Key points of management of spotted forktail catfish culture

Key points of management of spotted forktail catfish culture

Spotted forktail  native to North America, belongs to the catfish,  family fish, camp benthic life, eating miscellaneous, more bulious, with fast growth rate, strong adaptability, fresh and tender meat, high nutritional value and other advantages, since 1985 by the Hubei Provincial Fisheries Research Institute introduced to China, has been in Hubei, Sichuan, Guangdong, Jiangsu, Henan and other regions of large-scale promotion of aquaculture. At present, the annual output of spotted forktail  high-quality fish species in the country is 1.1 billion (mainly from Jiayu County, Hubei Province), with an annual output of 380,000 tons of spotted forktail  adult fish, mainly for domestic consumption, mainly sold to processing plants and grilled fish shops.

Jiangsu Dongxin Farm Aquaculture Co., Ltd. is a large-scale state-owned aquaculture unit under Jiangsu Agricultural Reclamation, with an existing aquaculture water surface of more than 30,000 mu, with an annual production of more than 30,000 tons of high-quality aquatic products such as spotted forktails, grass carp, carp, crucian carp, And South American white shrimp, and has been identified as "pollution-free agricultural product production base" by the Jiangsu Provincial Bureau of Oceanography and Fisheries. In recent years, the company has made full use of the advantages of state-owned organization, continuously adjusted and optimized the breeding structure, introduced spotted forktail aquaculture, and accumulated sufficient experience technology and sales channels. The key points of the management of spotted forktail  culture are summarized as follows.

1. Stocking of seedlings

Spotted forktail is a scaleless fish, and the stocking of fry is prone to injury and infection, so caution is required. Seed stocking is recommended to be carried out at water temperatures above 15 °C, and stirred every 2 hours during the long-distance transport of fingerlings to prevent spotted forktails from piling up at the bottom of the fish box for hypoxia. After the fingerlings arrive at the stocking pond, the water in the fish tank is discharged, and the water in the fish pond is continuously added by the water pump for 15 minutes, so that the spotted fork tail can adapt to the mild water quality of the fish pond and reduce the stress response. After draining the water, use 1% to 2% salt water to disinfect the fish tank for about 10 minutes, and the fish fingerlings should be put into the pond immediately when they are restless during the disinfection process. The fish species are disinfected with thiosefloxacin or salicylic acid and iodine preparations the next day after the stock is released, and the disinfection is repeated once after two days.

Second, feed feeding

Spotted forktail  immediately after the pond is domesticated and introduced, at this time, polysaccharides, multi-dimensional and other immune enhancers can be added to help quickly restore physical fitness. From March to April, feeding sediment, protein content of 28%, feeding twice a day, slow feeding, daily bait rate of 0.5% to 1.5%; May to July, with the rise of water temperature, spotted forktail  into the peak growing season, feed extruded material, feed protein to 32%, feeding twice a day, daily bait rate of 1.5% ~ 2.5%; in August the water temperature is higher, the growth rate of spotted forktail  slows down, can be fed pellets, feed protein is reduced to 30%, fed twice a day, the daily bait rate is about 2%. September to October for the golden growth period, increase the amount of feed feeding, feed protein 32%, feeding twice a day, bait rate of 2.5% to 2.8%, after the middle of October gradually change the extruded material to sedimentary material and gradually reduce the feed, in the water temperature below 10 ° C every two days at noon feeding, fish pond ice after the stop feeding.

Third, water quality regulation

1. Pay attention to the bottom of the spotted forktail  is a benthic fish, and the bottom should be changed in the process of breeding. During the peak period of breeding from June to September, the bottom is changed every 7 days or so, and the biological bottom is used in conjunction with the chemical bottom change; the bottom is changed every 15 days or so in March-May and October-December, mainly chemical bottom change. If the water quality or substrate is poor, the frequency of bottom modification can be increased.

2. Strengthen the fertilizer water to replenish bacteria Through the fertilizer water to create a fat, live, tender and refreshing water quality environment, reduce the content of toxic and harmful substances such as ammonia nitrogen, nitrite, hydrogen sulfide, etc., which is conducive to reducing the occurrence of diseases and reducing the bait coefficient. Fertilizer water can be used urea, calcium superphosphate, amino acid fertilizer aquatic products sold on the market, after applying sufficient base fertilizer and good water, mainly to supplement fertilizer, a small amount of frequent supplementation. In order to reduce costs, self-cultured photosynthetic bacteria, bacillus, EM bacteria, lactic acid bacteria and other microbial preparations can be used once every 7 days.

3. Timely drainage of water In the summer, the high temperature season in August will fill the fish pond water; due to the accumulation of a large amount of residual bait and feces throughout the year, more than 1/2 of the water must be discharged before the winter overwintering to fill the fish pond water; when the water quality is too poor, part of the pond water can be discharged and new water can be added.

