Why does the giant salamander cry like a child?

Giant salamander is a rare animal endemic to China, which is only distributed in some rivers in China. Because it cries like a child's cry, it is also called "giant salamander".

The giant salamander is the largest amphibian in existence, generally 0.6-0.7 meters long, and the largest can reach 1.8 meters -2 meters, weighing 20-25 kilograms. It looks strange, with a big head and a big mouth, but small eyes and nostrils, a big tail and a flat side at the back. The whole body is smooth, without scales, with four short and fat legs and front legs like baby's arms.

The giant salamander lives in a stream with clear water, low water temperature and many deep pools at an altitude of 1, 200- 1300m, and lives in caves and crevices. The caves are spacious and flat. When swimming, the limbs cling to the abdomen and move forward by swinging the tail and flapping the body against the water. It also has the ability to climb trees on all fours. Because my eyes are afraid of light, I sleep during the day and go out for food at night. They mainly feed on fish, shrimp, crabs, insects, snakes and frogs. It usually doesn't take the initiative to attack when foraging, but waits for food to be delivered to the door. Its teeth cannot be chewed. After food is swallowed, it can be digested slowly in the stomach. It is very hungry. It can survive without eating for months and hibernate like a frog in winter.

Giant salamanders usually breed in June-August. The female giant salamander lays eggs in caves and attaches to rocks in slow-flowing areas, and can lay hundreds of eggs at a time. After 265,438+0 days, the eggs naturally hatched into larvae. Larvae grows very slowly, and only grows to 0.2m long after 3 years, and its weight is less than100g.

The giant salamander has been hunted by people for a long time. Although it has been listed as a national second-class protected animal, poaching still occurs from time to time. At present, the number of giant salamanders is very rare, and giant salamanders in some places have even disappeared.

Giant salamander is the largest and most precious amphibian in the world. It sounds like a child, so people call it "giant salamander", which is a national second-class protected aquatic wild animal and a key development variety of agricultural industrialization and characteristic agriculture. It is a wild animal genetic protection variety.

Chinese name: giant salamander

Latin scientific name: giant salamander

Common names: giant salamander, mermaid, giant salamander, barracuda, cod, foot fish, crow fish and wax dog.

Taxonomic status: fauna in the animal kingdom → Chordata in Chordata → Vertebrates in Vertebrates → Amphibians in Amphibia → Uropoda in Anura → Cryptobranchia in Cryptobranchia → Andreas in Andreas → Andrias.

Grade of national key protected animals: Grade II

IUCN: To be determined (I)

Endemic species: Yes.

Endangered level: endangered

Protection measures: artificial breeding, artificial breeding, national level, existing protected areas.

Among amphibians, the species of Anura are the most, with the total length of 1 m and above, and the heaviest can exceed 100 kg, but the shape is somewhat similar to that of lizards, but it is fatter and flatter. Recently, scientists found that the giant salamander breathed through its gills when it was a child and its lungs when it grew up. 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 color of giant salamander can change with different environment, but it is generally taupe. The body surface is smooth and scale-free, but there are various stripes and mucus. The belly of the body is light in color.

Giant salamanders are fierce carnivores, feeding on aquatic insects, fish, crabs, shrimps, frogs, snakes, turtles, rats and birds. The predation mode is "waiting for the rabbit". Giant salamanders usually live in the crevices of mountain streams, and their caves are below the water surface. At night, it stays quietly in the stone pile at the mouth of the beach. Once it finds its prey passing by, it will launch a surprise attack. Because the teeth in its mouth are sharp and dense, it is difficult for prey to escape after entering its 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, and it will not starve to death if it is put in cold water for two or three years. 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.

Chinese giant salamander has not been reported in Xinjiang, Tibet, Inner Mongolia, Jilin and Taiwan Province provinces, but distributed in other provinces and regions, mainly in the mountains and streams in the middle and upper reaches of the Yangtze River, Yellow River and Pearl River.

