拉萨河流域外来鱼类的分布、群落结构及其与环境的关系

NON-NATIVE FISHES: DISTRIBUTION AND ASSEMBLAGE STRUCTURE IN THE LHASA RIVER BASIN, TIBET, CHINA

  • 摘要: 为揭示当前拉萨河流域外来鱼类的现状及其主要影响因素,于2010、2012及2014年对该流域的鱼类群落结构及水体环境进行了调查。共捕获4目6科17属25种鱼类,包括13种外来鱼类和12种土著鱼类。在42个采样点中的19个发现了外来鱼类,包括12处的湿地、6处的河流及1处水库采样点。外来鱼类基本都分布在下游,除了鲫(Carassius auratus)分布到了上游,鲤(Cyprinus carpio)、鳙(Aristichthys nobilis)和泥鳅(Misgurnus anguillicaudatus)分布到了中游。分布最广、数量最多的土著鱼类是拉萨裸裂尻鱼(Schizopygopsis younghusbandi younghusbandi)、东方高原鳅(Triplophysa orientalis)和西藏高原鳅(Triplophysa tibetana),最常见的外来鱼类为泥鳅、鲫和麦穗鱼(Pseudorasbora parva)。典范对应分析表明,该流域的鱼类群落同时受局域和区域环境因素的作用,二者对鱼类群落变异的总解释量为33.9%。海拔、圆石的比例和沙的比例与鱼类群落结构的关系最为紧密。今后应当开展外来鱼类的监控和清除工作,减少人为活动对河流生态系统的干扰,以促进该地区外来鱼类的防控工作及土著鱼类的保护。

     

    Abstract: The Lhasa River is the biggest tributary of the Yarlung Zangbo River, Tibet, China. Non-native fishes were found recently in the basin, but the distribution of non-native fishes and fish assemblage in the whole basin were poorly known. We examined fish assemblage and its relationship with the environmental factors in the basin in 2010, 2012 and 2014. 25 fish species were collected, and 13 of them were non-native fishes. Non-native fishes were distributed at 19 of 42 sampling sites, including 12 wetland sites, 6 river sites and 1 reservoirs above dam. Most non-native fishes occurred in the downstream with the exception of Carassius auratus in the upstream and Cyprinus carpio, Aristichthys nobilis as well as Misgurnus anguillicaudatus in the middlestream of the river. The most widely distributed and abundant native fishes were Schizopygopsis younghusbandi younghusbandi, Triplophysa orientalis and T. tibetana, and the most widely distributed and abundant non-native fishes were M. anguillicaudatus, C. auratus and Pseudorasbora parva. Canonical correspondence analysis indicated that the fish assemblage structure was impacted by both local environmental and regional environment factors, and the non-native fishes and native fishes had different relationships with the environment factors (elevation and substrate).

     

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