Key Points of Broodstock Rearing Technology and Feeding Management Methods

1. Broodstock Rearing

(1) Sexual Maturity The sexual maturity age of Wuchang bream (Megalobrama amblycephala) is 2 to 3 years, and the sexually mature body weight is above 0.5 kg. The spawning and breeding period is from May to June.

(2) Male and Female Identification Sexually mature male fish have a large number of "nuptial tubercles" on the head, pectoral fins and caudal peduncle, with a rough feel when touched by hand; the abdomen is narrow and small, and when sexually mature, lightly pressing the testis area of the abdomen causes milky white semen to flow out; the first fin ray of the pectoral fin is thick and wavy-curved. Female fish have no "nuptial tubercles" or only a small number of tubercles on the eyes and back, and the abdomen is obviously swollen and soft; during the reproductive season, the urogenital pore is red and swollen, protruding outward; the first fin ray of the pectoral fin is thin and straight.

(3) Selection and Rearing of Broodstock The broodstock used for breeding should weigh above 0.5 kg, be 2 to 4 years old, healthy and uninjured. Generally, 15 to 22.5 kg of broodstock are stocked per 100 sq m. Wuchang bream mainly feeds on green feed; during the breeding season and before and after spawning, compound feed or refined feed such as soybean cake and rapeseed cake should be additionally provided, with a feeding amount of 2% to 3% of the broodstock body weight. When the water temperature rises above 18 to 20°C, male and female broodstock should be reared separately to prevent the broodstock from spawning naturally as the water temperature rises.