Technical points of artificial breeding of perch broodstock in high ponds
Zhou Huixia
Percocypris pingi is mainly distributed in the upper reaches of the Yangtze River such as the Minjiang River, Yalong River, Tsingyi River and the lower section of the Jinsha River in Sichuan, which is a ferocious carnivorous fish with tender flesh and is an important economic fish in the production area. In recent years, the artificial breeding technology of perch has gradually matured, providing a seedling guarantee for the promotion of artificial breeding of perch. Combined with the practice of breeding, the author introduces the technical points of artificial breeding broodstock in the high pond of perch carp as follows, in order to provide you with a reference for breeding.
First, life habits
Sea bass is suitable for living water temperature 13 ~ 25 ° C, when the water temperature is lower than 10 ° C, the feeding intensity is significantly weakened, when the water temperature is as low as 5 ° C, basically stop feeding; the water quality requirements are higher, not tolerant of low oxygen, dissolved oxygen needs to be guaranteed at more than 8 mg / l; timid, easy to be frightened, like to hide in groups in dark places; there is a habit of biting bait fish and eating only part of it.
2. High-ranking pond conditions
The high-level pool should be selected in a place with sufficient water sources and water quality to meet the living of the perch, the depth of the pool is 2 meters, and the control water level is at least 1.6 meters; the pool shape is preferred to be circular or circular, and the square can also be square; the pool area can be planned according to the site site, and the single mouth area is not less than 100 meters
2 Is appropriate; the high-level pool needs to be equipped with a complete inlet and drainage system, and the design of the inlet can form a flow state in the pool, and the shading and oxygenation facilities of the high-level pool need to be considered.
Third, broodstock selection and stocking
Select perch carp that are over 5 years old, have a size of 1.5 to 2 kg/tail, and are physically strong as broodstock. Before stocking, the high pond should be cleaned up and disinfected with 10 mg/L of chlorine dioxide; the utensils should be soaked in 50 mg/L potassium permanganate solution for 30 minutes; the toxicity of the disinfectant drugs in the pond should be checked by testing the water, and the toxicity should disappear before the fish can be released. New breeding ponds need to be used after alkaline has disappeared and tested the water. Broodstock stocking density should not be too large, 1 to 2 per square meter can be stocked to ensure that the perch has sufficient space to move.
4. Breeding management
1. Feed selection and feeding
Fishery floating compounds with protein levels of at least 48% and a particle size of 4 mm or 6 mm are selected as domesticated feeding materials for sea bass. Usually choose to domesticate food, and can be adapted to artificial feed in about two weeks. Under normal circumstances, feed is fed once a day in the morning and once in the evening, and the daily feeding amount is 1% to 1.5% of the total body weight of the fish. The feeding of sea bass is more fierce, and in order to avoid concentrated grabbing when feeding, it is necessary to appropriately expand the feeding area of feed or bait fish.
2. Daily management
In the process of breeding perch broodstock, it is necessary to do a good job in the water quality management of the high-level pond, focusing on dissolved oxygen and substrate, and turning on the aerator when the dissolved oxygen is less than 8 mg/L. In the case of guaranteed water sources, it should be ensured that the water should be completely changed at least once a week; when the water body is turbid, it is not advisable to enter the water, and it is also necessary to reduce the amount of feeding and turn on the aerator.
3. Strengthen management
From February to April every year, the intensive breeding stage of the perch is carried out. This phase requires fortification and management fortification. On the basis of daily feeding, in addition to adding multi-dimensional to the feed, it is also necessary to feed the bait fish once every other day. Select live carp and crucian carp fry with a body length of 3 to 5 cm, 2% to 3% of the total body weight of the fish are fed each time, and disinfect with 5% salt water for 5 minutes before feeding the bait fish. The next day, the bait fish that has been killed and not eaten needs to be picked up in time. At this stage, it is necessary to strengthen the flushing, especially at night, and if necessary, an open water pump can be added to increase the intensity of the flushing.
4. Prevention and control of fish diseases
There are relatively few diseases in the breeding process of perch carp, and on the basis of daily comprehensive prevention and control, it is not easy to cause large-scale, group-like virulent fish diseases. Adhere to the principle of "prevention first, prevention and control combination", routine disinfection every month, generally choose povidone iodine, glutaraldehyde and other relatively less irritating disinfection drugs. In the high temperature season, according to the actual situation, it is necessary to increase the frequency of water change and disinfection, and at the same time add astragalus polysaccharides, multi-dimensional and other immune enhancers to the bait.
The common parasitic disease of the sea bass is mainly anchor head, which can cause redness, swelling and inflammation of the surrounding tissues of the parasite, which is contagious, but the fatality rate is extremely low, usually the diseased fish will form granulation tissue in the affected area to surround the anchorhead. To kill the perch anchorhead seabream, the whole pond of 0.5 to 0.7 grams of crystal enemy insects can be sprinkled 2 to 3 times per cubic meter of water or add 2 to 2.5 grams of fish insects per kilogram of feed, and mix well with the feed for 3 days.