Abstract
A puffer Arothron immaculatus (Schneider, 1801) is recorded for the first time from Kochi Prefecture, southern Japan on the basis of a 24.5mm standard length specimen. This specimen was collected from a seagrass bed of Zostera japonica on depths shallower than 1m in the Kakise River (33°00′３４″N, 133°00′25″E) in Kuroshio Town. In the waters around Japan this species has been known only from the Ryukyu Islands, the southernmost district of Japan. This specimen representing the northernmost record of A. immaculatus is described and figured.
