Lions live in the White Sea and Barents Sea. Their body length is 50 cm, and their appearance is not kind. Their names seem to give people a cruel impression of the law of the jungle. But who would have thought that the male lionfish has a fatherly heart and the skills to take care of children?
Because the female lionfish lays eggs at the edge of the low tide sea, the male lionfish assumes the responsibility and obligation of his father in time. In addition to protecting fish eggs from fierce animals, you should also spray water from your mouth on them at low tide to keep them moist. Occasionally, they beat the sea water with their tails and spray the splashing water on the fish eggs. After the eggs hatch into young fish, their father's love has not decreased, and they still accompany and guard the young fish as always. In case of danger, the young fish with suckers swam to the fish father. Soon, the fish father was surrounded by young fish that absorbed his body. It seems that they don't know who is guarding who between father and son. In this way, the loving father swam to a safe place in the deep sea, full of small fish adsorbed on his whole body.
Fish's "bearing children"
Fish is an animal with amazing reproductive ability. However, in terms of bearing children, they have always been masters of extensive cultivation and poor management. Most fish reproduce by laying eggs. Bream spawns about 25,000 eggs each time, carp and pike spawn 65,438+million eggs each time, winter cave fish 300,000, mountain catfish 500,000, sturgeon and cod as high as several million. Molas spawn the most in the world, 300 million at a time. After laying eggs, most fish ignore the survival of offspring, so only a few percent of children can grow into big fish.
But there are also very few fish animals who care about the healthy growth of their offspring. Stichopus japonicus has the properties of nesting and guarding fish eggs. Male Stichopus japonicus in mating period has beautiful skin and body color. They tirelessly spread the branches and stems of aquatic plants in pre-dug pits, and the roof and walls of the nest are also made of the same building materials. The stems, branches and leaves of these nesting grasses are firmly stuck with mucus. Some sticklebacks also hang spherical nests in aquatic plants. After the "delivery room" is completed, the male fish leads the female fish. After spawning, the female fish abandon the nest, and the male fish stick to his post, guard the eggs in the nest, and swing the fins from time to time to maintain the circulation of living water in the nest and promote the development of eggs. Even after the young fish hatch, males still care about their healthy growth for a certain period of time.
Some ornamental fish (such as fighting fish) kept in fish tanks are also made by males. However, they never use plants as building materials. Instead, we choose an inexhaustible special building material-bubbles made of fish mouths. The male fish tries to make a fish egg in each bubble, which requires the bubbles to be evenly distributed. All this work is done by a fish mouth. If the eggs unfortunately sink to the bottom of the water, the male will try his best to salvage them and put them back into the bubbles suspended in the water. During the whole hatching process of fish eggs, males carefully adjust the position of bubbles to make them evenly distributed. After the small fish hatch, the male betta should not only guard against the injury and attack of other fish, but also prevent the tragedy of the female spawning fish swallowing their own children. Even attack the fingers that dare to reach into the fish tank to ensure the safety of young fish.
The tail of a mudskipper
An elusive mudskipper grows in India. It lives in mud for a long time, and can't live without water, but it can move freely on land, climb trees and prey on insects. Its unique lifestyle of breathing with its tail is even more fascinating. The skin on the tail of the mudskipper covers the branches of blood vessels. It is found that when it goes ashore to catch insects, it always puts its tail into the water together with its tail fin. After it flies and lands, its tail will still stay in the water.
The mudskipper may draw oxygen from the water with its tail, but the test results (the oxygen content in the water is extremely low) refute this guess. It turns out that the mudskipper put its tail in the water not to absorb oxygen but to absorb water. The purpose of water absorption is to keep all parts of the body moist and moist, which further meets the need to secrete a lot of mucus from the body surface to obtain oxygen in the air, and the oxygen obtained through the tail is very small. The reason why the mudskipper can stay out of water for a long time is that its tail can supply water to its body, so that it can breathe on its surface. In this way, its tail becomes a serious respiratory organ.
