太湖五里湖仔稚鱼时空分布特征

SPATIAL AND TEMPORAL DISTRIBUTIONS OF FISH LARVAE AND JUVENILES IN LAKE WULI, LAKE TAIHU

  • 摘要: 为探究五里湖仔稚鱼群落结构及分布特征,于2016年4—10月对五里湖仔稚鱼进行系统调查。期间共采集仔稚鱼70678尾,共鉴定出鱼类20种(属),隶属于7目8科18属。五里湖仔稚鱼密度均值为3825尾/100 m3,主要优势种为䱗属(Hemiculter sp.),其数量占比为68.76%。五里湖仔稚鱼主要采集于4—8月,密度高峰期为6月,各物种密度高峰期存在差异,最早的为鲤(Cyprinus carpio)、鲫(Carassius auratus,4月),最晚的为短吻银鱼属(Salangichthys sp.,8—9月)。五里湖仔稚鱼分布具有显著的空间差异,沿岸带仔稚鱼密度显著高于(P<0.05)敞水区,密度分别为5650和310尾/100 m3。西五里湖仔稚鱼的密度高于东五里湖,密度分别为4482和3600尾/100 m3。典范对应分析结果显示,水温、溶解氧、浮游植物和浮游动物密度是与仔稚鱼分布显著相关的环境因子(P<0.05)。研究结果显示,五里湖鱼类主要繁殖期为4—8月,主要产卵和育幼水域为沿岸带,其中西五里湖的育幼功能优于东五里湖,因此进一步维持对西五里湖的生境保护,加强东五里湖沿岸带植被恢复及入湖支流水质监控,控制外源污染物,对促进五里湖生境优化及鱼类资源自然增殖具有积极意义。

     

    Abstract: To explore the scale and distribution characteristics of fish larvae and juveniles, a systematic investigation was conducted in Lake Wuli from April to October 2016. A total of 70678 larvae and juveniles were collected, and 20 species of larvae and juveniles from 18 genera, 8 families, and 7 orders were recorded. The density of annual average larvae and juveniles in Lake Wuli was 3825 ind./100 m3, and Hemiculter sp. was dominant throughout the year. Based on the temporal density variation, the spawning period in Lake Wuli lasted from April to August, and the peak spawning month was June. The dominant species changed monthly: the earliest were Cyprinus carpio and Carassius auratusatus (April), and the latest was Salangichthys sp. (August to September). Significant spatial differences in the distribution of larvae and juveniles were observed in Lake Wuli. The density of larvae and juveniles in the coastal zone was significantly higher than that in the pelagic zone, with densities of 5650 ind./100 m3 and 310 ind./100 m3, respectively. The density in eastern Wuli Lake was lower than that in the west, with densities of 3600 ind./100 m3 and 4482 ind./100 m3, respectively. Canonical correspondence analysis indicated that water temperature (WT), dissolved oxygen (DO), and phytoplankton and zooplankton abundances were strongly correlated with the distribution characteristics of larvae and juveniles. The study showed that in Lake Wuli, the main breeding period of fish is from April to August, and the main spawning and parenting waters are coastal belts. Additionally, the results determined that the breeding function of western Wuli Lake is better than that of eastern Lake Wuli. Therefore, further maintaining the habitat protection of western Lake Wuli, enhancing the vegetation restoration in the coastal area of eastern Wuli Lake, and improving water quality monitoring of the tributaries in the lake, and controlling the external pollutants are of great importance for habitat optimization and natural proliferation of fish resources in Wuli Lake.

     

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