REVISION OF GENARCHELLA SPECIES (DIGENEA, DEROGENIDAE) PARASITIZING FRESH-WATER FISHES IN MEXICO AND CENTRAL-AMERICA

Halipegine trematodes of the genus Genarchella Travassos, Artigas et P ereira, 1928, parasitic in Mexican and Central American freshwater fis hes, are revised. The species G. thorsoni (Watson, 1976) is synonymise d with G. tropica (Manter, 1936) and three Genarchella species are con sidered to be valid: (1) G. tropica (Manter, 1936) (syn. G. thorsoni ( Watson, 1976)) from the pimelodid catfish Rhamdia guatemalensis (Gunth er) and R. managuensis (Gunther); (2) G. astyanactis (Watson, 1976), p arasitizing the characid Astyannax fasciatus (Cuvier); and (3) G. isab ellae (Lamothe-Argumedo, 1977) (syn. C. luistoddi (Jimenez, Guajardo e t Briseno, 1981)), a parasite of cichlid fishes of the genus Cichlasom a and the pimelodid R. guatemalensis. All species are redescribed and the distribution and host specificity of individual taxa are briefly d iscussed.