基于Cytb基因的东印度洋鸢乌贼系统发育关系和种群遗传结构

通过测定东印度洋北部、赤道、南部3个鸢乌贼（Sthenoteuthis oualaniensis）群体的线粒体DNA细胞色素b（Cytb）基因序列，分析了东印度洋鸢乌贼的系统发育关系。研究表明，东印度洋鸢乌贼整体具有高单倍型多样性（h=0.939）和高核苷酸多样性（π=0.015）。3个鸢乌贼群体间的F_st值为0.661，群体间遗传分化水平很高，具有明显的遗传分化现象，可分为以东印度洋北部群体为主的谱系1（东印度洋北部谱系）和主要由东印度洋赤道与南部群体组成的谱系2（东印度洋南部谱系），且谱系2经历过群体扩张。东印度洋巨大的南北水文差异可能是鸢乌贼产生南北谱系分化的原因，在东印度洋鸢乌贼资源的利用和管理方面应考虑南北谱系的差异和特点。

Phylogenetic relationship and population genetic structure of Sthenoteuthis oualaniensis in the Eastern Indian Ocean based on Cytb gene

In this study, we determined the mitochondrial DNA cytochrome b gene (Cytb) sequences of the northern, equatorial and southern populations of Sthenoteuthis oualaniensis in the Eastern Indian Ocean, and analyzed the phylogenetic relationship.It was shown that S. oualaniensis in the Eastern Indian Ocean had an overall high haplotype diversity of 0.939 and a high nucleotide diversity of 0.015.F_st value among three populations was 0.661 (P<0.01), reaching a high level of interpopulation genetic differentiation with significant genetic structure. Two lineages were revealed in three S. oualaniensis populations in the Eastern Indian Ocean. Lineage 1(the northern lineage of the Eastern Indian Ocean) is dominated by individuals from the northern population of the Eastern Indian Ocean; lineage 2(the southern lineage of the Eastern Indian Ocean)mainly consists of individuals from the equatorial population and the southern population of the Eastern Indian Ocean,and lineage 2 underwent population expansion. The great north-south hydro-logical difference in the Eastern Indian Ocean may be the reason for the north-south lineage divergence of S. oualaniensis in the Eastern Indian Ocean. The differences and characteristics of the north-south lineages should be considered in the utilization and management of S. oualaniensis resources in the Eastern Indian Ocean.