What constellation is the giant salamander _ What constellation is the giant salamander?

What kind of fish is giant salamander?

salamander

brief introduction

Alias giant salamander, crow fish and pike fish, they belong to cryptobranchia, with Latin scientific name Andrias davidianus and English name giant salamander. The largest species in the existing order, the maximum hair length can exceed 1 m, and the body length can reach 1.8 m in some places. Giant salamander's head is flat and blunt, and a pair of small eyes are embedded in it. It has a big mouth, undeveloped eyes and no eyelids. The front of the body is flat, and the tail gradually turns to the side. 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, which are slightly webbed. The tail is flat and round, with fins up and down. The body surface is smooth and covered with mucus. The back of the body is mixed with brown and red, and the ventral color is lighter.

living environment

Inhabits in the mountainous area at an altitude of 200- 1500 m, where the water is fast, the water quality is cool, and there are many stone cracks and caves.

Predation and feeding habits

It is not good at hunting, but hides among the rocks at the mouth of the beach and suddenly attacks when it finds its prey passing by. Because the teeth in its mouth are sharp and dense, it is difficult for the prey to escape after entering the mouth. Its teeth can't chew, just open its mouth and swallow the food, and then slowly digest it in its stomach. Giant salamander has a strong hunger tolerance, even if it doesn't eat for two or three years, it won't starve to death. It can also overeat, and a full meal can increase one-fifth of the weight. When food is scarce, cannibalism will occur, and even eggs will be used to satisfy hunger. I like to eat fish, crabs, shrimps, frogs, snakes and other aquatic animals.

classify

Amphibia, uropoda, cryptobranchia.

Be distributed

It is found in mountains and streams in northeast and southeast Yunnan, and distributed in 17 provinces in China.

Living in Qingxi in mountainous areas, they usually hide in the crevices of the mountain stream, and the caves are below the water surface. The cry is also like a baby crying, so it is commonly known as "giant salamander".

China is endemic to North China, Central China, South China and Southwest China. The heart has a special structure and some reptilian characteristics, which has important research value. The number is scarce and needs protection.

type

Every year from July to August, each tail lays more than 300 eggs. After the female lays eggs, the "mission" 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 incubating eggs, and the little giant salamander will not disperse until 15-40 days later.

Giant salamander protection

Because of its tender and delicious meat, it has been hunted in large quantities for a long time. The number of producing areas has dropped sharply, and some producing areas are on the verge of extinction.

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 it looks a bit like a lizard, but it is fatter and flatter. Giant salamanders live in mountain streams and caves with clear water quality, low sediment concentration, rapid water flow and backwater. The giant salamander has a flat and blunt head, a big mouth, underdeveloped eyes and no eyelids. The front of the body is flat, and the tail gradually turns to the side. There are obvious skin folds on both sides of the body, short and flat limbs, and slightly webbed fingers and toes. The tail is round and has fins up and down. The body surface is smooth and covered with mucus. The back of the body is mixed with brown and red, and the ventral color is lighter. Giant salamanders lay eggs from July to August every year, with more than 300 eggs per tail. The male giant salamander wraps its eggs on its 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 has been killed. Resources have been severely 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.

artificial insemination

1. Design and construction of giant salamander culture pond Giant salamander lives in a mountain stream at an altitude of 300 ~ 800 m, and has the characteristics of liking shade and being afraid of wind, being quiet and being scared, being clean and being dirty. It is best to imitate the living conditions of giant salamander in nature to build an artificial giant salamander breeding pond. 1. 1 farm site selection requirements 1. 1 water resources requirements According to the analysis results of water samples collected in our hospital for many years, the overall requirements for water for giant salamander breeding are: sufficient water sources, non-toxic and harmless, and meeting the standards for fishery water use. Specifically, in terms of water sources, it is best to use clear, cool and flowing water such as mountain streams, reservoir water and groundwater to achieve free irrigation and drainage; The water temperature should be strictly controlled within 0 ~ 28℃, and 10 ~ 22℃ is the best. In terms of water quality, it is required to be rich in dissolved oxygen, above 3.5 mg/L, and the PH value is 6.5 ~ 7.5. The total hardness, total alkalinity, chloride, sulfate, silicate and ammonia nitrogen in the water cannot exceed the fishery water standard. 1. 1.2 The environment requires that the environment around the aquaculture pond should be quiet, cool and fresh, surrounded by mountains, with lush trees, sparsely populated and relatively independent. In addition, the transportation is convenient, and the local fish, shrimp, crab or animal viscera bait resources are abundant. 1.2 Design and construction of farm The growth of giant salamander has obvious stages and metamorphosis, and the breeding pond for artificially breeding giant salamander should be designed and constructed in stages. The area of the breeding pond depends on the size of the giant salamander, and the juvenile pond (tadpole period 1 year) is 0.5 ~ 1 m2, and the juvenile pond (juvenile salamander period 1 ~ 2 years) is1m2. The shape of giant salamander culture ponds in each stage is preferably rectangular or oval, and the length-width ratio is 3∶2. Its height requirement is 2 to 3 times that of the giant salamander. The periphery and bottom of the culture pond should be flat, and the top should be provided with escape prevention facilities or covered with escape prevention nets. Multiple caves can be designed in the pond to facilitate the giant salamander to hide, and each breeding pond should be equipped with independent irrigation and drainage facilities to ensure that the water level can be effectively adjusted. The whole farm should establish perfect facilities to prevent the giant salamander from escaping, stealing and hurting.

