Studies On Biology And Genetic Diversity Of Two Endemic Fishes In Lakes Of Yunnan Plateau

The native fishes of Lake Fuxian, Spinibarbus yunnanensis, and Sinocyclocheilus tingi were selected as the experimental fishes in this paper. Age, growth and reproduction of S. yunnanensis and S. tingi in Lake Fuxian were investigated. 454 bp DNA sequences of mitochondrial D-loop gene were sequenced from 33 samples of S. tingi and 175 samples of Sinocyclocheilus grahami to analyse their genetic diversity. Fish species composition in seven Lakes of the Yunnan Plateau from 1990s to 2004 were compared to investigate variation and reasons for endangered native fishes. The main results were following:1. The ages of S. yunnanensis can be identified through the characteristics of the annual rings of the scales, otoliths and dorsal fin spines. The annul rings are formed once a year, mainly from October to March. The formation of false annuli, which regularly arose on scales and dorsal fin spines during the juvenile stage, may be caused by shift diet during development. The relationship of body weight to total length for all samples is W=9×10-6TL3.0424. The Von Bertalanffy growth equation for all samples is Lt=950.573[1-e-0.105(t+0.218)],Wt=10352.83[1-e-0.105(t+0.218)] 3.0424. Compared with other Spinibarbus, growth of S. yunnanensis is slower. The apparent stunted growth of the S. yunnanensis in Fuxian Lake may indicate the extreme oligotrophic conditions, commercial over-fishing, or both.2. The ages of S. tingi can be identified through the characteristics of the annual rings of the scales and dorsal fin spines. But the scales are unsuitable for age identification for samples 6 years or older. The annul rings are formed once a year, mainly from March to May. The relationship of body weight to total length for all samples is W=2×10-6TL3.3257. The Von Bertalanffy growth equation for all samples is...