Fingerfish fry breeding techniques
Ma Jianbo
Acrossocheilus fasciatus is a stream-based economic fish, commonly known as freshwater grouper, belonging to the cyprinid, cyprinid family, light-lipped fish genus, and prefers to live in mountain streams and middle and upper reaches of rivers and other rapids. This kind of fish is tender and delicious, rich in nutrition, high in DHA and EPA content, which is quite popular with consumers; the body side has stripes, bright body color, and has high ornamental value. Under natural conditions, it prefers to eat moss and algae that grow on the rocks under the water, which also plays an important role in purifying water quality; feeding compound feed under artificial breeding conditions grows well. During the breeding season, eggs are laid in the sand under the water. The key technologies for the breeding of bare-lipped fish are briefly introduced as follows.
1. Nursery facilities
1. Broodstock breeding pond and spawning pond Both broodstock breeding pond and spawning pond are cement ponds, with an area of 25 to 50 meters and a depth of 1 to 1.4 meters. The upper end of the pool is provided with a controllable flow of water inlet pipe, the other end of the pool is provided with a drainage port, the center of the pool bottom and around the gas stone is set up for inflation and oxygenation, and the upper part of the pool is covered with nylon net to prevent bird damage.
2. Fry breeding pond and breeding pond With the steel pipe bracket canvas pond purchased on the market as a fry breeding pond and breeding pond, the breeding pond is square, each pond area is 6 meters 2, the height of the pond is 0.7 meters, and the drainage hole is set up at the bottom of the pool wall 5 cm for drainage, the bottom oxygenation facility is placed at the bottom of the pool for oxygenation, and the awning is set up above the pool to shade the light and block the rain.
3. Tailwater treatment facilities Use the large storage bucket purchased on the market to add sand gravel as a tailwater treatment facility, the sand is filled with storage buckets, the seedling breeding tailwater is discharged into the storage bucket from the upper part, and the treated water is discharged from the bottom into the purification pool.
2. Broodstock rearing
In mid-March, broodstock broodstock ponds are disinfected and water stored with bleach powder with an effective chlorine content of more than 25%. On sunny and cool mornings, individuals with robust, disease-free, injury-free, complete scales, good body shape, bright body color and typical biological characteristics are selected from the captive breeding group as broodstock. It is required that the age of 3 years or older, the male fish weigh more than 50 grams, the female fish weigh more than 60 grams, with 3% to 5% salt water solution soaked for 5 minutes, according to the male and female 1:1 ratio into the breeding tank, density 10 ~ 15 fish / meter 2, water depth 50 ~ 60 cm, keep the pool water in a flowing state. Compound feed is given once a day in the morning and once in the evening, and the amount of feeding is 3% to 5% of the body weight of the fish. During broodstock rearing, it is fed with vitamin E and coarse protein content of more than 40% with pelleted feed for nutritional fortification to promote gonadal development. The water in the pool comes from the filtered water of the reservoir, the daily water turnover is more than 100%, and the continuous aeration and oxygenation make the dissolved oxygen of the pool water more than 6 mg/L, and the pH is 6.8 to 7.2. The sewage residue at the bottom of the pool is cleaned regularly.
3. Spawning and egg collection
In late May, after the pond water temperature is above 20 °C, the female fish's abdomen is swollen and soft, the reproductive hole is ruddy, the male's body color is bright, the snout is prominent, and the milky white semen can flow out of the abdomen under light pressure, 3 to 5 40 cm × 50 cm × 20 cm imitation ecological ovary can be placed at the bottom of the broodstock breeding pond, and the ovaries are placed in 5 cm thick gravel or marble balls, and the sexually mature female broodstock are paired into the ovary to breed, lay eggs, and then collect the sperm eggs for incubation.
4. Incubation
The fertilized eggs are scattered on the sieve of the incubation frame, and the incubation box with a size of 60 cm × 50 cm is placed with 4000 to 5000 fertilized eggs. Place the incubation frame in the incubation tank with the water level 3 to 5 cm above the top of the incubation frame. Incubation adopts micro-flowing water and oxygenation, the daily water turnover is more than 200%, the dissolved oxygen is not less than 6 mg/l, the pH is 6.8~7.4, and the water temperature is 23~27 °C. The fertilized eggs hatch into fry after more than 40 hours.
5. Fry rearing
Endogenous nutrition is camped within 3 days after hatching, foraging is open on the 4th day, and exogenous nutrition is lost on the 7th day. Generally, from day 4, the watered egg yolk or yellow powder worm pulp filtered by the 120 mesh mesh is fed, and the feeding amount is 15 to 20 grams per 10,000 piglets, and it is fed three times in the morning, middle and evening. As the fry grow, the feeding volume is gradually increased. After the fry size reaches 2.0 cm, the compound feed is started, generally fed with egg yolk with a powdered eel feed with a protein content of 45%, and the daily feeding amount is 5% to 7% of the total weight of the baby fish, and it is fed once in the morning, middle and evening. When the fry size reaches more than 3 cm, it can be reared out of the pond.