Detailed Explanation of Key Points and Management Methods for Freshwater Grouper Aquaculture

Because freshwater grouper has a beautiful appearance and delicious, nutritious meat, it can be kept as an ornamental fish and also farmed as a commercial fish to gain profit value. Today, freshwater grouper has become a new type of individual aquaculture species. So what aquaculture techniques are there for farming freshwater grouper? What needs attention? Let us take a look together.

Freshwater Grouper Aquaculture Techniques

Freshwater grouper is a tropical fish, generally growing in freshwater, and is a somewhat carnivorous fish. Freshwater grouper can be raised through polyculture, and two methods can be used in polyculture:

1. Polyculture of a small number of freshwater grouper in a pond, with about 22-50 freshwater grouper per mu of water surface. After half a year of farming, the average body weight can reach more than 300 grams, and after one year of farming, the body weight can reach about 500 grams.

2. With freshwater grouper as the main cultured fish, the polycultured species include tilapia, grass carp, crucian carp, etc., with 150-200 freshwater grouper per mu of water surface and 300 polycultured fish. During the rearing period, artificial compound feed is fed, and fresh tender pasture can also be fed. When zooplankton in the pond is insufficient, an appropriate amount of topdressing is needed to cultivate zooplankton. After half a year of farming, the average body weight of freshwater grouper can reach about 200 grams, and after one year of farming, the body weight can reach more than 250 grams.

Grouper Fry and Fingerling Rearing Techniques

1. Requirements for the fry pond: For freshwater grouper fry and fingerling rearing, an earthen pond is best, and an outdoor cement pond can also be used. Generally, a single pond has an area of 50-100 m³, with a water depth of 1-1.5 m. Before stocking the fry, 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 are put into the pond.

2. Fry stocking: Before stocking the fry, test the water first. The specifications of fry stocked in the same pond should be neat and uniform in size. The stocking density depends on food, the level of farming technology, and the rearing specifications. Generally, the stocking density is about 100 fry/m3. Before the fry enter the pond, soak the fish bodies in sop salt water for 15-20 minutes.

3. Feeding: When freshwater grouper larvae are put into 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; 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. After 2-3 days, a small amount of artificial compound feed mixed with fish paste is added for feeding, and afterward the proportion of artificial compound feed is gradually increased while the amount of fish paste is reduced, 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) Regulating water quality: During the fry rearing process, due to fertilizing and feeding, the remaining fecal residue and leftover bait most easily spoil the water quality. For this reason, water should be changed once every 3-5 days, with each water change being 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 facilitate the fry's hiding and feeding.

(2) Timely grading and rearing: 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 for rearing in time. The fry in the same pond should be kept as uniform in specification as possible, so as not to affect the survival rate of the fry.

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

Bait Management for Freshwater Grouper

The newly hatched larvae of freshwater grouper have a total length of 0.58-0.6 cm and gather at the bottom of the pond in constant motion. At a water temperature of 26-28°C, the yolk sac completely disappears on the sixth day after hatching, and the larvae swim to the middle and upper water layers and no longer gather at the bottom of the pond. After the yolk disappears, the small fry can be fed small zooplankton such as rotifers and cladocerans. When they are slightly larger, they can be switched to high-protein dough-like artificial bait for domesticated feeding. After about 1 month of rearing, when the body length reaches about 10 cm, they can be put into the pond for adult fish farming. In southern regions, the summer period is relatively long. Stocking fry with a body length of about 10 cm, after 100 days of farming, the body weight can reach more than 500 g. The maximum body weight of freshwater grouper can reach more than 1200 g.

Living Habits of Freshwater Grouper

Freshwater grouper is a tropical fish, growing in freshwater, and can also grow in seawater with a salinity below 10%. Its suitable temperature range is 25~30°C. When the water temperature drops to 20°C, feeding is obviously reduced, and when the water temperature drops to 15°C, the body loses balance. Therefore, areas where pond water drops below 15°C in winter are not very suitable for farming this fish, unless insulation measures are taken. During overwintering, it is best to keep the water temperature above 19°C. Freshwater grouper is a bottom-dwelling fish, tolerant of low oxygen and with strong disease resistance. Fish diseases rarely occur during the farming process. It can be polycultured with tilapia and crucian carp to clear small fry in tilapia and crucian carp ponds, achieving high quality and efficiency.

Freshwater grouper is a somewhat carnivorous fish. At the fry stage, its carnivorous characteristic is quite strong, mainly feeding on zooplankton. Fry with greatly disparate sizes will kill each other, so attention should be paid to graded and separate pond management during farming. After reproduction, the small fry should be pulled out in time so as not to be swallowed by the parent fish. Starting domestication feeding from the fry stage, they will eat artificial compound feed and can be fed floating eel-family fish feed.

Above we have learned about the aquaculture techniques and living habits of freshwater grouper. Only by mastering reasonable and correct farming methods can very healthy grouper be raised, and only then can economic value be obtained. We hope this article can help everyone.