抄録
A survey of the spatial distribution pattern of the gnathiid isopod, Elaphognathia cornigera (Nunomura, 1992), inhabiting the sponge Halichondria okadai (Kadota), was conducted on a rocky intertidal shore on the Izu Peninsula, southern Japan. While the number of adult male Elaphognathia cornigera is related to sponge size, larvae tended to aggregate in smaller sponges. The vertical distribution of the isopod overlapped with that of the sponge. No particular patterns were observed in the distribution of E. cornigera adults, but larvae mainly occurred around mean tide level. This may be explained by the behavior of larvae migrating between sponges and host fishes.
