Conservation and Utilization of Fish Resources Introduces the domestication, broodstock breeding and conservation techniques of wild broad-bodied loach

Conservation and Utilization of Fish Resources Introduces the domestication, broodstock breeding and conservation techniques of wild broad-bodied loach

He Siyi

Broad-bodied sand loach ( Sinibotia reevesae ) belongs to the order Cyprinids , Loachidae , subfamily Sand loach , and sand loach. Its meat is tender and delicious, and it is a unique and important economic fish in the upper reaches of the Yangtze River. This paper mainly introduces the domestication, broodstock breeding and conservation techniques of wild broad-body sand loach, in order to provide guidance for the subsequent industrial development and resource conservation of the fish. [Yoshiyama Huayao self-media network debut]

First, the domestication of wild broad-bodied sand loach

1. Transportation and trauma control. Under hypoxic stress conditions, the surface of the broad-body sand loach and the gill epithelial mucus cells secrete a large amount of mucus, which hinders breathing and causes the fish to die of hypoxia. At the same time, it has underground spines, which is easy to puncture the plastic bag when stressed, so it is necessary to ensure that the oxygen in the water body is sufficient during transportation, and ice cubes can be added to the water to reduce the consumption of oxygen by the fish body.

Broad-bodied loach has fragile skin and is highly susceptible to injury during fishing and transportation, and new breeding fish need to be temporarily reared in 200 liters of culture barrels after water, and disinfected with iodine for 3 days at a dose of 0.24 ml/m³. At the same time, the wide-body sand loach is timid and easy to frighten, and it is necessary to add detoxification stress spirit (0.45 g/m³) to the aquaculture water body to prevent convulsions, random collisions and jumping tanks caused by fish body stress.

2. Feeding domestication. Wild broad-body loach does not actively feed on artificial compound feed, but first selects ground fresh fish for feeding, and then domesticates with fresh fish + compound feed until it is possible to actively prey on compound feed.

3. Breeding environment settings. The broad-body loach camp lives on the ground floor and has high athletic ability. In the rearing, it is necessary to use flowing water culture and partially shade the cultured water body or arrange a shelter with tiles for them to hide. Aquaculture water should be kept clear and transparent, and tap water or other water sources with good water quality should be used when feeding daily. Wide-body loach likes to drill gaps or holes, and needs to cover the inlets and outlets in the pond to prevent a large number of fish from burrowing in and causing death.

2. Broodstock rearing

1. Broodstock source. The domesticated wild broad-bodied loach was screened, and individuals with a body length of more than 10 cm and a weight of more than 15 grams were selected as broodstock, and the ratio of male to female was 1:(1~1.5).

2. Broodstock rearing ponds. An indoor circulating aquaculture system is adopted, with a rectangular shape of the fish pond, with water in one corner on one side and drainage at the bottom on the other side. Natural water temperature (12~30°C) cultivation.

3. Water quality control. The breeding water is filtered to remove feces and residual bait, plants are removed from nitrogen, ultraviolet sterilization and recycled, and the amount of new water is supplemented. The dissolved oxygen of aquaculture water is controlled at more than 5 mg/L, and the ammonia nitrogen is controlled below 0.01 mg/L.

4. Breeding density. Broodstock culture density is 20 to 40 fish/m2.

5. Bait feeding. Homemade artificial compound feed is fed once every two days at 12:00 noon in early December and february, and once at 7:00 a.m. and 6:00 p.m. in the rest of the months, on the principle that 80% of the fish are full.

3. Disease prevention and treatment

1. Precautions. Aquaculture water disinfection can choose iodine 0.20 ml / m³, disinfection every 15 days, every 1 week feeding bait, the formula is allicin 3 g / kg, gold multi-dimensional 2 g / kg, hepatic and gastric le 2 g / kg and three yellow powder 0.5 g / kg.

2. Treatment of water mold disease. It occurs in winter and early spring, and is often caught or startled by fishing or scaring the skin with thorns sticking out of the eye. The diseased fish is restless and often rubs against other solids, after which the fish body increases in weight, swims slowly, loses appetite, and then dies. It can be treated with a mixture of 1% table salt and 0.04% soda for 20 minutes, once a day, while taking antibacterial drugs internally. During the high incidence of the disease, disturbance should be avoided, and stress spirits should be added to prevent stress in the fish.

3. Treatment of small melon worm disease. The initial manifestations are mainly loss of appetite, isolation, restlessness, a small number of mutual friction or friction with the pool wall and the cover tiles, at the same time, the body surface is covered with a large amount of mucus, there are a large number of white spots at the head, body surface and fins, and the skin of the white spots attached to the site is not ulcerated. The incidence is about 70%. At the beginning of the disease, 0.5 kg of pepper and 1.0 kg of ginger should be weighed per mu of water (water depth 1 meter) and boiled in an appropriate amount of water for 30 minutes, and then sprinkled once a day for 5 consecutive days after cooling. Do not change the water during the treatment period, keep the water temperature above 28 ° C.

4. Treatment of surface ulcer disease. Initially active, it stays in the corner or pool in an isolated or clustered manner. Faded spots are often present on the surface of the diseased fish and there are significant congestion and bleeding phenomena around the faded spots. In the later stages of the disease, ulcers appear in many parts of the skin of the fish body, and in severe cases, the bones are exposed. Bait is required for treatment, bait formulation (by feed weight, 2% bait amount): vitamin C2 g/kg, enrofloxacin (10% effective content) 0.5 g/kg, florfenicol (effective content 10%) 0.5 g/kg, immunogly polysaccharide 3 g/kg, stress 3.75 g/kg. In addition, glutaraldehyde is required for disinfection treatment every day, the dose is 0.07 ml / m3, for 5 days, no water change during the treatment period and sufficient dissolved oxygen is ensured.