How to raise the striped snakehead gudgeon (grouper)? A detailed explanation of pond aquaculture technical specifications

Grouper, also called the striped snakehead gudgeon, is an important economic species for aquaculture along the coast of the South China Sea in our country, so can grouper be raised in freshwater? How is it raised? What are the pond aquaculture technical specifications?

1. Fry rearing technology

1. Requirements for fry ponds: for freshwater grouper fry rearing ponds, earthen ponds are best, and outdoor cement ponds can also be used; generally a single pond area is 50,100 m3, with a water depth of l,1 (5 m. Before the fry are stocked, drain the pond water, thoroughly clear the pond and disinfect it with quicklime, and apply sufficient base fertilizer to fertilize the water quality, so that the fry can eat natural food as soon as they enter the pond.

2. Fry stocking: before the fry are stocked, test the water first. The specifications of the fry stocked in the same pond should be neat and uniform in size. The stocking density depends on the feed, the level of aquaculture technology and the rearing specifications, and generally the stocking density is about 100 fish,m3. Before the fry enter the pond, soak the fish body in sop salt water for 15,20 minutes.

3. Feeding: when freshwater grouper larvae enter the pond, they feed on zooplankton; as the fry grow, their food intake increases, while the zooplankton in the pond gradually decreases. At this time, first, zooplankton can be cultivated by topdressing fertilizer, and second, additional soybean milk can be fed. After 15,20 days of rearing, when the fry reach more than 3 cm, their feeding habits begin to change; at this time, fish paste can be fed on a feeding tray for domestication feeding, 2,3

days later add a small amount of artificial compound feed mixed with fish paste for feeding, then gradually increase the proportion of artificial compound feed and reduce the amount of fish paste, until artificial compound feed is used entirely. The daily feeding amount is about 20, of the fish body weight, with 3 feedings per day.

4. Rearing management:

(1) Adjusting water quality: during the fry rearing process, because of fertilizing and feeding, the remaining fecal residue and leftover feed most easily spoil the water quality; therefore, change the water once every 3,5 days, each time changing 1,4 of the pond water. Some aquatic plants such as duckweed or water hyacinth can also be transplanted into the pond to purify the water quality and provide concealment and feeding convenience for the fry.

(2) Timely grading: when there is a relatively large difference in the growth specifications of the fry, because they have the habit of the big eating the small, they should be screened and graded in time. The fry in the same pond should strive to be uniform in specification, so as not to affect the survival rate of the fry.

(3) Daily management: mainly pond patrol, observing the fry's feeding, activity, water color changes and other conditions, so as to adjust the feeding amount in time and do a good job in fish disease prevention.

2. Adult fish aquaculture technology:

Freshwater grouper grow-out can adopt polyculture, and two methods can be used in polyculture:

1. Polyculture a small amount of freshwater grouper in a pond, about 22,50 freshwater grouper per mu of water surface; after half a year of aquaculture, the average body weight can reach more than 300 g, and after one year of aquaculture the body weight can reach about 500 g.

2. With freshwater grouper as the main fish, the polyculture species include tilapia, grass carp, crucian carp, etc.; stock 150,200 freshwater grouper per mu of water surface and 300 polyculture fish; during the rearing period, feed artificial compound feed, and also feed fresh tender pasture grass; when the zooplankton in the pond is insufficient, apply an appropriate amount of topdressing fertilizer to cultivate zooplankton. After half a year of aquaculture, the average body weight of freshwater grouper can reach about 200 g, and after one year of aquaculture, the body weight can reach more than 250 g.