| The genus Rhinogobius is widely distributed in eastern Eurasia and some islands of the Western Pacific, and is the largest genus of freshwater gobies in this region, includes about68species. The present research chose Qiantangjiang Basin to study biogeography of Rhinogobius, aimed to learn species composition and distribution characters of Rhinogobius in this basin, promote the understanding of Rhinogbius, and provide the basis for protecting Rhinogobius and other stream fishes.During the period Sepetember2009to October2010,7times of field studies were carried in Qiantangjiang River basin, which covered30countied and most tributeries, thus we obtained more than1500specimens. The results are summarized as follows:(1)11Rhinogobius speices are distributed in Qiantangjiang Basin, viz. R. giurinus (Rutter,1897), R. davidi (Sauvage&Dabry,1874), R. leaveli (Herre,1935), R. cliffordpopei (Nichols,1925), R. wuyiensis Li&Zhong,2007, R. aporus (Zhong&Wu,1998), R. lentiginis (Wu&Zheng,1985) and4undescribed species which are described as R. sp. A, R. sp. B, R. sp. C and R. sp. D, respectively. This research commented the former reports, suggested that Ctenogobius clarki should not be placed in the genus Rhinogobius, and the record of R. shennongensis in Qiantangjiang Basin might be a wrong identification of R. leaveli.(2) Rhinogobius lentiginis and R. aporus were reclassified in this research and their validities were verified. R. lentiginis has complete type of sensory canal pores, while R. aporus has no sensory canal pores. The former described "R. lentiginis" which without sensory canal pore in most references is actually R. aporus. The relationship of R. lentiginis, R. aporus and R. sp. D (defined as R. lentiginis complex in present study) are discussed in the paper, and the geographical distribution laws of them are defined:R. aporus is mainly distributed in Oujiang Basin, Aojiang Basin, Dajingxi Basin and Wuyijiang River which is a tributary of Lower Qiantangjiang Basin in Southern Zhejiang Province, R. lentiginis is distributed in Lingjiang Basin, Tingpangxi Basin, Lower Yangtze Basin and Caoejiang River which is a tributary of Lower Qiantangjiang Basin, R. sp. D is only distributed in the upper and middle Qiantangjiang Basin. We discussed the especial distributing pattern of the three species in Qiantangjiang Basin, and presume that the type locality of R. davidi should be in the upper of Oujiang River in Western Zhejiang Province based on the laws of geographical distributions of R. lentiginis complex.(3) The field studies analyse habitat selection feature of11Rhinogobius species mainly by investigating the characteristics of substrate and water velocity, compare their different modes of habitat use, and summarize the ecological distribution patterns of different species. The results indicated that the selection of substrate and water velocity were similar among the most species, the commensalism was usually observed among R. wuyiensis, R. davidi, R. lentiginis and its allied species (R. aporus and R. sp. D). However, some species have selection preference compared to other species, for example, R. sp. A prefer riffle areas with coarse particle substrate (usually cobble) sediment, and R. sp. C prefer slowly-flowing areas with fine particle substrate (usually sand and gravel). Amphidromous species usually are the dominant species in lower river and lake, and were seldom found in upper river, for example, R. giurinus and R. cliffordpopei prefer calm water areas like lake and reservoir, and R. leavelli mainly lived in lower river. The body size may affect the selection of substrate and water velocity. Water temperature could be the important factor of selection of habitat for some species.The survey also found that human activities have affected the ecosystem of Qiantangjiang Basin enormously. Rhinogobius is threatened by the serious destruction of habitats. We made proposals for the protection of Rhinogobius and other stream fishes, and the further study of Rhinogobius. |
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