How to raise pomfret and what matters should be paid attention to?

Golden pomfret is a kind of warm-water pelagic fish, with large size, large appetite, fast digestion and fierce feeding. It grows rapidly. The market standard of 400-600 g can be reached in 3-6 months from the beginning of breeding. According to the fast growth rate of golden pomfret, farmers can choose to increase the feeding amount in June, July and August. Artificial culture of pomfret mainly includes cage culture and pond culture.

net-cage culture

I. Sea Area Selection and Cage Preparation

The cage for breeding egg-shaped pomfret should be selected in the sea area with certain wind barrier or relatively small wind and waves, smooth water flow, sufficient water exchange, fresh water and pollution sources in the inner port and relatively stable water quality environment. The water depth is generally required to be 10 m ~ 15 m (after low tide). If it is a deep-water cage, it can be set in the sea area with a water depth of more than 20 m. Generally, the distance from the bottom of the cage to the seabed should be at least 2m at the lowest tide. In order to ensure the success of aquaculture, the water quality in the aquaculture area should meet the following conditions: salinity 20 ‰ ~ 30 ‰, water temperature 18℃ ~ 32℃, pH 7 ~ 9, transparency 8 m ~ 15 m and dissolved oxygen above 5 mg/L.

Usually, the cages used to breed egg-shaped pomfret are made of polyethylene mesh. The mesh size is 2.5 ~ 3.0 cm, and the cage size can be adjusted according to the fry size and actual situation, ranging from 3m× 3m× 4m to 4m× 4m× 4m. With the popularization and application of deep-sea cage, it has been proved that oval pomfret is also suitable for cage culture. Therefore, in deep-sea areas, deep-water cages made of high-strength polyethylene (PE) with a diameter of more than 20 meters can be used for aquaculture. According to the size of cages, tidal current and wind waves, a single cage can be fixed at a single point, or a plurality of cages can form a net row, and the net row composed of a plurality of cages should keep an appropriate spacing, generally more than 3 meters, to ensure smooth water flow.

Second, the stocking of fish species.

The breeding time of golden pomfret is from April to May every year, and the stocking specification is 2-3 cm. When the water temperature rises and stabilizes above 18℃, it is the right time for fish to be released. The stocking density of ovate pomfret should be flexibly mastered according to the environmental conditions of water quality in the sea area, the level of aquaculture technology and daily management, the source of bait, output and specifications. Generally speaking, if you want to harvest early, fry with a body length of 10 cm can be placed in a water body with 40 ~ 50 fish per cubic meter. If you are not in a hurry to harvest, you can appropriately increase the breeding density. Disinfect fry before stocking to kill pathogenic bacteria and parasites; After stocking, it is necessary to strengthen the early nutrition of fry, strengthen fry and enhance their anti-stress ability.

Three. Feeding and management

1, feed feeding

Egg-shaped pomfret is a carnivorous fish. In the past, it was mainly fed with minced fresh miscellaneous fish, but now it can also be fed with compound feed all the time, and the breeding effect is very good. In the cage culture of golden pomfret, high-grade puffed compound feed for marine fish is widely used in culture.

Golden pomfret eats a lot and digests quickly. In the case of artificial feeding, it will not stay for a long time after feeding. If it is fed with the food it likes, it will still compete fiercely. Therefore, in June, July and August when the water temperature is suitable for its growth, the daily feeding amount can be controlled at more than 20% of the fish's weight, and the feeding amount can be appropriately reduced in other months when the water temperature is low. In order to make them grow quickly and shorten the growth cycle, some farmers increase the daily feeding amount to 40% of their body weight by increasing the feeding times in high temperature season.

2. Daily management

The daily management of cage culture should be "five diligence and one refinement", that is, diligent observation, diligent inspection, diligent detection, diligent box washing, diligent disease prevention and patient and meticulous feeding to prevent accidents such as strong wind, pollution and man-made. It is necessary to patrol the cultured ovate pomfret regularly, and pay attention to the activities of fish schools, water color and water quality. Generally, the water temperature and air temperature are measured once every morning and evening, and the PH value 1 time and transparency are measured twice every week. The body length and weight of egg-shaped pomfret were sampled and measured every 15 ~ 20 days to understand its growth speed and law, so as to determine the feeding amount of bait, and at the same time, to check whether the egg-shaped pomfret has diseases.

