Revision of the monogenean subfamily Thoracocotylinae price, 1936 (Polyopisthocotylea: Thoracocotylidae), with the description of a new species of the genus Pseudothoracocotyla Yamaguti, 1963.

Members of the subfamily Thoracocotylinae are gastrocotylid monogeneans of Spanish mackerels (scombrid fishes of the genus Scomberomorus) from warm to warm-temperate seas around the world. We revise the diagnosis of the subfamily and recognise two genera and three species as valid. The genus Paradawesia Bravo Hollis & Lamothe Argumedo, 1976 is synonymised with Thoracocotyle MacCallum, 1913, and Dawesia Unnithan, 1965 and Methoracocotyle Lebedev, 1984 are synonymised with Pseudothoracocotyla Yamaguti, 1963. Thoracocotyle crocea MacCallum, 1913 (syns T. paradoxica Meserve, 1938 and Paradawesia bychowskyi Bravo Hollis & Lamothe Argumedo, 1976) is recorded from two species of Scomberomorus in the eastern Pacific (California to Peru) and four in the western Atlantic (South Carolina to Brazil). Pseudothoracocotyla ovalis (Tripathi, 1956) Yamaguti, 1963 (new syns Dawesia indica Unnithan, 1965, D. incisa Lebedev, 1970, Methoracocotyle scomberomori (Young, 1968) Lebedev, 1984, M. gigantica (Rohde, 1976) Lebedev, 1984 and Thoracotyle indica (Unnithan, 1965) Murugesh, 1995) is recorded from the gills of seven species of Scomberomorus from the Indo-west Pacific (eastern South Africa north to the Persian Gulf, and east to Fiji). Pseudothoracocotyla whittingtoni n. sp. is described from an eighth Indo-west Pacific scomberomorid, S. munroi, in Australian waters.