The Biological Characteristics and Breeding Techniques of Amur Sturgeon (2)

2 Artificial propagation of Amur sturgeon 2.1 Source and selection of broodstock 2.1.1. Origin of broodstock Broodstock is collected in the middle and lower reaches of Heilongjiang Province. The collection time is from May to the end of June of each year. There is no injury to the body of the selected fish, with 15 to 40 kg for females and 7 kg for males. 2.1.2 Identification of male and female individuals of the gonads of Castanopsis sinensis matured with large abdomen and erythematous pores. The male has a small abdomen, tight genital holes, and a slight pressure on the abdomen. 2.1.3 Maturity Appraisal Mature females are thin, long kiss, long bone plates, mucous surface, thin abdominal wall, large abdomen, soft and elastic. Mature eggs are oval, gray-green or black-green, shiny and elastic, more than 3.1mm egg diameter, animal extreme appearance of "white top" or ring polar spot clear. Observe the slices and the nucleus is close to the egg membrane. Mature males gently press on the abdomen with a small amount of semen flowing out of the excretory hole and scattered after entering the water. 2.2 Broodstock 2.2.1 Fish ponds The temporary holding pools are generally cement pools. Round and duck eggs are preferred, while rectangles are the second, and ponds are poor. The area is related to the amount of temporary fish, generally more than 10 per broodstock, water depth is 1 ~ 1.5m, water flow is 3 ~ 5L/s. 2.2.2 The riverside is bolted to the riverside shallow water area, with a water depth of 1.2 to 1.5m and a flow rate of 1.0 to 1.5 m/s. The water is clear and the grazing soil is kept quiet at the sandy bottom. Females are upstream and males are at intervals of 10m or more. 2.3 Oxidation production 2.3.1 Production water temperature The optimum production water temperature is 17 to 20°C. 2.3.2 Types of Oxytolucent Agents Dosage and Injection Methods Oxygen-promoting hormone-releasing hormone analogues (LRHA) and carp pituitary glands are commonly used in oxytocic diets. The latter are of small origin and are not economical, and are generally not used. Females were injected with 4-10 mg of pituitary gland or 3-4 μg of LRH per kilogram, and males had half the dose of females. Both male and female brood fish were injected with back muscle or pectoral fin base. The dose is divided into two injections or one injection according to the mature condition of the broodstock and the water temperature. Two-needle injection, the first needle injection of 10% of the total dose, after the interval of 12 hours, the second needle injection of the remaining dose. 2.3.3 Collection of mature spermatozoa Insemination and degumming and hatching The effect time of broodstock under different water temperature conditions is different, the water temperature is 16~17.5°C, the effect time is 20h; the water temperature is 19~20.5°C, the effect time is 12~14h; the water temperature is 22 ~ 24 °C, the effect time is 6 ~ 10h. After injecting the oxytocic acid, the male fish can catch sperm when they frequently hit the surface of the water or yankee raise the rope. The semen was collected using an extrusion method. First, a dry towel was used to dry the fishbirth genital hole and the abdomen and fin waterdrops around the abdomen, and the abdomen was turned outwards into an arch, and the chest and abdomen were patted, and the abdomen was squeezed to obtain a large amount of semen. High-quality semen is milk-like, milky white, slightly thick, and water is scattered. A large amount of eel semen, a male weighing 15kg can collect more than 300mL of semen. Fertile male fish can be used 2 to 3 times. The collected semen is stored in a chilled and dark place at 1 to 4°C, and its preservation for 70 h does not affect fertilization. When the female ovulates, her swimming activity is active and the ovary has a clear flow phenomenon. After gently pressing the abdomen, a few eggs can flow out to collect eggs. Generally, caesarean section or hand-pushing is used to extract eggs. One body weighing 20kg can produce 200,000 to 250,000 eggs. Semi-dry artificial insemination. The amount of semen used was 10 mL of semen per kilogram of fish eggs. Semen was diluted with sterile water and the ratio of semen to water was 1:200. When insemination, the hen's eggs are put into the semen water and stirred with feathers for 3 to 4 minutes so that the eggs can be fully combined, put aside for a while, and the sewage is discarded and rinsed. Sturgeon produces viscous eggs. The fish eggs appeared viscous 4 to 5 minutes after insemination, and the stickiness reached the maximum after 16 to 18 minutes. The 10% yellow mud water was filtered through a 80 mesh sieve or the 