Loach is a kind of fish with higher economic value and has higher nutritional value and medicinal value. In 1998, the Fisheries Station of the County Water Conservancy Bureau carried out the "Seedling Artificial Propagation and Seed Breeding Trial." A total of 430,000 fertilized eggs were obtained, and 286,000 tails of various specifications were cultivated. The main techniques are summarized below.
1 basic facilities
The experiment was conducted in the Huacun Reservoir Management Office. At the end of March, more than 1 month before artificial propagation, 15 concrete pools were constructed in places sheltered from sunlight and sunlight, including: 1 area of ​​10m2 cultivating pool, 1m deep in the pool, 4 4.5m2 hatching ponds, and 0.5m deep pool There are 10 nursery ponds with an area of ​​20m2 and a depth of 0.8m. In addition, 4 acres of ponds can be used for the cultivation of loach species. The bottom of the concrete tank is flat and rectangular. The drainage pipe is installed at the poolside. All cement pools are soaked with water for about 15 days before use, and are washed for several times to remove alkali from the pool and expose them for use.
2 artificial propagation
2.1 Intimate selection and cultivation: Intimate loach comes from river fishing. Breeding pond uses 20cm of mud at the bottom of the tank for 7 to 10 days before use. Dissolve 150 to 200g of quicklime in the whole pond. Water injection is 40~50cm. The water injection is filtered with a 40-mesh sieve to prevent harmful organisms from entering the pool. Use wire to set up escape prevention nets. After the water temperature stabilizes at about 18°C ​​in early May, the body length is 15-20cm, and the body weight is 30-50g. The body is robust, and there is no disease or injury. The gonads have good gonadal development as the broodstock. The pectoral fins of the female puffer are relatively short, and the front of the fins is relatively rounded. Fan-shaped, with the fins unfolded on a flat surface at rest, the pectoral fins of the males are relatively long, and the tips of the leading edges rise upward. The trapped loachworms were placed in a culturing pool at a ratio of 1 to 2 for intensive cultivation, and the stocking density was 8 to 10 tails/m2. During the cultivation period, animal feed such as animal minced meat, chopped viscera, and fish meal is mainly fed, and the amount of daily feeding accounts for 5 to 8% of the body weight of the pro-gallium, supplemented with a small amount of plant feed such as rice bran, wheat bran and fresh water grass, due to mud Like to feed at night, feeding should be mainly evening. Every 2 to 3 days, it replaces new water once, and changes 1/4 to 1/3 of the pool each time.
2.2 Artificial oxytocin production: After the sunny water temperature reaches 20°C or above on May 20th, the selective glandular mature and mature probiotic loach from the nursery pond, the abdomen of the female cricket is large, and the abdomen has a colorless and transparent ooze out of the abdomen. Plenty, squeezing the abdomen with milky white semen. All artificial oxytocin administration uses intramuscular injection. Each female quail is injected with 800 to 1000 IU human chorionic gonadotropin. The dosage of the male quail is halved. The injection is performed with a 1 ml syringe and a 4th needle, and the muscles are injected on both sides of the dorsal fin in front of the needle. The direction of the head is 45 degrees with the intimacy, the depth of the needle is about 0.4cm, and the female armpit is injected with 0.2ml. In order to facilitate artificial insemination after the injection, the inbreds are placed in two cages (1m1m0.5m, mesh 0.3-0.5cm) in the incubation tank for observation of estrus and spawning and timely insemination.
2.3 Artificial insemination: The female loach swims in front of the animals before spawning. The male loach is pressing behind and the loach estrus is more active on the surface of the water. The injecting oyster-producing pro-mud was about 20°C in water temperature. After 20 hours, the estrus spawned. The females were found to lay eggs and the broodstock was immediately removed for dry fertilization. Dry the body surface water with a clean towel, squeeze the female loach eggs into the porcelain bowl, porcelain basin or plastic basin, and immediately carry out the squeezing of the male raccoon. One female quail egg is equipped with 2 tails of male sap, and the mixture is stirred by feathers. In minutes, the semen and eggs are mixed, fully fertilized, sprinkled on the nest, and placed in the hatching pool for hydrostatic incubation. The fish nest was disinfected with a 20 ppm potassium permanganate solution. The washed willow roots and small grasses were bundled into small bundles. The entire fertilization process was conducted away from strong light.