2. Breeding and fry identification of giant salamander 2. 1 Disinfection of newly-built breeding ponds, especially cement ponds, must be soaked for more than two months, and fry can only be released after its alkalinity disappears. For the original culture pond, disinfection drugs generally use 1PPM bleaching powder or 0.5PPM 90% crystal trichlorfon to kill harmful organisms such as bacteria or parasites, and then rinse them with clean water, and then release the fry after injecting fresh water. 2.2 Disinfection of giant salamander species In order to prevent the giant salamander species from bringing pathogenic microorganisms into the culture pond, all the stocked giant salamander species should be soaked in water containing 0.2g or 0.5g of methylene per cubic meter of water for 5 minutes, and then the liquid medicine and giant salamander species should be gently put into the culture pond. 2.3 seedling identification 2.3. 1 giant salamander seedlings are different from other seedlings in amphibians. In the family Ranidae, Ranidae, Ranidae and other species are very similar to the giant salamander. The main difference between them is the comparison of morphological characteristics, which mainly includes the following three points: Pinaceae, Pinaceae, Pinaceae. High-quality giant salamander fry should be healthy, muscular, free from scars and parasites, and have intact external gills before metamorphosis. On the other hand, it is inferior giant seedlings. 2.4 stocking density the stocking density of the giant salamander breeding pond depends on the specifications of the giant salamander and the water source, water body, bait and other factors of the farm. In general, it is considered that the giant salamander has a small range of activities, weak feeding ability and relatively high stocking density at seedling stage, which is convenient for centralized management and feeding. In the adult stage, the giant salamander has a wide range of activities, strong feeding ability and attacks each other, so the stocking density should be small. According to our years of breeding practice, the stocking density is 60 ~100 fish /m2 in the seedling stage and 5 ~ 20 fish /m2 in the adult stage. When stocking, the specifications should be kept as neat as possible, and the difference between individuals should not exceed 0.5 times.

3. Culture management 3. 1 Fresh fish, shrimp, crab, frog and animal viscera are the best bait for feeding giant salamander, and its bait feeding should be "four-fixed", that is, "timed, located, qualitative and quantitative", just like fish culture bait feeding. Every once in a while, according to the activity of giant salamander, feeding is mostly carried out at night; Positioning, the bait should be placed near the giant salamander hole to facilitate the lazy giant salamander to feed; Qualitative identification shows that the giant salamander has strict requirements on the quality of the bait, and the variety of the bait cannot be changed too much, so as to avoid the giant salamander refusing to eat; In terms of quantity, giant salamander is greedy, and the feeding amount should be from less to more, step by step. Generally, it is fed according to 10 ~ 15% of the body weight, and the specific feeding is appropriately adjusted according to the water temperature, weather conditions and individual situation of giant salamander. In addition, when feeding the baby fish bait, try to make the baby fish not frightened and avoid spitting. 3.2 Adjusting the water quality When breeding giant salamanders, the water quality of the giant salamander pond should be kept fresh and pollution-free, with high water transparency and high dissolved oxygen, and the PH value should be between 6.8 and 7.8. In the actual breeding process, it is necessary to remove the residual bait and excrement in time, adjust the water quality with quicklime regularly, and keep the pool water flowing for a long time. 3.3 Adjusting the water temperature and light The giant salamander has strict requirements on the water temperature. If it exceeds its tolerance, it will cause the giant salamander to hibernate or sleep in summer. When it is hot in summer and cold in winter, measures must be taken to reduce or increase the temperature to ensure that the giant salamander has a suitable water temperature growth environment. In addition, giant salamander is afraid of light, so the farm should take measures to avoid light, and can't shoot with strong light at night. 3.4 The ability to escape and steal the giant salamander is very strong. It is agile on land or in water and can climb the top heavy objects. If it is not careful, it will run away. Always pay attention to escape, especially in heavy rain. All water inlets, water outlets and land passages of the aquaculture pond and the whole farm should be equipped with escape prevention facilities. The economic value of giant salamander is high, so we should always pay attention to prevent it from being stolen by criminals during the breeding process. 4. Disease prevention of giant salamander In the artificial breeding environment, due to the influence of environment, bait and density, the morbidity and mortality of artificial breeding giant salamander are dozens of times higher than that of wild giant salamander. To improve the survival rate of cultured giant salamander, we must pay attention to prevention on the premise of strengthening daily management, so as to ensure the success of giant salamander breeding.

