's try to sing frog songs ourselves. Repeat after me. (Onomatopoeia on the model of the teacher).
People like frogs to sing differently. One likes it and gives pleasure. In Japan, for example, frogs are kept in the house and listen to their croaking. And in France, in the old days, rich people made their servants beat the water all night with sticks to stop the frogs croaking. But the frogs do not give concerts for a long time, as soon as the females spawn, the frogs will calm down. By this time, all the brides and the entire territory have already been divided by the males and there is no need to yell: "Here is my bump, not yours!", "This is my bride, not yours!".
Frog weddings take place in the water, as the female spawns only in the water. There are a lot of eggs. First, tadpoles appear from the eggs, then they grow into such fry, but when the tails of the fry fall off, they become real frogs.
There’s even a riddle about this:
Grew up -
The tail was growing
She wore a dark dress.
Grew up -
It turned green
I changed the tail to the oars.
How do you understand the expression "changed the tail to the oars"? (Answers of children). Arrange the pictures in order of what happened first and then what. (The work of one child with pictures at the board "egg-tadpole, male-frog").
While the frog grows, he sheds four times. What does it mean "shedding", "molting"? (Answers of children). Shedding means changing the skin, and the time for changing the skin is called molting. The skin comes off first from the legs, then from the body, and when the frogs are released from it, then they immediately eat it.
Let's move a little bit, play the fun game “Two Frogs”.
The game "Two Frogs"
We see, jumping along the edge
(Turns to the sides)
Two green frogs.
(Half squats left and right)
Jump-jump, jump-jump,
(Crossing from toe to heel)
Jump from heel to toe.
There are two girlfriends in the swamp
Two green frogs,
(Hands on the belt, half-squats left and right)
Wash your face early in the morning
The towel was rubbed.
(Perform movements in accordance with the text)
Stomped feet
They clapped handles.
Leaning to the right
Leaning to the left.
That's health is the secret
(Walking on the spot)
Hello to all my friends!
Frogs feed on insects, but on occasion eat tadpoles (both their own and others), fish fry, snails. But their main food is mosquitoes and all kinds of midges. Listen to another frog puzzle:
The riddle of a frog
The little animal is jumping, Not a mouth, but a trap. Will fall into the trap Both mosquito and fly.
Frogs are wonderful hunters. During the night they eat whole clouds of mosquitoes and midges. That's what they help people! But some people do not like frogs. It is believed that if you take it in your hands, then warts will appear on your hands. Firstly, this is not true, and secondly, why grab frogs with their hands. Their body temperature is colder and our hands seem hot to them, like stoves. And some, completely unreasonable people, believe that if you kill a frog, it will rain. What can you say about this? (Answers of children). Everything in nature was not created by chance, and every creature has the right to life. And to kill someone means not only to do evil, but to embitter your heart, to make it cold and callous. But I am sure that you will never do this, because your hearts are kind and you love nature.
And there are enough enemies for frogs and besides humans: Birds of prey, weasels, wild boars, martens, snakes and, of course, water birds. Which of them do you know? (Answers of children). Cranes, herons, storks.
The frog belongs to amphibians. Let's try to figure out for yourself what an "amphibian" animal means. What words does this word consist of? How do these words relate to a frog? (Answers of children). Listen to the saying about the frog: "Maybe because the frog is amphibian, because it does not understand where it is better?" That's right, amphibians are called those animals that live in water and on land. Can you remember some other amphibians? (Answers of children). Turtles, toads.
Listen to the story of N. Sladkov “Zhaleikin and the Frog”.
"Zhaleikin and the Frog"
Under a hummock in a wet swamp, Zhaleikin noticed a small weak frog.
- Poor, miserable baby! - exclaimed Zhaleikin.
“How bad you are, poor thing, in this dirty swamp!” Dark, damp, cold! But do not be discouraged! I will save you, at my place you will feel good and comfortable.
At home, Zhaleikin put the frog in the most beautiful painted casket, laid soft dry cotton wool on the bottom, put the casket in the warm sun and laughed merrily with joy.
Remember, frog, my worries! You will live now in warmth, dryness and purity. Not like in your dirty swamp!
