Egyptian pond horn fish, whose scientific name is Silurus aegypti, also known as Silurus Gezi and Egyptian pond lice, is a kind of freshwater catfish native to the Nile valley in Africa. In recent years, the culture of Egyptian pond horn fish has become popular and achieved considerable economic benefits. After 198 1 was introduced to China, it was popularized in southern provinces for several years, which proved that the fish really had excellent economic characteristics of fast growth and large size. After 3-4 months' feeding, the fry generally weighed more than 250 grams, and the largest individual could reach 750 grams. At the same time, Egyptian horn fish has the advantages of high adaptability, strong vitality and miscellaneous eating habits, and can be raised singly in common ponds or mixed with domestic fish. Its feeding habits are similar to those of local pond angle fish and Thai catfish, but it is much bigger than the latter in growth speed and body shape. Egyptian pond horn fish is a new freshwater aquaculture species with great economic value, which is very suitable for the promotion and cultivation in rural areas in southern China.
Egyptian pond fish belong to Silurus, Silurus and Silurus, which belong to the same species as local Silurus, Silurus Thailand and Silurus Thailand.
(1) Morphological characteristics: It is similar to local pond angle fish and Thai catfish, with elongated body, flat tail, flat head and abdomen, round back, large head, flat head and back, and many radially arranged bony protrusions on the skull. The kiss is wide and blunt, with a wide mouth, a comprehensive upper and lower face and a raw plate-shaped tip with a plow bone. There are four pairs of beards. There is mucus on the surface of the body, and the back of the body is dark in color, with many cloud-like stripes on the surface and massive black spots occasionally. The abdomen is white. The pectoral fin is round with a thick hard spine.
(2) Living habits: It is an aquatic fish, but it has no obvious habit of burrowing, and often inhabits the pond in groups. This fish, like this pond horn fish, has respiratory auxiliary organs on gills.
Egyptian horn fish is a tropical fish, and its tolerance to low temperature is worse than that of local horn fish. The water temperature can still survive at 9℃, and 6.5℃ is the lethal water temperature.
(3) Feeding habits: Egyptian horn fish is an omnivorous fish, which mainly feeds on animal feed and also eats plant feed. It has a large food intake, which can reach10 ~15% of its own weight each time. Fish, shrimp, small aquatic animals, various decaying animal carcasses and peanut cakes can be used as feed.
giant salamander
Alias giant salamander, crow fish and pike fish, they belong to the family Cryptbranchiaceae, with Latin scientific name Andrias davidianus and English name Giant Salamander. The largest species of the existing order Anura, its maximum gross length can exceed 1 m, and its body length can reach 1.8 m in some places. Giant salamander's head is flat and blunt, with a pair of small eyes embedded in it. It has a big mouth, undeveloped eyes and no eyelids. The front part of the body is flat, and gradually turns to lateral flat at the tail. There are obvious skin folds on both sides of the body, and the limbs are short and flat, with five toes on the forelimbs and four toes on the hind limbs, and slightly webbed. The tail is flat and round, with fins above and below the tail. The body surface is smooth and covered with mucus. The back of the body is mixed with black and brown red, and the ventral color is light.
living environment
Habitat in the mountainous area with an altitude of 200-1500m, where the water is fast, the water quality is cool, and there are many stone cracks and rock holes.
Predation and feeding habits
Foraging is not taking the initiative to attack, opening your mouth and waiting for the prey to be trapped. Like to eat aquatic animals such as fish, crabs, shrimps, frogs and snakes.
classify
Amphibia, uropoda, cryptobranchiaceae.
be distributed
It is found in the mountains and streams in northeastern Yunnan and southeastern Yunnan, and distributed in China 17 provinces and regions.
Living in clear streams in mountainous areas, they generally hide in stone crevices of mountain streams, and caves are located below the water surface. The cry is also like a baby crying, so it is commonly known as "giant salamander".
China endemic species, produced in North China, Central China, South China and Southwest provinces. The heart structure is special, and some reptilian characteristics have appeared, which has important research value. The number is scarce and needs to be protected.
breed
Every year from July to August, each tail lays more than 300 eggs. After the females lay eggs, the "task" is over. The male salamander wraps the egg belt around his back and hatches after 2 ~ 3 weeks. From then on, the male giant salamander will take on all the tasks of hatching eggs until15-40 days later, the little "giant salamander" will live in scattered life.
Protection of giant salamander
Because its meat is tender and delicious, it has been hunted in large numbers for a long time. The number of producing areas has dropped sharply, and some producing areas are on the verge of extinction. It has been listed as a national class II protected animal and CITES Appendix I..
Alias giant salamander, it belongs to Amphibia with uropoda. Among amphibians, it is the largest, with a total length of 1 m to 1.5 m, and the heaviest can exceed 100 kg, but its appearance is a bit like a lizard, but it is fatter and flatter. The giant salamander lives in streams in mountainous areas, and lives in caves with clear water quality, low sediment concentration, rapid water flow and backwater. The giant salamander has a flat and blunt head, a large mouth, underdeveloped eyes and no eyelids. The front part of the body is flat, and gradually turns to lateral flat at the tail. There are obvious skin folds on both sides of the body, the limbs are short and flat, and the fingers and toes are slightly webbed. The tail is round with fins above and below it. The body surface is smooth and covered with mucus. The back of the body is mixed with black and brown red, and the ventral color is light. The giant salamander lays eggs from July to August every year, with more than 300 eggs per tail. The male giant salamander wraps the eggs around his back and hatches after 2-3 weeks.
Produced in North China, Central China, South China and Southwest provinces. Giant salamander is an endemic species in China, and it is commonly called "giant salamander" because its cry is like a baby crying. The heart structure of giant salamander is special, and some reptilian characteristics have appeared, which has important research value. Because the meat is delicious, it is regarded as a treasure, and it has been killed. The resources have been seriously damaged and need to be protected. It belongs to the national second-class protected animals.
Economic and ecological value
Giant salamander has a wide range of social, economic and ecological values, and can be used for food, medicine, scientific research, ornamental and industrial tanning.