中国南海西沙群岛海域鸢乌贼角质颚生长特性

角质颚是头足类重要的硬组织之一,被广泛用于研究类头足类渔业生物、生态学。根据我国灯光罩网渔船2016年1—3月和2017年1—3月在中国南海西沙群岛海域采集的818尾鸢乌贼样本,研究了鸢乌贼角质颚的外部形态生长特性。主成分分析表明,鸢乌贼的上头盖长(UHL)、上脊突长(UCL)、上翼长(UWL)、上侧壁长(ULWL)、下头盖长(LHL)、下脊突长(LCL)、下翼长(LWL)和下侧壁长(LLWL)可以作为鸢乌贼角质颚外形变化的特征参数。协方差分析表明:UHL、LWL与胴长的生长关系存在性别间显著性差异,其余参数均不存在显著性差异;所有外形特征参数与体质量间的生长关系均存在性别间显著性差异。AIC分析表明:除LLWL和雄性个体的UHL与胴长的关系最适合用线性方程表示外,其余均最适用指数方程表示;雌性个体所有外形参数与体质量的生长关系均最适合用对数函数表示,而雄性个体除UCL和UWL最适合用指数函数表示外,其余均最适合用线性方程表示。

Beak growth characteristic of Sthenoteuthis oualaniensis in the waters of Xisha Islands in the South China Sea

The beak was one of the most important hard tissues of cephalopods which was widely used in the study of cephalopod fisheries biology and fishery ecology research. According to the measurement of the morphological parameters of the beak from 818 Sthenoteuthis oualaniensis samples collected by Chinese falling-net fishery during January to March of 2017 and 2018 in the Xisha Islands waters of the South China Sea, the morphological growth characteristic of the beak of S.oualaniensis was studied. The principal component analysis showed that the upper hood length (UHL), the upper crest length (UCL), the upper wing length (UWL), the upper lateral wall length (ULWL), the lower hood length (LHL), the lower crest length (LCL),the lower wing length (LWL) and the lower lateral wall length (LLWL) could be used as themorphological characteristic parameters to study the morphological changes of the beak. The analysis of covariance (ANCOVA) showed that there were significant differences in the relationships between UHL, LWL versus mantel length (ML) between males and females, but no significant difference was found in other characteristic parameters. The relationships between beak morphological variables and body weight (BW) differed significantly between males and females in all of the morphological characteristic parameters. The relationships between LLWL,UHLof males and ML were optimally described by the linear growth models, and exponential functions were optimal for the other parameters. The logarithmic functions were optimal for the relationship between the ULWL, LHL, LCL, LWL, LLWL and BW for females, however exponential equations were optimal for the UCL,UWL, and linear functions were optimal for the other parameters for males.