九龙江口春秋季鱼类种类组成及数量分布特征

根据2013年春季（4月）和秋季（11月）在九龙江口开展的鱼类资源调查资料，分析该海域鱼类的种类组成、区系特点和数量分布的季节变化等。调查结果显示，九龙江口春秋季鱼类有41种，隶属于11目25科35属，其中以鲈形目最多，有19种，占鱼类总种数的46.3%；调查海域鱼类适温性以暖水性种类为主（占65.9%）、分布水层以底层和近底层种类（合占85.4%）居多；春季优势种有条纹斑竹鲨（ Chiloscyllium plagiosum ）、叫姑鱼（ Johnius belengerii）、粒突鳞鲬（ Onigocia tuberculatus）和半滑舌鳎（ Cynoglossus semilaevis），秋季优势种有条纹斑竹鲨、何氏鳐（ Raja hollandi）、小眼魟（ Dasyatis microphthalmus）、凤鲚（ Coilia mystus）、半滑舌鳎和焦氏舌鳎（ Cynoglossus joyneri），春秋季优势种均以经济鱼种为主。调查海域春秋季的鱼类渔获率分别为4.85 kg/h和6.40 kg/h。春秋季的鱼类生物量均以峿屿岛附近海域为高。

Species composition and quantitative distribution of fishes in spring and autumn in Jiulongjiang Estuary

Based on the data of fish resource survey from Jiulongjiang Estuary in spring （ April） and autumn （November） 2013, the fish species composition, floristic characteristics and quantitative distribution were analyzed. The results showed that there were 41 kinds of fishes in Jiulongjiang Estuary in spring and autumn, belonging 11 orders, 25 families and 35 genera, in which fishes in Perciformes were most, accounfed for 46. 3% in total species. The warm waters fishes accounted for 65. 9%, and the demersal and near-benthic fishes together accounted for 85. 4% in survey waters. The dominant species were Chiloscyllium plagiosum、Johnius belengerii、 Onigocia tuberculatus and Cynoglossus semilaevis in spring, the ones were Chiloscyllium Plagiosum. Raja hollandi、 Dasyatis microphthalmus、 Coilia mystus、 Cynoglossus semilaevis and Cynoglossus joyneri in autumn, and the dominant species were mainly economic fish both in spring and autumn. The fish catch rate in survey waters in spring and autumn were 4. 85 kg/h and 6. 40 kg/h, respectively. The high val-ue areas of fish biomass were concentrated in adjacent waters of Wuyu island in spring and autumn.