STUDY ON CHANGES IN REPRODUCTIVE BIOLOGY CHARACTERISTICS OF SEPIELLA MAINDRONI(ROCHEBRUNE) OFFSHORE ZHEJIANG
浙江近海曼氏无针乌贼(Sepiella maindroni)繁殖生物学特性变化研究

To understand the reproductive biology characteristics of Sepiella maindronifrom the coastal waters of the East China Sea in Zhejiang Province, compared the variant regularity of the gonadosomatic indices (GSI), biology shape and the relationship between the individual fecundity and the biological character indices of S. maindroni from the coastal waters of the East China Sea in Zhejiang Province in different period, by the conventional biological method and statistics regression analysis. The result showed that the GSI of S. maindroni reached the highest 9.51%±7.23% in April. Compared with S. maindroni in the early 1960s and 1980s, the gonadal development of S. maindroni advanced, and the genital stage of S. maindroni extended. The biology shape, brood amount and individual fecundity of S. maindroni in the early 1980s were greater than that of the early 1960s and now. These indicators of cultured S. maindroni were significantly higher than that of contemporary wild S. maindroni. The individual fecundity of S. maindroni increased as the mantle length (ML), body weight (W), ovary weight (WO) and GSI. There was significant (P<0.01) correlation between individual fecundity and these biological indicators, in addition to body mass relative fecundity (FW). Multiregressive analyses showed that the individual fecundity were significantly correlated with WO. The fecundity were mainly dependent on the size of WO.