Fourth, disease prevention and control

1. Spring fulminant death Spring fulminant death is the disease that is most harmful to spotted forktail in recent years, with a high incidence and a large number of deaths. The onset time is from March to April of each year, the onset water temperature is 15 to 25 ° C, the symptoms are sluggish, swimming slowness, body surface ulcers, round faded spots of varying sizes, gill filament enlargement, redness and swelling, autopsy can see liver fibrosis, spleen blackening, purple, kidney enlargement, gastrointestinal no food, serious inflammation and pus, hind intestine has a sleeve of intestinal phenomenon (see color in the picture 2).

Prevention and control methods: water temperature below 15 ° C to reduce irritation, try not to move the net, frequently add water; can not stop eating prematurely before wintering, feed health care materials to enhance physical fitness, maintain water body fertility during wintering; slowly add materials after spring, feed health care materials to restore the fish as soon as possible. For the mouth of the disease pond, due to the low temperature at this time, the amount of food intake of the spotted fork tail is small, the absorption effect of the drug is poor, and the effect of the drug is not obvious, at this time, attention should be paid to the maintenance of water bodies to reduce disinfection and sterilization. After the disinfection of the milder external iodine preparation, the algae supplement is timely to ensure adequate dissolved oxygen, good water quality and substrate, and the internal administration of florfenicol or enrofloxacin with liver and gallbladder protection drugs and multi-dimensional 5 to 7 days, reduce the stimulation of the drug on metabolic organs, and after the end of the course of treatment, use liver and gallbladder protection drugs plus multi-dimensional rehabilitation health care for a course.

2. Summer hemorrhagic disease The epidemic season is from July to August in summer, the onset is urgent, the loss is large, and it is usually accompanied by the death of polyculture species such as crucian carp and silver carp in fish ponds. The base of the abdomen is congested around the eyeballs, jaws and fins of the diseased fish, the abdomen is swollen with ascites, the muscles and internal organs are bleeding, and the gastrointestinal congestion is pus (see color in the picture 2).

Prevention and control methods: diligently change the bottom, good fertilizer water, multi-supplement bacteria, remove toxic and harmful substances such as ammonia nitrogen, nitrite, hydrogen sulfide and other toxic and harmful substances in the water body, create a good water quality environment; regularly add liver and gallbladder protection drugs, polysaccharides, vitamins and other nutrients to improve the immunity of the fish body; after the onset of the disease, reduce the material 1/3 to 1/2, continuously pour benzalkonium bromide + glutaraldehyde compound twice, conditions allow drug susceptibility experiments to find sensitive antibiotics, and then add liver and gallbladder protection drugs and multi-dimensional feeding for 5 to 7 days.

3. Intestinal sepsis Epidemic season is May-June and September-October, caused by Edwardian infection, also known as "a little red", the sick fish lose balance on the surface of the water, the head has a red line, the eyeball is protruding, the gills are pale, there are small erythema on the body surface, the abdominal cavity is enlarged, the internal organs have bleeding points and necrosis points, the intestines are hyperemic, and some have a sleeve of intestine.

Prevention and control methods: also caused by bacterial infection, the prevention and control methods are the same as spotted fork tail  summer hemorrhagic disease.

4. Parasitic diseases mainly include small melon worms, wheel worms, cup worms, anchor head loach, more harmful spotted forktail  fish species, especially small melon worms, there is no special medicine, the harm is extremely great (see the picture in the color of 2). Prevention and control methods: completely clear the pond after the dry pond of the fish pond; maintain a reasonable stocking density; do a good job of fertilizer and water work in winter and early spring; change the bottom diligently during the breeding process to maintain a good substratum environment; due to the characteristics of the spotted forktail  scaleless fish, try to use Chinese herbal insecticides or milder insecticides such as avermectin and ivermectin after the occurrence of insect infestations.

5. Product sales

Unlike other traditional breeds, there will be uneven sizes due to differences in food grabbing in the breeding process, and there are three kinds of commodity specifications: "nerd goods" specifications are more than 1.6 kg / tail, "Beijing goods" specifications are 1 ~ 1.6 kg / tail, and "Chengdu goods" specifications are 0.5 ~ 1 kg / tail. Among them, the "Beijing goods" market has the largest sales volume and the highest price, so the spotted forktail needs to be sampled in time in the breeding process, pay attention to the growth trend, and reach the "Beijing goods" specifications under the ideal situation of the market, that is, move the sales, increase the proportion of "Beijing goods" in the whole pond, and improve the sales value. At the same time, through the wrench net, it is possible to catch large and retain small, accelerate the growth rate of fish in the pond, shorten the breeding cycle, and increase the output of fish ponds.