INTENSIVE CULTURE AND NATURAL SPAWNING OF BROODSTOCK COILIA NASUS UNDER ARTIFICIAL FEEDING CONDITIONS

The current study investigated water temperature, chemical factors of water quality, feeding regime, and the natural spawning mechanism of Coilia nasus under intensive culture conditions. Results revealed that water temperature of culturing broodstock of C. nasus in one year was ranged from 5℃ to 34℃. The maturation rates of female broodstock reached to 16.5% while fish were fed with live fry of Cirrhinus molitorella and Caridina nilotica gracilipes, and reared with specific feeding regime during their growth periods including enhanced cultivation, over winter and induced mature. The average survival rate of the females reached 97.6%. Fish spawning time were mainly at 20:00-20:30 for a peak season from May to June. The fertilization rates ranged from 80% to 92%. A total of 569000 eggs were collected during this experiment. Results indicate that water temperature is the key factor to C. nausu spawning, and the optimal water temperature for C. nasus to spawn were 20℃ to 28℃.