The natural distribution of the origin of Chinese giant salamander is mainly concentrated in four areas of China: First, Zhangjiajie, Jiangyong, Yueyang and Xiangxi Autonomous Prefecture in Hunan; The second is Fangxian and Shennongjia in Hubei; The third is Ankang, Hanzhong and Shangluo in Shaanxi; The fourth is Zunyi, Guizhou, Yibin, Sichuan and Wenxing. Others are scattered in Hefeng, Enshi, Hubei, Jing 'an, Jiangxi, Liuzhou, Yulin, Wenxian, Gansu, Lushi, Haoxian, and Qiandongnan, Guizhou. Among them, Xiang Yan in Guiding County, Guiyang, Guizhou Province has become the "hometown of Chinese giant salamanders". According to statistics, there are about 90,000 natural resources of giant salamanders, most of which are in hilly and mountainous areas, and the resources in economically developed areas are even more insufficient due to the intensification of industrial pollution. Female salamanders lay eggs from July to August every year, with more than 300 eggs per tail, and the rest of the rearing tasks are given to male salamanders. Male giant salamanders bend their bodies into a semicircle and surround their eggs to avoid being washed away by the water or being hurt by the enemy. 2-3 weeks after the young giant salamanders hatch, 15-40 days, the young giant salamanders scatter their lives, and the male giant salamanders are willing to leave. The life span of giant salamanders is also the longest among amphibians. Under the condition of artificial feeding, it can live for 130 years Because of its tender meat and delicious taste, it has been hunted by people for a long time. The number of producing areas has dropped sharply, and some producing areas are on the verge of extinction. 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.

China has a vast territory, complex landforms, numerous rivers and lakes, and diverse climate, which provides superior natural conditions for the formation and development of various biological and ecosystem types, thus becoming one of the countries with the richest biodiversity in the world. China's ecosystem mainly includes six types: forest, grassland, desert, farmland, wetland and ocean. Among them, forest is the most important terrestrial ecosystem, which contains a large number of biological species and is the most diverse ecosystem type. There are many kinds of forests in China with complete functions, which have a particularly important impact on the environment and climate in China and even in the world. Forests in China are distributed from north to south according to climatic zones, including cold temperate coniferous forests, temperate coniferous and broad-leaved mixed forests, warm temperate deciduous and coniferous forests and subtropical evergreen broad-leaved forests.

Wild resources of Chinese giant salamander. It is estimated that the total stock of China is 50,000, and the real wild giant salamander may not reach 50,000 in nature. Of course, more realistic figures need to be evaluated through in-depth investigation and study. Artificial breeding of giant salamander The annual breeding volume in China is reported to be 65,438+10,000, and now the artificial breeding has exceeded 200,000.

We should attach great importance to the preservation and protection of giant salamander germplasm resources, because only with "species" can seedlings grow, otherwise they 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.

The first giant salamander ecological park in China recently started construction in Sanzhaolun National Demonstration Forest Park in Jing 'an County, Yichun City, Jiangxi Province. The total investment of this project is150,000 yuan, covering an area of 80 hectares, and it is a key construction project of the Ministry of Agriculture.

The first phase of the project will be completed in June 5438+10 this year, which can form the capacity of breeding 50,000 giant salamanders and rescuing 1000 giant salamanders every year. The ecological park integrates the protection of giant salamander resources, cultivation and appreciation, tourism and leisure, cultural exchange and development and utilization, which is the first of its kind in China.

Jing 'an County, Yichun City, Jiangxi Province is the main producing area of Chinese giant salamander resources and the only "hometown of Chinese giant salamander" in China. The county is the first in the country to issue a notice to protect giant salamanders, the first to establish a giant salamander nature reserve, the first to set up a special giant salamander research institute, and the first to artificially breed the first, second and third generations of giant salamanders. In 200 1 year, Jing' an designated the giant salamander as the county mascot to be protected.

The heart structure of giant salamander is special, and some reptilian characteristics have appeared, which has important research value.

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.

Giant salamander is a traditional precious medicinal animal. Modern clinical observation shows that giant salamander has the effects of nourishing yin and tonifying kidney, enriching blood and promoting qi circulation, and has obvious curative effects on anemia, cholera and malaria. At the same time, giant salamander is also an economic animal with high edible value, with tender meat, unique flavor and high nutritional value. Its meat protein contains 17 amino acids, 8 of which are essential for human body.