And the little frog is not happy. A little frog isn’t fun. He is very ill, he is a little alive. He overheated in the sun, withered and tangled in cotton.
As Zhaleykin saw him, he roared. In total, the frog doused with tears, and on time: a little more - and the frog would have died (died). Jaleikin rushed with a frog to the swamp. The one where it is damp, dirty and cold, but where the frog is as good as Zhaleikin in his warm and clean room.
Nowadays, in some countries, frogs have become a rarity. This is a warning to people: frogs must be protected! And in any case, do not take them from nature to your home as if out of pity. In fact, this person destroys a living harmless creature. Everything that exists in nature must be preserved, regardless of whether we like this plant or animal, or not. There are no useful and harmful in nature, each is important, each has its own role and place. Popular wisdom says: “Where he was born, there he came in handy.”
Now we will make a frog of colored paper with you. And in order for everything to work out wonderful, we will practice our fingers a little.
Finger gymnastics
Two funny frogs
(Children clench their hands into fists and lay them down on the table)
Not a minute sitting
(The fingers straighten sharply as if bouncing over the table)
Cleverly jumping girlfriends.
(Lay palms on the table)
Only spray up fly.
(They clench their fists sharply and again put them on the table)
The design of the paper "Frog".
The questions are:
1. Where do frogs live?
2. How do frogs winter?
3. Tell us about frog weddings.
4. When do frogs croak? Are all frogs croaking?
5. How do people relate to frog singing?
6. How are frog babies born?
7. Do frogs molt? When?
8. What do frogs eat?
9. Why are frogs amphibians?
10. Name the enemies of the frogs.
After noon:
The mobile game "Frogs and Heron" is held, music game "About frogs and mosquitoes."
Learning the Poet "Laughing Frogs"
(tell poems with your hands)
Objectives: To develop memory, attention, motor skills, rhythmic movements.
Two laughter frogs
(Showing the index and middle fingers, the rest pick up)
Jumped, jumped.
(Depict jumping in the air with fingers)
Paw - clap,
The other is clap
(Palm clapping rhythmically on the leg)
Cheeks were bloated.
(Show roundness with fingers around cheeks)
They saw a mosquito
(They make a pinch of three fingers, depict the flight path of a mosquito, trace it with eyes)
Shouted: “Kwa-kwa-kwa!”
(The thumb is placed against all the others, portraying the opening and closing of the mouth)
A mosquito flew away like the wind.
(Make a sharp movement of the hand forward, stretching out the index finger)
Good to live in the world!
(Stroking a palm across the chest)
At first, the children only repeat the movements (slowly), then arrange individual words, then whole phrases.
Talk about frogs? Do not think that you know everything about them !!! Personally, while I was collecting information about frogs on books and websites, I read so many interesting things !!! I’ll share something here with you)))
The first on our list of amazing frogs will be -
Poisonous frogs and toads
The tiny Cuban frog is very poisonous. The poison of this baby can paralyze or even kill a person. Among tree frogs, there is one person "named" pumilio - the dose of the poison secreted by her can be the last for several adults at once.
The Indians applied the venom of the toad to the tips of their arrows in order to kill the enemies.
And the glands tree frogs - Drevolaza secrete hallucinogens, causing a change in consciousness, hallucinations.
So do not rush to stroke the frogs and, even more so, do not kiss them in the hope of the appearance of a substitute for an amphibian - a beautiful princess. To Ivan Tsarevich at the time, too, a hallucinogenic frog is possible.
Centenarial frogs
The Spur frog can live 33 years, and the gray toad feels quite well for 36 years. Our frogs do not reach champions, their life expectancy is about 18 years.
Frogs are able to remove foreign objects from their bodies.
The discovery was made absolutely by accident by Australian scientists. During the experiments, sensors were implanted in the bodies of frogs. Three weeks later, the frogs were caught and it turned out that most of devices moved to the amphibian bladder. Specialists found that when a foreign body appears, soft tissues begin to grow to it, which gradually envelop the object and draw it into the bladder.
Jumping champions
Tiny tree frog from South America, the size of which does not exceed 17 mm can jump to a distance of 75 cm. A long-legged nimble frog, living in northeastern Spain and southeastern Europe, can jump up to 1 m in height and up to 3 m in length.
