Techniques of Artificial Breeding of Wattlewifery
2018-05-24 16:00:38
Vallissula is a common freshwater fish species in China's rivers and lakes. The Vallis yellow sturgeon likes to inhabit quiet water and run in benthic habitats. It inhabits the bottom of the water during the day and swims to the top during the night. The variety is not only environmentally friendly, low-temperature resistant, low-oxygen-resistant, disease-resistant, and miscellaneous, but also delicate in meat, delicious in taste, rich in nutrition and high in economic value. It is the growth rate of currently farmed stingray fish. A faster one. In order to meet the needs of the market and develop its commercial aquaculture, it is necessary to first solve the source of seedlings. The study of artificial propagation of S. vachellii in the provinces of the Yangtze River Basin has been carried out well and has accumulated some experience, while there are fewer in Guangdong Province. The Aquaculture Technology Promotion Station of Foshan City conducted the first artificial breeding experiment on August 18, 2001 and achieved success.
Origin and cultivation of broodstock
At the beginning of May 2001, the gonads of the sexually mature Goliabella stellatus were purchased directly from Dongting Lake in Hunan, and transported using the live fish tanker and pure oxygen. Due to the high temperature at that time and the long transportation time, the brooded fish brought back were severely disabled. After the fish's constitution was restored, the broodstock that had matured and spawned began to degenerate. At the beginning of June, the aphrodisiac was consciously carried out in order to promote the re-development and maturation of the gonads and the female fish. After the aphrodisiac broodstock was placed in a pond with an area of ​​about 2 mu and a water depth of 1.5 m, the bottom was less muddy and flattened. Specialized management, feeding pellet feeds with a protein content of 35% or more, feeding wild fish litter every 3-5 days, feeding once daily from 4:30 to 5:30 in the afternoon, and feeding for 2 hours after feeding After eating within the standard, usually 2% to 5% of the fish's body weight, change the water every 10 days or so, to improve water quality, increase dissolved oxygen in the water, and use water to stimulate the development of gonads.
Oxygen production hatching 1. The spawning ponds are two square concrete pools with an area of ​​6m and 6m and a depth of 0.8m. The outlet is protected against escape with a 50-mesh screen, and a shading net is set up above the pool. The reason is that the spawning stingray should be protected from light, otherwise direct exposure to ultraviolet light will kill the fertilized egg or cause abnormal embryonic development. The use of shading nets is also conducive to inhabiting and feeding of broiled larvae.
2. Artificial fish nests use palm pieces for nests of Vallisnaire salmon. First soaked in 10ppm malachite green for 24 hours and then exposed to the sun. Before infusing the broodstock with a second needle of oxytocide, 80% of the total number of fish nests are laid on the bottom of the pool along the edge of the pool, and the other 20% are laid out in other places, and the fish nests are fixed with brick iron bars.
3. The pro-fish production was based on the forecast of the Foshan Meteorological Observatory. At the end of August, the weather was cooled for several consecutive days. Then on August 16th, the broodstock began to stop feeding. On the 17th, pumping reduced the level of broodstock ponds (due to the lower scraping rate of Wattlewort stingrays). On the 18th, the nets were caught to catch the broodstock and then the broodstock was selected. Selection criteria: females have gonopores and urine pores, the abdomen expands during the breeding season, is soft, and the genital pores are slightly red. Mature females exerted pressure on the abdomen with the outflow of eggs, and the outline of the ovaries was obvious. Male individuals are large, the abdomen does not inflate, and only the excretory hole is papillary. The tip is pink, but no semen can be squeezed. After selection, 108 groups were obtained. The average female had a weight of 110 grams per tail and 190 grams for the male. At 22:30 on August 18th, the broodstock was injected with the first needle of the broodstock (PG) with male and female doses, and the 5th needle was used as the dorsal fin base injection. The water temperature was 27°C. At 10:30 a.m. on the 19th (12 hours from the first needle), the abdomen of the female was quite soft and the outline of the ovary was more pronounced, indicating that the first needle had worked. A second needle injection was then performed and the injected fish pair was placed into two pools. The second needle used a combination of domoxone (DOM) + LRH-A + HCG, and a hermaphrodical dose.
