Zoological Studies

Vol. 40 No. 2, 2001

Phylogeny of the Specialized Schizothoracine Fishes (Teleostei: Cypriniformes: Cyprinidae)

Zi-Ming Chen1,2 and Yi-Feng Chen1,*

1Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, China
2Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan 650223, China

Zi-Ming Chen and Yi-Feng Chen (2001) To elucidate phylogenetic relationships within the specialized schizothoracine fishes, we used 41 variable osteological and external characters among this groups, three species of Schizothorax, and 1 fossil species. When the 3 species of Schizothorax were desig- nated as an outgroup and all 41 characters were set as unordered with equal weighting, the data matrix yielded a single most-parsimonious tree with a tree length of 71 steps, a consistency index of 0.6761, and a retention index of 0.7416. Meanwhile, a bootstrap test was conducted to verify the reliability of the results. The matrix was also analyzed for different conditions: all characters were ordered and the fossil species was added as an outgroup. The phylogenetic analyses presented herein support the following hypotheses. 1) All species of the specialized schizo-thoracines fishes form a monophyletic group. 2) Monophyly of the genus Ptychobarbus is not supported by the bootstrap test or when these characters are ordered. 3) The genus Gymnodiptychus forms a monophyletic group. 4) All species of Ptychobarbus and Gymnodiptychus form a monophyletic group with Diptychus as its sister group.

Key words: Cyprinidae, Specialized schizothoracine fishes, Character analysis, Phylogenetic relationships, Tibetan Plateau.

*Correspondence: Tel: 86-27-87647725. Fax: 86-27-87875132. E-mail: chenyf@ihb. ac.cn