Xiphonectes gracillimus (Stimpson, 1858)

— Stimpson (1858, 1907, as Amphitrite gracillima sp. nov.: Futami Bay, Chichi-jima I., 18m); Takeda & Kurata (1976a, as? Portunus gracillimus: Eboshi-iwa Islet, Futami Bay, Chichi-jima I.)