An observation of the loss of genetic variability in prenant’s schizothoracin, Schizothorax prenanti, inhabiting a plateau lake

Prenant’s schizothoracin (Schizothorax prenanti) was found naturally distributed in a plateau lake (Lake Wuxu) in upper reaches of the River Jiulong. The genetic diversities of the populations from L. Wuxu and R. Jiulong were investigated according to analysis of mtDNA control region and compared against three other reported river populations. The L. Wuxu population showed lower haplotype (h = 0.74) and nucleotide (π = 0.001) diversities compared to the R. Jiulong population (h = 0.87; π = 0.012); the lake population had suffered from a bottleneck, which might contribute to its low genetic diversity; the lake population significantly differentiated from the river populations, and significant gene flow was hardly found between river populations and L. Wuxu population, suggesting that there is a strong population structure between the lake and river populations. The L. Wuxu population was ecologically isolated from the R. Jiulong population, while the relatively low genetic variability had not affected its viability.