Survey on status of fish resources in mainstream of Zijiang River of Dongting Lake water system

Abstract

As one of the important branches in Dongting Lake water system, Zijiang River is important in maintaining or making up for the fish resources of Dongting Lake and even Yangtze River. We conducted a survey on the present status of fishery resources in Zijiang River during November, 2010 to December, 2012, having collected 82 fish species which belong to 7 orders, 18 families and 52 genera. Cyprinids were dominant, accounting for 48. 78% of the total species. The numbers of species found in the upstream, mid- stream and downstream were 52, 73 and 77, respectively; the fish communities in the upper section were highly similar to those in the middle and lower sections, and those in the middle and lower sections were extremely similar. The fish communities in Zijiang Riv- er were diversified in migratory, feeding and perching habit. Despite the catch compositions in various sections were different, the main species were lake-settlement fishes such as Carassius auratus, Cyprinus carpio, Hemiculter leucisculus, Culter alburnus, C. mongolicus, Saurogobio dabryi, Silurus asotus and Pelteobagrus fulvidraco, etc. ; the ratio of migratory species such as four major Chinese carps was extremely low, and the commercial fishes showed significant miniaturization.