Distribution characteristics of freshwater fish in Jeju-do, Korea

In order to examine distribution characteristics of freshwater fish in Jeju-do, freshwater fish were examined at 17 stations including three reservoirs, 13 stations in six streams, and one estuary wetland. A total of 396 fish individuals of seven species in four families were collected at the three reservoir stations and Lepomis macrochirus, an introduced species that disturbs the ecosystem, was the dominant species (71.7%). There were 770 fish individuals of 22 species in 15 families collected from the six streams. The dominant species was Chaenogobius urotaenius (22.6%). A total of 26 fish of four species in three families were found at the Hadori wetland and the dominant species was Tridentiger obscurus. There were five species of fish found for the first time in Jeju-do during this study; Micropterus salmoides, Eleotris sp., Tridentiger brevispinis, Redigobius bikolanus, and Scatophagus argus. In particular, Eleotris sp. of Eleotridae had not so far been recorded in Korea.