Mitochondrial phylogeny of notothenioids: a molecular approach to Antarctic fish evolution and biogeography

Antarctic waters represent a unique marine environment delimited by an oceanographic barrier, the Polar Front Zone, and characterized by constant subzero temperatures and presence of sea ice. A group of teleost fish, the Notothenioidei, have adapted to these challenging environmental conditions, undergoing a remarkable diversification. In the present study a total of 798 base pairs, generated from partial sequencing of 16S and 12S mitochondrial ribosomal RNA genes, were examined in 33 notothenioid species representative of all families included in the suborder Notothenioidei. Phylogenetic trees, reconstructed on the basis of sequence data using different methods, indicate that traditional hypotheses on notothenioid systematics and biogeography might be in need of reexamination. Molecular evidence suggests that vicariant speciation could be invoked to explain the early divergence of Eleginops maclovinus, a species previously included in the family Nototheniidae, which is now proposed as ...南极海域是一类独特的海洋生境，以海洋学屏障——极锋带（Polar Front Zone）为界，其特征为常年维持零下低温且存在海冰覆盖。真骨鱼（teleost fish）下的南极鱼亚目（Notothenioidei）类群已适应这一严苛的环境条件，并经历了显著的物种辐射分化。本研究针对南极鱼亚目所有科的33个代表性物种展开分析，所用序列为通过对16S及12S线粒体核糖体RNA基因进行部分测序获得的共计798个碱基对。基于序列数据采用多种方法重构的系统发育树显示，有关南极鱼亚目分类学与生物地理学的传统假说或需重新审视。分子证据表明，可借助异地物种形成（vicariant speciation）假说来解释裸南极鱼（Eleginops maclovinus）的早期分化——该物种此前被归入南极鱼科（Nototheniidae），如今则被提议作为...