Distribution of Coreoperca kawamebari and C. herzi and fish community structure in realting to environmental variations in their sympatric areas of Boseong River, Korea

초록

The current distribution area of Coreoperca kawamebari was known to be restricted to Tamjim River and several streams flowing into the southern part of the West sea, and C. herzi distributes throughout the country except the distribution areas of C. kawamebari in South Korea. We first found sympatric areas of both species in Boseong River, a tributary of Seomjin River, and Jiseok Stream, a tributary of Yeongsan River. Local scale distribution of two Coreoperca species, fish assemblages and environmental variables were surveyed in Boseong River to investigate effects of environmental factors on fish community structures in their sympatric stream. The diversity of environments were closely related to complexity of fish community structures and the sympatric and allopatric distribution patterns of two Coreoperca species. The result of CCA (canonical correspondence analysis) showed that C. kawamebari distributed in pool areas while C. herzi distributed in faster water velocity areas with the boulder substrate. In conclusion, fish community structures were simple and two Coreoperca species were allopatric in simple environmental areas, but diverse environments provided two species to be sympatric and more complex fish community structures existed.