4. Spawning and brooding broodstock began estrus 11 hours after the second injection at 21:30 on the 19th and reached climax after 1 hour. Obvious phenomenon of chasing madness can be clearly seen, and then submerged into the bottom to begin ovulation and fertilization. Divided several times into continuous and intermittent spawning, the distribution of eggs is not uniform, especially in the pool edge, especially in the pool corner and draining iron frame mesh around the more dense. The wall of the pool also disperses the eggs. Spawning takes a long time and lasts until dawn. After the spawning is completed, the broodstock should be removed in time so that the broodstock will not eat and feed the fertilized eggs. The postpartum broodstock was examined, and the rate of inducing spawning and emptying rate were high, reaching over 95%. However, the fertilization rate is low and uneven. The fertility rate is about 80%, and the lowest is less than 10%. At that time, due to the high water temperature outside the shed, more than 30 °C, can not be run water hatching, but with a small air pump, dissolved oxygen is maintained at 5 mg / liter or more. The water-expanded egg diameter is about 2 mm. Incubation water temperature between 27-29 °C, from the fertilized egg to the dehydration lasted 40 hours. The newly hatched larvae have a large yolk sac, pale yellowish green, and the fish body is colorless and transparent, with a total length of 4.5-5.5 mm. After the hatching of the fertilized eggs is completed, the fish nests together with the bad eggs are removed in time to prevent the destruction of the water after the dead eggs are corrupted. The pool water was then drained off by 80% and re-injected with water that had been prepared, disinfected and precipitated, and had a consistent water temperature a few days earlier.
The fry cultivation water temperature is between 27-30.5°C. The larvae disappear after about 65 hours since the larvae were stripped. The body color slowly turns into a dark brown, and it is gathered from the bottom of the pool and becomes adsorbed on the surrounding pool wall. At the same time, the larvae have a total length of about 7 mm. At this time, the larvae start feeding and can feed the bait. Freshly hatched larvae were fed to smaller cladocera and copepod zooplankton. Due to the small number of fry individuals, the amount of otters that can be cast cannot be large. It is best to filter with a mesh of 40 mesh. In addition, the amount of the larvae to be cast should not be too small to prevent self-mutilation of fry. The larvae hatched on the 5th day, and the total length reached 12-14 mm. The fins were clearly differentiated and formed, and the outline of the body of the frogfish was clearly visible. Since the water exchange conditions are limited, clean water is used to raise fry. In order to ensure good water quality, photosynthetic bacteria are added before the larvae are opened and then supplemented every 3-4 days. No disease was found during the entire cultivation process and the fry grew robustly. On August 30th, the 7th day of opening, the average length of the sturgeon's fry was up to 15 millimeters, and its size was relatively uniform, so it was transferred to a pond for cultivation. Because of the scale-free appearance of the Wattlewort stingray, the skin of the juvenile is thin and delicate, and it is very easy to injure the fry with careless operation. Optional 80-mesh or above, soft texture, nylon pool with specification of 2-3 buckets, two persons cooperate with each other, each station stands one by one to straighten the two sides of the bucket pool, one of the sides is close to the wall, and the bottom is upward, slow Slowly throw the fry into the nylon pool for collection. About 100,000 juveniles were collected this time. The fish fry pond is ready for the cultivation of the pond before: choose a shallow shallow sediment (20-30 cm), water depth of about 1.4 meters, water and fertilizer, convenient water, good water quality, an area of ​​1.5 acres of ponds. Ten days ago (when the spawning was used for spawning), the water was filled, and the whole pond was disinfected with tea bran, bleaching powder and Hing Po to kill wild fish and predators. After the toxicity disappears, photosynthetic bacteria and decomposed base fertilizers are used to cultivate water quality. The pond was equipped with a 0.75 kW aerator.
Summary 1, Warp herring multiple times a year mature in early June, artificial aphrodisiac Vallis yellow sturgeon, artificially intensively cultivated, early July examination, most of the already mature. Checking with an egg digger, most of the eggs have developed to stage IV. This shows that Vallisnichthys geometridis is artificially intensified and cultivated under the natural conditions of Guangdong, and can be recaptured at a month or so. .
2. Spawning and fertilization Wagewort stingray prefers spawning in the mud, especially where the pool angle is more subtle. The fish nests at the corners of the pool overlap many of the eggs, some of them even pile up on top of each other, and the distribution of eggs in the middle of the pool is less. Therefore, using natural spawning, the setting of artificial fish nests should mainly focus on the bottom edge of the pool, especially the location of the pool corners. In order to avoid excessive spawning at the fish's nest at the corner of the pool, a round or oval production pool may be appropriate. The fertility rate of artificial reproduction of Wattlewort was low, mainly due to: 1 high temperature, spawning, and water temperature at hatching of 28-29°C; 2 no spawning, hatching conditions; 3 no rigorous selection of broodstock, especially Male fish. In mature males, the gonads of the gonads are pink in color. At the time, because there were not many males captured, some of them were not up to standard.
