The parent fish for artificial breeding should be male fish over 3 years old and female fish over 4 years old. Choose more individuals weighing 0.5 ~ 1 kg, and the parent fish should be healthy and free from injuries. The selection and retention of parent fish should be carried out when the fish are caught in autumn. Before stocking parent fish, remove excessive silt and wild fish from the bottom of the pool. Stocking 50 ~ 80 parent fish per mu. Organic fertilizer should be properly applied to the breeding pond to maintain a certain water quality and transparency of about 25 cm, and at the same time, all kinds of concentrated feed should be fed to ensure that the parent fish have sufficient nutrition. Generally, the salinity of parent fish culture ponds is about 10‰. Barracuda reared in fresh water or low salinity water below 3‰ must go through "saltwater transition" before spawning. During intensive cultivation in spring, fresh seawater must be replenished to the pond regularly, which is beneficial to the gonad development of parent fish.
It is best for the male fish to gently press the abdomen near the reproductive hole, so as to have a thick milky white outflow. The female fish should choose the one with swollen abdomen, soft and elastic, ruddy reproductive pores and slightly prominent. Eggs were taken out of the ovary by inserting an egg extractor into the reproductive hole for macroscopic and microscopic observation. If the fish eggs are beige, full and shiny, with 65,438+0 translucent circles around them, the diameter of the fish eggs is greater than 0.60 mm, and the adhesion between the fish eggs is loose, which can be dispersed by stirring in water, they can be used as parent fish for spawning. The male-female ratio of spawning parent fish is generally 1: 1.5. If the maturity of male fish is poor, the proportion can be increased appropriately.
Oxytocin has pituitary gland of carp and barracuda, and the dosage per kilogram of body weight is15 ~ 30 mg; Or chorionic gonadotropin 3500-3000 international units; Or luteinizing hormone releasing hormone analogue 100 ~ 300 micrograms. Used alone or in combination, 1 or 2 injections are generally used. Mature oval is full, crystal clear under the microscope, with 1 oil ball. When the mature eggs are put into 1 drop of seawater, it is observed under the microscope that the quality of * * * is good, that is, the eggs can be squeezed and artificial insemination can be carried out. The fertilized egg sinks below 10‰, floats around 13‰, and floats above 15‰. Therefore, the incubation salinity of still water should be above 15‰, the incubation salinity of running water should be 7 ‰ ~ 13 ‰, the pH7~9 value should be 7~9, and the water temperature should be 14 ~ 240℃. The incubation time is generally 35 ~ 56 hours.
Reproduction of fry: 4-5 days after the fry hatch, the yolk sac has contracted, and the fish can swim horizontally, open its mouth and eat the bait. At this time, the fry are moved into the nursery pond for cultivation. The fry will be fertilized in tang qian for 4-5 days, and then released, with 70,000-80,000 fry per mu. In the pool with good water exchange conditions, the number of seedlings can be appropriately increased. In the early stage, fertilization and splashing soybean milk were the main methods, and the fry were directly fed with bean cake paste in the later stage. Feed twice a day, and the feed is scattered in the shallow water around the pool. Fish fry enter the pool and the water is shallow. As the fry grow, water should be gradually added to the pond. Feeding 1 month or so, when the mullet grows to 2.5 ~ 3 cm, it can be pulled in time and trained in different ponds.
Feeding management: 6000 ~ 7000 barracuda are raised per mu, which can be cultivated into 12 cm fish species in that year. You can also mix shrimps at 500 per mu. Freshwater fish can be mixed in low salinity seawater or freshwater ponds. Rice bran, bean cake, peanut cake or distiller's grains can all be artificially fed. As the object of port culture or pond culture.
Adult fish culture
The area of barracuda culture pond should be as large as possible, generally between 10-20 mu. The shape of the pond should be rectangular, the depth of the pond should be 1.5-2.0 m, and the bottom material should be mud and sand structure. Fish ponds should be selected in places with sufficient water, convenient transportation and electricity. It requires a long illumination time and a perfect water inlet and drainage system in the pond.
20 days before stocking fish, the pond must be thoroughly cleaned and disinfected. This method can refer to the disinfection method of fry culture pond. After disinfection, the pond was filled with water about two weeks later, and the water was filtered with 80 mesh nylon gauze or polyethylene net. Then hang bags at the four corners of the pond to pile up fermented organic fertilizer, and the oozing fertilizer water can play a role in cultivating water quality after entering the pond. The amount of fertilizer used in the pond is per mu 100-200kg * * * 667 m2 * *.
If cultured according to the density described above, the disease probability of barracuda will be lower. However, the prevention of barracuda diseases should also be done during the breeding period.
In terms of prevention, first, be careful when stocking and fishing to avoid scratching fish; The second is to disinfect the water body regularly, and use 0.2 g dibromohydantoin disinfectant per cubic meter every half month to spill the whole pool.