4. Breeding conditions: both indoor and outdoor can be cultivated. Outdoor is a specially built open-air breeding pond, and indoor is a breeding pond transformed from various idle facilities. Aquaculture ponds only need to be safe, firm, watertight, keep running water or equipped with aerators. The size of indoor aquaculture ponds can range from 1 square meter to tens of square meters. Before stocking, the culture pond needs to be soaked in water 1 month to keep the pH below 6.4. Generally, strong light is not needed, and only weak light or no light can be kept.

5. Seedling raising and stocking: giant salamander breeding generally introduces young giant salamanders over 10 cm, and about 20 giant salamanders can be released per square meter of water surface. Before stocking the fry, the breeding ground was soaked in 2 mg/L copper sulfate for 5 hours for disinfection, and the giant salamander was soaked in 5% sodium chloride 10 minute. A cave was built with granite in the pool in advance, and aquatic plants were placed for the giant salamander to hide.

6. Feeding: the culture pond is equipped with a bait table, and the table top is slightly higher than the water surface. It is better to feed on natural bait, which mainly includes plankton, insects, meat, fish and shellfish. Feed it once every morning and evening, before 7: 30 in the morning and before 10: 30 in the evening. When throwing the bait, clean up the last residual bait first. The feeding amount is 5- 10% of the body weight. When the water temperature is 16-23℃, the feeding amount should be increased, and the frequency and time can remain unchanged.

7. Daily management. The daily management of giant salamander is very simple, but it is very important. When feeding, keep three points: timing, fixed point and quantitative. It is very important to understand the ecological habits of giant salamander. Giant salamander likes silence, is afraid of noise, likes clear water and muddy water, and likes darkness and bright light. We should try our best to take care of these habits in breeding. In addition, the giant salamander body and culture pond should be disinfected regularly to prevent diseases, and the water temperature should be controlled not to exceed 26℃ in summer to prevent "summer sleep", and the water temperature should not be lower than freezing point in winter.

A snack in Heze, Shandong Province.

Made of bean jelly into small water droplets, similar to small fish, so it is called giant salamander.

When cooking, the giant salamander is cooked, soy sauce, vinegar, cumin and other seasonings are added to the bowl, and the cooked giant salamander is put into the bowl.

A bowl of small, white, elastic giant salamander that swims without stopping can be eaten with a spoon, and seasoning can be added according to your own taste.

Current situation of giant salamander fry breeding

Chinese giant salamander is a national second-class protected animal, which has high economic value and broad development and utilization prospects in food, health care, medicine and ornamental, so it has attracted much attention from all walks of life. At present, the reality is that giant salamander is a precious wild resource, which is mainly caused by human factors, especially the loss of living environment, the destruction and over-utilization of habitat, which has caused a serious threat to the survival of giant salamander, resulting in a sharp decline in population and a doubling of distribution area, and is in an endangered state. Before discussing the current situation of giant salamander seedling breeding, the author thinks that we should first speak out loudly and attach great importance to the preservation and protection of giant salamander germplasm resources, because only "species" have seedlings, otherwise it will become passive water and trees without roots. That is to say, the breeding of giant salamander seed should start with the source of germplasm resources, quickly establish a Chinese giant salamander germplasm resource bank and a Chinese giant salamander original seed breeding base, and completely solve the "provenance" problem of giant salamander seed breeding. At present, the competition for wild giant salamander resources in the market is becoming more and more fierce, and the price is soaring, which shows the seriousness and urgency of the problem.

Wild resources of Chinese giant salamander. Some people estimate that the total stock in China is 50,000. The author thinks that the real wild giant salamander in nature may not reach 50,000, but the more realistic figure needs in-depth investigation and evaluation. It is reported that there are 65438+ 10,000 giant salamanders cultured artificially in China every year, but the author thinks that it may be insufficient in fact. According to the situation of China's main population, it is around 80 thousand.