Community structure of demersal fish in Nature Reserve of Acipenser sinensis in Yangtze River estuary

Chinese sturgeon,Acipenser sinensis,listed among the first class of protected animal in China,is an anadromous fish,which as present understood,is distributed in the East China Sea,Yellow Sea and the main channel of the Yangtze River.In autumn,larvae,after hatching in the upper reach of the Yangtze River,begin to swim downstream along the main channel of Yangtze River.Juveniles gradually reach the Yangtze River estuary(hereafter abbreviated as YRE) from May to June of the next year,in where juveniles spend almost 3 months on foraging and other physiological adaptation for entering into the sea.The small-sized demersal fish in YRE are the main food resource for juveniles.So,it is very important to understand the community structure and its variation feature of demersal fish in YRE for protecting this endangered species effectively.We designed 15 sampling sites(Z1-Z15) in the Nature Reserve of A.sinensis in YRE.The sampling sites are located at 121 degree 32.08'-122 degree 11.65'E,31 degree 19.58'-31 degree 38'