The artificial propagation technology of squid Sui Yewen, Zhang Shi'an, Chen Nan, Wang Jiaofu, et al. In order to select mature glandular mature carp, stimulating using different hormones and different doses. Different stimuli were given to broiled broodstock. Different hatching methods were adopted for the collected fertilized eggs. The results showed that: broodstock breeding is the key, broodstock well-developed broodstock, as long as provide appropriate spawning conditions (spawning pool, fish nest, water), mixed with HCG + LRH-a Hormone injection can achieve the desired oxytocin effect. Different hatching methods are adopted. At a suitable water temperature (16°C - 28°C), as long as the fertilized eggs can obtain sufficient dissolved oxygen, a high hatching rate can be obtained. Salmon fry seedlings are grave. After a few days of filming, they could eat each other. Key words carp, Parasilurus asotus is a common economic fish in China. The carp is widely distributed in China, and it is an adaptable, meat-eating omnivorous fish with delicate meat, less muscle pricks, rich nutrition and high economic value. It is of great significance to study the development of this fish industry. 1 Materials and methods 1.1 Prenatal broodstock bred This experiment was conducted at the Dajing Reservoir fishery in Shou County in 1994-1997. The broodstock comes from Wadi Lake and local reservoirs and is caught and collected during autumn and winter. Females weigh from 500 to 1500 grams and males from 300 to 1,000 grams. The broodstock collected were placed in a 700-square-meter fishpond to be reared, and 2 months before delivery, the loach and wild fish were fed. The fish was flushed once every two months to promote the development and maturation of the gonads. Broodstock can also be mixed in other fish ponds. Keep the water fresh. 1.2 Preparation of spawning tanks, screens, fish nests, etc. The spawning pool can be selected from the “fish†spawning pool, or the general cement ponds, ponds, etc., and sterilized with bleaching powder or quicklime one week before the start of production. The mesh screen is made of 40 mesh and 25 mesh polyethylene nets, and is generally made into a specification of 411 meters or 221 meters. The mesh screen should be soaked in water for several days and then disinfected with malachite green or potassium permanganate. The nest of fish will be rooted in willow, palm or bamboo silk. After being tied, it will be 2-3 meters long, and it will be connected with a rope. Fish nests are sterilized with malachite green or potassium permanganate before use. 1.3 The ratio of male to female and broodstock selection ratio of male to female is 1:1. In the non-reproductive season, male and female broodstock are not easily distinguished. In the reproductive season, the female body is fresh, smooth, full of shiny sensation, the abdomen is enlarged, the outline of the ovary is looming, the gonogenic hole is reddened, enlarged, rich and moist, there are radial spots around the genital hole, and a little pressure is exerted on the back of the abdomen to extrude 1 - 2 eggs, P the first hard spine trailing edge is less powerful, slightly smooth. Males showed a longer and lighter appearance. Male fish with well-developed gonads exhibited a little white semen out of the abdomen. The jagged teeth on the male P are stronger and the hand feels cut. 1.4 artificial oxytocin: artificial oxytocin using different combinations of hormones, different doses of aphrodisiac broodstock. Injection of HCG, female 3000 ~ 2500IU/kg. Male fish 1500 to 1300 IU/kg. Injection of HCG+LRH-a, female HCG3000IU/kg+LRH-a15ug/kg, male HCG1500IU/kg+LRH-a7ug/kg. The dose of artificial injection fluid is not less than 1ml per female. Basically, one-time intramuscular injection was used and two injections were used for comparison. 1.5 Post-Oxidation Stimulation Methods In order to find the optimal environmental conditions for broodstock spawning, different stimuli were given to the bred broodstock. 1 Put the broodstock gently into the spawning tank, put it into the fish nest 2-3 hours later, and stimulate it with microfluidic water. 2 Bring the broodstock into a mesh screen. The mesh screen is hung in the spawning tank in advance, then put into the fish nest and stimulated with circulating water. 3 Bring the broodstock into the spawning pool and give it a circulatory water stimulus. 4 Put the broodstock into a mesh sieve. The mesh sieve is suspended in the pond beforehand. The pond has micro-flowing water. 1.6 Incubation mode of fertilized eggs 1 The fertilized eggs adhere to the fish nest evenly, and they are gently moved into a mesh sieve. The mesh sieve is suspended in the cement pool, and the cement pool is kept in a microfluidic state. 2 The fertilized eggs adhere to the mesh sieve more evenly, and the mesh sieve is suspended in the cement pool, and the microfluidic state is maintained. 3 The fertilized eggs adhere to the fish nest more evenly, gently put it into the mesh sieve, and suspend the mesh sieve in the pond, in a microfluidic state. 4 Put the collected fertilized eggs into the loop and incubate the looped water. 1.7 Fish fry The hatching of fish fry begins to feed on the second day. The best bait is rotifer, and egg yolk can also be used. Three to five days later, young cladocera, copepods, and small zooplankton, Artemia larvae, and leeches were bred. Facilities for fry cultivation can be compared using mesh screens, concrete tanks, and earthen ponds. The earthen pond cultivation should splash bean water one week ahead of time to cultivate palatable bait. 2 Results 2.1 Incubation situation Total oxytocin 163 groups, spawning number of 115 groups, spawning rate was 71%, a total of 1.02 million eggs, the average number of eggs per female spawned 0.87 million, a total of 80 seedlings Million-tailed, the average number of females per female was 0.77. The fertilization rate is 80 to 90%, the hatching rate is 90 to 95%, the estrus time is 12 to 17 hours, and the spawning effect time is 13 to 21 hours. The tolerance to hormone HCG is in the range of 2500-3000IU/kg for females and 1300-1500IU/kg for males. Spawning suitable water temperature is 16 ~ 28 °C. 2.2 Effect of hormone dose and variety on oxytocin production 1HCG dose of female is 300IU/kg, male fish 1500IU/kg of broiler oyster has