The prestige of cobia
The reputation of cobia, even its prestige, comes from its radiant appearance. Raccoon fish not only has a distinctive body color, but also has special luminous points arranged neatly, which are like metal buttons decorated on officers' uniforms and shiny military medals. Not only dazzling, but also the number of bright spots is amazing, with about 300 lantern-like luminous organs.
The surface of these luminous organs is covered with an opaque film, and its inner surface has high smoothness and can reflect light. There is a lens device at the front end of the light-emitting organ, which leads to the light-gathering effect. A kind of mucus inside the light-emitting device has the property of emitting light in the dark. I don't know whether cobia naturally doesn't like to be conspicuous, or because of the consideration of saving energy, it hardly needs its own "spotlight" to illuminate. Only in the mating season will cobia release its "light control" and show its prestige and shine.
The "golden voice" of fish
Most people always think that fish is silent. In fact, all fish can not only pronounce, but also make a "golden voice".
People's favorite yellow croaker has a golden voice and can sing three different sounds: "flower", "giggle" and "cough". Its "singing voice" often leads to disaster. Fishermen can judge the number and swimming direction of yellow croaker according to its special sound, volume and melody, so as to catch them all. Dog tongue fish, a kind of fish that lives along the coast of China, has a pleasant singing voice, crisp and changeable, sometimes like a frog, sometimes like a harp, and sometimes like a bell. You're a genius at ventriloquism. There is also a kind of sea chicken, also known as cockroach, which can imitate the cock crow; Drum fish will make a sound like a drum. If we can gather all kinds of "golden voices", we can really form a fish symphony orchestra.
The secret of fish's voice lies in fish whoring. When the swim bladder is squeezed and contracted by muscles, bubbles are released in the swim bladder, thus forming sound. Usually, not all fish sounds can reach people's ears. Many times, when fish perform singing skills, humans don't appreciate it because of the barrier of water. If you have the opportunity to collect all the wonderful songs of fish and hold a concert of fish, it will definitely make people very happy.
How much do you know about the types of goldfish?
Goldfish evolved from wild crucian carp. But today's goldfish and its ancestor crucian carp have nothing in common. Goldfish are colorful, including red, yellow, black, blue, purple and various variegated colors; The posture is also varied, with various shapes, including long body and short body; Tail fin has single and double layers, including upper single, lower double and three tails, vertical tail, unfolded tail and so on; There are also a variety of head types, including flat head, goose head and lion head; Eyes include normal eyes, longan eyes, celestial eyes and bleb eyes. All kinds of colors.
The combination of body shape, head shape and eyes constitutes different varieties of goldfish. How many kinds of goldfish are there? According to statistics, there are more than 200 kinds of goldfish today.
How did so many varieties of goldfish come into being? Zoologists investigated the family history of goldfish with great interest. According to the available data, goldfish were domesticated from wild to domestic from about AD 1 163. Goldfish have been living in domestic ponds for about 300 years. Since 1547, goldfish have been kept in ponds, not in family basins. While enjoying goldfish in the goldfish bowl at home, people began to pay attention to protecting and preserving some beautiful varieties and eliminating some less beautiful ones. After so many years of domestication, especially through conscious artificial hybridization and artificial selection, goldfish have finally formed so many dazzling goldfish varieties today.
Talking about electric fish
The voltage generated by different kinds of electric fish generators varies greatly. Known as "Shockman", the double-fin torpedo can generate 45-80 volts, the electric catfish in the Nile in Africa can generate about 450 volts, and the electric eel in South America is even more powerful, which can generate 900 volts. If people and animals step on electric eels, they will be electrocuted and life-threatening. The discharge frequency of electric fish is different, and the high frequency discharge can reach 250 ~ 280 times per second. Low frequency discharge is only 10 ~ 20 times per second. The discharge of electric fish is not endless. When the electric energy is exhausted, the discharge will stop, and after a period of rest, the discharge ability will recover.