1. Design and construction of giant salamander culture pond

Living in a mountain stream at an altitude of 300 ~ 800 m, the natural giant salamander has the characteristics of being fond of shade and afraid of wind, being quiet and afraid of earthquakes, and being clean and afraid of dirt. Therefore, it is best to imitate the living conditions of giant salamander in nature by artificially building a giant salamander breeding pond.

1. 1 farm site selection requirements

1. 1. 1 water resource demand

According to the analysis results of water samples collected in our hospital for many years, the general requirements of water for giant salamander culture are: sufficient water source, non-toxic and harmless, and meeting the standards of 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 environmental requirements

The environment around the culture pond should be quiet, cool and fresh, surrounded by mountains, 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 the farm

The growth of giant salamander has obvious stages and metamorphosis process, so the breeding pool of artificial giant salamander should be designed and built 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. Each aquaculture 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 aquaculture ponds

Newly-built aquaculture ponds, especially cement ponds, must be soaked for more than two months, and the 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 sterilization of giant salamander species

In order to prevent giant salamanders from bringing pathogenic microorganisms into the culture pond, all the released giant salamanders should be soaked in 0.2 g or 0.5 g methylene per cubic meter for 5 minutes, and then the liquid medicine and giant salamanders should be gently put into the culture pond.

2.3 seedling identification

2.3. 1 Difference between giant salamander fry and other fry

Among 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.

2.3.2 Identification of the quality of giant salamander seedlings The quality of giant salamander seedlings is directly related to the success of feeding. 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 giant salamander culture pond depends on the specifications of giant salamander culture and the water source, water body and bait 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. Breeding management

3. 1 bait feeding

Fresh fish, shrimp, crab, frog and animal viscera are the best bait for giant salamander, and its bait feeding should be "four fixed", that is, "fixed time, fixed location, qualitative and quantitative", just like fish 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 Regulating water quality

The water quality in the giant salamander pond should always be kept fresh and pollution-free, with high transparency and dissolved oxygen, and the PH value is 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 Adjust the water temperature and light.

The giant salamander has strict requirements on 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 Prevention of escape and theft

Giant salamander has a very strong ability to escape. 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. 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 be equipped with an aerator. 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 stocking:

Giant salamander breeding generally introduces young giant salamanders above 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.

Step 6 feed:

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 are disinfected regularly to prevent diseases, and the change of water temperature is paid attention to. The water temperature is controlled not to exceed 26℃ in summer to prevent "summer sleep" and prevent the water temperature from falling below freezing point in winter.

8. Disease control

In the artificial breeding environment, due to the influence of environment, bait, density and so on. The morbidity and mortality of artificially cultured giant salamander are several times higher than those 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.

Prevention and treatment of rotten tail disease

First, the reason for the rotten tail of giant salamander.

(A) the impact of water quality

Giant salamanders often grow in deep mountains and running streams, and the water quality is fresh, lively and pollution-free. However, the water quality of artificially cultured giant salamander is easily polluted, and a large number of pathogenic microorganisms often breed in polluted water. When the giant salamander is injured, these pathogenic microorganisms take advantage of it and cause pathological changes.

(B) the impact of environmental conditions

Because of the artificial giant salamander farm, it is difficult to meet the natural environmental conditions in the wild, especially the wall (bottom) of the newly built giant salamander pond is rough, which is easy to scratch the giant salamander skin. When the giant salamander crawls, it is more vulnerable to damage because its tail keeps swinging.

(C) the impact of the size difference of stocking specifications

Generally speaking, the density of artificially stocked giant salamanders is relatively high. For example, when there is a big difference in specifications and sizes, when there is a lack of bait, there will often be fights for food. The ability of small individuals to compete for food is weak, and they are often attacked and bitten by large individuals, and their tails are often targeted.

(d) the effects of feed malnutrition.

Giant salamander is a carnivorous amphibian, which often takes animal bait as its staple food. When the feed is unpalatable and lacks necessary nutrients, especially animal protein and some trace elements, such as zinc, iron, calcium and probiotics, it will induce giant salamanders to kill each other.

