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


Terumi Ikawa, Department of Liberal Arts and Sciences, Morioka College, 808 Sunagome, Takizawa, Iwate, 020-0173 Japan. Email: trmi@pop02.odn.ne.jp


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.