Multiplication Techniques for Jewel Spots
2019-07-19 16:02:09
The gem spot is native to the freshwater waters of Australia and is of the order Diptera. In 2001, southern China began to introduce experimental aquaculture. The fish has the characteristics of rapid growth, strong ability to adapt to the environment, and resistance to hypoxia. It has small head and tail, back hypertrophy, high meat yield, no intermusculoskeletal, white and tender meat, delicious taste, strong gumming, and no defects. taste. What is more valuable is that the gemstone spots are rich in highly unsaturated fatty acids, proteins with a content of up to 18.9% or more, and essential amino acids. They also contain more “DHA†(decanedioctahexanoic acid) and “EPA†(carbon Pentaenoic acid, etc., has the effect of inhibiting platelet coagulation, antithrombosis, and regulation of blood lipids to prevent cardiovascular disease, and has a good effect on promoting development, improving brain function, and enhancing memory.
1, breeding technology
1.1 Selection of Broodstock and Identification of Maturity The 3rd-instar fish was selected and the fish was disease-free and non-injury. The males had body weight of 800g or more, total length of 280mm or more, female weight of more than 1000g, and individuals having a total length of 250mm or more. The male and female individuals in the non-reproductive phase have no obvious characteristics. The male and female fish in the reproductive phase have no maternal sex and star-crossing sex vices. The specific identification methods are:
1.1.1 Sexually mature female individuals are emaciated and have many mucous on the surface. The abdominal wall is thin and soft, the abdomen is inflated and full of elasticity, and the gonad profile is obvious. Use a special egg digger to remove a few eggs from the middle of the ovaries in the gonads and check the egg's color, shape, and polarization.
1.1.2 There is no change in the body color of male individuals, and the body size is lanky. Generally, individuals with body weights above 800 g are mostly mature. During the examination, see the tail of the fish bent into a "bow" shape, and the genital papillae are extended by 1 to 2 cm. The milky white color is displayed. The semen is gently pressed by the genital hole by hand, and the male fish at this time can be used for breeding.
1.2 artificial production when the water temperature rises to 24 o'clock can be artificial oxytocin. The oxytocic agents are mostly selected from squid and carp pituitary releasing hormone analogues or chorionic gonadotropin. The method of injection and the dose used depend on the maturation of the broodstock. Two injections were used to promote the synchronized maturation of the male and female gonads. The practice is: the first injection dose is 10% of the dose, males use half of the female dose and are injected at the second injection of the female fish; males with better maturity may also not be injected. The injection site is generally located at the base of the pectoral fin.
After the bred broodstock, the male and female are raised in separate pools and stimulated by running water. Observe the broodstock activities and observe the effect time from time to time. The water temperature was controlled at (24+0.5) °C and the flow rate was 3t/h. After 10 hours, the eggs were not extruded. The flow rate was increased. When the effect time reached 18 hours, the females were active and frequently hit the water surface. The females showed obvious signs of flow, and they gently pressed the abdomen to the oocysts at the gonopore. At this point you can take the eggs.
1.3 Insemination by artificial dry fertilization, that is, artificial egg collection, sperm extraction, and fully mixed, immediately after mixing with feathers to add a small amount of water to complete the fertilization process; rinse fertilized eggs with water 2 to 3 times, washed away debris and blood clots, The fertilized eggs were evenly placed on a 40cm20cm nylon egg-bearing plate. About 15,000 eggs were laid on each plate, and the eggs were incubated in the incubator. The broodstock that produced the eggs are sterilized and returned to the broodstock pool.
1.4 Incubation incubator water dissolved oxygen is not less than 6mg/L, incubation temperature is controlled at about 23 °C. The special special incubator specifications are generally 380cm65cm30cm. There is an inlet and drain system and timing dialing device. The first time hatching eggs of 400,000 gems are hatched, the influent amount is (50-60)L/min, and the automatic dialing device is for every minute. Once, the hatching rate was 85%.
2. Seed cultivation techniques Seed cultivation can be divided into two stages: cultivation of small-size seedlings and cultivation of large-scale seedlings.
2.1 The cultivation of small-sized seedlings The cultivation of small-scale seedlings is a process in which waterflooding is cultivated for about 20 days so that the total seedling length can reach 2.5cm or more. Its food can be used for aquatic oligo-type (water fleas), Cladocera and other live bait.
2.1.1 The cultivating pool is an indoor cement pool with an area of ​​3 to 10 square meters. It is round and has surface flute type water supply. There is a drainage hole in the middle of the pool. The surface of the pool bottom and pool wall should be smooth, and the bottom of the pool is not leaky. The cultivation pond should be sterilized with 300.000001 KMnO4 solution before use, and the depth of water in the lower pool is 20-40 cm.