The electric fish generator is a tool for its self-defense or predation. The generator is controlled by the brain, and the electric fish can completely control the intensity and time of its discharge. So far, any kind of energy storage device of human beings has never surpassed the fish generator in structure and efficiency. The fish with power generation capacity are collectively called electric fish, and there are about 250 known species. Among them, there are electric eels living in tropical waters of South America, electric gill long-billed fish in tropical waters of Africa, double-fin torpedoes, single-fin torpedoes and hard-skinned torpedoes in the South China Sea of China.
The electric fish can generate electricity because it has a generator. The basic structure and power generation principle of this generator are basically the same as those made by human beings, but the components are different. The generator of electric fish is composed of muscles or some tissues, and the wires are nerve endings, while the artificial generator is mainly composed of some metal components, and the metal wires are used to transmit current. The generator of electric fish consists of many polygonal muscle columns, which are divided into many small spaces and separated by connective tissue electrodes, thus forming a battery-like structure in series. The electrodes in the column are like the electrodes of a battery. One side of the electrode is connected with a cluster of nerve endings, and the other side is a positive electrode without nerves. The electrode is dominated by the brain and spinal nerves. When the brain sends out a discharge signal, the circuit of the generator is immediately energized and then discharged; When the brain stops sending out signals, the circuit of the generator is immediately interrupted. The ingenious point of stopping power generation is the research interest in bionics.
"Fish Doctor" for Malaria Control
Everyone knows that malaria is a disease that makes patients feel cold and hot, and the vector of this disease is annoying mosquitoes. Indeed, in the process of malaria infection and transmission, the damn mosquitoes played a disgraceful role. Mosquito-eating fish, which originated in America, is the bane of mosquitoes. Although mosquito-eating fish are small, only 2.5 ~ 3 cm long, and their living environment is not high, their ferocity in preying on mosquitoes is unambiguous. Because of this, mosquito-eating fish were introduced to malaria endemic areas all over the world, and successfully propagated in various water surfaces and rice fields under natural conditions, effectively preventing malaria epidemics and even playing a decisive role in the battle to eliminate malaria viruses. Back here, mosquito-eating fish is well-deserved as a "fish doctor" to prevent and treat malaria.
Professional mosquito eater
There are many "experts" who eat mosquitoes among fish. According to statistics, there are more than 90 kinds of fish that eat mosquitoes all over the world. Crucian carp, carp and catfish from China are all experts in swallowing young graves. Among them, the wicker fish, which enjoys the reputation of "professional" mosquito-eating fish, is one of the best. Wicker fish is very small, about 1 ~ 3 inches long, and its body is as long as willow leaves. Swim fast, often shuttle between aquatic plants to catch mosquitoes for a living, and can prey on more than 200 cockroaches every day. Someone has done statistics. In 10,000 cubic meters of water, as long as a wicker fish is released, all animals in the water can be destroyed. This kind of fish is also a kind of "prolific" viviparous fish, which can breed once a month or so, with an average of about 30 per fetus. Nowadays, many countries breed a large number of wicker fish to kill mosquitoes.
The betta fish in China, also known as "Yan Qian fish", is slightly inferior to the wicker fish, but its reputation as a mosquito-eating fish is not small, and it can eat more than 160 every day. In addition, arhat fish also takes catching mosquitoes as its own responsibility, preying on about 50 dragonflies every day.
Why can fish thrive in water?
"The sea is wide and the fish jumps, and the sky is high and birds fly." The sky is the domain of birds, and water is the world of fish. Why can fish dominate and thrive in the vast sea and lakes? Because nature gives it the ability to live in water.
