梵净山及邻近地区鱼类资源的现状

为了了解梵净山及邻近地区鱼类资源的现状及变化趋势,2001–2003年对这一地区乌江水系和沅江水系鱼类进行了系统的调查。本调查设立了19个调查点,共采集鱼类标本3614号,经鉴定为85种(亚种),分属5目14科61属。除胡子鲇(Clariasfuscus)为外来种外,其他均为土著鱼类。海南拟餐(PseudohemiculterHainanensis)、峨眉后平鳅(Metahomalopteraomeiensisomeiensis)和福建纹胸鱼兆(Glyptothoraxfukiensisfukiensis)为本地区土著鱼类新记录种。鱼类组成以鲤形目鲤科为主体,并以适应急流生活的鱼类占多数,小型野杂鱼类所占比例较高。乌江水系和沅江水系鱼类物种组成存在差异,分别属于长江上游鱼类区系成分和长江中下游区系成分。结果还表明这一地区土著鱼类物种数呈下降趋势,其中鲤形目鱼类物种数减少较多。导致该地区土著鱼类物种数下降的原因是酷渔滥捕和水域生境的破坏。

Fish resources around Fanjing Mountain, Guizhou

Fanjing Mountain is situated in Guizhou Province, southwestern China. Having the best preserved ecological system in the region, it has been designated as a national nature reserve. From 2001 to 2003, to explore the status and dynamics of the species diversity of fishes, we conducted three surveys in both the Wujiang River and the Yuanjiang River systems in the area around Fanjing Mountains. A total of 3,614 specimen were collected from 19 sites, belonging to 85 species/subspecies, 61 genera, 14 families, and 5 or-ders. Of these, Clarias fuscus is an introduced species while the others are indigenous. Pseudohemiculter hainanensis, Metahomaloptera omeiensis omeiensis, and Glyptothorax fukiensis fukiensis were newly re-corded in this area. The fish fauna mainly comprised members of the family Cyprinidae of the order Cy-priniformes, and fishes living in swift-flowing streams and small-sized species were dominant. Our study, combined with literature review, showed that indigenous fish species had decreased. Additionally, the species in Cypriniformes decreased much more than those in other orders in the area. The rapid decrease of species richness of indigenous fishes probably resulted from over-fishing and destruction of the river environment. Measures for protection of indigenous fish in this area are also discussed.