Frogs are amphibians, and the most primitive frogs began to evolve in the early Triassic. The earliest frog with jumping action appeared in Jurassic. Because frogs are amphibians, they must live by the water.

Frogs belong to the animal kingdom, Chordata, Amphibia, Anura, Protozoa, Metazoa and Newborn Animals. English name frog.

Anurak is an amphibian. Adults are basically tailless. Eggs are usually produced in water, hatch into tadpoles and breathe through gills. After metamorphosis, adults mainly breathe through the lungs, but most skin also has some breathing function. It mainly includes two kinds of animals: frogs and toads. There is no strict difference between these two animals, and some families have both. Generally speaking, toads live on land, so their skin is rough; Frogs are slim and good at swimming. The two bodies are similar, with inconspicuous necks and no ribs. The ulna and radius of the forelimb healed, the tibia and fibula of the hind limb healed, the claws could not rotate flexibly, but the limbs were muscular.

Anurak is the first step for creatures to land from the water, which is more advanced than other amphibians. Although most of them can survive without water, their reproduction is still inseparable from water, and eggs need to undergo metamorphosis in water to grow. So it is not as advanced as reptiles, and it is completely possible to live without water.

[Edit this paragraph] Frog

There are about 4,800 kinds of frogs, most of which live in water, and some live in trees in the humid environment of the rainforest. Eggs are born in water, and some tree frogs can get through the tadpole stage by accumulating residual puddles in tree holes or plant leaf roots. In 2003, a new species of "purple frog" was discovered in western India. It lives in underground caves all the year round and only comes out to give birth when the monsoon brings rain.

It is difficult to distinguish frogs from toads absolutely. Some families, such as Bufonidae, include both frogs and toads.

The smallest frog is only 50 mm, which is only equivalent to the length of a human thumb. The biggest frog is 300 mm (more than a foot long). Its pupil is horizontal, its skin is smooth, its tongue is forked, and it catches insects head down along the front of its mouth. There are three eyelids, one of which is transparent to protect the eyes in water, and the other two upper and lower eyelids are common. There are two sound sacs on both sides of the head, which can produce * * * and amplify sound. Smaller varieties have higher frequency of calls.

Some frogs' skin secretes venom to prevent natural enemies. A tree frog secretion living in the Amazon rain forest was used by local Indians to make curare and seal their throats with blood.

Frogs are distributed all over the world except Caribbean islands and Pacific islands. However, it is rapidly decreasing around the world, mainly due to environmental pollution, climate change, invasion of alien species, human expansion and other reasons.

Frogs reproduce in a similar way to toads. They also feed on insects, but large frogs can prey on small fish and even mice. They basically hunt at night.

Frogs prey on a large number of field pests, which is beneficial to human beings. It is not only the natural enemy of pests, but also the guardian of harvest. The familiar and pleasant sound of frogs is actually like beautiful music that nature can never play, and it is a quiet and harmonious field song. "There is a bumper harvest in Taoxiang, listening to frogs." Farmers have the hope of sowing with frogs, and the joy and joy of harvesting with frogs!

Once upon a time, there were wide ponds in the suburbs and villages of the city, where frogs lived. However, almost overnight, it was swallowed up by the spread of the city. Some of the remaining frogs became real frogs at the bottom of the well. Although they survived by luck, they unfortunately lost their fields, lost their seedlings, lost the freedom of the world and activities, and even dared not call softly and slowly in the dead of night, as if afraid of disturbing the magnificent dream of the city, and as if calling away from their companions all the time. But more and more of their companions are moaning in despair in other corners of the city! A pair of greedy hands caught them from the ground and they were bought by a pair of numb hands. They haven't had time to take a look at this strange city, and they have become meat on the table of every household! Compared with those greedy or numb hands, their resistance is so weak and powerless, they only let out a cry of sadness and despair!

Most species of amphibians have declined on the earth, and the crime of making living species endangered is attributed to many aspects, the most important of which is the frequent human activities and the rapid development of global industry. On the one hand, it causes species extinction; On the other hand, due to industrial pollution, especially chemical industry pollution, the ecological environment has deteriorated more and more seriously, and wetlands have been destroyed on a large scale.