3. Water quality Artificial breeding of Wattlewort yellow sturgeon, water consumption is not large, the best conditions for the selection of water temperature and water quality are more appropriate and stable groundwater as a water source.
Origin and cultivation of broodstock
At the beginning of May 2001, the gonads of the sexually mature Goliabella stellatus were purchased directly from Dongting Lake in Hunan, and transported using the live fish tanker and pure oxygen. Due to the high temperature at that time and the long transportation time, the brooded fish brought back were severely disabled. After the fish's constitution was restored, the broodstock that had matured and spawned began to degenerate. At the beginning of June, the aphrodisiac was consciously carried out in order to promote the re-development and maturation of the gonads and the female fish. After the aphrodisiac broodstock was placed in a pond with an area of ​​about 2 mu and a water depth of 1.5 m, the bottom was less muddy and flattened. Specialized management, feeding pellet feeds with a protein content of 35% or more, feeding wild fish litter every 3-5 days, feeding once daily from 4:30 to 5:30 in the afternoon, and feeding for 2 hours after feeding After eating within the standard, usually 2% to 5% of the fish's body weight, change the water every 10 days or so, to improve water quality, increase dissolved oxygen in the water, and use water to stimulate the development of gonads.
Oxygen production hatching 1. The spawning ponds are two square concrete pools with an area of ​​6m and 6m and a depth of 0.8m. The outlet is protected against escape with a 50-mesh screen, and a shading net is set up above the pool. The reason is that the spawning stingray should be protected from light, otherwise direct exposure to ultraviolet light will kill the fertilized egg or cause abnormal embryonic development. The use of shading nets is also conducive to inhabiting and feeding of broiled larvae.
2. Artificial fish nests use palm pieces for nests of Vallisnaire salmon. First soaked in 10ppm malachite green for 24 hours and then exposed to the sun. Before infusing the broodstock with a second needle of oxytocide, 80% of the total number of fish nests are laid on the bottom of the pool along the edge of the pool, and the other 20% are laid out in other places, and the fish nests are fixed with brick iron bars.
3. The pro-fish production was based on the forecast of the Foshan Meteorological Observatory. At the end of August, the weather was cooled for several consecutive days. Then on August 16th, the broodstock began to stop feeding. On the 17th, pumping reduced the level of broodstock ponds (due to the lower scraping rate of Wattlewort stingrays). On the 18th, the nets were caught to catch the broodstock and then the broodstock was selected. Selection criteria: females have gonopores and urine pores, the abdomen expands during the breeding season, is soft, and the genital pores are slightly red. Mature females exerted pressure on the abdomen with the outflow of eggs, and the outline of the ovaries was obvious. Male individuals are large, the abdomen does not inflate, and only the excretory hole is papillary. The tip is pink, but no semen can be squeezed. After selection, 108 groups were obtained. The average female had a weight of 110 grams per tail and 190 grams for the male. At 22:30 on August 18th, the broodstock was injected with the first needle of the broodstock (PG) with male and female doses, and the 5th needle was used as the dorsal fin base injection. The water temperature was 27°C. At 10:30 a.m. on the 19th (12 hours from the first needle), the abdomen of the female was quite soft and the outline of the ovary was more pronounced, indicating that the first needle had worked. A second needle injection was then performed and the injected fish pair was placed into two pools. The second needle used a combination of domoxone (DOM) + LRH-A + HCG, and a hermaphrodical dose.
