Abstract / Introduction / Summary:
An ovigerous female of a marine fish buccal-cavity parasite Ceratothoa oxyrrhynchaena Koelbel, 1878 was accidentally found on the grounds of the Nie-ura Fishing Port, Mie Prefecture, central Japan. Although its fish host was not examined, it is most likely that the parasite fell off an infected host, one of the fishes commercially caught in the Kumano-nada Sea, part of the Northwestern Pacific Ocean, because those fishes were landed at the fishing port. To date, seven fish species have been reported as hosts of C. oxyrrhynchaena from Japan, and six species of them [blackthroat seaperch Doederleinia berycoides (Hilgendorf, 1879); yellowback sea-bream Dentex hypselosomus Bleeker, 1854; royal escolar Rexea prometheoides (Bleeker, 1856); ara Niphon spinosus Cuvier, 1828; deep-sea smelt Glossanodon semifasciatus (Kishinouye, 1904); aome-eso Chlorophthalmus albatrossis Jordan and Starks, 1904] are known to occur in the Kumano-nada Sea.