2.1.2 Larval larval rearing The larval rearing refers to the feeding and management of the newly hatched larvae, which is maintained in the cultivation pond for a period of time before the start of eating.
The larvae are photophobia and should avoid direct sunlight and shading facilities on the pool. During the temporary period, the temperature of the water must be kept constant, and in particular, the water temperature must not suddenly drop or rise. At the same time, the flow in the pool is controlled at (3~5)L/min and the dissolved oxygen is above 4.5mg/L.
2.1.3 Feeding When bait is fed at a water temperature of 22 to 24°C, larvae hatched for 6 to 7 days can be fed. Its open bait is Artemia nauplii, small Cladocera or otter. Because the larvae often swim to the surface at night, at the beginning of feeding, besides feeding three chopped blisters during the day, an Artemia nauplii or small horn must be added at night. When the larvae feed normally, the chopped leeches can be fed three times a day. The daily feeding rate is about 20%, and the feeding amount depends on the slightest remaining amount of each feeding.
2.1.4 Water quality control The color of the water is bean green. There are plenty of plankton in the water, but they do not clump or cluster and cannot be swarmed in water. If there are too many food organisms, new water should be injected to reduce the biological density and keep the water fresh.
2.2 Cultivation of large-scale fry
2.2.1 Pond selection Choose a pond with an area of ​​0.1-0.2 square hectares and a water depth of about 1.5m. It requires a flat bottom and silt thickness of about 10cm. It is convenient for water intake and drainage. The water is fresh and pollution-free. The pH is 6.8-7.5, and the dissolved oxygen is 4.5mg/ Above L, 1 pump per pool.
When the fry is stocked, the fry is first sterilized in a bowl containing 5% salt water for 10 minutes, and then the fish can be poured into the cultivation tank.
2.2.2 Feeding The fish should be fed 3 days after the seedlings are fed. The eel seedlings should be fed first, and about 80,000 carp seedlings with a body length of 1.2 cm or so should be fed every 667 square meters. When the fry grows to more than 5cm, it begins to tame. The method is: first stop the cast salmon fry for 2 days, and start feeding the fresh minced fish on the third day. The method of throwing and domesticating should be adopted, firstly feeding in small quantities, and then gradually increasing the amount of feeding, which can be fully adapted after 4 to 5 days. Feed 2 times a day, 70% to 80% of the day's volume, and 40% to 40%. The daily feeding amount was 8% to 12% of the body weight of the fish.
2.2.3 Water quality management Fry should be shallow shallow pools. On the one hand, it can increase the bait density of the unit water in the pond and facilitate the feeding of fish fry. On the other hand, it can increase the water temperature and promote the growth of fry. With the rapid growth of fry, the pool water is gradually deepened, and water depth is added to 1.2m after 14 days. Change the water once every 7 days, and change the water volume every time from 1/5 to 1/6 of the pool water. Each morning, mid-night and evening patrols were conducted 3 times to observe fish feeding, activities, growth and pond water quality changes. 1 o'clock in the afternoon to 2 o'clock with the pump water oxygenation 1.5h, and regular measurement of dissolved oxygen, pH changes, etc., in order to adjust the amount of feeding in time, do a good job of fish disease prevention. After 30 days of intensive cultivation, the fry size can reach 9.5cm in length.
3, Cheng (pro) fish breeding technology
3.1 The pond is selected with large-sized fry.
3.2 The bait feed is mainly fed with the bait, the crude protein content of the bait is about 40%, and it is fed 2 to 3 times per day. The daily feeding amount is 3% to 5% of the pond fish weight and varies with the weather and water temperature. , fish movements, etc. at any time increase or decrease.
3.3 Water Quality Management Every 4 hours, the sewage shall be discharged once and the residual baits and feces shall be timely discharged. Change the water 1 to 2 times a day in the calm pool, change the pool water by 25% to 30% each time, and start the aeration facility in time to ensure that the dissolved oxygen in the pool water is above 5mg/L.
4. Disease prevention and control In addition to the strong resistance factors of the gemsops themselves, following the principle of “prevention over treatment and active treatmentâ€, the following measures have been taken:
1 Routine prevention: keep the water fresh; whole pool splash povidone iodine, concentration 0.2mg/L or 0.2mg/L concentration of chlorine dioxide Quanchiposa. 2 Saprophytic control: Be careful and avoid infection; Adjust water temperature above 25°C or soak in 0.5%-0.6% saline solution for 1 hour. 3 Trichodinosis control: 0.7mg/L copper sulfate Quanchiposa. 4 control of small melon disease: concentration of 30mg/L formalin Quanchiposa, every 3 ~ 4d spill once, once every 3 times. 5 Hemorrhagic disease prevention and treatment: Orally taking ciprofloxacin baits, add 50mg per kg of body weight, 5d for a course of treatment.