In cage culture, it is very important to clean and replace cages. The cage system soaked in seawater for a certain period of time will more or less attach barnacles, oysters and other shellfish and various algae, which will hinder the smooth flow of water and the exchange of water bodies to a certain extent, thus affecting the growth of egg-shaped pomfret and aggravating the sinking force of the cage system. Therefore, in daily management, the nets should be replaced and cleaned according to the attached biomass and fish culture. In general, the net should be replaced every 3 to 6 months. When changing the net, it is necessary to prevent the cultured fish from being caught by the net angle and causing scratch and death, and the operation should be careful. Cage cleaning can use high-pressure water gun spraying, fresh water immersion, exposure and other methods.

3. Safe production

In the process of cultivating egg-shaped pomfret in seawater cages, the safety of cages should be checked frequently. Always check the accessories of the cage system, whether the cage is damaged, whether all kinds of cable bones are worn, and whether the fixing facilities of the cage system are firm and hard. If problems are found, we should take corresponding measures to deal with them in time. Before disastrous weather happens, we should cover the net; Check and adjust the tension of anchor and pile rope, and reinforce the drawstring and fixed rope of hanging cage; Check the firmness of frames, anchors and piles; Take measures, such as moving aquaculture personnel and ships to a safe place to prevent them.

Step 4 harvest

Egg-shaped pomfret fry hatched in that year were generally released at about 65438±00cm, and the commercial specifications of more than 400g could be reached after 4 ~ 5 months of cultivation. Generally speaking, the market price of ovate pomfret is better when it is above 600g/ tail, so it is suggested to harvest it at this time. In addition, farmers can determine the time to start breeding or the specifications of releasing seedlings according to the growth situation and market forecast of the ovate pomfret, so as to obtain the maximum benefit.

Soil pond culture

First, the breeding conditions

There are three experimental ponds in Ganwen Ecological Aquaculture Demonstration Zone in Zini Town, with the same size, each pond is rectangular, with an area of 12 mu. The ponds are open to the sun from north to south, with a depth of 2m, a slope ratio of l: 2.5 and sediments of 6cm- 10cm. The water source is the water from Jiulong River Port, which is convenient for irrigation and drainage, and can be drained through tidal changes. The water is fresh and pollution-free, with a pH value of 7.0-8.2, a salinity range of 5‰- 12‰, an ammonia nitrogen content of less than 0.5mg/L and a nitrite content of less than 0.1mg/L. ..

Second, pond renovation and pond cleaning and disinfection

After exposure to the sun, the dry pond in winter shall be ploughed and leveled, the pond bank shall be reinforced and raised, the leakage and collapse of the inlet and outlet gates shall be maintained, and excessive silt shall be removed. The depth of the pond is 2.5m Each pond has an independent water inlet and drainage system, and a 40-50 mesh screen is installed at the water inlet to prevent wild fish from entering. Each pool is equipped with four 0.75kW water wheel aerators. A temporary pond with an area of 1 mu-1.5 mu is built in the pond. After transformation, water was made with quicklime 100kg per mu, and then sprayed in the dry pool for disinfection.

Third, the transportation and management of seeds.

1. Before sowing 15 days, water is 80cm, and each mu is soaked in warm water of 10 kg- 15 kg, and then sprinkled in the whole pond to kill wild fish eggs. Apply 100kg~ 150kg fermented organic fertilizer per mu. When the pool water is yellow-green or brown, fry can be prepared.

2. By mid-May, when the water temperature reaches 20℃, 2,500 egg-shaped pomfret fry with a body length of 2.5 cm -3 cm will be stocked per mu, which will be purchased from Xiamen and put into a temporary breeding pond for breeding. 200 fish eggs and 4,000 prawns with a body length of 65,438 0.5 cm are mixed and put into the pond directly. When the seedlings are released, the pond water is brown, rich in natural bait organisms, with transparency of 30cm and salinity of 80‰.

