Living habits of crocodiles

There is only one kind of crocodile in China, that is, the small freshwater crocodile-the Chinese alligator. It is a national first-class protected animal. Living in water is one of the ways to survive. From reptiles to birds and mammals, there are many kinds of aquatic life. Generally, such animals have special adaptations

Crocodiles are temperature-changing animals, and they can hardly generate body heat themselves, so they have to rely on the outside temperature. When the crocodile is warm, its body basks in the sun or lies in a warm place, and when it is cold, it lies in the shade of a tree or enters the water. Their bodies have a special sense of the sun and wind direction. When the crocodile is warm, its heart beats faster, and more blood flows to the surface, which accelerates the absorption of heat and spreads it around the body, thus accelerating food digestion and body growth. But if you are exposed to the sun, you will die in a short time without any way to sweat or emit heat quickly. When the temperature is low, it will stop eating and become dull. Generally, when the temperature is 15 degrees, it will lose interest in food. When it is below 7 degrees, it will not be able to exercise normally and maintain balance in water.

Crocodiles breathe by their lungs, and they will drown in water for a long time. There is a bulge from the upper part of their nostrils to the tip of their snouts, and the internal cavity is backward to the throat. A tongue rises from the bottom of their mouths to the top in front of their throats, so that the crocodile's throat is closed when biting food or chewing underwater, so that water cannot enter the trachea. At the same time, the bulged trachea on the tip of their snouts can keep breathing normally on the water without using their mouths.

An adult crocodile lays an average of 4 eggs a year, which can last for 4 years, while a female crocodile cannot reach sexual maturity until 1 to 15 years. The nest is made of sand, plant leaves and grass roots. The female crocodiles grab the eggs and lay them in piles, and always guard the nest. The eggs laid are hard-shell like duck eggs, and they are white and opaque. The fertilized eggs can be identified when they are laid, and there is a more opaque white spot or band in the inner layer of the eggshell. Hatching depends on temperature. The heat generated by the decay of plant leaves and roots keeps the temperature in the nest, and before the crocodile breaks its shell, the temperature at this time will determine its sex.

"Don't believe crocodile tears"; It's a very popular mantra. Actually, it's a salt solution excreted by crocodiles. Because the kidneys of crocodiles don't completely excrete the system, in order to excrete excess salt solution, it produces special glands to help the kidneys in the eyes, so it will "weep" when chewing food, which is to excrete excess salt solution.

The crocodile's eyes are protected by a membrane, and a transparent instantaneous membrane will hang down in the water to adapt to the environment. The eyes are located on both sides to make the field of vision in front of them very wide, which makes the images of both eyes overlap visually and make the images three-dimensional; Under strong light, the iris shrinks into a seam to block most of the light out of the retina, so it is beneficial to observe the environment through the seam.

Crocodiles are carnivores. Their teeth are deeply embedded in the gums and are conical or cylindrical. They are used to kill their prey without chewing food. When they encounter hard food and lose their teeth, new teeth will grow out quickly. Crocodiles grow new teeth all their lives, and food is digested by their stomachs.

Crocodiles belong to vertebrate amphibians and reptiles. Most of them are fierce and violent. They like small animals such as fish and frogs, and even kill people and animals. There are more than 2 species of crocodiles in the world, among which Chinese alligator, Thai Crocodile and Crocodile Luoluo are famous. At present, the largest crocodile breeding base in China is Panyu Farm in Guangzhou, which covers an area of nearly 7 hectares and has nearly 1, crocodiles, such as Crocodiles Luoluo, Chinese alligator and South American alligator.

Most crocodiles live in temperate regions except a few. It has a long face and a long mouth, and there is a saying that "the king of the world is nothing like a crocodile". Crocodiles are rich in ornamental value. Crocodiles also have many medicinal and health-care effects. Crocodiles are also valuable food. Because it is full of treasures, some countries in the world actively develop crocodile farming.

Crocodiles are a species of Crocodiles. Also known as bay crocodile or sea crocodile. Distributed along the coast of Southeast Asia to northern Australia. With a total length of 6-7 meters and a maximum length of 1 meters, it is the largest reptile in existence. Crocodiles live in the bay or across the sea. In the tree-lined hills near the freshwater river (more than 6, meters away from the sea), they sweep out a platform of 7-8 meters with their tails. On the platform, there are nests for placing crocodile eggs with a true diameter of 3 meters. The nests are about 4 meters away from the river and are made of leaves. Each nest has about 5 white hard-shell eggs with a size of about 8×55 mm; The female crocodile waits at the side of the nest, always sways its tail and sprinkles water to wet the nest, keeps the temperature at 3 ~ 33℃ and hatches for 75 ~ 9 days; The hatchling crocodile is 24mm long, and it can grow to 48mm in one year and 1156mm in three years, weighing 5 ... The spring flowers are filled with laughter and firecrackers.