Culture technique of catfish with big mouth

I. Biological characteristics

Big mouth catfish is one of the fastest and largest species of catfishes in the catfish family. It is common to have a body weight of 5~10KG, and the largest individual weighs up to 60KG. Its head is wide and flat, its eyes are small and its mouth is big, so it is called big-mouthed catfish. Its upper and lower jaw are covered with inward barbed teeth, making it difficult to escape once its prey is bitten. Adult fish have two pairs of whiskers, one of which is very long on the upper jaw, and the other is very short, which is often difficult to find, but there are three pairs of whiskers in the juvenile stage. The dorsal fin is short, clustered, without hard thorns; the pectoral fin has a stout hard thorn, and there is no obvious sawtooth on the outside, but the hand feels rough; the anal fin is long and connected to the caudal fin; the caudal fin is small, concave in the middle, and the upper lobe is longer than the lower lobe. The body color of big-mouthed catfish varies with environment and food type. The back and side of the body are mostly yellowish brown, bluish gray, yellowish green, the abdomen is grayish white, mixed with black spots, but no cloud pattern, each fin gray-black.

First, pond main culture

The main results are as follows: 1. In order to improve the survival rate and breeding efficiency, the larvae of big-mouth catfish should be above 8cm, and the size should be neat. The stocking density 8cm-1Ocm should put 1000-1500 fish per mu, 10cm-12cm-1200 fish per mu, and the pond with 150g-250g large-size silver carp and bighead carp fingerling to regulate the water quality. 2. the catfish is a carnivorous fish, which mainly takes live fish or chilled fish and animal viscera as bait, but it can also be fed with artificial compound feed through artificial domestication. The main results are as follows: (1) carnivorous bait: when the larvae of big-mouth catfish are put in, the smaller species such as common carp and crucian carp are still chilled fish and can also be fed to pig lungs, cow lungs and other animal offal every day. When these animal feeds can not be guaranteed, it can be domesticated artificially and ingested artificial compound feed, which can achieve better results. (2) artificial formula feed: the protein content of formula feed is 41% Mel 50%, and there are (2-4) bait tables in each pool to facilitate the observation of food intake. 3. Daily management patrol the pond three times a day in the morning, middle and evening, observe the feeding and growth of fish, change water every 5d-7d, strictly prevent the floating head of big-mouth catfish and take corresponding preventive measures. Second, the pond culture in the wild miscellaneous fish more adult ponds, parent fish ponds or large lakes, reservoirs, depending on the abundance of bait fish, per mu of 8cm-10cm large size catfish 15-30, without increasing bait input, does not need special management, does not affect the main fish culture premise, the year can increase the production of 30kg-50kg commercial catfish (tail weight 1.5kg-3.5kg). The technique of capturing big-mouth catfish in adult fish ponds is simple, the investment is less and the income is high, but it should be noted in production that big-mouth catfish should not be cultured in the same pond with carnivorous fish such as mandarin fish and snakehead, and should not be put into small size big-mouth catfish, and the specification should be above 8cm.

III. Cage culture

1. According to the specifications of fish species, the cage is equipped with three different kinds of cages: first-class fry box, second-class fry box and adult cage. First class fish box: mesh 0.6cm-0.8cm, specification is 4mx4mx2m or 5mx5mx2m, single-layer warp knitted unknot polyethylene open cage; second class fish box: polyethylene nodule open cage with mesh 1cm-1.5cm, specification 4mx4mx3m or 5mx5mx3m; adult cage: mesh 2.5cm-4cm, specification 4mx4mx3m or 5mx5mx3m double-layer polyethylene nodule closed cage. 2. The larval catfish reared for first-class stocking is the most suitable to be released in the first and middle of May every year. The stocking density is 500 / m2-600 / m2 according to the specification 4cm-5cm. After raising 15d-20d, the catfish is reared in boxes according to the size. Specification 8cm-10cm, stocking 350ind / m2-450ind / m2, transfer to the second-class box in time when reaching more than 15cm, stocking 250ind / m2-300ind / m2, when the fish species is about 25g, transfer to adult fish box, stocking 40ind / m2-60ind / m20.

3. The bait table is set up in the feeding cage, which is easy to observe the feeding condition of fish and make full use of the food. Generally, a bait table is set up for each 1Om2, which is suspended at the bottom of the 20cm-30cm in the box. When the catfish is full-length 5cm-10cm, the daily feeding rate is 8% Mel 10% of the fish body weight; when the full-length 10cm-20cm is, it can be adjusted to 4% Mel 6%; and when the full length is above 20cm, the feeding rate is 1% Mel. Feed it three times a day in the morning, afternoon and evening. Among them, slightly increase the amount of bait at night, the bait can be wild fish, chilled fish, animal viscera, but also through artificial domestication to feed artificial compound feed. The method is as follows: after the fish are put into the box, stop feeding 1d-2d to make them feel hungry, then put a small amount of attractant on the feed table every day, and slowly feed the artificial formula feed, with the adaptation of the artificial formula feed, reduce the bait dose accordingly, until the big mouth catfish completely adapt to the artificial formula feed. (1) Feed formula for fish fry period: fish meal 42% daidya-starch 15%, soybean meal 10.9%, peanut kernel meal 18%, yeast powder 3.3%, scallop meal 5.2%, fish oil 3.1%, premix 2.5%, crude protein content 35%. (2) the feed formula for the adult period is as follows: fish meal 25%, secondary meal 18%, soybean meal 18%, peanut kernel meal 18%, yeast powder 5%, fish oil 1.1%, corn 10.4%, compound amino acid 2%, premix 2.5%, crude protein content 35%. 4. The breeding and management of fish species should be screened in separate boxes in the stage of fish breeding. Regular box separation is the key measure to improve the survival rate of fish species. In general, fish species are screened every other 15d-20d and raised in separate boxes according to specifications. When 8cm-10cm is transferred to the second class fish box, when reaching the right side of 25gL, it can be raised in adult boxes. In daily feeding, the mouth and teeth of the catfish are sharp, and it is easy to bite through the net clothes when the bait is insufficient or ingest the bait next to the cage. At ordinary times, the cage damage should be checked regularly, the bait table should be cleaned regularly to ensure that the water body inside and outside the box is smooth, the bait on the bait table should be checked regularly, the rotten and deteriorated residual bait should be picked up, and the amount of feeding should be increased or decreased appropriately according to the remaining amount of the bait.