Due to the influence of various environmental conditions in water, fish have various shapes. But the fish that live best and have the largest number are spindle-shaped. Streamlined spindles can greatly reduce the resistance when swimming in the water. People with good figure often have a slippery liquid, which is mucus secreted by fish skin. This mucus is evenly coated on fish scales, which makes the streamlined appearance look like lubricant and reduces the friction between fish and water during movement. There are many fins on the trunk of fish, which are the moving organs of fish, including paired pectoral fins and ventral fins, as well as unpaired dorsal fins and buttocks. Each fin has its own division of labor. The pectoral fin and ventral fin are responsible for balancing and changing the direction of movement, while the caudal fin, gluteal fin and dorsal fin control the direction of movement to prevent the fish from swinging from side to side. The underwater world is not a peaceful world, sometimes the wind blows high; Sometimes it heats up, sometimes it cools down, sometimes it is cold and sometimes it is hot; Sometimes there are other kinds of "sneak attack" and "robbery". For these, fish have their own coping instinct. On both sides of the fish body, there is a special sensory organ. Sensory organs communicate with the outside world through small holes in scales. Many small holes in the fish scales are distributed on both sides of the fish along the sensory organs, in a line. This line consisting of the arrangement of scale holes is called lateral line. Through this lateral line, fish can feel the direction of water flow, water fluctuation, water temperature and sound waves in the water. Once the wind blows "water", the side line will immediately notify the fish, and the fish will immediately make emergency preparations.
Nature endows fish with "18 martial arts", so it is no wonder that fish can spread all over almost all waters in the world and develop their own teams, making fish the largest family of vertebrates.
Bullfrog's "bull" temper
Bullfrog originated in North America, so it is called bullfrog, because it has a kind of "cow" temper.
Walking into the territory where bullfrogs live is like walking into a cattle farm. Cleisthenes's cows can be heard two or three kilometers away. This is the cry of a bullfrog. No wonder people call it bullfrog, and it really lives up to its reputation. The bullfrog is huge among frogs, with a body length of 20 cm and a weight of 600 grams. In particular, its hind leg muscles are very developed, which can be compared with the muscles of cattle's hind legs. The hind leg muscles are not only strong, but also as nutritious as beef. This is a delicious dish. Because the bullfrog is huge, it can only be caught by shooting with tiny shrapnel, but the bullfrog is a protected animal and can only be hunted at a designated place and time. Bullfrogs have a big appetite, too. They can eat all kinds of insects and mollusks, catch small fish and even catch ducklings playing in the water.
Toads are not bad.
The scientific name of toad is toad, which is an amphibian in the subphylum of vertebrates. The so-called amphibians can live both on land and in water.
Toads are bumpy all over, and they often make ugly cries together during the breeding season, which makes people feel very unhappy at the sight of toads. Toad is ugly, but it's not bad.
Toads are experts in eating harmful insects. A large toad living in Central America and South America has made great contributions to exterminating pests for many times. This big toad is 25 cm long, 12 cm wide and weighs 1 kg. Its main food is some insects harmful to tropical crops. /kloc-in the 0/9th century, tropical crops in the West Indies were attacked by pests, and this big toad was transported there, where it preyed and propagated, and the local pests were completely eliminated. In 1930s, 65,438+050 big toads were transported by plane to Hawaii Islands to protect the sugarcane fields there. A few years later, the toad multiplied rapidly and successfully completed the task. Later, the descendants of these big toads bred in Hawaii were transported to the Philippines, New Guinea, Australia and other areas with tropical crops. The toad also performed well, creating brilliant achievements in eliminating pests.
To understand the good things toad has done to mankind, should we change our impression of it? In fact, the acne on its skin is just some skin glands that can secrete mucus, which can always keep the skin moist. Some papules may also secrete venom, which is mainly used to deal with pests. There is a gland behind toad's ear, which can secrete a substance called toad venom and can be processed into medicine.
Sky blue frog
As the name implies, the skin of "frog" should be turquoise, of course, many frogs are brown-gray. But few people know that the beautiful sky blue will become a frog's coat. A frog with a pointed nose. When spring comes to the earth and everything recovers, it is also like people taking off their winter clothes, putting on their own spring clothes-a special erotic color. But this sky-blue body color only appears in water. Once it leaves the water, its body color returns to its original color-not very bright brown-gray.
In fact, in the animal kingdom, many animals, such as stickleback fish and betta fish (ornamental fish), all have physiological phenomena similar to the body color variation of the pointed-nosed frog in estrus. Sensitive lizards used to be gray-brown, but they turned into beautiful bright green in spring, and they can maintain this vivid and gorgeous image throughout the breeding period.