After 5-6 months of cultivation, the average weight reaches about 500 grams, and it can be caught and marketed.
sphyraenus
First, the transportation and cultivation of fry.
* * * Transportation of fry The transportation of barracuda fry is generally carried out from early May to mid-June. Mainland farmers mostly buy fry from barracuda farms in coastal areas, and the vehicles for transporting fry are ordinary vans or agricultural transport vehicles. Fish fry are usually packed in self-made double-layer plastic film bags, commonly known as "oxygen bags". Each bag of fry is 0.25-0.3cm * * 3500-4000. After oxygen is sufficient, plastic bags are put into paper packaging boxes. During transportation, check the fry movement every 10- 12 hours 1 time, and replenish oxygen to several bags with insufficient oxygen in time. After the fry are transported to the destination, they are put into cement pools or large pots respectively, and pollution-free tap water or river water is used. Before throwing, fry are soaked in 2%-3% salt water for 2 minutes and then put into the pond.
* * * Two * * fry are fed boiled eggs the next day, every 4 hours 1 time. 1 week, feed bean cake, fish meal, etc. Fish meal is easy to cause foaming disease of fry, so it should be fed as little as possible. 1 month, and then put it into ponds and other waters for culture.
* * * Three * * * Daily management discharges 10 cm sewage from the bottom of the pool every two days, and supplements fresh water. Spraying bleaching powder with the concentration of/kloc-0 /×10 * * every 15 days to prevent diseases, and sampling the weight and length of fry every 15 days to understand the growth and development.
Second, adult fish culture.
* * * A * * The pond area is generally 0.33- 1 hectare, with convenient water intake and drainage, abundant water sources and excellent water quality, with a water depth of about 1.5 meters, especially for sediment. The ecological environment with ponds and reeds is the most ideal for breeding barracuda in reservoirs.
* * * 2 * * Remove excessive silt from the pond before releasing the fertilized fry. Then clean the pond with 100 kg of quicklime every 0.067 hectare, inject clean water with water depth of 0.5- 1 m, and apply 200 kg of organic fertilizer. 1 week, the toxicity of quicklime disappears. When the water turns slightly green, the transparency of the water is about 25 cm, and the fry can be put into the pond for culture. Barracuda is cultured in the reservoir, and a fertilization point is generally set every 50 meters in the shallow water area, and about 300 kilograms is fertilized every 0.067 hectare.
* * * Three * * * fry are released in most areas of China. In mid-June, when the water temperature rose and the plankton in the pond and reservoir reached its peak, the fry were released. Soak the fry in 3% salt water for 5 minutes before putting them in to disinfect the fish. There are 600 polyculture fish ponds per 0.067 hectare, 1200- 1500 intensive culture fish ponds with specifications of 4-5cm.
* * * Four * * * Feeding Feeds On the premise of maintaining a certain fatness of the aquaculture water, there is a *** 1.5 square meter ** 1 feed table 30-50 cm below the water surface. The feed table is made of bamboo poles, sewn with dense mesh, slightly concave in the middle and slightly high around. Feeding began the next day after stocking fry. When feeding, clap your hands or knock to make a sound, thus forming a conditioned reflex to lure fish to eat. When throwing bait, we should achieve "four determinations", that is, timing, quantitative, fixed-point and qualitative. Feeding at 9 am every day accounts for 40% of all-day feeding, and feeding at 4 pm accounts for 60%. At the same time, it is necessary to flexibly control the feeding amount in combination with comprehensive factors such as water temperature, weather, fish body specifications and foraging conditions, so as not to waste and make the fish full. Breeding varieties mainly include rice bran, bean cake, peanut cake, cotton cake, tea seed cake, wheat bran and so on.
* * * Five * * * Water Management In the central and western regions of China, the water temperature is still low in June, and the pool water should be kept at around 1 m to facilitate warming. With the increase of water temperature and fish body, fresh water should be added 1 time every 10 day, about 10 cm each time, until the maximum water body for culture is reached.
In the future, change water and inject water in time according to the change of water quality to keep the water fresh and the dissolved oxygen sufficient. When changing water, drain water first and then inject water, and each change of water shall not exceed 10 cm. For example, quicklime is sprayed 1 time every month for disinfection and disease prevention, and the concentration is15×10 * * * *. In the process of barracuda culture, we should also strengthen the inspection of the pond to prevent the damage of floating head, dam break and enemy animals and aquatic plants.
Third, fishing.
Generally, barracuda can be caught in one year, but the individual weight is only about 150g, and it grows rapidly in the second year, and the fish weight can reach 650- 1200g.
The main fishing methods of barracuda are: thin net fishing, gradual fishing, water fishing, trawling and so on. Producers should choose different methods according to their own needs and market conditions when fishing barracuda.