Technical specification for breeding of grouper

Water for raising seedlings: directly used after sand filtration

Main facilities:

① water supply facilities include 1 sand filter well, 1 submersible pump group, 1 sand filter tank, 1 reservoir and 1 set of inlet and outlet pipes.

② inflatable facilities have 1 group of blower, 1 set of inflatable pipe, inflatable head (2 × 4 / cu), and ③ nursery workshop has ten nursery ponds (specification is 2.5-4-1.2 m3). Temporary cage (60 ~ 100c), 1 set of stainless steel screen, 1 group of filter screen, several FRP incubator buckets.

Fish eggs come from their own source.

Water quality standard: dissolved oxygen ≥ 5mg/L, PH 7.8-8.4, salinity 28 ‰ ≤ S ≤ 33 ‰, ammonia nitrogen ≤ 0.3mg/L, nitrite ≤ 0.01mg/L, water temperature 25 ℃≤ T ≤ 32 ℃

Breeding process

1 treatment and hatching of fertilized eggs: the fertilized eggs were soaked in povidone iodine containing 20ppm in 100-day silk screen for 2 minutes, then poured into a glass fiber reinforced plastic incubator according to the density of 80 ~ 1 million fertilized eggs per cubic meter of water to hatch (dim light, weak exposure). The water temperature was kept at 29.5 ℃ ~ 30.5 ℃. After about 20 hours of hatching, the larvae can be hatched, and the larvae can continue to be temporarily reared in the incubator. The hatching water is purified and maintained with live bacteria king 5ppm + big bubble king 0.6ppm. When the larvae begin to prey after hatching for 40 hours, they should be immediately fed with artificial baits such as Prawn Crackers and Bp, which are filtered through a 250-mesh sieve and fed (domesticated bait). After feeding for 2 hours, it was transferred to the seedling pond with a sieve net to continue to breed, and the breeding density was 3000-5000 tails / mu.

2When hatching the fertilized eggs, the water used for raising seedlings was treated with live bacteria king 3~5ppm + probiotics 0.1-0.2ppm to activate and purify the water quality after entering the seedling pond to 0.8-1.0 meters. After adding the larvae, change the water 10cm to 30cm every day, and replenish the live bacteria king 3~5ppm after each change of water. During the whole breeding process, according to the cleanliness of the bottom of the nursery pond, the pollution should be properly absorbed to keep it clean, so as to avoid the deterioration of water quality and keep the inflation boiling all the time.

(3) the types of bait and the bait used in the process of raising seedlings are artificial diet, rotifer, copepod, larva and adult, etc. From the beginning of feeding to the stage of abnormal adult fish, the larvae are fed artificial compound feed three times a day (5:30, 9:30 and 15:30). The feed should be filtered through a silk net and fed. Feed one live bait (rotifer or copepod or harvest larva) at 8: 00 in the morning. The live bait must be cleaned and sterilized before feeding. In addition, the number of live bait in the water should be checked regularly to make sure that the number of live bait in the water is more than 1 / ml. Avoid self-harm because of hunger. After the larvae metamorphosed into juveniles, the artificial pellet bait was given twice a day (8:00 and 14:00). The pellet bait should be softened with lactic acid bacteria to increase palatability and strengthen physique. Adult or copepod once (time is 5:30) should also be washed and sterilized before feeding.

4 Juvenile fish grading: when it is estimated that the juvenile fish in the nursery pond is more than 90%, the juvenile fish of the same specification should be graded immediately with a stainless steel mesh, and the juvenile fish of the same specification should be temporarily reared in the same temporary cage with a temporary culture density of 2500 to 3000 fish / mouth, so as to avoid self-harm due to uneven size. Juvenile fish should be screened and graded once every 2 days.

5 Young fish out of the pool and counting: the juvenile fish can be out of the pool when the body length is more than 3 cm. Generally use 300 milliliters of plastic bowl to count, usually with how many tail 1 bowl as the standard.

6 Disease prevention and control: in order to prevent the larvae from getting entangled and the juveniles from dying due to poor vitality, ① generally uses high stable C1 once a day during the breeding period to improve the vitality and stress resistance of the fry. ② used Suan once a day during metamorphosis in order to improve the abnormal survival rate of larvae.