基于DNA条形码对南极Yelcho站周边海域鱼类种类鉴定

南极鱼类是南极海洋生态系统的重要组成部分, 在食物网的物质循环和能量流动中起着重要的作 用。利用中国第32 次南极考察暨中智第2 次联合南极半岛综合科学考察采集Yelcho 站周边海域南极鱼类, 并基于形态学和DNA 条形码技术对其进行种类鉴定。序列相似性结果显示仅2 尾鱼类能准确鉴定到种, 剩 余6 尾属于模糊种; 结合GenBank 中的同源序列对其进行系统发育分析, 结果显示所有样品能明显分为4 个组群, 且各物种的最小种间遗传距离均高于该物种的最大种内遗传距离, 存在明显的条形码间隙, 证明 各物种鉴定结果的有效性。8 尾样品内存在3 个有效种, 南极鱼科7 尾, 裸南极鱼科1 尾, 在一定程度上反 映出Yelcho 站周边海域鱼类在物种组成和生物量上均以南极鱼科鱼类为主。

Identification of Antarctic fish from the sea adjacent to Yelcho Station based on DNA barcoding

As an important part of the Antarctic Ocean ecosystem, Antarctic fish play a role in material cycling and the energy flow within the food web. Individual Antarctic fish specimens were collected from the sea adjacent to Yelcho Station during the 32nd Chinese National Antarctic Research Expedition, and morphological analysis and DNA barcoding were employed in their identification. After running blast searches in NCBI, sequence similarity results showed that only two individuals were identifiable to the species level, while six individuals were unmatched. Combined with a homologous sequence from GenBank, phylogenetic analysis was performed and four groups were unambiguously identified from the NJ tree. There was clear overlap (barcoding gap) between intraspecific and interspecific variabilities in each species, as the smallest interspecific divergences were well below 2%, while the largest intraspecific divergences were above 2%. Three valid species were detected from eight individuals, encompassing seven Nototheniidae fish and one Harpagiferidae fish. Finally, all results further confirmed that notothenioid fish were dominant in terms of species diversity and biomass in the investigated seas.