20% talcum powder solution was de-stick for 30 to 60 minutes. After detacking, the eggs are transferred to the incubator for hatching. Catfish hatching generally use a screen type water incubator. The incubator is divided into 4 incubators, and automatic dialing of eggs is performed once per minute. The intake and displacement per minute is 50 to 60L. It can contain 400,000 fertilized eggs at a time. The optimum incubation water temperature is 17 to 21°C. In the hatching process, 5g/m3 of malachite green was used to disinfect twice a day for 2 minutes. Fertilized eggs usually hatch from 1800 to 1980 (°Ch). The larvae that have just ruptured the membrane have a body length of 1.1 to 1.3 cm. If they are worm-shaped and do vertical movements, they should be moved to the holding tank (groove) immediately. . 3 Seedling cultivation 3.1 Fish rearing Freshly hatched larvae rely entirely on their own yolk for nutrition, which is an endogenous nutrition stage. At this stage, the fry should be raised in a holding pool (tank). The holding pool (slot) is circular, with a diameter of 2.2-2.8m, a depth of 0.5-0.8m, and a water flow rate of not more than 0.1m/s. The stocking rate is 25 to 35 tails per liter of water. Spray oxygen can be used or micro aeration pump. When the fish fry appear to have horizontal spots when they start to exercise, seedlings can be cultivated in separate ponds. 3.2 Water sources and cultivation ponds The cultivation water of eel fry can be taken from rivers, deep wells, reservoirs, etc. The water quality meets the “Fisheries Water Quality Standards” and the water quality is fresh. The water temperature is between 18 and 22°C. Dissolved oxygen requirement is above 6.0mg/L. Seed cultivation ponds are concrete pools or glass steel tanks. The cement pool is 20m long, 2m wide and 1.2m deep. The diameter of the FRP troughs is 2.2 to 2.8m, and both of them have injection and drainage facilities. 3.3 larval fish stocking stage: 600 cement ponds / water body, glass steel tank 1000 ~ 2000 tail / water body. Juvenile stage: 400 to 500 concrete tanks/body, 800 to 1000 FRP tanks/water body. Juvenile stage (5g): 200 concrete ponds/water body, 300 FRP troughs/water body. 3.4 Rearing When the yolk of the larvae absorbs 2/3 of the time, they are fed with rotifers, small horned horns, or artificially matched opening feeds (particle size 3.5 management 3.5.1 live baits need to be sterilized with 0.2% oxytetracycline or 3% saline Feeding bait is based on the principle of a small number of times.The carp mainly relies on the sense of smell and smell to prey, while the juvenile period must ensure that the water body has a certain bait density.3.5.2 Daily removal of residual baits, excrement and dead in the water should be timely. Fish, brush and wash basins (slots) regularly and sterilize them every week.4 Value and breeding prospects of A. stramineus 4.1 Food value and economic value of A. stramineus Eel is a precious fish in the world, and the whole body is a treasure, its meat and eggs nutrition. High value, protein content of 18.1% and 26.2%, respectively, and “black caviar sauce” made from processed salmon eggs, which are world-renowned for high-end nutritious foods, including kiss, gastrointestinal, fin, liver, gills, The fish muscles (notochord) are all excellent dishes, and their meat can be used for braised, baked meatballs, and smoked.The economic value of squid is extremely high, fresh fish are sold in Beijing, Guangdong and other places at a price of 200 yuan/kg or more. The export price of sauce is 200 to 300 US dollars/kg.Kiss, Notochord, Origin Acquisition The price is 240 yuan/kg or more 4.2 Medical health care value and industrial value Salmon carragine has anti-cancer effect, fish carp has special effects of heat-clearing and detoxification, carp oil has special effects on scald, long-term consumption of carp, low back pain, stomachache and Hair loss, etc. have a curative effect.鲟 Kiss, cartilage and leather can be made of glue, and the leather is also the raw material of high-grade leather, and its belt can be comparable to crocodile skin.. 4.3 Ornamental value The shape of an eel is very similar to a shark. Its shape is conical and it is covered with five elements. Bone plate scales, such as armor, black back, gray belly, white back, dorsal fins rear, tail tail shape, swift swim like a shuttle, sink like a submarine, is a high-grade ornamental animal. Large individuals, long life, high survival rate of juveniles, rapid growth, large genetic plasticity, strong resistance to diseases, etc., and easy to artificial domestication.At present, China's Dalian, Beijing, Sichuan, Guangdong and other places have carried out the scale of artificial Breeding, its prospects are very broad.