Culture technique of Misgurnus anguillicaudatus

Chinese sand Loach belongs to carp-shaped order, Loach family, sand Loach subfamily, sand Loach genus, commonly known as dragon needle, steel Loach. Misgurnus anguillicaudatus is an endemic fish in the upper reaches of the Yangtze River, with delicate meat, delicious taste, both nutritional value and medicinal value, slender body, bright body color, beautiful markings on the body surface, high ornamental value and high edible value. The market price is 400,500 yuan / kg. It is a valuable and rare Loach fish with high quality in the middle and upper reaches of the Yangtze River. The amount of wild resources of Misgurnus anguillicaudatus decreased sharply in recent years. in order to restore the resources of Misgurnus anguillicaudatus in the upper reaches of the Yangtze River, the Fisheries Research Institute of Sichuan Academy of Agricultural Sciences carried out artificial transplanting and domestication of wild Misgurnus anguillicaudatus in the upper reaches of the Yangtze River, and successfully achieved a breakthrough in artificial culture technology.

Biological characteristics of Misgurnus anguillicaudatus

1. Morphological characteristics.

The total length of Chinese Misgurnus anguillicaudatus is 90mm and 180mm. The body is long, flattened on the side and round in the abdomen. The head is small and conical; the snout is long and laterally flat, which grows up in the sum of the length of the head behind the eyes; the eyes are small and the distance between eyes is narrow, which is also the main difference between Misgurnus anguillicaudatus and Misgurnus anguillicaudatus.

2. Life habits

Chinese sand Misgurnus anguillicaudatus is a bottom-living fish, which is mainly distributed in the middle and upper reaches of the Yangtze River, lives in the running water environment, and moves in the middle and lower layers of the water body. It is also common in the beach migration area or the place where the running water is slow between big stone piles. It is a small benthic fish in the open water area. The main food objects of juvenile fish are Cladocera, copepod, rotifer, water earthworm and so on, while the main food of adult fish is aquatic insects, benthic invertebrates and rotting corpses in rivers. Misgurnus anguillicaudatus lives in a running water environment and is sensitive to light, dissolved oxygen and temperature. Therefore, as long as it provides suitable bait and suitable living environment for Misgurnus anguillicaudatus, it can be domesticated in different places.

3. Growth and reproductive characteristics.

In the middle and upper reaches of the Yangtze River, the climate is humid, the bait resources are rich, and the water temperature is suitable for fish growth, but Misgurnus anguillicaudatus is a small fish with slow growth rate. The breeding season of Misgurnus anguillicaudatus is from April to July every year, the type of spawning is once a year, and the breeding peak is from May to June every year. Produce drifting eggs without stickiness. Artificial propagation of Misgurnus anguillicaudatus can avoid its unfavorable factors under natural conditions, improve its survival rate and growth rate, and shorten the culture cycle at the same time.

Artificial domestication technique of Misgurnus anguillicaudatus

1. Domestication conditions

The area of the domestication pond of Misgurnus anguillicaudatus should not be too large, generally at 20,200 square meters, but to maintain a certain depth, generally at 1.0 to 2.0 meters. Before stocking, clean all the water in the pond, remove the sludge and sundries from the bottom, and disinfect it with quicklime 120 kg / mu 7-10 days before stocking. In addition to thoroughly disinfecting the bottom of the pond, the wall of the pond must be thoroughly disinfected. The specific disinfection method is to sprinkle the raw calcareous water all over the pool, expose it in the sun for 3 to 5 days after disinfection, and then inject water after disinfection. At the same time, the intake gate and drainage gate of the domestication pond should be checked, and the damaged gate and fish fence should be repaired. Pay attention to the change of water quality during domestication. Dissolved oxygen, pH, ammonia nitrogen and nitrite are above 5.0mg / L, 7.0mg / L, 8.5mg / L, 0.03mg / L and 0.01mg / L respectively. It is usually better to use surface water such as reservoirs, streams and lakes. If tap water or deep well water is used, it must be thoroughly aerated before use.

2. Collection and transportation

Wild fish of Misgurnus anguillicaudatus should be transported immediately after collection. Considering the difference of bearing capacity between wild fish in rivers and farmed fish in ponds, and the rich mucus on the body surface of Misgurnus anguillicaudatus, it is easy to form flocs in the water after stimulation, resulting in Gill blockage and death, so repeated operation should be avoided in the process of collection and transportation. Chinese Misgurnus anguillicaudatus has two prickles, which are sharp and easy to pierce plastic bags, so it is best to use plastic buckets when transportation. if the transportation time is within 1 hour, the water can not be changed during transportation; if the transportation time is more than 1 hour, must be equipped with oxygenation device or change water halfway. In the course of transportation, we must pay attention to the oxygen filling situation at any time to avoid the lack of oxygen caused by the falling off of the oxygen pipe and oxygen head. at the same time, we should pay attention to observe whether there is hypoxia in the transportation process and deal with it in time. When the weather is hot and the temperature is more than 25 ℃, ice bags should be added to the water to control the water temperature below 20 ℃, which can effectively improve the transport survival rate and reduce the stress reaction. After arriving at the destination, pay attention to adjust the water temperature before releasing the fish, bring water during the operation and pay attention to handle it gently to avoid mechanical damage to the fish.

3. Feed and feeding

The wild Misgurnus anguillicaudatus began to feed in the pond, mainly animal feed water earthworms. The first is to feed at a fixed time, that is, twice a day, once a day at 8 ∶ 30 and 17 ∶ 00 respectively, and the other is to fix the quality and feed fresh food to keep the fresh ingredients relatively stable and nutritionally balanced. The third is quantitative, that is, the daily feed intake is 4%-8% of the total body weight of Misgurnus anguillicaudatus, which should be given priority to in the evening, accounting for about 65% of the total feed. The specific daily feeding amount should be flexibly controlled according to the water temperature, weather, feeding conditions and so on. Misgurnus anguillicaudatus has a particularly strong appetite when the water temperature is 20: 25 ℃, and the daily feeding amount is about 5%-8% of the total body weight. When the water temperature is higher than 30 ℃, the appetite of Misgurnus anguillicaudatus is decreased, so it should be fed less or not; fourth, bamboo strips are used to make bait table during domestication to feed in a fixed place, so that the Loach can develop the habit of eating at a fixed point, and it is easy to observe the feeding situation and clean the residual bait to prevent the water quality from deteriorating.

4. Domestication and management

Keep patrolling ponds every day, pay attention to changes in water quality, change water regularly according to water quality, transparency and water level changes, and add fresh river water. The stress response of Misgurnus anguillicaudatus is very strong, and the disturbance is reduced as much as possible in the process of culture. Don't be too hasty when changing water. The growth and fish disease were checked every 30 days. Chinese sand Misgurnus anguillicaudatus does not like strong light, so it can be sheltered by foam board on the surface of the pond or cement board at the bottom against the wall of the pond.