西江来宾江段鱼类群落结构季节变化特征

Seasonal Variation Characteristics of Fish Community Structure in the Laibin Section of Xijiang River

2020年10月—2021年7月按季度对西江来宾江段鱼类群落结构进行调查,并分析其物种组成、多样性及季节变化特征。共采集鱼类3 600尾,隶属于3目12科68属92种,其中鲤科Cyprinidae鱼类最多,59种,占总物种数的64.13%;鱼类物种组成以定居性、杂食性、底层鱼类为主。各季节优势种差异较大,东方墨头鱼Garra orientalis和子陵吻[鱼叚]虎鱼Rhinogobius giurinus仅是春季优势种,唇[鱼骨]Hemibarbus labeo、银■Squalidus argentatus和点纹银[鱼句]Squalidus wolterstorffi仅是夏季优势种,伍氏华吸鳅Sinogastromyzon wui和莫桑比克罗非鱼Oreochromis mossambicus仅是秋季优势种,■Hemiculter leucisculus、南方拟■Pseudohemiculter dispar、鲫Carassius auratus和齐氏罗非鱼Coptodon zillii仅是冬季优势种。夏季的多样性指数最高,春季最低,季节间差异不显著(P>0.05)。数量生物量比较曲线显示,西江来宾江段受到较大干扰;生物量谱法结果表明,西江来宾江段以小型鱼类为主。建议渔政部门加强管理,降低捕捞强度,修复受损鱼类栖息地,加大增殖放流力度,以保护西江来宾江段渔业资源。

The fish community structure in the Laibin Section of Xijiang River was investigated 4 times from October 2020 to July 2021,and its species composition,diversity and seasonal variation characteristics were analyzed. A total of 3 600 fishes including 92 species belonging to 68 genera,12 families and 3 orders were collected,and Cyprinidae(59 species,accounting for 64. 13% of the total species)was the most abundant. The species composition of fish were mainly sedentary,omnivorous and demersal fishes. The dominant species varied greatly among seasons,and Garra orientalis and Rhinogobius giurinus were the dominant species in spring,Hemibarbus labeo,Squalidus argentatus and Squalidus wolterstorffi were the dominant species in summer,Sinogastromyzon wui and Oreochromis mossambicus were the dominant species in autumn,and Hemiculter leucisculus,Pseudohemiculter dispar,Carassius auratus and Coptodon zillii were the dominant species in winter. The diversity index was the highest in summer and the lowest in spring,and there was no significant difference between seasons(P>0. 05). Abundance-biomass comparison curves showed that the fish in the Laibin Section of Xijiang River was greatly disturbed. The results of biomass size spectra showed that the Laibin Section of Xijiang River was dominated by small fishes. Therefore,it is suggested that fishery administration departments should strengthen the management,reduce the fishing intensity,repair the damaged fish habitat,and increase the intensity of proliferation and release to protect fishery resources in the Laibin Section of Xijiang River.