Redescription of <i>bicotyle Reticulata</i> (monogenea: Heteraxinidae) from <i>pampus Punctatissimus</i> (scombriformes: Stromateidae) in the Seto Inland Sea, Japan

Bicotyle reticulata (Goto, 1894) (Monogenea: Heteraxinidae) is redescribed from the gills of Pampus punctatissimus (Temminck and Schlegel, 1845) in the Seto Inland Sea, Japan. Although its taxonomic position had been frequently revised, B. reticulata remains solely documented from the original description, 130 years ago. The present study revealed that B. reticulata exhibits subsequent diagnostic characters of Bicotyle Tripathi, 1956: clamps on either side of the haptor unequal in size and number, the genital atrium armed with several spines, and a convoluted germarium. The phylogenetic analysis based on 28S rDNA sequences suggests that B. reticulata and Heteraxinidae constitute a monophyletic group. All currently known species of Bicotyle are listed, and a key to six species of the genus is provided.