Xiangyun crucian carp culture technology?
(a) Xiangyun crucian carp seed production technology?
The schematic diagram of the seed production process of Xiangyun crucian carp is as follows:
2N Cell Engineering Technology 4N (Gene Bank Fish) ×2N (Japanese White Crucian Carp) The male parent 3N (Xiangyun Crucian Carp) Xiangyun Crucian Carp has many excellent characteristics, such as self-sterility, fast growth, wide appetite, strong disease resistance, tolerance to hypoxia and low temperature, easy fishing and so on. The meat is tender and delicious, and it is suitable for fishing. The fish is suitable for breeding in ponds, lakes, reservoirs, rice fields and cages. Under general pond conditions, the fish can be produced by polyculture of 60 ~ 100 kg per mu, and by monoculture of 500 ~ 800 kg per mu. The net yield of cage culture is 50 ~ 90 kg per square meter. ?
(2) Biological characteristics?
Xiangyun crucian carp is a complete crucian carp The results of LDH and EST isoenzymes detection and mtDNA analysis show that Xiangyun crucian carp is inherited by its female parent, but it also has gene expression of Xiangjiang wild carp, Beijing crucian carp, Xiang crucian carp and tetraploid fish, so it is different from ordinary crucian carp as follows:
1. What's the difference between Xiangyun crucian carp and other crucian carp?
Xiangyun crucian carp is similar to common white crucian carp in appearance, but superior to other varieties in size. Because of infertility, the proportion of gonads is small, so the internal organs are few, the abdomen is small, the back muscles are thick, and the body shape is slimmer than other crucian carp varieties. The scales on the back of Xiangyun crucian carp are often a little messy (this phenomenon is rare in other crucian carp), and the lateral scales are generally in the range of 30 ~ 32. ?
2. Xiangyun crucian carp has abnormal gonad development and cannot reproduce itself?
Xiangyun crucian carp is a triploid crucian carp, which cannot reproduce and has no sexual pursuit. Therefore, it can be stocked in any aquaculture waters, which will not cause the resources of other crucian carp to be mixed, and will not lead to the decline of the quality of commercial fish due to over-breeding. ?
3. Xiangyun crucian carp grows fast and is not limited by sexual maturity?
Generally speaking, the early sexual maturity of crucian carp affects the growth rate and limits the individual growth. Xiangyun crucian carp (Carassius auratus gibelio) not only has obvious advantages in hybrid growth, but also is completely used for growth because of its sterility, so the growth of individuals will not be limited by sexual maturity. The growth rate of Xiangyun crucian carp is 1 times higher than that of its female parent (Japanese white crucian carp) and 3 ~ 5 times higher than that of common crucian carp. The maximum growth weight of fry in that year can reach 0.5 kg. Generally, the adult fish cultured in spring slices can reach 0.5 ~ 1 kg, and the largest individual can reach 1.5 kg. ?
4. Is Xiangyun crucian carp resistant to adversity?
The hybrid advantage of Xiangyun crucian carp also lies in its strong resistance to harsh natural environment, which is mainly manifested in the following aspects:
(1) has strong disease resistance and wide adaptability.
After years of promotion, it has been cultivated in 20 provinces and cities across the country, and it can adapt to the local environment. There are no reports of heavy losses caused by infectious diseases. ?
(2) Strong hypoxia tolerance
It can still grow well in the environment with high stocking density and small water body (for example, cage culture raises 200 fish per square meter, and the output reaches 57 kg/square meter). When there is submerged hypoxia in pond culture, grass carp, silver carp and bighead carp all die to varying degrees, while Xiangyun crucian carp rarely dies. ?
(3) Good low temperature resistance
It can be eaten all year round in Hunan, and it can still be eaten and grown at the water temperature of 10℃ (four big fish have stopped eating). ?
5. Wide feeding habits and low feed coefficient?
Xiangyun crucian carp not only has a wide diet and is resistant to coarse bait, but also maintains the characteristics that female Japanese white crucian carp can eat some plankton. In addition, the nutrients it eats are completely used for growth, so the feed utilization rate is higher than other crucian carp. ?
6. easy to catch?
Xiangyun crucian carp cultured in ponds do not "drill mud", and the net catching rate can reach about 80%, unlike ordinary crucian carp, which needs to "dry the pond". ?
7. Good quality?
Xiangyun crucian carp is tender and delicious, which keeps the flavor of crucian carp. At the same time, it has fewer spines, less internal organs and more edible parts, and it is large in size and has higher glutamic acid content in muscles, which is better than ordinary crucian carp and is very popular among consumers. ?
