Alligator

Chinese alligator, Chinese ancient books called "鼍", the people of the place called it "Tulong", "Pig Po Long", is a crocodile living in fresh water, originally distributed widely, inhabiting the lakes and swamps along the middle and lower reaches of the Yangtze River, Reeds, bamboo forests and miscellaneous irrigation areas in the foothills of the hills.

The adult Chinese alligator has a total body length of about 2 meters, and its tail length is similar to its length, like a large lizard. The Chinese alligator has a flat head and a long kiss. The outer nostril is located at the end of the kiss. It has a flap and a sharp tooth in the mouth. It can easily shred the prey. The surface of the body is covered by large scales, and the scales are arranged in a nearly rectangular shape. Two rows of scales protrude into two ridges, and the abdomen is very soft. The alligator has short limbs and pointed claws at the toe. The back of the body is brown, the front of the abdomen is gray, and the back of the anus is grayish and yellow.

The Chinese alligator usually used to sink his body in the water, and he kept his head out of the water for a long time, like a lonely piece of rotten wood floating in the water.

Due to the destruction of the ecological environment, the population of Chinese alligator has declined sharply. The 1973 International Convention for the Conservation of Wildlife listed it as a dangerous species and an embargoed species. In 1981, the results of a joint survey of Chinese and American scientists were: the number of wild Chinese alligators was only 300-500. In order to save the Chinese alligator, the Chinese government invested in the construction of the Anhui Alligator Breeding Research Center in Xuancheng, Anhui Province in 1982. At the same time, some scholars have carried out extensive research around the population distribution and quantity, habitat, diet, reproduction, hibernation, caves and activity patterns of Chinese alligator. Chen Bihui and his colleagues systematically studied the population and distribution of Chinese alligator, the morphology and ecology of Chinese alligator, and published the monograph "Chinese Alligator" in 1985. Although the artificial hatching of Chinese alligator was successful as early as 1976, the problem of yolk induration during the artificial feeding of young crocodile resulted in the death of a large number of young crocodile. Chen Bihui analyzed the wild ecological conditions of the young crocodile after birth, determined the energy metabolism of the young crocodile, and calculated that the young crocodile had to digest all the yolk in the body and found that the feeding of the young crocodile was too early to cause the young crocodile yolk. Difficulties in digestion and the cause of induration. The measures taken according to this are as follows: First, raise the hatching temperature of juvenile crocodile to 31-32 °C to accelerate the yolk absorption rate of young crocodile; second, delay the feeding time until 18-20 days after hatching of young crocodile, so that the yolk is completely absorbed. At the same time, it was found that in the first 20 days of incubation, the humidity was above 95%, and after 20 days, it was reduced to about 90%, which could increase the hatching rate and eliminate the swelling phenomenon of hatching eggs. In 1987, the hatching rate of the Chinese alligator was over 95%, while the mortality rate of the young crocodile was only 2.1%. The viscous material outside the eggshell of the Chinese alligator has important ecological significance for preventing egg dehydration and excessive external water into the egg. If the viscous material is destroyed, the hatching rate will be reduced. Pan Jihong et al found that the death of some young crocodiles was caused by liver disease caused by Proteus or by the infection of P. faecalis, Pseudomonas and Proteus. Recently, Wang Renping of the Alligator Breeding Research Center found a large number of nematodes in the gastrointestinal tract of the dead young crocodile. Therefore, nematode infection may also be one of the causes of the death of young crocodile.

This is the living fossil - the Chinese alligator.