Third Eye
Yes Yes Yes! Frogs have three eyes. In addition to the two familiar eyes, they also have a third, frontal eye, epiphase. In appearance, it looks more like a simple wart. Frogs use it as a thermometer. Unfortunately, scientists have not yet been able to solve the mystery of the third eye, but it is known that in ancient times it also performed a visual function.
Why frogs often blink often during eating
Frogs cannot chew food and cannot tongue push it into the throat. How do they get out of the situation? They push food with their own eyes, drawing them into the skull with special muscles - this is why frogs often blink while eating.
Frogs - Parents
Dark frog frogs, sweeping eggs, do not leave it to their own devices. Hatched larvae climb onto the parents' backs, adhere to them and are thus transported in search of food.
A male midwife toad spins one or more of his “wives” on himself, forming something like a cocoon. He remains immovable until such time as the kids get stronger and leave his body.
Snub-nosed frogs carry their eggs in the stomach, and hairy ones in the mouth.
The toad - peeps on the back have special craters with caps, sort of houses for frogs.
It is interesting that among the toads there are also viviparous. And even more interesting is that the pregnancy of the toad lasts exactly 9 months.
Singing frogs
The most loud-voiced representatives of frogs are able to cover a radius of several kilometers with their singing! There are those who sing exclusively in unison. Often the tunes are very beautiful, as the males adapt to the songs of their neighbors. The voice of a Japanese frog, a longhorn, is like a bird singing. And when you hear the singing of a frog - a bull, you can easily panic in a panic, deciding that there is an unknown huge beast nearby.
The organ of hearing in the lungs?
Panamanian gold frogs lack the outer and middle ears. But they are able to distinguish and recognize sounds. The primary perception of sound waves occurs in these frogs in the lungs. True, scientists have not yet figured out how sound from the lungs reaches the inner ear.
The frog (Rana) is a representative of the class of amphibians belonging to the order of tailless, a family of real frogs.
Frog description
All representatives of frogs do not have a pronounced neck, their head as if fused with a wide and short body. The absence of a tail is reflected in the name of the detachment to which these amphibians belong. On the sides of a large and flat head are convex eyes. Like all terrestrial vertebrates, frogs have upper and lower eyelids. Under the lower eyelid, you can find a blinking membrane, the so-called third eyelid.
Behind each frog eye there is a place covered by a thin skin (tympanic membrane). Two nostrils, which have special valves, are located slightly above the huge mouth with small teeth.
The frog's forepaws, equipped with four fingers characteristic of all amphibians, are rather short. The hind legs are highly developed and have five fingers. The space between them is tightened by a leathery membrane, the fingers of the limbs do not have claws.
The only outlet located in the back of the torso is the cloacal opening. The frog's body is covered with bare skin, thickly greased with mucus, which is secreted by special subcutaneous glands.
The frog sizes range from 8 mm to 32 cm, and the coloring can be both one-color (brown, yellow, green), and motley.
Species of frogs
The entire diversity of these amphibians is represented by subfamilies:
- frog-shaped frogs;
- buccal frogs;
- african forest frogs;
- real frogs;
- dwarf frogs;
- discoled frogs.
In general, there are more than 500 species of frogs in the world. In the territory Russian Federation the most common are pond and grass frogs. The largest frog in the world reaches a length of 32 cm - this is a goliath frog. The smallest frog in the world is a leaf frog, 2 cm in size. In general, all species of frogs are striking in their diversity in size and color.
Where does the frog live?
The distribution range of frogs is huge. Due to the fact that the representatives of this species are cold-blooded, it does not include areas with a critical climate. You will not find a frog in the sandy deserts of Africa, on the ice fields of Taimyr, Greenland and Antarctica. Some islands of New Zealand once did not enter the area where frogs were distributed, but now there are separate populations of these animals on them. The distribution of some species of frogs can be limited both by natural causes (mountain ranges, rivers, deserts, etc.), and man-made (freeways, canals). In the tropics, the diversity of species is much greater than in areas with a temperate or cold climate. There are separate species of frogs that are quite capable of living in salt water or even beyond the Arctic Circle.