(3) seed cultivation?
1. Summer flower cultivation?
Although the hybrid advantage of Xiangyun crucian carp is obvious, the summer flower cultivation period is just from April to early May, with low temperature and bad climate, which brings great difficulties to fry production. In addition to strictly following the routine cultivation procedures, special attention should be paid to the following points:
(1) Strict pond cleaning and disinfection
The nursery pond where Xiangyun crucian carp is stocked should be thoroughly disinfected, and the wild miscellaneous fish and enemies should be cleaned up, and then the water should be strictly filtered to prevent new enemies from entering. Because of the low temperature, fry grow slowly, while wild miscellaneous fish and enemy creatures breed quickly. A few wild miscellaneous fish, such as wheat-ear fish, wild crucian carp and grass shrimp, which escape the net, breed rapidly, which will seriously threaten the survival rate of Xiangyun crucian carp fry, and often lead to "total annihilation" in serious cases. At the same time, in low temperature weather, the medicinal properties of clear soup disappear slowly, so the toxicity of pool water must be carefully tested before sowing. ?
(2) Adhere to the principle that the fry enter the pond with fat and water.
Because Xiangyun crucian carp has strong hypoxia tolerance, fertilizing a pool of "good water" in advance has a significant effect on improving the survival rate of summer flowers, and avoids the shortcoming that Xiangyun crucian carp seedlings are not full because of low temperature and rainy weather when they enter the pool. To improve water quality, we should pay attention to "fat and cool" to prevent the emergence of "old water" and "white water" in which large fleas multiply. ?
(3) monoculture with appropriate density
The summer flowers of Xiangyun crucian carp should not be mixed with other fry, and the stocking density should be sparse rather than dense, and 800 ~ 65438+10,000 fry can be stocked per 1 mu. It is best to plant thinly, 40,000 ~ 60,000 per mu. Summer flowers of about 3 cm can be cultivated in about 15 days, and then the pond is freed to cultivate summer flowers of four big fish, which can improve the utilization rate of the seedling pond. If there are special circumstances, the stocking density must be increased, and the ponds should be divided in time after 8 ~ 10. ?
(4) timely supplement concentrate
In the early stage of Xiangyun crucian carp seedling, plankton was used as bait, as long as fertilization was used to keep the water color. After 8 ~ 12 days in the pond, the feeding habits of fry began to differentiate. When the fry begin to "show their bellies", they should be supplemented with rice bran, vegetable cake powder and other concentrates in time. If fry are found swimming around the pond in groups, it is insufficient concentrated feed, so more concentrated feed should be put along the pond, otherwise the survival rate will be seriously affected. ?
As long as the characteristics of Xiangyun crucian carp seedlings are paid attention to and carefully managed, serious diseases will not occur in the summer flowering period, and the survival rate can reach above 80%. ?
2. fish farming?
In addition to directly using the fry of summer flowers to cultivate fish, it is generally necessary to cultivate the summer flowers of Xiangyun crucian carp into 40 ~ 50 grams of fish, and cultivate them into fish in winter or the following spring to make full use of the advantage that the growth of Xiangyun crucian carp is not affected by sexual maturity. There are several ways to cultivate fish species. ?
(1) single feeding
The single culture pond of Xiangyun crucian carp should not exceed 15 mu, and the water depth is in the range of 1.5 ~ 2.5 meters, which is convenient for irrigation. Before stocking, the pond should be cleaned and disinfected strictly, and the stocking quantity should be 6 000 ~ 65 438+00 000 fish per mu, which can be matched with 65 438+00 000 silver carp and bighead carp, or 200 spring slices, and about 5% grass and mandarin fish species should be put in as appropriate. In addition to feeding feed regularly and quantitatively every day, fresh water should be supplemented frequently to keep the oxygen content in the pond water in a normal state (4 ~ 6 mg/L), and attention should be paid to preventing fish species from escaping (Xiangyun crucian carp has the habit of going against the water). After half a year's cultivation, it can reach 40 ~ 60g/ tail, the average yield per mu can reach 300 ~ 350kg, and the pond with good management conditions can reach 500kg. ?
(2) polyculture
Generally speaking, as long as other varieties of crucian carp and crucian carp are not mixed, Xiangyun crucian carp and summer flowers can be mixed in the spring pond. Generally, 300 ~ 500 tails are stocked per mu. In addition to conventional feeding methods, concentrate feed should be properly supplemented at the turn of autumn and winter to meet the bait needs of Xiangyun crucian carp. It can increase the yield of Xiangyun crucian carp by 50 ~ 70 kg per mu. ?
