淠河流域河源溪流鱼类空间分布格局及主要影响因素

Fishes in headwater streams of the Pihe River Basin: Spatial distribution pattern and its main influencing factors

淠河是安徽省内淮河右岸最大的支流,也是淮河中游重要的水源地.为了解淠河流域河源溪流鱼类的空间分布格局及其主要影响因素,本研究于2015年4—5月对6条河源溪流鱼类及其环境因子进行了调查.研究结果表明,6条溪流共采集鱼类19种,其中杂食性种类占57.9%,肉食性和植食性种类分别占26.3%和15.8%.所有种类中,宽鳍鱲(Zacco platypus)是主要优势种,绿太阳鱼(Lepomis cyanellus)为研究区域首次报道的外来入侵种.就6条溪流各样点的平均值而言,淠河西部3条溪流鱼类种类数及个体数均明显高于东部3条溪流,但重量却并没有类似趋势.Sorensen相似性分析表明,6条溪流鱼类组成具有较高相似性,且相对较小值主要位于高、低海拔溪流之间.除趋势对应分析二维空间排序与相似性分析结果一致.Pearson相关分析表明,影响鱼类种类数的主要是局域栖息地参数(包括海拔、流速、底质、水深、河宽和电导率)和溪流的空间位置参数(溪流级别、流量量级和下游量级);影响鱼类个体数和重量的均仅有局域栖息地参数中的底质因素.本研究结果可为淠河流域鱼类的保护和管理提供重要的基础资料.

Pihe River is not only the largest tributary on north bank of the Huaihe River in Anhui Province, but also the important water source area in middle reaches of the Huaihe River. To determine the spatial distribution pattern of fish community and its influenced factors, a field investigation was conducted in six headwater streams of the Pihe River Basin from April to May, 2015. The results showed that （1） a total of 1762 individuals were collected and identified as 19 species representing 7 families in the six headwater streams. Among them, the omnivore species is accounted for 57.9% of the total species, while the carnivore and herbivore only comprised 26.3% and 15.8%, respectively. Zacco platypus was the main dominant species with an index of relative importance of 2471.94. Lepomis cyanellus was the first reported exotic invasion species in this basin. （2） As for the average value per site of the six streams, the species number and individual number of the three west headwater streams were obviously higher than those of the three east headwater streams, but such a tendency was not found as for the weight of fish. （ 3 ） Sorensen similarity analyses showed that great similarity of the fish species was detected among the six streams, and there was the relative smaller similarity between high and low altitudes of streams. The detrended correspondence analysis ordination of the six streams was further examined for the accuracy of similarity analyses. （4） Pearson correlation indicated that the fish species number had significantly correlated with local habitat parameters （including altitude, velocity, substrate type, water depth, water wide, and conductivity） and with spatial location parameters （including stream order, link, and D-link）. However, the individual number and fish weight were only significantly correlated with the river substrate type of the local habitat parameters. The results of this study can provide important basic data for the protection and management of fish resources in Pihe River Basin.