Morphological description and molecular barcoding of the aegathoid stage of Nerocila japonica Schioedte & Meinert, 1881 (Crustacea: Isopoda: Cymothoidae) infesting red seabream Pagrus major (Temminck & Schlegel, 1843)

Abstract

Here, the aegathoid stage of Nerocila japonica Schioedte & Meinert, 1881 is described based on a specimen collected from the Seto Inland Sea, Japan, and its identity is confirmed by both morphology and molecular barcoding. Cytochrome c oxidase subunit I and 16S rRNA sequences of the collected individual shared ≥99% similarity with the previous DNA records of N. japonica. In terms of morphology, the aegathoid stage of the specimen examined in the present study differed from that of N. phaiopleura Bleeker, 1857 by intermediate size of the eyes and setation on pereopods. This is the first record of N. japonica infesting the red seabream Pagrus major (Temminck & Schlegel, 1843).