基于耳石形态特征的南海鸢乌贼群体判别分析

Discriminant Analysis of Purpleback Flying Squid(Sthenoeuthis oualaniensis) Groups Based on Statolith Morphology in the South China Sea

【目的】通过耳石形态参数对南海鸢乌贼(Sthenoeuthisoualaniensis)不同群体进行判别。【方法】采用2012年4月-2013年1月采自南海南沙群岛、东沙群岛和中沙西沙群岛周边海域灯光罩网渔获的268尾鸢乌贼耳石样本(雌性166尾、雄性102尾),通过耳石总长(TSL)、最大宽度(MW)、侧区长(LDL)、背侧区长(DLL)、吻侧区长(RLL)、吻区长(RL)、吻区宽(RW)、翼区长(WL)和翼区宽(WW)9个形态参数进行主成分分析,采用不同校正方法判别分析3个不同海域和3个不同体型群体的耳石差异性。【结果】统计并分析鸢乌贼耳石形态参数可知,南海鸢乌贼耳石具有翼区宽大、侧区次之、背区稍小、吻区长窄的形态特征。主成分分析表明,鸢乌贼的耳石长度参数TSL、LDL、DLL、WL和宽度参数MW可代替9项形态参数来描述耳石的形态特征;函数拟合结果,5项表征与鸢乌贼胴长有较强的线性函数关系。判别分析表明,比值校正法对3个地理群体判别中具有较好稳定性,总体成功率为60.4%;中沙西沙群体和微型群体的耳石形态在判别中有较好的区分度。【结论】不同群体的南海鸢乌贼耳石形态特征具有较大差异性,中、西沙群体和微型群体与其他群体存在较高的区分度。

【 Objective 】 Exploring the results of discriminating different groups of Sthenoeuthis oualaniensis from the South China Sea through the statolith morphology parameters.【Method】Analysis was performed using 268 statolith samples of the purple back flying squid S. oualaniensis(the 166 females and 102 males) collected by light attracting falling nets in Nansha Islands, Dongsha Islands, and Zhongshaxisha Islands sea areas in the South China Sea from April 2012 to January 2013. Principal component analysis were conducted on nine morphologic parameters including total statolith length(TSL), wing length(WL), rostrum length(RL), ventral dorsal dome length(DLL), rostrum lateral dome length(RLL), maximum width(MW), lateral dome length(LDL), wing width(WW), rostrum width(RW) of the statoliths. Discriminant analysis of three different sea areas and body groups by different correction methods.【Result】(1) Statistics and analysis of the statolith morphology showed that S.oualaniensis in the South China Sea has wide wing region, the lateral region is second, the back region is slightly smaller, and the kiss region is narrow morphologically.(2) Principal component analysis shows that the statolith length parameters TSL, LDL, DLL, WL and width parameter MW of S.oualaniensis could replace the 9 statolith morphological parameters, obtained by function fitting results.The five characterizations parameters and mantel length has a strong linear function relationship(3)Discriminant analysis shows that the ratio correction method has good stability in the discrimination of three geographical groups, and the accuracy is 60.4%;.The statolith morphology of the ZhongshaxiSha group and dwarf group has a good discrimination.【Conclusion】The morphological of statoliths in different groups of the South China Sea have a large difference. The ZhongshaxiSha group and dwarf group have higher discrimination with other groups.