Revision of the monogenean subfamily Neothoracocotylinae Lebedev, 1969 (Polyopisthocotylea : Thoracocotylidae)

Members of the subfamily Neothoracocotylinae are gastrocotylinean monogenea ns on the gills of scombrid fishes of the genera Scomberomorus and Acanthoc ybium, and reportedly of a coryphaenid fish belonging to the genus Coryphae na. We revise the diagnosis of the subfamily and its two genera and accept only two species as valid. Neothoracocotyle acanthocybii (Meserve, 1938) Ha rgis, 1956 is known from Acanthocybium solandri throughout the Pacific Ocea n and in the western Atlantic. N. coryphaenae (Yamaguti, 1938) Hargis, 1956 , known only from a single specimen and described from Coryphaena hippurus in Japan, is synonymised with N. acanthocybii. The sole member of Scomberoc otyle, S. scomberomori (Koratha, 1955) Hargis, 1956, infects five species o f Scomberomorus in the eastern Pacific Ocean and the western and eastern At lantic. We record this worm from several new hosts and/or localities, inclu ding S. sierra and S. concolor in the eastern Pacific (Mexico to Colombia), S. maculatus and S. cavalla in the western Atlantic (USA to Brazil), and S . tritor in the eastern Atlantic (Sierra Leone to Nigeria).