3. The rattan tea fry is inflated and oxygenated for 24 hours in the temporary culture pond. After 2 days, zooplankton or newly hatched Artemia nauplii were fed. 1 week, add minced fish, add 30% powdered eel compound feed, mix and knead into balls, and put them into a temporary breeding pool, with 6 in each mouth. After 20 days' cultivation, the egg-shaped pomfret grows to 4cm-5cm, so the temporary culture pond can be opened and the fish can enter the pond.

Four. Aquaculture management

1. Feeding management Egg-shaped pomfret is fed with special puffed pellet feed with crude protein content of 43%, and mixed mullet and Penaeus monodon are not fed separately. According to the size of the fish, different types of feed are selected, including 0# feed and 1# feed in the early stage, 2# feed and 3# feed in the middle and late stage. Adjust the feeding amount flexibly according to the climate and water quality. Generally, feed less in cold and rainy days and feed more in sunny days. The water temperature is about 20℃, and it is fed twice a day, and the daily feeding amount is 8%-10% of the fish weight; When the water temperature is 25℃-35℃ from June to September, the egg-shaped pomfret eats vigorously and grows rapidly, eating 3-4 times a day, and the daily food intake increases to more than 15% of the fish weight; In hot and sultry weather, the amount of bait should be controlled moderately to avoid overeating of ovate pomfret. Feed the compound feed with comprehensive nutrition, and regularly add the product "Yinhuang Wei Hong VC" from American Naxin (International) Biological Nutrition Co., Ltd. or the product "Activated Peptide" from Weifang Oriental Ocean (University of Saskatchewan) Biotechnology R&D Center to regulate the intestinal microecological environment of the ovate pomfret, strengthen the intestinal absorption function, improve the feed conversion rate, improve the digestion and absorption of the body's disease resistance and stress resistance, and promote fish.

2. Adjust and control the water quality to maintain the water level, and gradually add water to the fish pond in the early stage of breeding, adding 5cm- 10cm every day, keeping the transparency of the pond water at 30cm-40cm, gradually changing the water to the depth of 1.5 m, and changing the water at 20cm-30cm every 2-3 days. During the period of high temperature, the water level should be kept above 2m, and the water exchange quantity and times should be increased appropriately. In the middle and late stage of culture, with the increase of bait dosage, a large amount of residue and excrement accumulated in the pond water, which increased the organic oxygen consumption of the pond. Therefore, the aerator should be turned on, and Weifang Oriental Marine product "Oriental Mushroom King" (ammonia nitrogen/nitrite degrading agent) 150-200/ mu should be applied every five days for efficient degradation. Stabilize PH value, inhibit the growth of fungi and pathogenic microorganisms through nutrition, competition in places and secretion of substances similar to antibiotics, and maintain the ecological balance of beneficial bacteria and plankton in water; Every 15-20 days, the oriental marine product "pioneer of sediment improvement" was spread all over the pond and immediately propagated into a dominant population, and its effect of improving water quality and sediment was obviously higher than that of conventional flora. Oxygen-increasing components release oxygen at the same time, increasing dissolved oxygen at the bottom of the pool and preventing floating head and flooding caused by hypoxia.

3. Daily management Daily management should inspect the pond at least three times in the morning, noon and evening to observe the feeding situation of the egg-shaped pomfret. If it is found that the egg-shaped pomfret has abnormal feeding or dead fish, it should find out the reason and deal with it in time. Check the filter screen of water inlet and outlet frequently, remove sundries, replace it in time if it is damaged, pay attention to the change of water quality, and replenish fresh water in time if it is found that the pool water is deteriorated. In the early stage of culture, the machine is turned on twice a day to increase oxygen, at noon for 1-2 hours, and before dawn for 3-5 hours; In the middle and late stage, the start-up time should be appropriately increased, and it should be started in time in rainy days and hot and humid days to prevent the oval pomfret from floating head due to lack of oxygen. Egg-shaped pomfret has the habit of gathering water and catching water. When adding water, the area near the water inlet is surrounded by a fence to prevent egg-shaped pomfret from gathering too closely around the water inlet and causing hypoxia, suffocation and death.