Miya M, Nishida M
Department of Zoology, Natural History Museum and Institute, Chiba, Japan.
Mol Phylogenet Evol. 1998 Aug;10(1):11-22. doi: 10.1006/mpev.1997.0479.
A portion of mitochondrially encoded 12S and 16S ribosomal RNA genes were sequenced from all four valid species of the midwater deep-sea fish genus Sternoptyx (Teleostei: Sternoptychidae) and four sternoptychid outgroup taxa. Secondary structure-based alignment resulted in a character matrix consisting of 865 bp of unambiguously aligned, combined sequences of the two genes, which were subjected to phylogenetic analyses using the maximum parsimony and maximum likelihood methods. The resultant tree topologies from the two methods were congruent and supported by various tree statistics. Although the single most parsimonious tree was not statistically different from the two second parsimonious trees, independent morphological evidence from the anal fin pterygiophore configuration and associated structures strongly supported the former as the preferred hypothesis. Mapping of the contemporary geographic distribution patterns of the four species onto the tree suggested that there was a common ancestor of Sternoptyx with a circumglobal distribution, which had been subdivided into southern and northern ancestral populations along 30 degrees S, possibly through some large-scale oceanographic event. There has been no discernible speciation event in the southern population, though the northern population has subsequently speciated into three contemporary species with largely allopatric/microallopatric distributions.
对深海鱼类星光鱼属（硬骨鱼纲：星光鱼科）的四个有效物种以及四个星光鱼科外类群分类单元的线粒体编码12S和16S核糖体RNA基因的一部分进行了测序。基于二级结构的比对产生了一个字符矩阵，该矩阵由两个基因明确比对后的865 bp组合序列组成，使用最大简约法和最大似然法对其进行系统发育分析。两种方法得到的树形拓扑结构是一致的，并得到各种树形统计的支持。虽然单一最简约树与第二简约的两棵树在统计上没有差异，但来自臀鳍鳍担骨构型和相关结构的独立形态学证据强烈支持前者为首选假说。将这四个物种的当代地理分布模式映射到树上表明，星光鱼有一个分布在全球的共同祖先，它可能通过一些大规模海洋学事件，沿着南纬30度被细分为南部和北部祖先种群。南部种群没有明显的物种形成事件，而北部种群随后分化为三个当代物种，分布主要为异域/微异域分布。
