Fishery biology of Cyanea nozakii resources in the waters of Dongshan Island
福建东山岛海域霞水母的渔业生物学研究

According to the investigations during April-September 1994, the peak date of Cyanea nozakii density of in the waters of Dongshan Island was from 25 June to 10 July,and that of its biomass was from 10 July to 5 August. The diameter of umbrella part of the stock ranged from 15 mm to 580 mm, averaging 247.48 mm,and the body weight ranged from 0.4 g to 10 250 g, averaging 1 274 g. The growth of the diameter of umbrella part and the body weight of Cyanea nozakii could be calculated using power equation and power exponential equation,respectively. Based on the bio economics principles,the optimal opening date was 15 July,and the rational fishing umbrella part was 360 mm