Second, the symptoms of giant salamander tail rot disease

At the early stage of the disease, red spots or spots often appear from the base of the tail stalk to the tail end of the giant salamander, and the surrounding tissues are congested and inflamed, and the epidermis is slightly gray. When the disease lasts too long, there are often a lot of pathogenic bacteria and sundries attached to the focus. In severe cases, muscle necrosis appeared in the focus, coccyx was exposed, the diseased giant salamander lost appetite or stopped eating, the activity ability was obviously weakened, the tail wagged weakly, and it was about to die.

Third, prevention methods.

(A) to create comfortable environmental conditions

When building catfish farms, lighting, irrigation and drainage pipes, bait tables, land habitats and other facilities should be considered. Because the giant salamander likes to live alone and is afraid of light, several artificial tunnels can be built with bricks in the pond, with a diameter of 12 ~ 20 cm. The cave is spacious and the walls are as smooth as possible. After the giant salamander pond is completed, the giant salamander species can't be released immediately, because the new cement pond has strong alkalinity, and the suitable pH value of giant salamander is 6 ~ 7.

The newly-built cement pool can be filled with water, soaked for 2-3 days continuously, then drained, and repeated several times. When the pH value of the pool water is close to neutral and a layer of smooth attachments is stuck on the pool wall and the cave wall, the giant salamander fry is put in.

(2) disinfection treatment

Before stocking the giant salamander, it was disinfected with gentian violet solution with the concentration of 1%. The method is to soak and clean the giant salamander for 20 minutes after the ratio of medicine to water is 1: 100. Gentian violet liquid has little irritation to the skin of giant salamander, and can effectively prevent the body surface infection of fungi and bacteria.

(3) control water quality and water temperature

The water quality of giant salamander pond should be kept fresh and pollution-free, and streams or clear springs should be used as much as possible. And change the pool water regularly. If conditions permit, the giant salamander pond can keep flowing all the year round. The suitable water temperature for the growth of giant salamander is 14℃ ~ 28℃, so it is more important to change the pool water in hot summer.

(four) stocking individual specifications neat

At present, the species of giant salamander are artificially propagated, and the individual specifications are basically the same, but after a period of feeding, the individual size difference is more and more obvious. At this time, it is necessary to screen and breed in different pools to avoid the phenomenon of bullying the small with the big and bullying the weak with the strong.

(5) feeding high-quality bait

The bait of the giant salamander is rich in nutrients such as protein and trace elements, such as fresh water, fish and shrimp, animal viscera, animal blood and leftovers, which are all good bait for the giant salamander. When feeding bait, adhere to the scientific feeding method of "timing, positioning, qualitative and quantitative", and do not directly throw animal viscera, blood clots, scraps, etc. Into the water, otherwise, it is easy to pollute the water. It is necessary to prevent the waste of bait and prevent some individuals from not eating or eating well.

Fourth, the treatment method

(1) When the giant salamander is found to suffer from tail rot, it should be kept in isolation in time. If it is not raised separately, there will be endless troubles, which may affect the whole giant salamander farm. First, pathogens spread continuously in the pool water and infect other individuals; Second, healthy individuals can suck the blood of sick salamanders at any time, which makes the sick salamanders worse and spreads pathogens to healthy individuals.

(2) Spray 0.3 ~ 0.4 ppm of strong chlorine essence or 0.2 ~ 0.3 ppm of chlorine dioxide (including perching on land, bait table, etc.) in the whole pond once a day. ) 3 ~ 4 days is a course of treatment.

(3) For the seriously ill giant salamander, first soak the diseased giant salamander in potassium permanganate with a concentration of 1 5-25 ppm or malachite green solution with a concentration of 0.3-0.5 ppm for 20 minutes, and thoroughly clean the wound surface attachments, and then smear the affected area with anti-inflammatory drugs such as Xiaozhilong ointment or sulfur ointment, once a day, 4 times a day.

(4) Chloramphenicol 2-3g Decadenafil powder 2g+Vc2g+Ve2g+Vb2g (the dosage per kilogram of body weight), the above medicines are evenly mixed into bait, and fed for 3-4 days.