Recent studies have found that triphenyltin, as an agricultural fungal inhibitor, may cause distortion and even death of several frogs even if its content is lower than that in the field.

The fungicide triphenyltin is mainly used to deal with diseases in beets and potatoes, but sometimes it is also used in many crops, such as onions and rice. This inevitably pollutes the aquatic ecological environment, some directly pollute rice fields, and some also pollute rivers and ditches through surface runoff. Triphenyltin is very toxic to aquatic organisms, especially to the central nervous system of tadpole brain, because of its slow degradation in liquid phase and its enrichment in water.

Generally speaking, the higher the concentration of fungal inhibitors, the greater the toxicity to organisms. For amphibians, chemicals often lead to slow development, which makes it difficult for them to escape predators. This is probably the reason for the extinction of frog population in some areas.

There are other pollutants that have led to the decrease of amphibians in more areas, and acid rain is one of the chief culprits. In fact, almost all amphibian eggs and larvae can't survive in water with pH below 4.5. However, the pH value of acid rain is generally 3.5, which can reduce the normal pH value of pond and stream water to a fatal level. In Canada, Scandinavian countries and Eastern Europe, it has been confirmed that acid rain is the reason for the decrease of amphibians in ponds and lakes.

Perhaps the reduction of ozone is an unshirkable responsibility for the decline of amphibian population in a larger region or even in the world. With the thinning of the ozone layer and the increase of ultraviolet radiation, amphibian eggs will not hatch into larvae. Other amphibians most likely to be affected by enhanced ultraviolet radiation are those living in colder and closer polar regions. The ozone layer in those areas is the thinnest, so amphibians must bask in the sun to regulate their body temperature. As a result, the amount of radiation increased and DNA molecules were destroyed.

Environmental hormones may also be the reason for the decline of amphibians in the world. Pollutants decomposed by pesticides such as DDT may seriously damage the reproductive capacity of amphibians, similar to aquatic organisms such as fish and crocodiles. In fact, it has been found that this environmental hormone makes some female tree frogs masculine, and at the same time, it also makes other kinds of male tree frogs feminine. Therefore, these tree frogs can't have children. This hormone molecule, which is not easily decomposed in the environment, is deposited in the mud at the bottom of ponds and lakes and swallowed by amphibian larvae living at the bottom. This hormone can take effect in a small amount and is easily dispersed in the wind. So no matter where you are from, it will pose a global threat.

The increasingly serious greenhouse effect on the earth not only makes the climate change strangely, but also increases the number of frogs that gradually change color. There are all kinds of orange, white and even pink frogs in many places. This phenomenon is definitely not a joke between nature and human beings.

Many deformed frogs found in North America are caused by the high content of vitamin A complex in the living environment. Vitamin A complex contains retinoic acid, which is a hormone that can control the development of vertebrates in several important aspects, and its excessive content will also lead to human reproductive malformation.

In the United States, some seriously deformed frogs appear in wetlands near lakes and rivers. Some have only three legs, some lack front legs, and some have three or four hind legs. This news has aroused the shock and close attention of environmental experts and people all over the world. In this regard, some people think that it is a ghost caused by parasites, some people think that the culprit is pesticides, and others think that the destruction of the ozone layer leads to excessive ultraviolet rays polluting the environment and causing animal deformities. The biggest one is probably caused by water pollution. At present, it is certain that the water source is polluted by many substances, including special pesticides, heavy metals, chlorides, and of course other chemicals are not excluded.

Because frogs are amphibians, they are generally regarded as an accurate barometer or indicator of environmental sanitation. Frog embryos are more susceptible to teratogens when they are directly immersed in water during development. For people, although their embryos are protected by many factors in the development process, frog malformation caused by hormones will also affect people, and the possibility of human abnormality also exists. There is no doubt that frogs can be deformed and people can be twisted. It's only a matter of time before this day comes.

So our conclusion is: protecting the ecological environment means protecting human beings themselves!

