Abstract / Introduction / Summary:
Ceratothoa oxyrrhynchaena Koelbel, 1878 was found in the buccal cavity of blackthroat seaperch, Doederleinia berycoides (Hilgendorf, 1879) (Perciformes: Acropomatidae), from the Kashima-nada Sea in the western North Pacific Ocean off southern Ibaraki Prefecture, central Japan. This represents the first record of C. oxyrrhynchaena from Ibaraki Prefecture, and the species is briefly described. While only eight fish were examined, four (50%) were infected by C. oxyrrhynchaena.