大宁河龙溪段鱼类早期资源研究

为了解十年禁渔背景下大宁河鱼类早期资源变化状况，2020和2021年5-7月在大宁河龙溪断面开展了鱼类早期资源现状的调查。结果表明，龙溪江段产浮性卵鱼类1种、漂流性卵鱼类4种、粘沉性卵鱼类19种；中华纹胸鮡（Glyptothorax sinensis）和大眼鳜（Siniperca kneri）的产卵规模相对较大,其卵占比分别达48%和30%以上；2020年的鱼类卵苗资源量和种类都少于2021年。RDA分析结果显示，中华纹胸鮡（Glyptothorax sinensis）、张氏?(Hemiculter tchangi)鱼卵漂流密度与水温变化呈现一定相关性，适宜水温促使中华纹胸鮡（Glyptothorax sinensis）、张氏?(Hemiculter tchangi)产卵；随着流速和流量增加，多鳞白甲鱼(Scaphesthes macrolepis)和云南盘鮈(Discogobio yunnanensis)卵漂流密度均相应增加；大眼鳜（Siniperca kneri）和峨眉后平鳅(Metahomaloptera omeiensis)产卵期间江水酸碱度相对较低。十年禁渔的实施对大宁河鱼类资源的恢复可能产生积极影响。

Study on the Status of the Early-Stage Fish Resources in the Longxi Section of the Daning River

In order to understand the status of early-stage fish resources in the Daning River under the background of a 10-year fishing ban, investigations were conducted on the current status of early-stage fish resources in the Longxi section of the Daning River from May to July 2020 and 2021. The results show that there ware 1 fish species with pelagic?eggs, 4 fish species with?drifting fish eggs, and 19 fish species with sticky and demersal eggs in the Longxi River section. The spawning scale of Glyptothorax sinensis and Siniperca kneri is relatively large, and the resource and species of fish eggs and larvae in 2020 were lower than those in 2021. The RDA analysis results show that there is a certain correlation between the drift density of Glyptothorax sinensis and Hemiculter tchangi eggs and changes in water temperature. The suitable water temperature promotes the spawning of Glyptothorax sinensis and Hemiculter tchangi ; As the Velocity and flow increase, the drift density of the eggs of Scaphesthes macrolepis and Discogobio yunnanensis both correspondingly increases; The acidity and alkalinity of the river water are relatively low during the spawning period of Siniperca kneri and Metahomaloptera omeiensis; The implementation of a ten-year fishing ban has had a positive impact on the recovery of fish resources in the Daning River.