Between July 2002 and June 2005, the fish fauna on the reef in the Tsushima Current, northern Kyushu, was surveyed on a monthly basis by SCUBA diving. A total of 138 species and 42, 769 individuals occurred in the investigated area (1, 200 m2). Five fish species (Halichoeres tenuispinnis, Chromis notata notata, Sebastes inermis, Siganus fuscescens and Girella punctata) comprised approximately 53% of the observed individuals. The number of species and individuals strongly affected the fishes. Based on cluster analysis of the appearance patterns, the observed fishes were grouped into five types: (1) perennial type (Type P) comprising 36 species and 18, 346 individuals, (2) spring type (Type S) comprising 17 species and 2, 655 individuals, (3) summer-autumn type (Type SA) comprising 33 species and 17, 613 individuals, (4) autumn type (Type A) comprising 47 species and 4, 144 individuals, and (5) the others. In addition, differences in the species composition were observed during each season. Thus, fish fauna drastically changed according to the season, which is similar to reefs in temperate waters of Pacific coast of southern Japan.