2.4 Artificial hatching: 10 days before hatching, the hatching pond is completely disinfected with quicklime, until the efficacy disappears, the water injection is 30cm, and the fish nests with sticking eggs are tied on the bamboo truss and dropped into the water with a stone, 2 square meters per square meter. ~ 30000 eggs, covered with canvas top of the pool to avoid strong light. At a water temperature of about 20°C, fry can be hatched in 3 to 4 days. The newly hatched seedlings are 2.5 to 3.6 cm in length. They are not free to move. They are sucked on the fish's nests and pool walls by ejectors on their heads. They begin after 3 days. Move, remove the fish nest and start feeding.
3 seed cultivation
The loach seedlings after the start of eating can be transferred to nursery ponds for cultivation. Nursery ponds are used 7 to 10 days before use. Disinfect with quicklime. The bottom of the pool is laid with 10 to 12cm of composted manure as the base fertilizer. Note new water 20 to 30cm. Wait until the water becomes green and the transparency is 15 to 20cm. Put the seedlings into the mud for cultivation. The stocking density is 1000-1500 tails/m2. The nursery should be combined with fertilizer and water in the early stage of nursery. Because of the strong selectivity of the loach to the open bait, the rotifers, leeches, etc. filtered by the 50 mesh standard sieve are mainly fed along the side. Animals, at the same time, throwing the manure 60 to 100g/m3 twice a week or dissolving 1 to 2g/m3 of chemical fertilizers. After about 20 days, the seedlings can grow up to 1cm in length. The loach can ingest insects and insect larvae. Foods such as organic matter crumbs can be fed to animal feed such as animal viscera, blood meal, and fish meal, as well as concentrates such as rice bran, bean flour, corn flour, and bean cake scraps. Each morning and afternoon, they are fed one at a time. Feeding accounts for 2 to 5% of the body weight of the loach seedlings, and the amount of daily input can increase to 10% with the growth of loach seedlings. After more than 1 month of cultivation, the body length of the loach seedlings can reach 3 to 4 cm. At this time, they should be transferred to ponds for feeding. The pond is put into the muddy seedlings 7 to 8 days before disinfection with quicklime, water injection 40 ~ 50cm, Mu Shi fermented manure 150 ~ 200kg to cultivate water quality, until the pool to produce a large number of plankton, put the muddy seedlings, density 100 ~ 150 / m2, Feeding is basically the same as above. After 3 months of breeding, a loach species with a length of 8 to 10 cm and a body weight of 5 to 8 g can be cultivated.
4 issues of attention
4.1 In order to prevent the deterioration of water quality during the incubation period, the embryo develops anaerobic death and new water should be added to the pool regularly to keep the water fresh and with sufficient dissolved oxygen. At the same time, in order to prevent egg mould from occurring, the 0.5-ppm Malachite green solution is periodically used to dip and wash the fish nests that are full of eggs. When the larvae are all out of the membrane, the dead eggs are quickly removed to prevent deterioration of the water quality caused by egg spoilage.
4.2 Satisfaction of loach seedlings Opening bait is the key to improving their survival rate. The newly hatched loach seedlings absorb the yolk nutrition, and within two months after the disappearance of the yolk, they mainly feed on rotifers and otter in the water. It is advisable to develop zooplankton, such as rotifers and otters, in special pools to feed loach seedlings. Manure and chemical fertilizers are good fertilizers for feeding loach. It is necessary to constantly increase the fertilizing material in the cultivation pond so that the loach species have enough natural bio-feed.
