Rough techniques and daily management steps of cultured grouper seedlings

1. The condition of rough standard

① site: it can be directly marked in the seedling pond, or the rough pond can be established in the culture pond. It is a rectangular cement pool with a volume of 10 to 25 meters and a water depth of 1 to 1.8 meters.

② lighting: natural light is used in indoor cultivation pond, direct sunlight should be avoided in outdoor cultivation pool during the day, and foam can be used to control light intensity.

③ water temperature: the suitable water temperature is 22-29 ℃. It is necessary to prevent drastic changes in water temperature day and night.

④ salinity: wide salinity, can grow in water with salinity above 10 ‰. The optimum salinity is between 25 ‰ and 29 ‰.

⑤ water environment: to keep the environment quiet, the water quality is fresh, it is best to keep running water feeding, the influent and discharge is balanced and normal, not more or less, the pH value is maintained between 7.8 and 8.4, and the dissolved oxygen is above 5mg/L.

⑥ stocking density: according to the size of fish fry size, large size can be released, small can appropriately increase the stocking density.

two。 Bait feeding

Fish fry of more than 2.4 cm can be fed with minced fish and shrimp, and food intake can be observed every day, and a small amount of Artemia adults can be added when the amount is insufficient; when the total length of fish fry reaches more than 3.6 cm, it can be converted to feed fresh minced fish, small shrimp or smaller live fry, and some artificial formula feed to help digestion can be added when the fry has a bad appetite.

Whether it is feeding fish or shrimp minced meat, or fresh minced fish, shrimp or smaller live fish fry, every kilogram of fish, shrimp minced fish and fresh minced fish, shrimp or smaller live fish fry should be mixed with 10ml active garlic treasure and 10g enzymatic hydrolyzed polysaccharide (or Jinpikang), which can not only protect the liver and intestines and stomach, promote food attraction and growth, but also enzymatic hydrolysis of worm eggs and prevent and control the growth of parasites. 3. Daily management

Maintaining stable and good water quality and bottom environment must be paid attention to at all times in management. Every 3 to 5 days according to each cubic meter of six control bottom health, granule spirit of 0.5 grams each, can keep the bottom quality and water quality fresh. In each feeding, the exchange of new and old water must be carried out. At the same time, the feeding situation and satiety rate of fish fry should be observed. Keep track of the amount of residual bait in the water body at any time in order to make timely adjustments. The bottom cleaning work is very important, and it is necessary to absorb dirt regularly every day. Change the pool in time when you find the pool dirty. Pay close attention to the physiological and ecological response of fish fry. Fish fry have individual differences due to different growth rates, and the obvious differentiation of populations will cause serious cannibalism. At this time, screening and cultivation should be carried out as soon as possible.

Divide the fry: divide the fry once every 10-15 days; sift the fry by hand. That is, visually distinguish the specifications, and then select a variety of sieves of different sizes. After being screened out, it was placed in each cultivation pool. Pay attention to be very careful in operation so as not to damage the body surface of the fish. A certain amount of drugs can be put into the newly replaced breeding pool to prevent infection caused by injuries caused by improper operation.

Grouper is a kind of carnivorous and ferocious fish, and it is its nature to eat each other. There are three reasons for this phenomenon: insufficient feed of ①, great individual difference of ②, and high stocking density of ③. Therefore, in order to improve the production effect, stocking density is a serious problem that can not be ignored. It is observed that the breeding density after sorting should be maintained at about 500-3000 tails / m3. The phenomenon of over-concentration of fish fry sometimes occurs when fish fry are transferred to benthic life. The main preventive method is to maintain running water cultivation as far as possible, and the water quality should be good. If you find a small number of diseased seedlings or weak seedlings, you should scoop out the isolation treatment in time.

4. Disease prevention and control

Because the grouper fry are thick under the condition of high water temperature, the water quality is easy to be polluted with the secretion of metabolites. Therefore, diseases are easy to occur in the process of roughing. The most common diseases are vibrio disease and white spot disease. It is observed that vibrio disease is mostly caused by dirty pools and is usually characterized by ventral fin decay. On the other hand, white spot disease can occur no matter under any circumstances, and it is mostly seasonal, with symptoms of decay and white spots in all parts of the head or body. Prevention and control measures: ① is diluted with Bai an Wei (0.5ml per cubic meter) and sprinkled in the whole pond, and then sprinkled in the whole pool the next day. Every kilogram of ② is mixed with 10 grams of active garlic treasure, Materia Medica Dakang, Jinyu Kang, Baogan Changling, 2 meals a day for 3 days. In addition, in the rough process, due to the influence of external factors, the symptoms of virus infection also occur from time to time, can be properly stopped feeding, at the same time with Budweiser (0.5 ml per cubic meter) diluted the whole pool sprinkle, the next day according to each cubic meter with six control bottom health, Dishu'an each 0.5 grams mixed dry sprinkle.