4. Spawning and brooding broodstock began estrus 11 hours after the second injection at 21:30 on the 19th and reached climax after 1 hour. Obvious phenomenon of chasing madness can be clearly seen, and then submerged into the bottom to begin ovulation and fertilization. Divided several times into continuous and intermittent spawning, the distribution of eggs is not uniform, especially in the pool edge, especially in the pool corner and draining iron frame mesh around the more dense. The wall of the pool also disperses the eggs. Spawning takes a long time and lasts until dawn. After the spawning is completed, the broodstock should be removed in time so that the broodstock will not eat and feed the fertilized eggs. The postpartum broodstock was examined, and the rate of inducing spawning and emptying rate were high, reaching over 95%. However, the fertilization rate is low and uneven. The fertility rate is about 80%, and the lowest is less than 10%. At that time, due to the high water temperature outside the shed, more than 30 °C, can not be run water hatching, but with a small air pump, dissolved oxygen is maintained at 5 mg / liter or more. The water-expanded egg diameter is about 2 mm. Incubation water temperature between 27-29 °C, from the fertilized egg to the dehydration lasted 40 hours. The newly hatched larvae have a large yolk sac, pale yellowish green, and the fish body is colorless and transparent, with a total length of 4.5-5.5 mm. After the hatching of the fertilized eggs is completed, the fish nests together with the bad eggs are removed in time to prevent the destruction of the water after the dead eggs are corrupted. The pool water was then drained off by 80% and re-injected with water that had been prepared, disinfected and precipitated, and had a consistent water temperature a few days earlier.
The fry cultivation water temperature is between 27-30.5°C. The larvae disappear after about 65 hours since the larvae were stripped. The body color slowly turns into a dark brown, and it is gathered from the bottom of the pool and becomes adsorbed on the surrounding pool wall. At the same time, the larvae have a total length of about 7 mm. At this time, the larvae start feeding and can feed the bait. Freshly hatched larvae were fed to smaller cladocera and copepod zooplankton. Due to the small number of fry individuals, the amount of otters that can be cast cannot be large. It is best to filter with a mesh of 40 mesh. In addition, the amount of the larvae to be cast should not be too small to prevent self-mutilation of fry. The larvae hatched on the 5th day, and the total length reached 12-14 mm. The fins were clearly differentiated and formed, and the outline of the body of the frogfish was clearly visible. Since the water exchange conditions are limited, clean water is used to raise fry. In order to ensure good water quality, photosynthetic bacteria are added before the larvae are opened and then supplemented every 3-4 days. No disease was found during the entire cultivation process and the fry grew robustly. On August 30th, the 7th day of opening, the average length of the sturgeon's fry was up to 15 millimeters, and its size was relatively uniform, so it was transferred to a pond for cultivation. Because of the scale-free appearance of the Wattlewort stingray, the skin of the juvenile is thin and delicate, and it is very easy to injure the fry with careless operation. Optional 80-mesh or above, soft texture, nylon pool with specification of 2-3 buckets, two persons cooperate with each other, each station stands one by one to straighten the two sides of the bucket pool, one of the sides is close to the wall, and the bottom is upward, slow Slowly throw the fry into the nylon pool for collection. About 100,000 juveniles were collected this time. The fish fry pond is ready for the cultivation of the pond before: choose a shallow shallow sediment (20-30 cm), water depth of about 1.4 meters, water and fertilizer, convenient water, good water quality, an area of ​​1.5 acres of ponds. Ten days ago (when the spawning was used for spawning), the water was filled, and the whole pond was disinfected with tea bran, bleaching powder and Hing Po to kill wild fish and predators. After the toxicity disappears, photosynthetic bacteria and decomposed base fertilizers are used to cultivate water quality. The pond was equipped with a 0.75 kW aerator.
Summary 1, Warp herring multiple times a year mature in early June, artificial aphrodisiac Vallis yellow sturgeon, artificially intensively cultivated, early July examination, most of the already mature. Checking with an egg digger, most of the eggs have developed to stage IV. This shows that Vallisnichthys geometridis is artificially intensified and cultivated under the natural conditions of Guangdong, and can be recaptured at a month or so. .
2. Spawning and fertilization Wagewort stingray prefers spawning in the mud, especially where the pool angle is more subtle. The fish nests at the corners of the pool overlap many of the eggs, some of them even pile up on top of each other, and the distribution of eggs in the middle of the pool is less. Therefore, using natural spawning, the setting of artificial fish nests should mainly focus on the bottom edge of the pool, especially the location of the pool corners. In order to avoid excessive spawning at the fish's nest at the corner of the pool, a round or oval production pool may be appropriate. The fertility rate of artificial reproduction of Wattlewort was low, mainly due to: 1 high temperature, spawning, and water temperature at hatching of 28-29°C; 2 no spawning, hatching conditions; 3 no rigorous selection of broodstock, especially Male fish. In mature males, the gonads of the gonads are pink in color. At the time, because there were not many males captured, some of them were not up to standard.
3. Water quality Artificial breeding of Wattlewort yellow sturgeon, water consumption is not large, the best conditions for the selection of water temperature and water quality are more appropriate and stable groundwater as a water source.