Key Technical Points for Summer Stocking of Largemouth Bass in Ponds

1. Pond drying and disinfection. Aquaculture ponds must be drained and dried for 10-15 days, the pond embankments repaired, and quicklime or bleaching powder used for disinfection.

2. Fingerling rearing. First, use early-breeding fry from Guangdong raised in dedicated ponds from late April to early May, and divide them into separate ponds when they reach about 5 cm; second, use locally self-bred largemouth bass, and select fingerlings that are robust, uniform in size, healthy and disease-free. Stocking density is 800-1200 fish per mu.

3. Culture management. (1) Feed. During the first 7 weeks, small-area concentrated temporary holding and acclimation management is needed, feeding 4 times daily; after transfer to the large pond, feed twice daily at fixed feeding stations. (2) Water quality management. In the early stage, apply inorganic compound fertilizer or biological rapid water-culture agent to the water to maintain transparency at 25-30 cm and keep the water “fertile, lively, tender and fresh.” After adding water in the mid-stage, use microbial preparations on sunny days for 10-15 days, applying them several times in succession to reduce harmful substances such as ammonia nitrogen and nitrite nitrogen in the pond. (3) Disease prevention and control: fingerlings must be given a medicated bath before stocking; after stocking, splash antiparasitic drugs once a month, and administer medication regularly within 5-6 days; an interval of 5-7 days is required between using insecticides and microbial preparations. (4) Preventing floating-head pond overturn: after entering the high-temperature season, run aerators for 1-2 hours at noon, pay attention to weather changes, adjust feed amounts promptly, and carry out pond patrols properly.

In addition, the culture model should also be optimized, specifically as follows:

1. Polyculture of largemouth bass with silver carp, bighead carp and crucian carp:

With largemouth bass as the main stocked species, additionally stock 10-20 bighead carp fingerlings, 40-80 silver carp and 100-150 crucian carp per mu; this can regulate water quality, clear residual feed, increase fish yield by 75 kg per mu, and raise income by 300 yuan per mu.

2. Polyculture of largemouth bass with river crab:

Stock river crabs first in February-March at 300-350 crabs per mu, with a size of 100-180 crabs per kg; install anti-escape facilities, plant aquatic plants, and release snails; then stock largemouth bass after May. Once the bass are being fed normally, the river crabs no longer need separate feed, as they clear the leftover bait.

3. Polyculture of largemouth bass with Australian red claw crayfish:

Stock Australian red claw crayfish in May at about 2 cm in size, 500-800 per mu; install anti-escape facilities, provide hiding places, and plant a small amount of aquatic plants. Once the largemouth bass are stocked and being fed normally, no separate feed is given for the Australian red claw crayfish.