Postmetamorphic adult females of the lernaeid co- pepod Lernaea cyprinacea Linnaeus, 1758 were col- lected from Rhinogobius similis Gill, 1859 (Gobiidae) from the lower reaches of the Arida River, Wakayama Prefecture, central Japan. This represents the first re – cord of L. cyprinacea from Wakayama Prefecture. The females were all attached by peritrich ciliates in the anterior region of the trunk.