Xenocypris argentea Crnther, commonly known as “scorpion†and “electionâ€, is a small economic fish that is widely distributed in rivers, lakes, reservoirs and lower waters. . Hunan Hengyang, Shaoyang and other places have long had a habit of raising silver cocoons in ponds, and their output can reach 10%-20% of the total.
1 The biological characteristics of silver carp
1.1 Morphological characteristics The silver carp is long and flattened; the head is small and hammer-shaped; the mouth is small and inferior, showing a transverse crack; the upper and lower jaws have developed horny edges; the back is grayish black, and the abdomen and the underside of the body are silver-white. . There are obvious orange patches on the lid. Dorsal fin III 7-8, anal fin II 9-10, fork tail type. Sideline scale 588-9/5-664, spine 39-40, ribs 14-15 pairs. The body length is 39.2 times the body height, which is 4.39 times the head length. Throat teeth 3 lines: 2,4,6/6,4,2; gut length is 4-5 times the body length.
1.2 Habits and habits The silver crucian has strong adaptability. It belongs to the warm fish of the plant and is mainly distributed in the waters of the Pearl River, Yangtze River and Heilongjiang. It usually inhabits the middle and lower layers of the water, with its developed mandibular keratinized edges, in the pool bottom or bottom mud. Scrape food. Under natural conditions, the silver carp is dominated by detritus sediment, and it also feeds on diatoms and fixed algae. Under the conditions of artificial breeding, in spring and summer, the detritus sediment was the main food, and the small amount of fixed algae was eaten. In autumn and winter, the detritus sediment was used as the food.
1.3 Age and growth in natural waters, the average body length of 1-2 years old fish is 13.3-15.7 cm, and the average body weight is 43.8-69.0 g; the average body length of 3-4 years old fish is 18.1-9.4 cm, and the average body weight is 103.3-129.6 g. . The weight of silver carp, which increases with age, can weigh up to 270 grams. The growth rate of silver cocoon grows faster with the first age, and after the second age, the growth rate slows down, which is related to the start of sexual maturation at the second age of silver cocoon. Under artificial breeding conditions, the average body length of a winter eel can reach 13.0-13.2 cm, the average body weight is 34.5-39.5 g, and the average body length in winter is 14.7-4.9 cm, and the average body weight is 52.8-55.1 g.
1.4 Breeding habits Under natural conditions, the silver crucian carp 2 is sexually mature in winter and is an annual spawning fish. The breeding season is from March to May, and April is the breeding season. The amount of cocoon of the silver cockroach is related to the size of the fish, and the amount of cocking eggs is generally 10,000 to 30,000 grains. Small egg diameter, floating eggs. Fertilized eggs hatch at 20-30°C for 30 hours. Under pond culture conditions, natural spawning cannot occur and artificial oxytocin production must be performed.
2 Artificial breeding of silver plover
2.1 Selection and retention of broodstock The broodstock that has been selected for artificial reproduction must be over 2 years old and have a minimum weight of 50 grams or more, and should be fat and strong without disease or injury. The election time is generally combined with winter fishing and dry pools. The broodstock breeding pond area is generally 600-700 square meters. The broodstock is stocked with 1,000 to 1,500 fish per 667 square meters. The water quality of the cultivation pool is fertile and the transparency is 25-30 cm. The cultivation of water quality is dominated by organic fertilizers. In the spring of the following year, feeds such as bean dregs and wheat husk are properly fed.
2.2 Artificial oxytocin production season In mid- and late April of each year, when the water temperature is stable at more than 18°C, select sunny weather and timely production.
The broodstock chose females with wide dorsoventral abdomen, pectoral fins slightly rounded, abdomen inflated, soft, ovary outlines, and vent holes reddish. Males are long and narrow, and their pectoral fins are slightly triangular and gently press on the abdomen. Milky semen flows out.
Oxygen production drugs and methods The silver carp oxytocin has good effects on the pituitary gland and the LRH-analogue. The female fish is injected with 0.5 pituitary or 30 μg LRH-analogue per side of the female fish, and the male fish is halved. Use the 4th needle to make a chest injection. Under the condition of water temperature of 18-24°C, the effect time is 10-15 hours.
