Distribution of the oceanic insects Halobates (Hemiptera: Gerridae) off the south coast of Japan

Specimens of ocean skaters Halobates were collected off the south coast of Japan in the East China Sea in 1995, and from the Kumano-nada Sea to the East China Sea in 1998 and 1999. Three species were identified: H. micans, H. germanus and H. sericeus. We found two species co-occurring in comparable densities in different years, a phenomenon not :hitherto reported in other regions of the ocean. We discuss distributions of the three Halobates species with special reference to the influence of the Kuroshio Current, temporal variations of sea-surface temperature, and monsoonal winds.