4.3 Loach has a partial eclipse and nocturnal feeding habits, such as changing its special habits, to be artificial domestication, feeding once a day, evening feeding, feeding amount from less to more, feeding time gradually, until it can be at 10 o'clock in the afternoon At about 5 o'clock, they ingest and feed on artificial feed.
1 basic facilities
The experiment was conducted in the Huacun Reservoir Management Office. At the end of March, more than 1 month before artificial propagation, 15 concrete pools were constructed in places sheltered from sunlight and sunlight, including: 1 area of ​​10m2 cultivating pool, 1m deep in the pool, 4 4.5m2 hatching ponds, and 0.5m deep pool There are 10 nursery ponds with an area of ​​20m2 and a depth of 0.8m. In addition, 4 acres of ponds can be used for the cultivation of loach species. The bottom of the concrete tank is flat and rectangular. The drainage pipe is installed at the poolside. All cement pools are soaked with water for about 15 days before use, and are washed for several times to remove alkali from the pool and expose them for use.
2 artificial propagation
2.1 Intimate selection and cultivation: Intimate loach comes from river fishing. Breeding pond uses 20cm of mud at the bottom of the tank for 7 to 10 days before use. Dissolve 150 to 200g of quicklime in the whole pond. Water injection is 40~50cm. The water injection is filtered with a 40-mesh sieve to prevent harmful organisms from entering the pool. Use wire to set up escape prevention nets. After the water temperature stabilizes at about 18°C ​​in early May, the body length is 15-20cm, and the body weight is 30-50g. The body is robust, and there is no disease or injury. The gonads have good gonadal development as the broodstock. The pectoral fins of the female puffer are relatively short, and the front of the fins is relatively rounded. Fan-shaped, with the fins unfolded on a flat surface at rest, the pectoral fins of the males are relatively long, and the tips of the leading edges rise upward. The trapped loachworms were placed in a culturing pool at a ratio of 1 to 2 for intensive cultivation, and the stocking density was 8 to 10 tails/m2. During the cultivation period, animal feed such as animal minced meat, chopped viscera, and fish meal is mainly fed, and the amount of daily feeding accounts for 5 to 8% of the body weight of the pro-gallium, supplemented with a small amount of plant feed such as rice bran, wheat bran and fresh water grass, due to mud Like to feed at night, feeding should be mainly evening. Every 2 to 3 days, it replaces new water once, and changes 1/4 to 1/3 of the pool each time.
2.2 Artificial oxytocin production: After the sunny water temperature reaches 20°C or above on May 20th, the selective glandular mature and mature probiotic loach from the nursery pond, the abdomen of the female cricket is large, and the abdomen has a colorless and transparent ooze out of the abdomen. Plenty, squeezing the abdomen with milky white semen. All artificial oxytocin administration uses intramuscular injection. Each female quail is injected with 800 to 1000 IU human chorionic gonadotropin. The dosage of the male quail is halved. The injection is performed with a 1 ml syringe and a 4th needle, and the muscles are injected on both sides of the dorsal fin in front of the needle. The direction of the head is 45 degrees with the intimacy, the depth of the needle is about 0.4cm, and the female armpit is injected with 0.2ml. In order to facilitate artificial insemination after the injection, the inbreds are placed in two cages (1m1m0.5m, mesh 0.3-0.5cm) in the incubation tank for observation of estrus and spawning and timely insemination.
2.3 Artificial insemination: The female loach swims in front of the animals before spawning. The male loach is pressing behind and the loach estrus is more active on the surface of the water. The injecting oyster-producing pro-mud was about 20°C in water temperature. After 20 hours, the estrus spawned. The females were found to lay eggs and the broodstock was immediately removed for dry fertilization. Dry the body surface water with a clean towel, squeeze the female loach eggs into the porcelain bowl, porcelain basin or plastic basin, and immediately carry out the squeezing of the male raccoon. One female quail egg is equipped with 2 tails of male sap, and the mixture is stirred by feathers. In minutes, the semen and eggs are mixed, fully fertilized, sprinkled on the nest, and placed in the hatching pool for hydrostatic incubation. The fish nest was disinfected with a 20 ppm potassium permanganate solution. The washed willow roots and small grasses were bundled into small bundles. The entire fertilization process was conducted away from strong light.
