Catfish (Silurus asotus) belongs to the catfish order, catfish family, catfish genus. Heilongjiang catfish is not only large, fast-growing, and resistant to low temperatures, low oxygen, meat flavor, by the northern alpine region producers and consumers love. Based on years of practice, the author will catfish pond culture technology is summarized as follows.

1 pond catfish artificial reproduction

1.1 Parent fish selection: select the tail weight of 0.5kg or more, female fish abdomen is enlarged, red and swollen genital pore, gently press the abdomen can squeeze out the egg. The male has a narrow abdomen and can squeeze out white semen by lightly pressing the abdomen. The ratio of male to female is 1:1~1.5, and the individual size is suitable.

1.2 Oxytocin: catfish breeding practice has proved that catfish parents after prenatal cultivation of the reproductive glands to reach the end of the Ⅳ stage, the best use of oxytocin maleate (DOM) and luteinizing hormone-releasing hormone A2 (LHRH- A2) combined, the dose of catfish injected per kilogram of 2mg ~ 5mgDOM + 2μg ~ 4μgLHRH -A2, the mixture of the two drugs back muscle one-time injection, catalytic rate can reach more than 80%.

1.3 Artificial cloth nest: in the spawning pool arranged catfish spawning attachments, the method is similar to carp, but catfish eggs are not as sticky as carp eggs, a part of the egg particles are easy to fall off from the nest, fall to the bottom of the pool easy to die. In order to improve the utilization rate of catfish eggs, should be arranged at the bottom of the spawning nest bottom nest, the method with a diameter of 0.8 ~ 1cm iron rod welded into a 3m × 1m rectangular frame, the middle of the middle with a sieve silk connected to the sieve silk above the sewing with the eggs of the palm fronds, the bottom of the nest with the egg rate of the total number of spawning of 20 ~ 40%.

1.4 Artificial incubation: catfish spawning should be taken out of the nest in time to put into the hatchery, to prevent self-inflicted damage to their eggs. Hatchery pools are best for cement pools, earthen pools, the bottom should be flat, no silt, the water depth of 0.5 ~ 1m or less, the area should not be too large, the density of eggs for 30,000 / m2 water surface. The water quality needs to be strictly filtered to prevent aquatic animals from harming the eggs, and other incubation processes are similar to those of carp. The water temperature at about 20 ℃ 3 ~ 4 days to break the membrane of the seedlings, just out of the membrane of the catfish seedlings adsorbed on the nest, in static water or micro-flow conditions, the development of tadpole-like shape, hatch 3 days after the nest should be taken out in time, timely pond.

2 pond culture technology

2.1 catfish fry pond: catfish out of the membrane 3 ~ 4 days can actively swallow large rotifers and small branch angle class, at this time should be timely in the pond. Catfish fry in the pond after the abundance of branch angle class is the key to the survival rate of catfish fry, the use of organic fertilizer method to cultivate a large number of branch angle class. When the natural bait is insufficient in the late stage, use a 50-purpose sieve net to fetch branches and horns from other ponds or fresh animal bait chopped and fed. Sufficient animal bait in the pool, catfish seedlings grow faster, generally 667m2 put about 90,000 tails, after 10 to 15 days of breeding summer flowers, the survival rate of up to 50%, hair pond water surface is best in 667m2 or less.

2.2 Fish breeding

2.2.1 Ecological breeding to cultivate catfish species: a large amount of organic fertilizer to cultivate zooplankton, benthic organisms, aquatic insects and small miscellaneous fish, to provide catfish with nutrient-rich animal live bait. This method has a high survival rate and large specifications. 2,500 catfish summer flowers were stocked in 4,000 m2 ponds in 1997, accounting for 54.3% of the total stocking, 700 silver chub summer flowers, accounting for 15.3% of the total stocking, and 1,400 silver chub summer flowers, accounting for 30.4% of the total stocking. Catfish fry stocked 17 days before the release of 200 crucian carp parents, so that its natural reproduction, each 667m2 apply base fertilizer and fertilizer each 500kg, and feed powder feed 150kg feeding crucian carp fry, after 90 days of feeding, catfish average per 667m2 produced 50.5kg, the survival rate of 94.8%, the specifications of up to 128g / tail. Chub survival rate of 78%, chub survival rate of 85%, this cultivation method technology is simple, easy to master, crucian carp fry as bait fish easy to obtain. Catfish fry stocking density should be determined by the number of bait fish, stocking time must be 10 days after the chub stocking before stocking catfish summer flowers.

2.2.2 Fish stocking pond with catfish summer flowers: in the fish stocking pond with less than 10% catfish summer flowers, not only can clear the pond wild fish, aquatic insects, tadpoles, etc., but also increase the yield of the main species of fish, improve the efficiency of the pond. 1995 in the domestication of the main species of carps in the pond stocked with 12.2% (500 tails / 667m2). 1996 stocking 6.67% ( 300 tails 667m2). 300 tails 667m2) of catfish summer flowers, without affecting the survival rate and yield of the main fish, per 667m2 increased catfish production 43.75kg (feeding part of the chicken intestines) and 16.2kg.

2.2.3 Adult fish pond set of catfish species: this method of investment is small, high efficiency, without adding other management measures, especially in the small miscellaneous fish more adult fish ponds every 667m2 stocked with 100 to 200 tails of catfish summer flowers, can be bred into each tail of 100 to 150g of catfish species 10 to 20kg, per 667m2 increased benefits 200 to 200 yuan.

2.2.4 Domestication of granular bait to cultivate catfish species: catfish eating natural animal bait or terrestrial animal bait grows faster and has a higher survival rate. Catfish also eat artificial granular bait under starvation, and can be domesticated in ponds with granular bait. However, the nutritional requirements of the bait is relatively high, the protein content of pellet bait in domestication culture should be higher than the content of carp, catfish species bait protein should be about 40%, animal protein (imported fishmeal) should account for more than 30% of the bait protein. The processing and domestication method of pellet bait is basically similar to that of carp, and the tail weight of catfish bred by this method can reach 50-100 g. In 1997, a pond of 667 m2 was stocked with 6,000 tails of catfish summer flowers, domesticated with pellet bait, and the production of 667 m2 was 93.5 kg, with a bait coefficient of 3, an average tail weight of 84.5 g, and a survival rate of 18.44%. The authors believe that the catfish species survival rate is mainly due to the bait is not suitable for the mouth, nutrition is not complete and lead to the size of the specification is not uniform, large individuals swallow small individuals, when the catfish weight of 10g or so, each other killing serious, is the main factors affecting the catfish scale production. In order to improve the survival rate of catfish species should be supplemented with some palatable animal bait from summer flowers.

2.3 Adult Fish Farming

2.3.1 Summer flowers raised into commercial fish: catfish summer flowers stocked in small mixed fish rich adult fish ponds, 667m2 set of about 30. The year can be up to 0.35kg or more, the largest individual up to 0.75kg. 667m2 increase catfish production 5 ~ 10kg. set up to water conditions, the pond miscellaneous fish how much flexibility to grasp the density.

2.3.2 Adult fish pond with catfish spring piece of fish species: catfish swim slowly, on the same specification swimming speed of farmed fish predation is generally not, the pond stocked with certain specifications of catfish can only clear the pool of small wild fish and sick farmed fish. Commercial fish ponds 667m2 stocked with tail weight 50 ~ 100 .