浙江近海鰓属鱼类形态描述及中国鰓属鱼类分子系统发育分析

为明确浙江近海鲵属鱼类物种组成, 对采自舟山和温州近海共计411尾鲵鱼样品进行形态学测定, 并基于线粒体细胞色素氧化酶Ⅰ亚基(COⅠ)基因片段探讨其序列差异及系统发育关系。结果显示: 浙江近海的鲵属鱼类为少鳞鲵和中国鲵, 两种鲵鱼形态特征鲜明, 鱼鳔形态差异明显。所测得的少鳞鲵和中国鲵COⅠ基因片段长度均为600 bp, 平均GC含量分别为46.6%和49.9%。依据Kimura-2-parameter模型(K2P), 少鳞鲵和中国鲵的种内平均遗传距离分别为0.002和0.000, 两种间平均遗传距离为0.211。采用邻接法构建的系统发育树显示, 中国鲵先和邵氏鲵聚为一支, 然后与少鳞鲵聚为一支, 再与其他鲵属鱼类聚类。研究结果明确了浙江沿海鲵属鱼类的物种组成, 并为探讨少鳞鲵和中国鲵的系统发育关系及基于COⅠ基因的鲵属鱼类物种鉴定提供了参考。

MORPHOLOGICAL DESCRIPTION OF SILLAGO SPECIES IN THE COASTAL WATERS OF ZHEJIANG AND PHYLOGENETIC ANALYSIS OF SILLAGO SPECIES IN CHINA

In order to determine the species composition of genus Sillago, this study measured 411 Sillago individuals, which were collected from the coastal waters of Zhoushan and Wenzhou, Zhejiang Province. The mitochondrial cytochrome c oxidase subunit 1 (CO I) gene sequences were used for genetic diversity and molecular phylogenetic analysis. The results showed that only Sillago japonica and Sillago sinica distributed in the coastal waters of Zhejiang. These two species were different in morphology, especially in the shape of swim bladder. We obtained 600 bp CO I sequences, and the GC contents for S. japonica and S. sinica in all position were 46.6% and 49.9%, respectively. The mean genetic distances by Kimura-2-parameter model within S. japonica and S. sinica were 0.002 and 0.000, respectively; and the mean genetic distance between S. japonica and S. sinica was 0.211. The NJ tree revealed that all 7 Sillago species formed monophyletic groups. This study classified the Sillago species in the coastal waters of Zhejiang, and reinforced the validity of DNA barcoding on classification of Sillago species based on CO Ⅰ gene.