长江口中华鲟自然保护区及临近水域鱼类种类组成现状

为了解长江口中华鲟自然保护区及其临近水域鱼类种类组成的现状，2004~2008年利用底拖网、插网、定置网和刺网等多种网具对该水域的鱼类组成状况进行了较为系统的调查。共调查到鱼类105种，隶属于18目43科86属，鱼类种类组成以鲈形目和鲤形目为主；生态类型中海洋鱼类和淡水鱼类各37种，河口定居性鱼类25种，洄游性鱼类6种；鱼类种类组成处于长江下游至东海的过渡类型，鱼类食性以底栖生物、有机碎屑和浮游动物食性为主，凶猛性鱼类较少。与以往调查资料相比，调查水域鱼类物种数有所减少，一些重要的物种更是濒临绝迹。保护区水域鱼类不仅具有较高的物种多样性、河口代表性、稀有性和很高的科研价值，同时其生态系统也较为脆弱，并已受到严重威胁，保护区的保护工作显得尤为重要.

PRESENT SITUATION OF FISH SPECIES COMPOSITION IN NATURE RESERVE OF ACIPENSER SINENSIS AND ADJACENT WATERS IN THE YANGTZE RIVER ESTUARY

In order to explore the present situation of fish species composition,we surveyed fish by using bottom trawl net,tide net, stake net and gill net in Nature Reserve of 〖WTBX〗Acipenser sinensis〖WTBZ〗 and adjacent waters in the Yangtze River estuary between 2004 and 2008.A total 105 fish species were collected,belonging to 18 orders,43 families and 86 genera.The fish species composition was mainly comprised of Perciformes and Cypriniformes.Freshwater and marine ecological guilds were both 37 species,and there were 25 species of estuarine fishes and 6 species of migration fishes.The fish species composition can be regarded as a transitional type between the lower reaches of the Yangtze River and the East China Sea.Most species were benthivorous,detritivorous, zooplanktivorous,and there are few piscivorous species.Compared to the pre survey data,we found that diversity of fish species in the study area decreased to some extent,and some important species had disappeared.By the reason of diversity of species,typical character of estuarine fish fauna,uniqueness national protected fishes,highly scientific research values,and the  vulnerable ecosystem facing with serious threat,conserving Natural Reserve of 〖WTBX〗Acipenser sinensis〖WTBZ〗 in the Yangtze River estuary is very important.