5. Key technical issues The key issues that need to be addressed in the industrialization of gemstone spot reproduction are: (1) The minimum age and body length of sexual maturation and the law of gonadal development. (2) The post-embryonic development and dietary and nutrient requirements during the developmental period, especially during the mixed nutrition period, and the rational formulation of the artificially-combined bait. (3) The normal range of intra-abdominal fat mass content and its main components, the effect of too much fat mass on growth and gonadal development.
1, breeding technology
1.1 Selection of Broodstock and Identification of Maturity The 3rd-instar fish was selected and the fish was disease-free and non-injury. The males had body weight of 800g or more, total length of 280mm or more, female weight of more than 1000g, and individuals having a total length of 250mm or more. The male and female individuals in the non-reproductive phase have no obvious characteristics. The male and female fish in the reproductive phase have no maternal sex and star-crossing sex vices. The specific identification methods are:
1.1.1 Sexually mature female individuals are emaciated and have many mucous on the surface. The abdominal wall is thin and soft, the abdomen is inflated and full of elasticity, and the gonad profile is obvious. Use a special egg digger to remove a few eggs from the middle of the ovaries in the gonads and check the egg's color, shape, and polarization.
1.1.2 There is no change in the body color of male individuals, and the body size is lanky. Generally, individuals with body weights above 800 g are mostly mature. During the examination, see the tail of the fish bent into a "bow" shape, and the genital papillae are extended by 1 to 2 cm. The milky white color is displayed. The semen is gently pressed by the genital hole by hand, and the male fish at this time can be used for breeding.
1.2 artificial production when the water temperature rises to 24 o'clock can be artificial oxytocin. The oxytocic agents are mostly selected from squid and carp pituitary releasing hormone analogues or chorionic gonadotropin. The method of injection and the dose used depend on the maturation of the broodstock. Two injections were used to promote the synchronized maturation of the male and female gonads. The practice is: the first injection dose is 10% of the dose, males use half of the female dose and are injected at the second injection of the female fish; males with better maturity may also not be injected. The injection site is generally located at the base of the pectoral fin.
After the bred broodstock, the male and female are raised in separate pools and stimulated by running water. Observe the broodstock activities and observe the effect time from time to time. The water temperature was controlled at (24+0.5) °C and the flow rate was 3t/h. After 10 hours, the eggs were not extruded. The flow rate was increased. When the effect time reached 18 hours, the females were active and frequently hit the water surface. The females showed obvious signs of flow, and they gently pressed the abdomen to the oocysts at the gonopore. At this point you can take the eggs.
1.3 Insemination by artificial dry fertilization, that is, artificial egg collection, sperm extraction, and fully mixed, immediately after mixing with feathers to add a small amount of water to complete the fertilization process; rinse fertilized eggs with water 2 to 3 times, washed away debris and blood clots, The fertilized eggs were evenly placed on a 40cm20cm nylon egg-bearing plate. About 15,000 eggs were laid on each plate, and the eggs were incubated in the incubator. The broodstock that produced the eggs are sterilized and returned to the broodstock pool.
1.4 Incubation incubator water dissolved oxygen is not less than 6mg/L, incubation temperature is controlled at about 23 °C. The special special incubator specifications are generally 380cm65cm30cm. There is an inlet and drain system and timing dialing device. The first time hatching eggs of 400,000 gems are hatched, the influent amount is (50-60)L/min, and the automatic dialing device is for every minute. Once, the hatching rate was 85%.
2. Seed cultivation techniques Seed cultivation can be divided into two stages: cultivation of small-size seedlings and cultivation of large-scale seedlings.
2.1 The cultivation of small-sized seedlings The cultivation of small-scale seedlings is a process in which waterflooding is cultivated for about 20 days so that the total seedling length can reach 2.5cm or more. Its food can be used for aquatic oligo-type (water fleas), Cladocera and other live bait.
2.1.1 The cultivating pool is an indoor cement pool with an area of ​​3 to 10 square meters. It is round and has surface flute type water supply. There is a drainage hole in the middle of the pool. The surface of the pool bottom and pool wall should be smooth, and the bottom of the pool is not leaky. The cultivation pond should be sterilized with 300.000001 KMnO4 solution before use, and the depth of water in the lower pool is 20-40 cm.
2.1.2 Larval larval rearing The larval rearing refers to the feeding and management of the newly hatched larvae, which is maintained in the cultivation pond for a period of time before the start of eating.
The larvae are photophobia and should avoid direct sunlight and shading facilities on the pool. During the temporary period, the temperature of the water must be kept constant, and in particular, the water temperature must not suddenly drop or rise. At the same time, the flow in the pool is controlled at (3~5)L/min and the dissolved oxygen is above 4.5mg/L.
