The argulid branchiuran Argulus coregoni Thorell, 1865 is reported based on two adult males from the dorsal skin of land-locked masu salmon, Oncorhynchus masou masou (Brevoort, 1856), caught in a mountain stream, Kyushu, the third largest island in Japan. This is the first record of A. coregoni from Kyushu.

First record of Argulus coregoni (Branchiura: Argulidae), a skin parasite of freshwater fishes, from Kyushu, Japan (Kazuya Nagasawa, Taka-aki Yoshino, Yukio Iwatsuki)