作　　者： ; ; ; ;

机构地区： 中国科学院水生生物研究所

出　　处： 《水生生物学报》 2010年第6期1172-1178,共7页

摘　　要： 2008年4月7日在长江上游重庆江津-珞璜31 km的江段采用标志物对自然条件下大流量河流漂流性鱼卵的漂流方式进行模拟实验。结果显示在流量稳定的情况下,在同一投放点投放的标志物的平均漂流速度具有显著差异,标志物在河流中的漂流密度以高峰值和低峰值相间的方式出现,高峰值随漂流时间的增加呈逐渐下降趋势。在水平方向上标志物的分布以主流水域的漂流密度高于缓流水域,缓流水域未采集到标志物。采用传统产卵规模计算方法对标志物投放数量进行估算,各组的估算数量均小于实际投放数量,估算数量的准确性随漂流时间的增加而降低,总体估算数量为实际投放数量的16.6%。根据实验结果,建议在长江上游鱼类产卵规模计算中引入时间系数以弥补随漂流时间的增加而引起的估算准确性降低。 Investigation of fish early life history is an important technique to calculate spawning sites and estimate spawning size for fish with drifting eggs.But,drift patterns of drifting eggs are greatly different for the diverse hydrological condition in different river reach.The drift pattern of drifting fish eggs was studied in this experiment with drifting tracers,and the classic estimate method of spawning size was tested to evaluate the applicability in upper Yangtze River.The experiment was conducted in the 31 km river reach in the upper Yangtze River from Jiangjin city to Luohuang town on 7th April 2008.A total of 485800 tracers were separated into 6 groups and dyed into red,green,white,black,blue and yellow respectively,the total number of tracers of every group was 80966,80968,80966,80966,80968 and 80966 in turn.Two releasing sites were set up to test the influence of configuration of river channel on the drifting speed.A total of 58 tracers were collected in the collecting site.The results showed that the mean drifting speeds of tracers released in the same releasing site were significantly different.Drift density of tracers showed a pattern of alternate with peak and low density,and the peak density showed gradual decline as drift time increase.All the 58 tracers were collected in the main stream,it reflected that drift density in the main stream was higher than the slow flow region.So we advise the main stream should be surveyed in the fish early life history investigation.Mean drifting speeds were 1.19 m/s,1.03 m/s,1.05 m/s and 1.22 m/s for red,green,white and black tracers respectively.There was no significantly difference for mean drifting speeds released in the two releasing sites.Estimated releasing numbers of red,green,white and black tracers were 8356,11141,12533 and 48741,and corresponding for 10.3%,13.8%,15.5% and 60.2% of the total number released respectively,so the accuracy of estimation showed greatly declining as drift time increasing.No blue and yellow tracers were collected for the low drif

关 键 词： 长江上游 标志物 漂流性鱼卵 漂流方式 产卵规模

领　　域： [农业科学] [农业科学]