三峡库区重要支流鱼类多样性初探

为了解三峡库区重要支流鱼类多样性情况，于2015年和2016年对三峡库区36条支流各进行了一次调查。长度〖JP〗小于50 km的河流设置4个调查断面，长度为50～100 km的河流设置6个调查断面、长度为100～300 km和超过1 000 km的河流均设置8个调查断面。共统计渔获物685.5 ，测量鱼类标本 35 507 尾，鉴定鱼类121种，分属于9目22科78属，种类组成以鲤形目及鲤科为主，其中中国特有种68种，长江上游特有种26种，外来物种9种。小江渔获物种类、中国特有种和长江上游特有种都最多，其次为綦江。研究表明：该区域鱼类以产粘性卵和底栖为主，食性以肉食性和杂食性为主；按照河流的长度分为4组，长度超过 1 000 km 的河流与另外3个河流长度组的平均分类差异指数（Δ+）有显著性差异（P<0.05），各河流长度组分类差异变异指数（Λ+）无显著性差异（P>0.05），Δ+和Λ+与河流长度无显著性相关性（P>0.05）；库区支流主要经济鱼类是鲤（Cyprinus carpio）、鲫（Carassius auratus）和光泽拟鲿（Pseudobagrus nitidus）。建议严防引进种逃逸，加大对珍稀特有鱼类的基础生物学研究，特别是人工繁殖工作，将对支流鱼类多样性保护发挥重要作用。

A Preliminary Study on Fish Diversity for Some Important Branches of Three Gorges Reservoir

In order to learn the fish diversity in some important branches of Three Gorges Reservoir, the investigation was carried out in the 2015 and 2016 respectively. All important branches can be divided into 4 types: <50 km, 50-100 km,100-300 km, and >1 000 km, and each of them was set to 4, 6, 8, 8 sampling sections respectively. A total of 685.5 kg catches was captured and 35507 samples were measured, 121 species of fish were identified, belonging to 9 order, 22 family and 78 genus, and Cypriniformes and Cyprinidae were the dominated order and family in this research, 68 species were endemic to China, 26 species were endemic to the upper reaches of the Yangtze River, and 9 species were exotic species. The number of total and endemic fish species to China and the upper reaches of the Yangtze River in Xiaojiang River were the largest compared to other rivers, and the Qijiang River followed. The investigation results showed that fish ecological types were mainly viscous eggs, benthic fishes, carnivorous and omnivorous in the study area; there were significant differences in the average taxonomic distinctness Δ+ between rivers greater than 1000 km and others by using t-tests (P<0.05), there were no significant differences in the variation in taxonomic distinctness Λ+ among 4 types of rivers with t-tests (P>0.05), and indicated that there were no significant correlations between Δ+, Λ+ and river length using Pearson correlation test (P>0.05); the main economic fish species included Cyprinus carpio, Carassius auratus, and Pseudobagrus nitidus. In conclusion, taking measures such as prevention introduced species escape and study on artificial reproduction of rare fish should be benefit for protecting fish diversity resources.