I, II, III, IV total of four batches of carp 119 groups, spawning group of 72 groups, production The egg rate was 60.5%, including 26 batches of I and VI batches, 26 spawning females, spawning rate of 100%, 60 batches of 60 batches, 32 spawning females, and egg production rate of 53%. Due to the first batch of broilers, the second batch of broodstock was raised in a small concrete pool of about 6 square meters for 4 days. It is speculated that the reason may be that the density of broodstock is too high and the oxygen is insufficient, which caused certain changes in the gonads that took place in the past 4 days. The broodstock laid its eggs smoothly. In addition, all broodstock after puerperium is put into a spawning pool, the density is also very large, it also has an impact on their spawning. The 33rd batch of carp group 33 and 14 spawning females were spawned at 42% because the third batch of broodstock was selected from the broodstock that was spawned on May 6th and May 9th, 1994. After more than one month of cultivation, the In the case of secondary oxytocin production, it is estimated that part of the gonad's gonadal re-growth is not mature enough. 2 The dose of HCG injection was 2500 IU/kg for females and VII and VIII for males with 1300 IU/kg. There were 16 groups of broodstock, 15 spawning females, and the spawning rate was 94%. 3 Injection of HCG+LRH-a, female HCG3000IU/kg+3000IU/kg+LRH-a15ug/kg, male HCG1500IU/kg+LRH-a7ug/kg, and IV and V batches of 28 groups, spawning female fish The number is 28 and the spawning rate is 100%. From the above it can be seen that salmon can be injected with HCG or HCG and LRH-a mixture, the injection dose is 2 to 3 times that of domestic fish. In general, the effect of injection of HCG+LRH-a mixture was best, estrus was earlier, estrus time was 12 to 15 hours, spawning was more concentrated, spawning effect was also the shortest time 13 to 18 hours, although the water temperature was biased. Low (see Table 1). 2.3 The squid began to estrus 12 to 17 hours after the hormone injection and began to lay eggs 13 to 21 hours later. This article has basically found out the time of estrus and spawning time, and has a certain guiding effect on production practice. The length of the estrus and the length of the spawning effect are mainly related to the maturity of the broodstock, the temperature of the water when elicited, and the dose and type of hormone used. In general, broodstock development is good, the water temperature during oxytocin is higher in the appropriate range, and the hormone HCG+LRH-a mixture is injected, the estrus time is shorter, and the oviposition time is shorter. In production practice, it has been observed that the eel's estrus persists for a long period of time, and spawning takes longer. 2.4 Carp spawning habits When the carp begins to estrus, the male fish chases the female and uses the snout to "collide" with the female's abdomen or near the genital hole. After several "collisions", the females began to spawn. The male body was tightly wound around the female's back abdomen. When the females discharged the eggs, the males discharged the sperms, and then the male and female breds used both tails to stir the flow. The spermatozoa are "combined" and fertilized and spread evenly. The egg and sperm of the male and female broodstock are not finished at one time, only a little bit at a time, and it takes several times to finish. The broodstock mating behavior lasts for 3 to 4 hours or even longer. When there is a fish nest, the brooding fish love to lay eggs near the fish nest, and evenly spread the eggs on the fish nest. When there is a net nest with a fish nest, the brood fish will evenly spread the eggs on the mesh sieve without a mesh sieve or a fish sieve. At the time, the eggs are placed in the water. 2.5 Squid spawning time Squid spawning time can be extended from the beginning of April to the end of June, spawning peak from late April to mid-May. Our time for brewing broodstock was from April 28 to June 20 in the late period, and we achieved good oxytocin production. Carp is suitable for oxytocin production and spawning time is longer. The appropriate water temperature for oxytocin production and spawning is 16-28°C. 2.6 squid can spawn many times in nature. We observed that squid spawning lasted for a longer period of time, and its offspring often formed different groups. For example, in the Wagatu Lake catchment, more than 10 cm of carp fry could be caught in summer. In the autumn, more than 10 cm of eel fry can be caught. From this phenomenon, it can be inferred that eels either have different reproductive groups or they can spawn multiple times. This article tested this and on June 20, 1994, the second oyster production was conducted on May 6 and May 9, 1994. The number of spawning groups was 33 and the number of spawning was 14. The spawning rate was 42% and 100,000 eggs were obtained, indicating that the squid can lay eggs several times. 2.7 Relationship between postnatal stimulation and spawning The success of spawning depends on the maturation of gonad gonads and the appropriate hormonal production. There is no significant difference in postpartum stimulation. Several methods of experimental design, the carp are able to successfully land eggs, II, III batch production of eggs is low, mainly gonads of the gonadal maturity changes. Appropriate spawning water, fish nests, and water flow are indispensable conditions for smooth eel production. 2.8 The relationship between hatching method and hatching rate There is no significant correlation between hatching rate and different hatching methods. Because of the high fertilization rate of carp, in the proper temperature range, there is sufficient dissolved oxygen in the fertilized eggs to timely remove unfertilized eggs. In order to prevent waterborne mildew infection, high hatching rates can be obtained. 2.9 Hatching and growing at a water temperature of 18 to 28°C, the higher the temperature, the shorter the fry hatch time. In the water temperature of 18 ~ 20 °C range, about 48 hours after hatching fish hatching film, 50 hours later, a lot of fish fry out the author: Kou Yewen (Anhui Province Fisheries Technology Extension Terminal) Zhang Shian Chen Nan Wang Jiaofu (Shou County Fisheries Bureau)
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