1 basic facilities
This test is carried out in the Huacun Reservoir Management Office, the source of water to the pipe to the reservoir. the end of March that is more than a month before the artificial propagation, in the wind and sunshine, full of light, the construction of cement pools 15, of which: the area of 10m2 cultivation pool 1, 1m pool depth, an area of 4.5m2 hatching pools 4, the pool depth of 0.5m, an area of 20m2 seedling pool 10 There are 10 nursery ponds of 20m2 with a depth of 0.8m, and 4mu of ponds in the management office can be used for the cultivation of loach species. Cement pool bottom is flat, rectangular, pool side of the injection drainage pipe, all cement pool in the use of about 15 days before, soaked in water, many times flushing, remove the alkaline pool, exposure to the sun to be used.
2 Artificial reproduction
2.1 Selection and cultivation of pro loach: pro loach from the river catch. Cultivation pool 7 ~ 10 days before the use of the pool bottom 20cm of fat mud, per square meter with 150 ~ 200g lime sprinkled with the whole pool disinfection, water injection 40 ~ 50cm, water injection with 40 mesh sieve silk filtration, to prevent harmful organisms into the pool, in the injection of the drainage outlet with wire set up escape nets. early May after the stability of the water temperature of about 18 ℃, the selection of body length of 15 ~ 20cm, body weight of 30 ~ 50g, body health, disease-free, gonads well developed. No injuries, gonads well developed loach as parent fish, female loach pectoral fins are shorter, the front end of the fins are more rounded, fan-shaped, resting fins spread on a plane, male loach pectoral fins are longer, the tip of the leading edge of the part of the upward fin up. The capture of the pro loach according to the male and female ratio of 1:2 into the cultivation pool for intensive cultivation, stocking density of 8 to 10 tails / m2. cultivation period, mainly feeding animal meat, minced offal, fishmeal and other animal feeds, the daily feeding amount of pro loach body weight of 5 to 8%, and supplemented with a small amount of rice bran, wheat bran and fresh water plants and other plant feeds, because the loach like to feed at night, feeding should be mainly in the evening. Every 2 to 3 days to flush new water, each time to change the pool of 1/4 ~ 1/3.
2.2 Artificial spawning: May 20 or so sunny day water temperature reaches 20 ℃ or more, from the cultivation of the pool to select gonadal development of mature loach, female loach abdomen round, gently press the abdomen with colorless transparent egg particles out of the male loach semen abundance, extrusion of the abdomen with milky white semen out of the semen. Artificial catalytic all use intramuscular injection, each female loach injection 800 ~ 1000 international units of chorionic gonadotropin, male loach dose halved, the use of 1 ml syringe and four-gauge needle injection, intramuscular injection in the dorsal fins on both sides of the anterior and inferior to the direction of the head of the needle and the pro loach at an angle of 45 °, the depth of insertion of the needle is about 0.4 cm, female loach injection of 0.2 ml, the male loach halved. After the injection of the pro loach to facilitate artificial insemination, male and female into the cultivation pool in two nets (1m × 1m × 0.5m, mesh 0.3 ~ 0.5cm) within the observation of oestrus spawning, artificial insemination in due course.
2.3 Artificial insemination: female loach before spawning in front of the swim, male loach in the back of the urgent, loach in heat more activities on the water surface. Injection of oxytocics pro loach in the water temperature of about 20 ℃, after 20 hours can be in heat to spawn, found that the female fish spawning, immediately fish out the pro fish for dry fertilization. With a clean towel to dry the body surface water, the female loach eggs squeezed into a ceramic bowl, ceramic pots or plastic pots, and immediately male loach extrusion of semen, a female loach eggs with 2 male loach semen, stirred by the feather for about 3 minutes, so that the semen and the egg particles are mixed well, after full fertilization, sprinkled in the fish nests, put into the hatchery for hydrostatic incubation. Fish nests sterilized with 20ppm potassium permanganate solution, washed willow roots, small grasses tied into small bundles made, the entire fertilization process is carried out by avoiding strong light.
