唐鱼野生种群在海南岛的新发现及其生态资料

于2007年在海南岛发现了国家Ⅱ级重点保护动物唐(Tanichthys albonubes Lin) 群,属种均为海南新记录.该属全球只有两种,种与种群间都呈间断分布,对研究鲤科鱼类的系统发育及古地理等均有重要的科研价值.由于早年过度采集作观赏鱼,加上珠三角地区的急速都市化发展,唐鱼曾被认为是野外已灭绝种.近年被重新发现后,迄今只知分布于广东省珠三角地区零散地点和越南广宁省下龙湾附近.海南岛足这个珍稀种首次在亚洲大陆以外被发现的地点,亦是唐鱼野生种群已知纬度最低的分布点.发现海南唐鱼的地点是一条低地小河,水质清澈,水流缓慢,水生植物茂盛,与广东省报道的唐鱼生境类似.发现海南种群的小河鱼类丰富,全今记录有共生鱼类20种,包括大量掠食性物种,但唐鱼足该地的优势种之一.在不同月份都可以发现体长10mm以下的仔鱼,显示海南岛的唐鱼无明显的繁殖季节.海南岛跟亚洲大陆隔离历史长,其唐鱼与亚洲大陆种群在形态、分子水平上是否存在明显差异,不同种群问的系统发育关系如何,海南唐鱼的保护重要性是否更为突出,是目前正在研究的课题.

Discovery of Tanichthys albonubes Lin 1932 (Cyprinidae) on Hainan Island, and Notes on Its Ecology

A wild population of the globally restricted and highly threatened freshwater fish Tanichthys albonubes Lin was recently discovered on Hainan Island, China. Prior to the present study, native populations were only known from isolated pockets in Guangdong Province of China and Quang Ninh Province of Vietnam; the Hainan record thus represents the first insular and southernmost distribution of this little-known species. Thus far it is known only from a single site in Hainan, despite repeated surveys of similar habitats throughout the island. The Hainan population occurs in a clean, sluggish coastal stream with abundant hydrophytes, and is sympatric with 20 fish species. Due to the unique geographic distribution of the Hainan population, and the conservation significance of the species, studies of its phylogenetic relationships with conspecifics populations elsewhere are underway. The exact locality of the newly discovered Hainan population cannot be revealed, but relevant government authorities have been notified and we are working to protect the site.