中国南海西沙群岛海域鸢乌贼耳石元素组成

耳石是头足类重要的硬组织,其微化学被广泛用于头足类生活史的重建、群体划分等研究领域.本文根据中国灯光罩网渔船于2017年5—8月在中国南海西沙群岛海域采集的鸢乌贼样本,利用激光剥蚀电感耦合等离子质谱法(LA-ICP-MS)分析了20枚鸢乌贼耳石的元素组成及其分布特性.结果表明: 西沙群岛海域鸢乌贼耳石主要由55种元素组成,含量最多的前10种元素分别为钙(Ca)、锶(Sr)、钠(Na)、磷(P)、硅(Si)、镁(Mg)、钾(K)、硼(B)、 铁(Fe)和钡(Ba).方差分析表明,不同性别间Ca、Sr、Na、P、Si、Mg、K、Fe、Ba和B的分布均不存在显著性差异;不同孵化群体间Ca、P、B、Fe和Ba的分布也不存在显著性差异,而Si、Sr、Mg、Na和K则差异显著;不同耳石部位间除了Ca和Fe的分布不存在群体间差异外,Sr、Na、P、K、Si、Mg、B、和Ba均存在显著性差异.表明Sr、Na、K 和 Mg可能比较适合用于鸢乌贼群体划分和生活史研究.

Element composition in the statoliths of Sthenoteuthis oualaniensis squid in Xisha islands waters of South China Sea.

Sthenoteuthis oualaniensis is the most important cephalopods fishery resource of the South China Sea, which supported the falling-net fishery of Guangdong, Guangxi and Hainan Provinces of China. Understanding the fisheries biology is essential for sustainable exploitation and management of this squid. Statolith is one of the most important hard tissues of cephalopods which were widely used in the research of fisheries biology and ecology. Elements of 20 statoliths of S. oualaniensis collected in the Xisha islands waters of South China Sea during May to August by the falling-net fishery of 2017 were analyzed with Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) for different sexes, different hatching groups, and history stages. The results showed that the statolith of the S. oualaniensis contained 55 elements, with calcium (Ca), strontium (Sr), sodium (Na), phosphorus (P), silicon (Si),magnesium (Mg), potassium (K), iron (Fe), barium (Ba) and boron (B) being the top ten abundant elements. The analysis of variance (ANOVA) showed that there was no significant difference in all element distributions between sexes for the most abundant ten elements. Significant differences existed in the contents of Si, Sr, Mg, Na and K but no significant difference was found in the contents of Ca, P, B, Fe and B between different hatching groups. There were significant differences in the contents of Sr, Na, P, K, Si, Mg, B and Ba, but no significant difference in the contents of Ca and Fe in the statoliths among different growth zones. Our results suggested that Sr, Na, K and Mg were probably the best four elements for life history reconstruction and examining population structure of the S. oualaniensis.