2.3 Embryo development and artificial hatching of fertilized eggs Embryo development Silver-gall fertilized eggs are gray-gray, crystal clear and buoyant. The embryonic development takes about 112 hours at a water temperature of 21-23°C.
Artificially hatched silver maggot fertilized eggs are light in weight and are buoyant eggs. The hatching method is basically the same as the method of hatching grass, grasshoppers, cockroaches, and quails. It is generally hatched with loop water, requiring fresh water, and the water temperature is above 18°C. The egg diameter of the silver carp is smaller than that of the domestic fish, and the juvenile fish after the filming is also small. Therefore, the water filter screen cloth of the hatchery ring should be denser, and a 55-mesh nylon window cloth is generally used. The length of incubation is closely related to water temperature. Water temperature 20-22 °C, after 28-32 hours hatch hatching; water temperature 23-36 °C, incubation time is only 26-28 hours. Under normal circumstances, the juveniles can be cultivated in the lower pool 4 days after hatching.
3 silver carp seed breeding methods
3.1 Qingpei Disinfectant fry 1 week before the lower pond, the nursery pond must be sterilized by the clear pond, remove the poolside weeds, remove excess silt from the bottom of the pond, and disinfect with 75-100 kg of lime per 667 square meters. After 2-3 days of exposure, 150-200 kg of manure was applied per 667 m2 of water, and the depth of water was maintained at 40-50 cm. The water quality was fertilized and plankton was propagated. The fish could be eaten under the fry.
3.2 Fry cultivation methods Silver carp seedling cultivation is usually monocultured, with 20-250 thousand tails per 667 square meters. After 15-20 days of cultivation, when the fish body up to 2 centimeters, it is necessary to play in time to play the net ponds, stocking 80,000 to 100,000 per 667 square meters. Later, depending on the growth of the fry, the cultivation density was gradually adjusted.
3.3 Attention to regulate water quality The culture of silver carp seedlings is usually a shallow pond. The depth of fish when the fish is in the pool is 50-60 cm, so that the water temperature rises quickly, which is conducive to the decomposition of organic matter and the reproduction of plankton. With the growth of fry, to gradually deepen the pool water, fry 5-6 days after the pool, should be appropriate to add new water 10-15 cm, after every 3-5 days plus a new water, the final pool water depth of 1-1.5 meters.
3.4 Strengthen daily management. Insist on a daily inspection of the pond and observe the feeding, activity and growth of the fry, and find out that the disease should be prevented and treated in time.
4 Silver puffer fish breeding Silver bream is a small economic fish, body fat, delicious meat, it is very popular with consumers. Our country can breed from vast areas from south to north. In the ponds dominated by grass, grasses, cockroaches, and cormorants, a certain percentage of silver cocoons are used to feed not only fixed filamentous algae that cannot be used by cod fish, but also to eat large amounts of food. The swarf bottom sludge reduces the oxygen consumption brought about by the decomposition of organic matter, purifies the water quality, accelerates the material circulation in the water, and turns the waste into profit to promote the production of the main fish.
The silver cocoon grows fastest in the first year, mainly relying on the group to increase the output. The following aspects should be paid attention to in the pond.
4.1 Culture methods Pond culture Silver cocoon has polyculture and nesting. Polyculture: using the old fish species every other year, once in the winter, once a year at the end of the water; sets of raising: is the artificial breeding of fry, to the summer flowering stage, set in May in the adult fish pond; if the stocking number More often, the supply of fish species for the following year will be sufficient. If the number of stocks is small, they will be listed at the end of the year.
4.2 The number of fertilizer ponds for stocking is sufficient, and the amount of bait is sufficient. 10 to 15 kg (8 to 10 g per tail) of polygamy and old-mouth species per 667 square meters, and 100 to 120 kg of merchandise from mercerized fish at the end of the year; ponds of medium quality, Every 667 square meters of mixed-breed silver bream old-fashioned fish species 8-10 kilograms, the output can reach 70-80 kilograms. The ponds with poor bait conditions, mixed breeds of old fish species 5-7 kg/667 square meters, the output up to 50-60 kg.
4.3 Precautions for cultured silver cocoons Silver cocoons are miscellaneous and have few diseases, so they can be managed according to the routine. However, it should be noted that silver crickets are less resistant to hypoxia, and when the weather is hot and the air pressure is low, the silver gibbons are the first to float. Therefore, ponds cultured with silver cockles often need to be filled with new water and oxygen to keep the water quality fat and cool.