2.4 Artificial hatching: 10 days before hatching, the hatching pond is completely disinfected with quicklime, until the efficacy disappears, the water injection is 30cm, and the fish nests with sticking eggs are tied on the bamboo truss and dropped into the water with a stone, 2 square meters per square meter. ~ 30000 eggs, covered with canvas top of the pool to avoid strong light. At a water temperature of about 20°C, fry can be hatched in 3 to 4 days. The newly hatched seedlings are 2.5 to 3.6 cm in length. They are not free to move. They are sucked on the fish's nests and pool walls by ejectors on their heads. They begin after 3 days. Move, remove the fish nest and start feeding.
3 seed cultivation
The loach seedlings after the start of eating can be transferred to nursery ponds for cultivation. Nursery ponds are used 7 to 10 days before use. Disinfect with quicklime. The bottom of the pool is laid with 10 to 12cm of composted manure as the base fertilizer. Note new water 20 to 30cm. Wait until the water becomes green and the transparency is 15 to 20cm. Put the seedlings into the mud for cultivation. The stocking density is 1000-1500 tails/m2. The nursery should be combined with fertilizer and water in the early stage of nursery. Because of the strong selectivity of the loach to the open bait, the rotifers, leeches, etc. filtered by the 50 mesh standard sieve are mainly fed along the side. Animals, at the same time, throwing the manure 60 to 100g/m3 twice a week or dissolving 1 to 2g/m3 of chemical fertilizers. After about 20 days, the seedlings can grow up to 1cm in length. The loach can ingest insects and insect larvae. Foods such as organic matter crumbs can be fed to animal feed such as animal viscera, blood meal, and fish meal, as well as concentrates such as rice bran, bean flour, corn flour, and bean cake scraps. Each morning and afternoon, they are fed one at a time. Feeding accounts for 2 to 5% of the body weight of the loach seedlings, and the amount of daily input can increase to 10% with the growth of loach seedlings. After more than 1 month of cultivation, the body length of the loach seedlings can reach 3 to 4 cm. At this time, they should be transferred to ponds for feeding. The pond is put into the muddy seedlings 7 to 8 days before disinfection with quicklime, water injection 40 ~ 50cm, Mu Shi fermented manure 150 ~ 200kg to cultivate water quality, until the pool to produce a large number of plankton, put the muddy seedlings, density 100 ~ 150 / m2, Feeding is basically the same as above. After 3 months of breeding, a loach species with a length of 8 to 10 cm and a body weight of 5 to 8 g can be cultivated.
4 issues of attention
4.1 In order to prevent the deterioration of water quality during the incubation period, the embryo develops anaerobic death and new water should be added to the pool regularly to keep the water fresh and with sufficient dissolved oxygen. At the same time, in order to prevent egg mould from occurring, the 0.5-ppm Malachite green solution is periodically used to dip and wash the fish nests that are full of eggs. When the larvae are all out of the membrane, the dead eggs are quickly removed to prevent deterioration of the water quality caused by egg spoilage.
4.2 Satisfaction of loach seedlings Opening bait is the key to improving their survival rate. The newly hatched loach seedlings absorb the yolk nutrition, and within two months after the disappearance of the yolk, they mainly feed on rotifers and otter in the water. It is advisable to develop zooplankton, such as rotifers and otters, in special pools to feed loach seedlings. Manure and chemical fertilizers are good fertilizers for feeding loach. It is necessary to constantly increase the fertilizing material in the cultivation pond so that the loach species have enough natural bio-feed.
4.3 Loach has a partial eclipse and nocturnal feeding habits, such as changing its special habits, to be artificial domestication, feeding once a day, evening feeding, feeding amount from less to more, feeding time gradually, until it can be at 10 o'clock in the afternoon At about 5 o'clock, they ingest and feed on artificial feed.