Vol. 45 No. 2, 2006

Molecular Identification of Two Sibling Species of Puntius in Taiwan

Chia-Hao Chang1, Yi-Ta Shao2, and Hsiao-Wei Kao1,*

¹Department of Life Science, National Chung Hsing University, Taichung, Taiwan 402
²Institute of Cellular and Organismic Biology, Academia Sinica, Nankang, Taipei, Taiwan 115

Chia-Hao Chang, Yi-Ta Shao, and Hsiao-Wei Kao (2006) Puntius fish from Taiwan and South China were collected and analyzed. Specimens from the northern and central Taiwan were characterized by the absence of barbels. On the contrary, specimens from the southern Taiwan and South China were characterized by the presence of barbels. These characteristics morphologically match P. snyderi and P. semifasciolatus respectively (Oshima 1919). We hypothesized that there were two species of Puntius in Taiwan. To test this hypothesis, we amplified and sequenced the cytochrome b gene from fish specimens of China and Taiwan. Phylogenetic analysis revealed the existence of two major clades of Puntius fishes with an average genetic distance of 0.12 between them. The fish specimens from southern Taiwan were clustered with P. semifasciolatus of China, but fish specimens from northern and central Taiwan were clustered together. The estimated evolutionary rate of cytochrome b gene for Puntius was 0.368% per million yrs (MY). Thus the divergence time between P. snyderi and P. semifasciolatus was about 26.93 million years ago (MYA) and the divergent time between Taiwan's and China's P. semifasciolatus was about 4.40 MYA. Taken together, our results supported the existence of two species of Puntius fishes in Taiwan. P. snyderi is distributed in northern and central Taiwan, while P. semifasciolatus is in southern Taiwan.

Key words: Cytochrome b gene, Freshwater fish, Molecular clock, Phylogenetic tree.

*Correspondence: Tel: 886-04-22840416 ext. 111 or 112. E-mail: hkao@dragon.nchu.edu.tw