Fur coat of hairy frog
Hairy animals are generally mammals. Frogs have always been hairless, but in Gabon, Africa, there is a hairy frog with long breasts and limbs.
Why did the frog put on a fur coat? Is it to keep out the cold? In fact, don't say that Gabon, which is located in the tropics, doesn't need to keep out the cold and freeze. Even frogs living near Europe and the North Pole don't have such "fur" equipment. Only by observing this strange "fur" under a microscope can we see its true colors. It turns out that those long hairs are just protrusions on the skin, which play the role of gills and are a special amphibious respirator. It is also found that only males have long hair, because male frogs consume a lot of physical energy during the breeding season. Without the help of these "body hairs", Rana chensinensis will have difficulty breathing and lack of oxygen in the body, which can not meet the physiological needs of special periods.
Frog's eccentricity
Frogs are nontoxic and easy to raise. It is a good species for medical biology research and in vivo experiments, but it also has a quirk, that is, it must use live animals to satisfy its hunger, otherwise it will hunger strike. The reason for this quirk is not that the frog is picky about food, but that its eyes can't see the motionless food at all. Frogs turn a blind eye to the colorful world, just like sitting in front of a faulty TV set and seeing only a gray color. Once any creature passes through this gray screen, it is impossible to escape from the frog's big eyes. Therefore, frogs often make sure that their prey is moving.
Frogs, as amphibians, lost their eyesight to observe the world when their ancestors climbed from the water to the land a long time ago. In addition, their organs that receive sound and smell information can't adapt well to the environmental transformation from water to land, so they have to rely on visual functions to get food, leaving a lifelong regret of "keeping silent when they see movement".
Frog ancestors
There is a cartoon called Little Tadpoles Looking for Mom. After many twists and turns, the tadpole found mother frog. Because "mother" and "child" look so different, tadpoles look for their mother according to their own appearance. No wonder it is difficult to find them.
Although tadpoles are "children" born by frogs, they are not like "mothers" from the outside to the inside. Tadpoles are all black, with a small tail behind their watermelon-seed-like bodies. Like fish, it can only live in water, but it can't live without water. The swimming organ is its small tail, and it breathes in the water with its gills. And its "mother", wearing a spotted "green coat", has strong limbs and no tail. She can swim in the water or live in wet land, because the frog has no gills after spending more time on land, and her skin can also breathe with her lungs.
Why are tadpoles and frogs so different? Because the ancestors of frogs originally lived in water, some rivers and lakes became land due to the change of living environment, and the ancestors of frogs gradually developed from water to land with the change of living environment. The change of living environment forced the ancestors of frogs to make corresponding "modifications" to their body organs to adapt to the change of environment. After many years, some species that can adapt to land life have survived. The moving organs have changed from tails swimming in water to limbs that can move on land and in water, and the respiratory organs have changed from gills. Some species that can't adapt to the change of land environment are either eliminated by nature and disappeared on the earth, or evolved into other animal species that still depend on water. The evolution of frog ancestors from aquatic to terrestrial is not complete, so the difference between tadpoles and frogs is the "legacy" left by frog ancestors during the development of frog larvae.
Reptiles of different sizes
The boa constrictor living in the Amazon River is the largest snake in the world. This python is 10 meter long and feeds on fish, birds, spiny rats and nutria. The smallest snake in the world is the blind snake, which is 20 ~ 30 cm long and about 8 mm thick. It lives in Transcaucasia and southern Central Asia and feeds on ants and other small insects.
The longest crocodile in the world is the bay crocodile, among which the elderly male crocodile is 10 meter long, good at swimming, and lives in some estuaries and coastal waters in Southeast Asia, northern Australia and New Guinea. According to archaeological excavations in Tertiary strata in India and America, an extinct ancient crocodile has a body 20 meters long.
Leatherback turtle lives in tropical waters of Indian Ocean and Pacific Ocean, and is the largest turtle in the world. Its turtle back is 2 meters long and weighs about 500 kilograms. Elephant turtle, which grows in the Galapagos Islands in the Pacific Ocean and some islands in the Indian Ocean on the west coast of South America, is the largest turtle on land, with a length of 1.5 meters and a weight of about 200 kilograms.