(3) cage culture
It is effective to use the characteristics of Xiangyun crucian carp, such as filter feeding, resistance to dense culture, disease resistance and suitability for commercial feed, to carry out cage culture of Xiangyun crucian carp when a large number of spring slices are needed and fish ponds are scarce. Cages should be placed on eutrophic water surfaces such as reservoirs, bays and tributaries, with running water, shelter from wind and sun, and the mesh size should match the specifications of fish species. Insist on feeding every day, clean the box and pay attention to prevent parasitic diseases. 400 ~ 500 summer flowers per square meter can reach 40 ~ 60 grams of fish in 4 ~ 6 months, and the survival rate can reach 90%. At the same time, cage rearing adult Xiangyun crucian carp is better than grass carp or other carp. Generally, a cage of 28 square meters can hold about 3,000 fish with a size of 50 grams. After six months of cultivation, the fish can reach 400-600 grams of adult fish. The net profit of each cage can reach about 4000 yuan, which is convenient for management. ?
(4) Adult fish culture technology?
1. How about Xiangyun crucian carp culture in Beijing suburbs?
From 65438 to 0998, adult fish culture experiments were carried out in four fishing grounds in Tongzhou, Pinggu and Haidian in the suburbs of Beijing. 1998 On May 20th, 10 ~ 20,153,000 summer flowers of Xiangyun crucian carp were purchased from Changsha Pilot Base of Hunan Science and Technology Commission and left the pond in mid-June. The experimental area of adult fish is 26.7 mu, and the total output is 13435 kg, with an average yield of 503 kg per mu, including 440 kg of Xiangyun crucian carp and 63 kg of silver carp. The survival rate of Xiangyun crucian carp was 93.6%, the average size was 193g/ tail, the feed coefficient was 1.28, and the input-output ratio was 65. Through the 1998 culture experiment, Xiangyun crucian carp has the following characteristics:
(1) has obvious growth advantages.
Xiangyun crucian carp grows faster, which is 1.5 times faster than common crucian carp. ?
(2) Low feed coefficient
The average feeding coefficient during culture was 1.2 ~ 1.5. ?
(3) Strong disease resistance and hypoxia tolerance.
During the breeding period, no large-scale fish diseases were found in all participating units. For example, the stocking density of Liangjiadian Fishing Ground in Haidian District reached 8 600 fish/mu, and no fish diseases occurred. The aerator was only turned on for a few days in the high temperature season during the breeding period, which indicated that the fish had strong hypoxia tolerance. ?
(4) Low temperature resistance
According to the rules of culture in Beijing, crucian carp and snakehead generally stop eating in the middle of June 5438+ 10, but fish can still eat in the late June 5438+ 10 when the temperature is low, which prolongs the growth period. ?
2. Several problems that should be paid attention to in the process of Xiangyun crucian carp culture.
(1) Intensive culture of Xiangyun crucian carp is beneficial to intensive culture, but attention should be paid to the proportion of silver carp and bighead carp.
Generally, there are 250 ~ 300 silver carp and 25 ~ 30 silver carp per mu, and the proportion of silver carp is basically controlled at 10: 1. Fish with strong predation ability such as grass carp should not be used in the breeding process, so as not to affect the feeding and growth of the main fish farmers. ?
(2) Xiangyun crucian carp has the characteristics of fast feeding, large area and short time, and the feeding frequency and area can be appropriately increased every day. 5 ~ 6 times a day in high temperature season (depending on water temperature and weather conditions), automatic bait feeder can be used to feed in qualified fishing grounds to increase the feeding area. ?
(3) Strengthening the feeding management in the early stocking period; Xiangyun crucian carp has strong collective feeding ability, and the key to forming this feeding habit lies in domestication within one month after releasing the seedlings, and the method of concentrating first and then separating the ponds should be followed. For example, 60,000 summer flower fry are cultured in Liangjiadian Fishing Ground in Haidian District, which is first put into a 5-mu pond and fed with scraps. When they grow to 25 grams each, the density decreases after being separated into ponds, but it does not affect the feeding of Xiangyun crucian carp. ?
(4) Stocking density According to the feedback from various aquaculture units, the smaller the stocking density of adult Xiangyun crucian carp, the slower the rising and grabbing speed, so the stocking density of adult crucian carp should be 3 000 ~ 3 500 per mu. ?