西沙群岛重要珊瑚礁海域鱼类区系

根据1998年5月、1999年5月和2003年5月在西沙群岛北礁、永兴岛、琛航岛、华光礁、浪花礁、金银岛、东岛和玉琢礁等8个岛礁的调查资料,研究了西沙群岛岛礁水域的鱼类区系。在8个岛礁共捕获鱼类48科261种,其中礁栖性鱼类占78.93%,在8个岛礁广泛分布的鱼类只有33种,各礁区之间种类的相似度不超过41%,因此,种类多样性高和相似度低是该区域鱼类区系的2个主要特征。与南沙岛礁(1998～1999)延绳钓、刺网和手钓以及南沙群岛西南陆架区(1991)、南海北部海域等底拖网鱼类相比较,物种相似度分别为34.0%、5.1%和6.8%。

Fish fauna of coral reef waters of the Xisha Islands

In May 1998,May 1999 and May 2003,three survey cruises were carried out in eight coral reef waters (Bei Reef,Yongxin Island,Chenhang Island,Huaguang Reef,Ianghua Reef, Jinyin Island,Dong Island and Yuzhu Reef) by handline,longline and bottom gillnet fishing.261species of Fishes were caught in these reef waters,78.93% of which were reef fish species,33 of which were common species occurring in at least 6 reef waters,and species similarity coefficients between various two reefs were less than 41%.Thus, high diversity and low species similarity are two main characteristics of fish fauna of the eight reefs.Compared with Nansha Islands(1998~1999),south-westers continental shelf waters of the Nansha Islands (1991) and northern of South China sea,species similarity coefficients are 34.0%,5.1% and 6.8%, respectively.