Saitoh Kenji, Miya Masaki, Inoue Jun G, Ishiguro Naoya B, Nishida Mutsumi
Tohoku National Fisheries Research Institute, Shinhama, Shiogama 985-0001, Japan.
J Mol Evol. 2003 Apr;56(4):464-72. doi: 10.1007/s00239-002-2417-y.
Ostariophysi is the second largest superorder within Teleostei. It contains five orders: Gonorynchiformes, Cypriniformes, Characiformes, Siluriformes, and Gymnotiformes. Resolving the higher-level relationships among ostariophysan and related fishes will aid in resolving basal teleostean divergence and provide basis to historical biogeographic analysis of major freshwater fish groups. In this study, we report the complete mitochondrial (mt) DNA sequences for eleven ostariophysan fishes and the results of phylogenetic analyses including these species plus four other ostariophysan and nine non-ostariophysan teleostean fishes. Maximum likelihood and maximum parsimony analyses reconfirmed clupeiforms as the closest relatives of ostariophysans. However, gonorynchiforms were closer to clupeiforms than to otophysans (ostariophysan groups excluding gonorynchiforms), thus raising a question over the current definition of Ostariophysi. The lack of clarity in otocephalan (ostariophysans + clupeiforms) basal relationships implies that such divergence took place over a short period of time. The monophyly of cypriniforms, characiphysans (characiforms, siluriforms, and gymnotiforms), and orders or superorders outside the ostariophysans examined here were conceivably reconstructed. The phylogenetic hypothesis suggests a Pangean origin of otophysans. Within characiphysans, gymnotiforms and siluriforms have independent evolutionary origins and evolutionary histories comparable to or older than that of characiforms. This helps to explain the present geographic distribution of characiphysans.
骨鳔鱼类是硬骨鱼纲中第二大的总目。它包含五个目：鼠鱚目、鲤形目、脂鲤目、鲇形目和电鳗目。解析骨鳔鱼类及相关鱼类之间的高级别关系将有助于解决硬骨鱼基部类群的分化问题，并为主要淡水鱼群的历史生物地理学分析提供依据。在本研究中，我们报告了11种骨鳔鱼类的完整线粒体（mt）DNA序列，以及包括这些物种加上另外4种骨鳔鱼类和9种非骨鳔鱼类硬骨鱼的系统发育分析结果。最大似然法和最大简约法分析再次确认鲱形目是骨鳔鱼类最近的亲属。然而，鼠鱚目与鲱形目的关系比与骨鳔鱼类（不包括鼠鱚目的骨鳔鱼类类群）的关系更近，因此对当前骨鳔鱼类的定义提出了质疑。骨鳔总目（骨鳔鱼类+鲱形目）基部关系不明确意味着这种分化发生在短时间内。鲤形目、骨鳔次亚目（脂鲤目、鲇形目和电鳗目）以及此处所研究的骨鳔鱼类之外的目或总目的单系性可以想象地被重建。系统发育假说表明骨鳔鱼类起源于泛大陆。在骨鳔次亚目内，电鳗目和鲇形目有独立的进化起源，其进化历史与脂鲤目相当或比脂鲤目更古老。这有助于解释骨鳔次亚目的当前地理分布。
