Anilocra clupei Williams & Bunkley-Williams, 1986 (Isopoda: Cymothoidae) parasitic on Japanese sardine Sardinops melanostictus (Temminck & Schlegel, 1846) in Japan, with a discussion on its host utilization and geographical distribution

Abstract

Both ovigerous and non-ovigerous females of the cymothoid isopod Anilocra clupei Williams & Bunkley-Williams, 1986 were collected from the body surface of Japanese sardine Sardinops melanostictus (Temminck & Schlegel, 1846) in Aso-kai Lagoon, Kyoto Prefecture, central Japan. The isopod is redescribed herein based on the collected females. Japanese sardine represents a new host record for A. clupei. Based on the previous and present studies, adults of A. clupei have been reported from three species of clupeiform fishes [Japanese sardinella Sardinella zunasi (Bleeker, 1854), round herring Etrumeus micropus (Temminck & Schlegel, 1846), and Japanese sardine], which indicates that these clupeiform fishes are preferred hosts of this parasite and, because of its frequent occurrence records from Japanese sardinella, this fish species is considered to serve as the most important host for the parasite. The isopod occurs in temperate and subtropical waters of Japan, which are possibly affected by two warm currents, the Kuroshio and its branch, the Tsushima Current. An identification key to the three nominal species of the genus Anilocra reported from Japan (A. clupei, A. prionuri Williams & Bunkley-Williams, 1986, and A. harazakii Uyeno & Tosuji, 2023) is also provided.