2.4 Artificial Incubation: 10 days before hatching, the hatching pool with quicklime thoroughly disinfected, to be the efficacy of the disappearance of the drug, injection of 30cm of water, the fish nests full of sticky egg particles tied to bamboo yu frame, with a stone fell under the water surface, 2 ~ 30,000 eggs per square meter, the top of the pool covered with tarpaulin, to avoid bright light exposure. At a water temperature of about 20 ℃, 3 to 4 days to hatch fry, just hatch loach fry body length of 2.5 ~ 3.6cm, can not move freely, with the head of the jet adsorbed in the nest and the pool wall, 3 days after the beginning of the swim, take out the nest, and start feeding.
3 Seedling Cultivation
After the opening of the food loach fry, can be transferred to the nursery pool to cultivate. Nursery pool 7 ~ 10 days before use, disinfection with quicklime, the bottom of the pool paved 10 ~ 12cm of rotted manure as fertilizer, injection of new water 20 ~ 30cm, to be green, transparency 15 ~ 20cm, into the loach seedling cultivation, static water stocking density of 1000 ~ 1500 tails / m2, seedling nursery should be fertilized in the early stage with a combination of feeding, due to the loach on the opening of the bait has a stronger selectivity, the main feeding along the side with 50 mesh, the main feeding, the main feeding, the main feeding, the main feeding, the main feeding, the main feeding, the main feeding, the main feeding, the main feeding. Mainly along the edge of the feeding with 50 mesh standard sieve filtered rotifers, water fleas and other zooplankton, while splashing twice a week fermented manure 60 ~ 100g/m3 or splashing dissolved fertilizer 1 ~ 2g/m3, after 20 days of cultivation of the seedling length of up to 1cm, at this time the loach can ingest insects, insect larvae in the water and organic debris and other food, you can feed the animal feeds such as broken animal offal, blood meal, fishmeal and other animal feeds. Rice bran, soybean meal, corn meal, soybean cake crumbs and other concentrate feed, every day in the morning, afternoon each feeding once, the beginning of the daily feeding accounted for the loach seedling body weight of 2 ~ 5%, later with the growth of loach seedling, the daily amount of casting can be increased to 10%. After more than 1 month cultivation loach seedling body length up to 3 ~ 4cm, at this time should be divided into pool to pond rearing. Pond put loach seedling 7 ~ 8 days before the lime disinfection, water injection 40 ~ 50cm, mu Shi fermented manure 150 ~ 200kg to cultivate water quality, to be cultivated in the pond a large number of plankton, put loach seedling, density 100 ~ 150 tail / m2, feeding the same basic, after 3 months of breeding can be cultivated body length of 8 ~ 10cm, body weight of 5 ~ 8g large specification loach species.
4 Attention
4.1 During incubation, in order to prevent the deterioration of water quality, embryonic development of oxygen-deficient deaths, should be regularly added to the pool of new water, to keep the water quality fresh, sufficient dissolved oxygen. At the same time, in order to prevent the eggs from water mold disease, regularly use 0.5ppm malachite green solution to dip and wash the nest of the fish sticking full of egg particles, when all the young fish out of the membrane, quickly fish out the dead eggs, so as to avoid egg corruption caused by the deterioration of water quality.
4.2 Meeting the opening bait of loach fry is the key to improve their survival rate. The newly hatched loach seedling absorbs the nutrition of yolk, and feeds mainly on rotifers and daphnia in the water within two months after the yolk disappears. It is best to cultivate rotifers, daphnia and other zooplankton in specialized pools to feed loach fry. Manure, fertilizer are good fertilizer for feeding loach, we should keep adding fertilizer to the cultivation pool, so that loach seedlings have enough natural biological bait.
4.3 Loach with partiality and night feeding habits, such as changing its special habits, to be domesticated artificially, feeding once a day in the evening, the amount of bait from less to more, feeding time gradually in advance, until it can be in the morning at 10:00 a.m., 5:00 p.m. or so ingesting and able to ingest artificial feed until.