2.1.3 Feeding When bait is fed at a water temperature of 22 to 24°C, larvae hatched for 6 to 7 days can be fed. Its open bait is Artemia nauplii, small Cladocera or otter. Because the larvae often swim to the surface at night, at the beginning of feeding, besides feeding three chopped blisters during the day, an Artemia nauplii or small horn must be added at night. When the larvae feed normally, the chopped leeches can be fed three times a day. The daily feeding rate is about 20%, and the feeding amount depends on the slightest remaining amount of each feeding.
2.1.4 Water quality control The color of the water is bean green. There are plenty of plankton in the water, but they do not clump or cluster and cannot be swarmed in water. If there are too many food organisms, new water should be injected to reduce the biological density and keep the water fresh.
2.2 Cultivation of large-scale fry
2.2.1 Pond selection Choose a pond with an area of ​​0.1-0.2 square hectares and a water depth of about 1.5m. It requires a flat bottom and silt thickness of about 10cm. It is convenient for water intake and drainage. The water is fresh and pollution-free. The pH is 6.8-7.5, and the dissolved oxygen is 4.5mg/ Above L, 1 pump per pool.
When the fry is stocked, the fry is first sterilized in a bowl containing 5% salt water for 10 minutes, and then the fish can be poured into the cultivation tank.
2.2.2 Feeding The fish should be fed 3 days after the seedlings are fed. The eel seedlings should be fed first, and about 80,000 carp seedlings with a body length of 1.2 cm or so should be fed every 667 square meters. When the fry grows to more than 5cm, it begins to tame. The method is: first stop the cast salmon fry for 2 days, and start feeding the fresh minced fish on the third day. The method of throwing and domesticating should be adopted, firstly feeding in small quantities, and then gradually increasing the amount of feeding, which can be fully adapted after 4 to 5 days. Feed 2 times a day, 70% to 80% of the day's volume, and 40% to 40%. The daily feeding amount was 8% to 12% of the body weight of the fish.
2.2.3 Water quality management Fry should be shallow shallow pools. On the one hand, it can increase the bait density of the unit water in the pond and facilitate the feeding of fish fry. On the other hand, it can increase the water temperature and promote the growth of fry. With the rapid growth of fry, the pool water is gradually deepened, and water depth is added to 1.2m after 14 days. Change the water once every 7 days, and change the water volume every time from 1/5 to 1/6 of the pool water. Each morning, mid-night and evening patrols were conducted 3 times to observe fish feeding, activities, growth and pond water quality changes. 1 o'clock in the afternoon to 2 o'clock with the pump water oxygenation 1.5h, and regular measurement of dissolved oxygen, pH changes, etc., in order to adjust the amount of feeding in time, do a good job of fish disease prevention. After 30 days of intensive cultivation, the fry size can reach 9.5cm in length.
3, Cheng (pro) fish breeding technology
3.1 The pond is selected with large-sized fry.
3.2 The bait feed is mainly fed with the bait, the crude protein content of the bait is about 40%, and it is fed 2 to 3 times per day. The daily feeding amount is 3% to 5% of the pond fish weight and varies with the weather and water temperature. , fish movements, etc. at any time increase or decrease.
3.3 Water Quality Management Every 4 hours, the sewage shall be discharged once and the residual baits and feces shall be timely discharged. Change the water 1 to 2 times a day in the calm pool, change the pool water by 25% to 30% each time, and start the aeration facility in time to ensure that the dissolved oxygen in the pool water is above 5mg/L.
4. Disease prevention and control In addition to the strong resistance factors of the gemsops themselves, following the principle of “prevention over treatment and active treatmentâ€, the following measures have been taken:
1 Routine prevention: keep the water fresh; whole pool splash povidone iodine, concentration 0.2mg/L or 0.2mg/L concentration of chlorine dioxide Quanchiposa. 2 Saprophytic control: Be careful and avoid infection; Adjust water temperature above 25°C or soak in 0.5%-0.6% saline solution for 1 hour. 3 Trichodinosis control: 0.7mg/L copper sulfate Quanchiposa. 4 control of small melon disease: concentration of 30mg/L formalin Quanchiposa, every 3 ~ 4d spill once, once every 3 times. 5 Hemorrhagic disease prevention and treatment: Orally taking ciprofloxacin baits, add 50mg per kg of body weight, 5d for a course of treatment.
5. Key technical issues The key issues that need to be addressed in the industrialization of gemstone spot reproduction are: (1) The minimum age and body length of sexual maturation and the law of gonadal development. (2) The post-embryonic development and dietary and nutrient requirements during the developmental period, especially during the mixed nutrition period, and the rational formulation of the artificially-combined bait. (3) The normal range of intra-abdominal fat mass content and its main components, the effect of too much fat mass on growth and gonadal development.
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