On an island called Komot in the Malay archipelago, a giant lizard grows, almost 4 meters long. It is hard to imagine that such a clumsy behemoth can still move with agility and ease. The sand lizard living in the desert of Central Asia is only 8 cm long. The smallest lizard in Central America weighs less than 5 grams and is 5 centimeters long. At the two extremes of this group of lizards, the body length is almost 100 times different.
Horned toad blood spray
Hypertension is the chief culprit of vascular system disorder and vascular rupture, which threatens human health and life. However, nature can also make use of the physiological phenomenon of hypertension to create a miracle of saving the day. A lizard (horned toad) grows in the Mexican desert of South America, which can skillfully use the local high pressure in the blood vessels of the head as a self-defense weapon.
When the horned toad encounters an emergency, the blood quickly enters the head and trunk parts such as the neck and back under abnormal high pressure. These congested parts will swell and straighten, the color will change, and its face will immediately become very scary.
The self-defense trick of horned toad lies in its unique bundle of special muscles-obturator internus. When it is desperate, the obturator internus will react quickly and pressurize the blood in the cerebral vessels until the pressure bursts the delicate blood vessels in the transient membrane, causing the blood to spray on the predator's face. The "blood rain" that Sui was caught off guard often made the attackers run away. It is said that within the radiation radius of 1.5m, this weapon can always defeat the enemy.
In addition to resisting foreign enemies, the obturator internus muscle also needs to meet its own development and growth. Jiao Shan's annual molting will never be so smooth, and then the obturator internus will glow. When the cerebral vessels are compressed, the expansion of blood vessels makes the head swell, thus tearing off the old skin. As soon as the old skin on the head is broken, the horned toad removes the old picture and the old shirt.
Strange eyes
At first glance, the word "evading service" sounds difficult to associate with an animal. However, refuge is actually the name of a arboreal reptile, also known as chameleon.
Among reptiles, the sanctuary family is the most perfect one. According to statistics, there are 85 species of refuge animals in the world. They are distributed in the African continent and Madagascar, and there is only one common refuge in southern Spain in Europe.
The escaped eyes have a special function, that is, the two eyeballs can "go their own way" and rotate in different directions without inhibiting each other. For example, when its left eye looks up and forward, its right eye can look down and back without interfering with each other. Conversely, the direction observation division of the left and right eyes can also be interchanged. One-eyed skill of jailbreaking; They can see in all directions without moving their bodies, and can catch all the clues and troubles, thus greatly improving their success rate of catching insects. It is not difficult for people who observe carefully to find that when they quietly approach insect prey, they will focus on the prey with one eye and look for shortcuts to attack and prey with the other eye.
Escape from exile island not only has special eyes, but also feet and tails that are good at climbing tree trunks. It can move freely on the branches and is quite agile. Its long tongue is usually curled. Once it meets a fighter, it will shoot out of its mouth like lightning, and its prey is assured.
There is also an instinct to change one's body color by putting oneself in another's shoes. They will change color with the stimulation of environmental color, which effectively protects themselves from accidental attacks by opponents. When they encounter an emergency, their mouths will hiss like snakes, and their lungs will expand rapidly, making their bodies become "behemoths" in a short time, posing as formidable figures and scaring off their opponents.
Crocodile's tail
Besides its long nose and big mouth, the most striking feature of crocodile is its big tail.
Crocodile is a reptile. It is speculated that its limbs and abdomen are muscular, so it can crawl on land and swim in the water. However, although its limbs are strong, they are big and short, and they can't swim in the water at all. Therefore, its tail shows superiority. In the water, the crocodile's tail is its only swimming organ. The big flat tail, like an oar in the water, pushes the crocodile forward with every stroke. But on land, crocodiles paid the price for their big tails. No matter how strong the crocodile's limbs are, it can only climb a short distance on land. It is very difficult to climb a long distance because of the drag of its tail. Perhaps because of this, crocodiles did not crawl from the water to the land in the evolution process and became terrestrial species, relying on that big tail to dominate the life of water.
