长江上游珍稀特有鱼类国家级自然保护区干流段鱼类组成及其多样性

2010年9-11月、2011年5-7月和9-11月、2012年5-7月在长江上游珍稀特有鱼类国家级自然保护区干流宜宾、合江及江津江段进行了4次鱼类资源调查,共采集鱼类样本27 836尾,隶属于7目17科111种(亚种),其中长江上游特有鱼类27种,产漂流性卵鱼类45种,外来鱼类6种。宜宾、合江及江津江段鱼类物种数分别为85、91及91种,宜宾与合江江段鱼类相似度指数为69.23%,合江与江津江段为71.70%,宜宾与江津江段为77.78%。铜鱼(Coreius heterodon)、南方鲇(Silurus meridionalis)、长鳍吻(Rhinogobio ventralis)及圆口铜鱼(C.guichenoti)为保护区干流主要经济鱼类,产漂流性卵鱼类占渔获物总重量的66.35%。鱼类Shannon-Wiener多样性指数在4次调查中江津江段均最高,宜宾次之,合江最低,但三江段之间多样性指数均无显著性差异(P>0.05)。与历史资料相比,该江段鱼类资源明显减少,急需加强保护措施。

Diversity and composition of fish in the mainstream of national nature reserve of rare and endemic fish in the upper Yangtze River

The composition and distribution of fish was investigated in Yibin,Hejiang and Jiangjin section of the mainstream of National nature reserve of rare and endemic fish in the upper Yangtze river for 4 times during September to November of 2010,May to July and September to November of 2011 and May to July of 2012.27836 fish samples belonging to 7 orders,17 families,111 species were collected.In these species,27 species were endemic to the upper reaches of the Yangtze River,45 species were those that spawn drifting eggs and 6 species were exotic fish.85,91 and 91 species were found in Yibin,Hejiang and Jiangjin section respectively.The Jaccard' s similarity indices were 69.23% between Yibin and Hejiang section,71.70% between Hejiang and Jiangjin section,and 77.78% between Yibin and Jiangjin section.Coreius heterodon,Silurus meridionalis,Rhinogobio ventralis and Coreius guichenoti were the main commercial species captured in the reserve area,and the fish which spawn drifting eggs accounted for 66.35% of weight of fishery catches.The Shannon-Wiener diversity index of Jiangjin section was the highest in every survey,Yibin section was middle and Hejiang section was the lowest.However,there was no significant difference of the Shannon-Wiener diversity index among the three sections(P>0.05).Compared with the historical data,the current fish resources in the upper mainstream of the Yangtze River decreased obviously,thus the protection measures of fish in the Yangtze River should be urgently enhanced.