斑纹薄鳅(Leptobotia zebra)应该为斑纹沙鳅(Sinibotia zebra)

斑纹薄鳅(Leptobotia zebra)最初是由Wu(1939)描述的一个新种,当时定名为斑纹沙鳅(Botia zebra),后来Chen(1980)根据眼下刺不分叉将其改归为薄鳅属的物种。本研究通过对线粒体DNA细胞色素b基因序列的测定和分析,发现斑纹薄鳅和薄鳅属(除斑纹薄鳅)物种间的平均遗传距离为0.177,和中华沙鳅属物种美丽沙鳅(Sinibotia pulcher)的平均遗传距离仅为0.057。系统发育分析发现斑纹薄鳅并未和薄鳅属的物种聚在一起,而是和中华沙鳅属物种美丽沙鳅聚在一起形成姐妹群。进一步对斑纹薄鳅进行形态学特征检视,发现该物种具有颊部裸露无鳞、颏部具一对纽状突起等中华沙鳅属鱼类的特征,但又具有眼下刺简单不分叉的薄鳅属鱼类的特征。结合分子数据分析的结果,将斑纹薄鳅订正为中华沙鳅属的物种,其命名为斑纹沙鳅(Sinibotia zebra)。另外,对沙鳅科鱼类属的划分标准及形态特征的演化也进行了讨论。

Leptobotia zebra Should Be Revised as Sinibotia zebra (Cypriniformes: Botiidae)

Botia zebra was first described by Wu (1939) but changed to Leptobotia zebra by Chen (1980) based on the presence of the simple suborbital spine. In the present study, sequences of mtDNA cytochrome b gene were analyzed to investigate the systematic position of this species. The molecular data showed that the average genetic distance between samples of Leptobotia zebra and other Leptobotia species was 0.177, while only 0.057 between Leptobotia zebra and Sinibotia pulcher. Molecular phylogenetic analyses indicated that samples of Leptobotia zebra did not cluster with Leptobotia species, they grouped with Sinibotia pulcher forming a sister-group. Further morphological observations were performed on the holotype of Leptobotia zebra and other specimens including formalin-fixed museum specimens and newly collected alcohol-fixed ones. This species was found to bear similar diagnostic characteristics with Sinibotia, such as no scales on the cheek, a pair of button-like papillae on the chin region, and the diagnostic characteristics of Leptobotia as well, such as a simple suborbital spine. Based on both molecular and morphological data, this paper proposes that Leptobotia zebra is a species of the genus Sinibotia, and its valid name should be Sinibotia zebra. Morphological character evolution of genera in the family Botiidae was also discussed.