There are not many crocodiles in existence, and the Chinese alligator in China is listed as a national protected animal.
Monty python nanny
Twenty-five years ago, a farmer in the Philippines hatched a small python from a snake egg. Since then, this python has lived with this farmer. Pythons eat only earthworms and frogs when they are young, and mice when they grow up. A bird and a rabbit. Later, the python grew into a 7-meter-long and 70-kilogram python, which could swallow a whole pig at a time.
This python, like a tame domestic dog, helps its owner do a lot of work. For example, looking after the yard and looking after the children of the host family. The child wants to play outside, and the python undertakes the task of protection in front. When the child is hot, the python will accompany the child to take a bath. When he was sleepy, the python rolled into a ball, surrounded the child in the middle and slept head to head. The master is busy with farm work all day and neglects to take care of the children. This python is inseparable from its owner's children all day and has become their "nanny".
Someone once suggested to the farmer to put the python back into the forest to see if it would like to return to nature. With the owner's consent, they sent the python to the forest by car. At first, the python crawled around for a while and drank some water by the stream, but returned to its owner's house three hours later.
Why do wild reptiles like pythons survive in the human family and work for their owners? This is a rather confusing question. But one thing is certain, animals also have feelings, but the way of expression is different from that of human beings. It can't use words, but only actions to express its likes and dislikes. As long as humans treat this domesticated animal harmoniously, people and animals can live in peace for a long time.
Snake tooth special effect
The teeth of poisonous snakes are scary, because snake venom comes from them. In fact, the poisonous snake's teeth are not poisonous, but the opening of the salivary gland that secretes venom is just in the alveolar space. Only when the snake bites hard, the small sac full of saliva at the root is compressed, and the snake venom will be released. When a poisonous snake bites a person or an animal, the snake venom is injected into the wound without omission, which quickly produces a terrible poisoning effect.
In the animal world, snakes are indeed "armed to the teeth." Cobra not only has superb biting skills, but also its exquisitely designed teeth greatly improve its poisoning effect.
Their distinctive teeth, the salivary glands used to inject venom into the esophagus, do not open at the regular tips, but are funnel-shaped at such a distance from the tips of the teeth. This design is obviously to pursue the spraying effect, that is, if the fangs don't bite deeply, their venom can't reach the deep muscles, but the poisonous fog formed by the funnel-shaped opening can cover the whole wound. Just like a shotgun, the farther the muzzle is from the target, the larger the killing area. In addition, cobra's terrible venom can range up to 4 meters, which makes the harm even more daunting.
The mystery of dinosaur extinction
Dinosaurs are huge animals that lived hundreds of millions of years ago. It belongs to the order Dinosaur among reptiles. Their size far exceeds that of elephants, rhinos and hippos today.
Now the world seems to be dominated by mammals, but it is conceivable that Mesozoic is the heyday of reptiles. Liang Long is the longest species in the dinosaur family. Its skeleton is 26.5 meters long from beginning to end, and its weight is less than 30 tons. Lei Long's bones are 24 meters long and weigh 50 tons. Brachiosaurus, Liang Long and Lei Long were vegetarians-they ate plants. Their bodies have a small head and a long neck. The limbs are stout and developed. Their habitats are generally distributed around lakes.
Raptor (Tyrannosaurus Rex) is the largest carnivorous dinosaur, with a body length of 14 meter and a height of about 5.5 meters. Raptors were also the most carnivorous animals in the world at that time.
Pterosaurs are flying dinosaurs. Agile pterosaurs are only as small as sparrows, while huge pterosaurs (pterosaurs) have a wingspan of 7.5 meters when they spread their wings with skin membranes.
Dinosaurs once had a glorious page in the history of biological evolution. However, this huge animal has not escaped the fate of extinction on the earth. This is because the living environment of dinosaurs is getting worse and worse when the climatic conditions have changed greatly. After all, the food provided by nature is limited, and the dinosaur's appetite is really amazing. More importantly, their bodies have not been able to adapt to the changes in the external environment, so they live in harmony with machines.