Frogs refer to amphibians without tails, such as frogs (frogs with black spots) and toads (commonly known as toads). They belong to chordates, vertebrates and amphibians in classification. Because the naked skin can't effectively prevent the evaporation of water in the body, they can't live without boiling water or humid environment, and they are afraid of drought and cold. Therefore, most of them live in tropical and temperate rainy areas, and there are very few species distributed in cold zones. There are about 130 species of frogs in China, and almost all of them are experts in exterminating forest and farmland pests.

The common frogs in farmland are Rana nigromaculata, Rana zewalskii, Rana aurea, Bufo raddei, etc. The bullfrog introduced from Cuba can be regarded as a "giant" among frogs, and its body length can reach 20 cm. Its Cleisthenes songs are very similar to those of Niu Jiao, so they are called bullfrogs. In fact, there are big frogs in China, such as the tiger frog living in the rice fields in the south of the Yangtze River, which is over 12 cm long and barks like a dog. Echinofrog, also known as "stone chicken", lives in the mountains and streams in the south of the Yangtze River, with a body length of about 12 cm. So how big is the smallest frog in China? Just a little bigger than broad beans. In early spring and February, when it was still snowing in the north, flowers were in full bloom on Hainan Island. At this time, the sound of "quack" can be heard near the rice fields during the day. This is the smallest frog, courting. The body length is only 2.5 cm. When singing, a big bubble blowing sac will bulge at the lower part of the throat. Sometimes, you can hear the squeaking sound of water plants, which is a small frog that is not easy to be found-floating frog. The floating frog is gray, only 2 cm long, and often floats among aquatic plants, only showing its head. As soon as there is any movement, dive to escape. Although these frogs are small, they are natural enemies of small pests and termites. There are about a dozen tree frogs in China. They are light and thin, with suction cups at their fingertips. They are good at climbing tall trunks or bushes, and their body color is consistent with their surroundings.

The reproductive characteristics of frogs are hermaphroditism, fertilization in water and oviposition. The breeding time is about the middle and late April of each year. In the process of breeding, frogs have a very special phenomenon-hugging each other. It should be noted that the frog hug is not mating, but a link in the breeding process. Studies have shown that if male and female frogs are artificially separated (that is, there is no hugging process), then even during the breeding period of frogs, female frogs cannot excrete eggs. It can be seen that the biological significance of cuddling is that it can promote female frog ovulation. Generally, frogs lay eggs and fertilize in water. After hatching, the egg becomes a tadpole, lives in the water, and then becomes a young frog ashore. However, tree frogs lay eggs in different ways. The eggs laid by tree frogs with spotted legs are like a mass of white soap bubbles and a mass of cream, which are attached to aquatic plants. The most interesting thing is the Emei tree frog, which lays its eggs on leaves near the water. The egg develops in the egg and then falls into the lake to continue its development. Another example is the piano frog, which sings very sweetly. Before laying eggs, it will build a mud nest and then lay eggs in it. Some frogs belonging to tree frogs don't climb trees, but live in water. Some tree frogs, such as the red webbed tree frog and the black webbed tree frog, have wide webbed feet between their fingers and toes, which can spread their webbed feet from high branches to low branches, so they are also called flying frogs. Besides tree frogs, frogs with suckers include rain frogs and rushing frogs. Among them, rapids are special. They like to live in fast-flowing waters and can quickly cross rapids and climb rocks. The tadpoles of the turbulent frog are also very strange. There is a sucker in its abdomen, which can be adsorbed on the rock to avoid being washed away by the rapids. Toad is a rare frog unique to China. It first appeared in Emei Mountain and was later found in several southern provinces. The snout of this frog is wide, round and flat, and there are 12- 16 pyramid-shaped horny black spines on the male maxillary margin, so it is called mustache toad. The function of these "beards" is still under study. There are many kinds of frogs, but no matter which one, they mainly feed on pests.

[Edit this paragraph] The history of frogs

Frogs are amphibians, and the most primitive frogs began to evolve in the early Triassic. The earliest frog with jumping action appeared in Jurassic. With the continuous evolution of frogs, there are all kinds of frightening and grotesque frogs. Some frogs secrete venom to guard against natural enemies. The secretion of a tree frog living in the rainforest of the Amazon River basin was used by local Indians to make poison arrows and seal their throats with blood.

