Present address: School of Biology, Georgia Institute of Technology, Atlanta 30332, GA, USA.
The youngest split in sympatric schizothoracine fish (Cyprinidae) is shaped by ecological adaptations in a Tibetan Plateau glacier lake
Article first published online: 7 AUG 2009
© 2009 Blackwell Publishing Ltd
Volume 18, Issue 17, pages 3616–3628, September 2009
How to Cite
ZHAO, K., DUAN, Z. Y., PENG, Z. G., GUO, S. C., LI, J. B., HE, S. P. and ZHAO, X. Q. (2009), The youngest split in sympatric schizothoracine fish (Cyprinidae) is shaped by ecological adaptations in a Tibetan Plateau glacier lake. Molecular Ecology, 18: 3616–3628. doi: 10.1111/j.1365-294X.2009.04274.x
Kai Zhao and Ziyuan Duan made equal contributions to this study.
Kai Zhao and Ziyuan Duan is interested in molecular evolution and biogeography of animals, with special interests in speciation and the adaptive evolution. The research group of Xinquan Zhao, Shunping He, and Zuogang Peng focuses on the animal ecology and population biology.
- Issue published online: 20 AUG 2009
- Article first published online: 7 AUG 2009
- Received 11 December 2008; revision received 7 May 2009; accepted 14 May 2009
- mitochondrial control region and cytochrome b;
- Pleistocene glaciations;
- schizothoracine fish;
- Tibetan Plateau
Although new empirical evidence shows that sympatric speciation has occurred in some species, there are few indisputable model organisms for this process of speciation. The two subspecies (Gymnocypris eckloni eckloni and G. e. scoliostomus) of the schizothoracine Gymnocypris fish species complex from a small glacier lake in the Tibetan Plateau, Lake Sunmcuo, fit several of the key characteristics of the sympatric speciation model. We used combined mitochondrial control region sequences and the cytochrome b gene (1894 bp) to address the phylogenetics and population genetics of 232 specimens of G. e. eckloni and G. e. scoliostomus, as well as all of its closely related sister species. We found that: (i) a total of four old lineages were uncovered in the widespread G. e. eckloni, of which only one was shown to be shared with all G. e. scoliostomus individuals and (ii) the new subspecies (G. e. scoliostomus) evolved in Lake Sunmcuo from the ancestral G. e. eckloni population within approximately 0.057 Ma. These two taxa of the species complex are morphologically distinct, and reproductive isolation is further suggested. Ecological disruptive selection based on morphological traits (e.g. mouth cleft characters) and food utilization may be a mechanism of incipient speciation of two sympatric populations within Lake Sunmcuo. This study provides the first genetic evidence for sympatric speciation in the schizothoracine fish.