长江芜湖江段鱼类多样性及其群落结构的时空格局

为制定合理的渔业资源保护措施与管理对策,2009年按季度共4次调查了长江芜湖江段鱼类多样性及其群落结构。结果显示:该江段现有鱼类54种,其中以似鳊(Parabramis pekinensis)、油(Hemiculter bleekeri bleek-eri warpacho)、短颌鲚(Coilia brachygnathus Kreyenberg et Pappenheim)、鲫(Carassius auratus)等中小型鱼类为常见种和优势种,表明了该江段的鱼类组成存在明显的小型化特点。长江干流沿岸浅水区的鱼类多样性最高,江心深水区最低,而青弋江支流、漳河支流和漳河河口的居中,青弋江的鱼类种数和个体数都显著低于沿岸浅水区,但漳河的鱼类数量与沿岸浅水区无明显差异。江心深水区的鱼类群落与其它样点明显不同,而青弋江的鱼类群落与沿岸浅水区、漳河及其河口的鱼类群落也存在部分差异。鱼类群落结构的季节动态无显著性。

Spatial and temporal patterns of fish diversity and assemblage structures in the Wuhu section of the Yangtze River

Identifying the spatial and temporal variations in fish assemblages is basic for fishery resource conservation and management.In this study,fish diversity and their assemblage structures in the Wuhu section of the Yangtze River were investigated seasonally during 2009.A total of 54 fish species were collected,of which the common and dominant species were Pseudobrama simony,Hemiculter bleekeri,Carassius auratus,Coilia brachygnathus,and so on,suggesting the miniaturization of fish species composition in this area.The highest species diversity was observed in the riparian shallow site of the mainstem,while the lowest diversity was in the middle deep site.Fish species and abundance in the Qingyijiang tributary were significantly lower than those in the riparian site of the mainstem,but no significant difference was observed between the Zhanghe tributary and the riparian site.The assemblage structures in the middle deep site of the mainstem were substantially different from those in other sampling sites,and an obvious separation in assemblage structures was observed between the Qingyijiang tributary and other sites.However,fish diversity and assemblage structures in the Wuhu section did not show significant variations across seasons.