Frog ancestors lived in water at first, but later, due to the change of living environment, some rivers and lakes became land, and frog ancestors gradually developed from water to land with the change of environment. The change of living environment forces frog ancestors to make corresponding "adjustments" to their body organs to adapt to the change of environment. Some species that can adapt to land life survived. The moving organ has changed from a tail that swims in water to limbs that can move on land and in water, and the respiratory organ has changed from gills to lungs. Frog's ancestors did not completely change from aquatic to terrestrial, so they showed up in the development of frog larvae. The difference between tadpoles and frogs is the legacy left by their ancestors.

[Edit this paragraph] Frog's skills

Insect trap

Frogs like to eat small insects. Its insect-catching action is: a frog crouches in a small pit, its hind legs are curled and kneeling on the ground, its front legs are supported, its mouth is open, its face is up and its stomach is bulging, waiting for something. A mosquito flew over and dangled in front of the frog. The frog jumped up with a jerk, turned his tongue and fell to the ground again. The mosquito disappeared, and it sat quietly waiting.

singer

There is a bulging thing on the frog's mouth that can make a sound. When does it love to sing loudly?

In hot summer, frogs usually hide in the grass and occasionally make short calls. If there is a cry, the people next to them will scream a few times, as if singing to each other. Frogs are happiest after the heavy rain. At this time, there will be dozens or even hundreds of frogs croaking endlessly, and the sound can be heard for miles away, like a magnificent symphony, as if singing a hymn to the agricultural harvest!

Vocal cords are the vocal organs of frogs. Located above hilar cartilage. On both sides of some male frogs' squabbles, there are external sound sacs that can expand and vibrate, and the sound sacs produce * * * sounds, which make the frogs' songs magnificent and loud. When you walk to the pond after the rain, you will hear the cries of male frogs echoing each other, one after another, forming a chorus. Scientists point out that frog chorus is a veritable chorus, which has certain rules, including lead singer, chorus, chorus and accompaniment, and is closely coordinated with each other. It is speculated that chorus is much better than solo because it contains more information. Chorus is loud and far away, which can attract more female frogs, so frogs often use chorus.

Master of physical education

Its eyes are bulging, its head is triangular, and its crawling action is very slow. You may think it is a bit silly. However, as soon as you get close, you jump into the pond with duckweed. This jump is 20 times its length! Then, swim to the other side in the most standard breaststroke posture.

The Great Impostor

This frog has a white belly, a yellow-green head and back, and some dark brown stripes. Some have three white marks on their backs. Why are frogs green? It turns out that the frog's green clothes are a good disguise. It is almost the same color as the grass in the grass and can protect itself from the enemy.

Frog's head has two round and prominent eyes, a wide and big mouth and a long tongue. The back of the body is green with dark stripes and the abdomen is white. There are four legs under the body, the front leg is short, the back leg is long, and there is webbed toes. Frogs are amphibians. They can jump on the ground and swim in the water. They will make a "croak" sound, and the male will cry loudly.

In spring, frogs lay eggs on aquatic plants, and the eggs gradually become tadpoles. Tadpoles are black, round and have a long tail. Tadpoles grow up day by day, first the hind legs, then the front legs, and the tail gradually shortens and degenerates, and finally becomes a frog.

Frogs are experts in catching pests. Frog catches pests with its long and wide tongue. The root of the tongue grows in front of the mouth, and the tip of the tongue branches backwards, with a lot of mucus on it. As long as a small flying insect flies by, it will suddenly jump up, open its mouth, quickly stick out its long tongue and eat the pests at once. Frog's eyes are slow to see still things, but keen to see moving things.

[Edit this paragraph] Network terms

Boys with bad looks are often called "frogs" on the Internet.

Legend source:

It is said that there was an ugly man whose family wanted to arrange a marriage for him. The matchmaker threw up and ran away as soon as he saw him. Many times he is used to this, but his parents are unwilling. Every time the matchmaker comes, he brings a spittoon and says please wow. It means, spit, I knew you were going to vomit, but please spit in the spittoon to avoid soiling the ground. Later, it was spread out, and all the neighbors knew. The word "please wow" gradually spread. Later, it evolved into seeing an ugly person and saying, please wow, which means the story of contacting this young man. You are ugly and bad, which makes people want to vomit. After a long time, the word slowly evolved into a frog.

