性成熟和个体大小对西北印度洋鸢乌贼耳石形态的影响

为研究性成熟和个体大小对西北印度洋鸢乌贼耳石外部形态的影响,判别耳石外形生长的拐点,实验根据2019年2—5月我国灯光罩网渔船在西北印度洋海域调查生产期间采集的1009尾鸢乌贼样本,以耳石总长(TSL)、侧区长(LDL)、翼区长(WL)和最大宽度(MW)作为耳石外形的生长指标,以耳石最大宽度与其总长之比(MW/TSL)...

Effects of sexual maturity and body size on statolith shape of Sthenoteuthis oualaniensis in the Northwest Indian Ocean

_{: Statolith is one of the most important hard tissues of Cephalopods to study the age and growth, population structure and life history of the Cephalopods.[Objective] In this paper, the effects of sexual maturity and body size on the statolith shape of Sthenoteuthisoualaniensisin the northwest Indian Ocean were studied, the growth inflection points of statolith shape was evaluated,which would provide a basis for the subsequent studies on the population identification and life history of the Sthenoteuthisoualaniensis. [Method] According to the samples of Sthenoteuthis oualaniensis totaled 1009 in number collected in the northwest Indian Ocean from February to May of 2019 by the Chinese light falling-net fishery fleets, the total statolith length(TSL), lateral dome length(LDL), wing length(WL) and maximum width(MW) are considered as the indicator of external form growth, and the ratio of MW to TSL is considered as the indicator of changes in statolith shape. The external form growth and statolith shape changes effected by sex, gonad maturity and individual size are analyzed by the analysis of variance(ANOVA) and Least-significant difference(LSD).[Result] The results indicated that the changes TSL, LDL, WL and MW between different sexes were statistically significant (P<0.01). For both female and male samples, the changes of TSL, LDL, WL and MW betweendifferent gonad maturity and different mantle length ranges were also statistically significant (P < 0.01).However, the ratio of MW to TSL changes in different sexes showed no significant differences (P > 0.05) and changes in different gonad maturity and different mantle length ranges showed verySsignificantSdifferences (P < 0.01).[Conclusion] The study shown that sexual maturation and size of Sthenoteuthis oualaniensis have an obvious effect on its statolith growth in both male and female. Stage III gonadal maturity and 300-500mm mantle length are the growth inflection points of statolith shape of female individuals, while there is no distinct inflection point in male individuals.}