1 The biological characteristics of silver carp
1.1 Morphological characteristics The silver carp is long and flattened; the head is small and hammer-shaped; the mouth is small and inferior, showing a transverse crack; the upper and lower jaws have developed horny edges; the back is grayish black, and the abdomen and the underside of the body are silver-white. . There are obvious orange patches on the lid. Dorsal fin III 7-8, anal fin II 9-10, fork tail type. Sideline scale 588-9/5-664, spine 39-40, ribs 14-15 pairs. The body length is 39.2 times the body height, which is 4.39 times the head length. Throat teeth 3 lines: 2,4,6/6,4,2; gut length is 4-5 times the body length.
1.2 Habits and habits The silver crucian has strong adaptability. It belongs to the warm fish of the plant and is mainly distributed in the waters of the Pearl River, Yangtze River and Heilongjiang. It usually inhabits the middle and lower layers of the water, with its developed mandibular keratinized edges, in the pool bottom or bottom mud. Scrape food. Under natural conditions, the silver carp is dominated by detritus sediment, and it also feeds on diatoms and fixed algae. Under the conditions of artificial breeding, in spring and summer, the detritus sediment was the main food, and the small amount of fixed algae was eaten. In autumn and winter, the detritus sediment was used as the food.
1.3 Age and growth in natural waters, the average body length of 1-2 years old fish is 13.3-15.7 cm, and the average body weight is 43.8-69.0 g; the average body length of 3-4 years old fish is 18.1-9.4 cm, and the average body weight is 103.3-129.6 g. . The weight of silver carp, which increases with age, can weigh up to 270 grams. The growth rate of silver cocoon grows faster with the first age, and after the second age, the growth rate slows down, which is related to the start of sexual maturation at the second age of silver cocoon. Under artificial breeding conditions, the average body length of a winter eel can reach 13.0-13.2 cm, the average body weight is 34.5-39.5 g, and the average body length in winter is 14.7-4.9 cm, and the average body weight is 52.8-55.1 g.
1.4 Breeding habits Under natural conditions, the silver crucian carp 2 is sexually mature in winter and is an annual spawning fish. The breeding season is from March to May, and April is the breeding season. The amount of cocoon of the silver cockroach is related to the size of the fish, and the amount of cocking eggs is generally 10,000 to 30,000 grains. Small egg diameter, floating eggs. Fertilized eggs hatch at 20-30°C for 30 hours. Under pond culture conditions, natural spawning cannot occur and artificial oxytocin production must be performed.
2 Artificial breeding of silver plover
2.1 Selection and retention of broodstock The broodstock that has been selected for artificial reproduction must be over 2 years old and have a minimum weight of 50 grams or more, and should be fat and strong without disease or injury. The election time is generally combined with winter fishing and dry pools. The broodstock breeding pond area is generally 600-700 square meters. The broodstock is stocked with 1,000 to 1,500 fish per 667 square meters. The water quality of the cultivation pool is fertile and the transparency is 25-30 cm. The cultivation of water quality is dominated by organic fertilizers. In the spring of the following year, feeds such as bean dregs and wheat husk are properly fed.
2.2 Artificial oxytocin production season In mid- and late April of each year, when the water temperature is stable at more than 18°C, select sunny weather and timely production.
The broodstock chose females with wide dorsoventral abdomen, pectoral fins slightly rounded, abdomen inflated, soft, ovary outlines, and vent holes reddish. Males are long and narrow, and their pectoral fins are slightly triangular and gently press on the abdomen. Milky semen flows out.
Oxygen production drugs and methods The silver carp oxytocin has good effects on the pituitary gland and the LRH-analogue. The female fish is injected with 0.5 pituitary or 30 μg LRH-analogue per side of the female fish, and the male fish is halved. Use the 4th needle to make a chest injection. Under the condition of water temperature of 18-24°C, the effect time is 10-15 hours.
2.3 Embryo development and artificial hatching of fertilized eggs Embryo development Silver-gall fertilized eggs are gray-gray, crystal clear and buoyant. The embryonic development takes about 112 hours at a water temperature of 21-23°C.