[Edit this paragraph] Frogs in Warcraft

The RPG diagram is real. The three countries have no equal middle finger.

[Edit this paragraph] Frog meat

Frog meat is forbidden for three reasons:

1. Frogs hibernate in the soil for more than half a year. After resuscitation, the body carries a variety of viruses and bacteria, which can not be completely eliminated even if cooked.

2. Nowadays, most crops use pesticides and fertilizers, and frogs often swallow pests of fertilizers and pesticides. If people eat it again, pesticide residues will poison people through the "food chain".

There is a parasite called Diptera in the frog. After people eat frogs with worms, Echinococcus bifidus parasitizes under the skin and around the kidneys, producing a liquid that causes local edema or abscess of these tissues. If it invades the eyeball, it can cause corneal ulcer, decreased vision and even blindness.

Frog meat, also known as frog, is now widely used in crops. Frogs often swallow pests with pesticides and fertilizers. If people eat them again, pesticide residues will poison the human body through the "food chain", forming chronic pesticide poisoning and even leading to various cancers.

Frog is a provincial-level protected animal that is forbidden by the state. However, in daily life, many people regard frog meat as a tonic or delicious food, which leads some vendors to kill frogs on a large scale. In fact, frog meat can't mend the body. Modern medical research has proved that frog meat not only has no special nutrition, but also affects human health and even gets parasitic diseases if eaten too much.

[Edit this paragraph] Dietotherapy value

Flesh of a frog, such as a black frog or a golden frog. Frogs are also called frogs, long stocks, frogs, green chickens, sitting fish and clam fish. It is widely distributed in China. The former covers almost all areas north of the Yangtze River basin except desert and northern grassland. The latter, north of the Yangtze River, north of Jiangsu, Anhui, Shandong, Hebei and other places are more. After getting it, remove the skin and internal organs, wash it and use it.

[Attribute] Sweet in taste and cool in nature. This product can tonify deficiency, strengthen stomach, induce diuresis, reduce swelling, and clear away heat and toxic materials.

[reference] contains protein, fat, calcium, phosphorus, iron, vitamins a, B 1, B2, B 12, c and nicotinic acid.

【 Use 】 Used for malnutrition, asthenia, malnutrition, emaciation and anorexia in children; Edema and swelling; Fatigue and fever.

[Usage] Cook soup, eat vegetables, or grind into powder.

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1, frog porridge: frog meat 100g, and appropriate amount of japonica rice. Add water to cook porridge. Season with salt and pig fat.

This recipe takes frog meat to nourish and tonify deficiency and stomach. Used for weakness and loss of appetite; Infants are malnourished and emaciated.

2, frog powder: 7 frogs, peeled, removed intestinal impurities, washed, wrapped with vegetable leaves, sealed with dilute yellow mud, marinated with fire, taken out and ground, once taken. Take it for 3 days.

This recipe uses frog meat to benefit stomach qi. Used for weak stomach, choking and nausea, and eating less. You can also seal frogs with mud and simmer cooked food.

3, clam fish: 3 frogs, put a little picrorhiza in each mouth, use 1 pork belly (washed), add frogs, tie them up, add appropriate amount of water, and simmer the pork belly until cooked. Send clothes with wine.

Originated from Shouyu Shenfang. This recipe uses frogs to tonify deficiency, induce diuresis to reduce swelling, pig's belly to tonify spleen and stomach, and picrorhiza picrorhiza to strengthen stomach. Used for spleen edema, sallow complexion, lack of food and weakness.

4, frog gourd powder: 2 frogs (dry), 7 crickets, aged gourd 15g, slightly fried. Grinding into fine powder or making into pills. Take 6g each time, with warm wine.

From Sheng Huifang. In this prescription, frog is used as a product for promoting diuresis and reducing swelling, and it is compatible with other good products for promoting diuresis and reducing swelling, such as strengthening body resistance and tonifying deficiency, mole cricket and aged wax gourd, and the effect is better. Used for "water is full of belly, sound is shaking, and skin is black." Modern used for nephritis edema, cirrhosis ascites.