Experience and Methods for Polyculture of Mandarin Fish in Adult Fish Ponds

1. Pond conditions. Adult fish ponds mainly stocked with bottom-feeding fish are generally 5-10 mu in area, while ponds mainly stocked with upper-layer filter-feeding fish are generally 10-20 mu in area, with a water depth of 2-3 m. Pond sediment should be relatively low, and there should be a complete water inlet and drainage system and equipment.

2. Fish fry stocking. Generally, 40-50 mandarin fish fry with a body length of 3.3-4.5 cm are stocked per mu; the stocking time is mid-to-late May, and no later than early June at the latest.

3. Sources of bait fish. When adult fish ponds are filled and drained, a certain number of wild trash fish often enter the pond. These wild trash fish, as well as the naturally reproduced fry of carp and crucian carp in the pond, can all become good bait for mandarin fish; another source of bait fish is to additionally stock a certain number of summer fry in the adult fish pond, generally 1000 fry per mu.

4. Pond management. The management of mandarin fish culture is mainly in two aspects. The first is water quality management. In ponds mainly stocked with feeding fish, water should generally be added and flushed once about every half month, with each water addition being 20-30 cm deep. During the high-temperature period from July to September, water should be added and flushed once a week; ponds mainly stocked with filter-feeding fish should be flushed frequently, and 1.5-2 kW aerator should be equipped for every 6-8 mu of water surface. At the same time, quicklime water should be splashed once daily, using 15-20 kg of quicklime per mu each time. The other aspect is pond inspection. Every morning before sunrise, the pond must be inspected to observe whether the mandarin fish are gulping air at the surface. In addition, the condition of the bait fish should also be checked frequently, and bait fish should be replenished in time.