Artificially hatched silver maggot fertilized eggs are light in weight and are buoyant eggs. The hatching method is basically the same as the method of hatching grass, grasshoppers, cockroaches, and quails. It is generally hatched with loop water, requiring fresh water, and the water temperature is above 18°C. The egg diameter of the silver carp is smaller than that of the domestic fish, and the juvenile fish after the filming is also small. Therefore, the water filter screen cloth of the hatchery ring should be denser, and a 55-mesh nylon window cloth is generally used. The length of incubation is closely related to water temperature. Water temperature 20-22 °C, after 28-32 hours hatch hatching; water temperature 23-36 °C, incubation time is only 26-28 hours. Under normal circumstances, the juveniles can be cultivated in the lower pool 4 days after hatching.
3 silver carp seed breeding methods
3.1 Qingpei Disinfectant fry 1 week before the lower pond, the nursery pond must be sterilized by the clear pond, remove the poolside weeds, remove excess silt from the bottom of the pond, and disinfect with 75-100 kg of lime per 667 square meters. After 2-3 days of exposure, 150-200 kg of manure was applied per 667 m2 of water, and the depth of water was maintained at 40-50 cm. The water quality was fertilized and plankton was propagated. The fish could be eaten under the fry.
3.2 Fry cultivation methods Silver carp seedling cultivation is usually monocultured, with 20-250 thousand tails per 667 square meters. After 15-20 days of cultivation, when the fish body up to 2 centimeters, it is necessary to play in time to play the net ponds, stocking 80,000 to 100,000 per 667 square meters. Later, depending on the growth of the fry, the cultivation density was gradually adjusted.
3.3 Attention to regulate water quality The culture of silver carp seedlings is usually a shallow pond. The depth of fish when the fish is in the pool is 50-60 cm, so that the water temperature rises quickly, which is conducive to the decomposition of organic matter and the reproduction of plankton. With the growth of fry, to gradually deepen the pool water, fry 5-6 days after the pool, should be appropriate to add new water 10-15 cm, after every 3-5 days plus a new water, the final pool water depth of 1-1.5 meters.
3.4 Strengthen daily management. Insist on a daily inspection of the pond and observe the feeding, activity and growth of the fry, and find out that the disease should be prevented and treated in time.
4 Silver puffer fish breeding Silver bream is a small economic fish, body fat, delicious meat, it is very popular with consumers. Our country can breed from vast areas from south to north. In the ponds dominated by grass, grasses, cockroaches, and cormorants, a certain percentage of silver cocoons are used to feed not only fixed filamentous algae that cannot be used by cod fish, but also to eat large amounts of food. The swarf bottom sludge reduces the oxygen consumption brought about by the decomposition of organic matter, purifies the water quality, accelerates the material circulation in the water, and turns the waste into profit to promote the production of the main fish.
The silver cocoon grows fastest in the first year, mainly relying on the group to increase the output. The following aspects should be paid attention to in the pond.
4.1 Culture methods Pond culture Silver cocoon has polyculture and nesting. Polyculture: using the old fish species every other year, once in the winter, once a year at the end of the water; sets of raising: is the artificial breeding of fry, to the summer flowering stage, set in May in the adult fish pond; if the stocking number More often, the supply of fish species for the following year will be sufficient. If the number of stocks is small, they will be listed at the end of the year.
4.2 The number of fertilizer ponds for stocking is sufficient, and the amount of bait is sufficient. 10 to 15 kg (8 to 10 g per tail) of polygamy and old-mouth species per 667 square meters, and 100 to 120 kg of merchandise from mercerized fish at the end of the year; ponds of medium quality, Every 667 square meters of mixed-breed silver bream old-fashioned fish species 8-10 kilograms, the output can reach 70-80 kilograms. The ponds with poor bait conditions, mixed breeds of old fish species 5-7 kg/667 square meters, the output up to 50-60 kg.
4.3 Precautions for cultured silver cocoons Silver cocoons are miscellaneous and have few diseases, so they can be managed according to the routine. However, it should be noted that silver crickets are less resistant to hypoxia, and when the weather is hot and the air pressure is low, the silver gibbons are the first to float. Therefore, ponds cultured with silver cockles often need to be filled with new water and oxygen to keep the water quality fat and cool.
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