洞庭湖水系资江干流鱼类资源现状调查

资江作为洞庭湖一级支流，对洞庭湖乃至长江水系鱼类资源的维持或补充有着重要作用。为了解资江的鱼类资源现状，于2010年11月～2012年12月对湖南境内资江干流鱼类资源进行调查。共采集鉴定鱼类82种（包括1种湖南鱼类新纪录，2种引进种），隶属7目18科52属。种类组成以鲤科鱼类为主，占48．78％。鱼类物种数按上、中、下游依次增加，分别为52种、73种和77种，其中上游与中、下游之间鱼类群落为中等相似，中游与下游鱼类群落为极相似。资江鱼类在洄游、摄食、栖息习性等生态类型上呈现多样化特征。调查江段渔获物组成虽存在差异，但主要以鲫（ Carassius auratus ） 、鲤（Cyprinus carpio ）、蟹（ Hemiculter leucisculus） 、翘嘴鲐（Culteralburnus）、蒙古铂（emongolicus）、蛇绚（Saurogobiodabryi）、鲇 （ Silurus asotus ） 和黄颡鱼（ Pelteobagrus fulvidraco ） 等湖泊定居性鱼类为主，“四大家鱼”等洄游性鱼类所占比例极低，鱼类小型化现象明显。

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

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. rrugngolicus, Saurogobio dabryi, Silurus asotu3 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.