Results of quantitative samplings in rockpools at four sites on the eastern coast of Kyushu, southern Japan. Solid bars and plots show mean density (error bars indicating standard error) and occurrence rates of each species of Chaenogobius (upper, C. annularis; lower, C. gulosus) at each site in the two seasons (left, spring; right, autumn) respectively. Abbreviations of the sites on the x-axis are as follows: Ot, Oita; N-My, N-Miyazaki, S-My, S-Miyazaki; TnI, Tanega-shima (these locality names correspond to those used in Fig. 3). Sample sizes, n = 5, except for Tanega-shima in autumn (n = 8).