Author(s): T SCHOLZ
A review of heterophyid trematodes found in Mexico, both as metacercariae encysted in ®sh and adults in ®sh-eating birds and mammals, is presented, including numerous new geographical and host records. Data on the morphology, spectrum of intermediate and de®nitive hosts, site of infection of metacercariae, distribution in Mexico and biology of the following species are provided (species ®rst reported from Mexico marked with an asterisk): *Ascocotyle (Ascocotyle) gemina Font, Overstreet and Heard, 1984; A. (A.) leighi Burton, 1956; A. (A.) tenuicollis Price, 1935; A. (Leighia) chandleri Lumsden, 1963; *A. (L .) mcintoshi Price, 1936; A. (L .) megalocephala Price, 1932; A. (L .) nunezae Scholz, Vargas- VaÂ zquez, Vidal-MartõÂnez and Aguirre-Macedo, 1997; Ascocotyle (Leighia) sp.; *A. (Phagicola) ampullacea Miller and Harkema, 1962; A. (P.) diminuta Stunkard and Haviland, 1924; A. (P.) macrostoma (Robinson, 1956); *A. (P.) longa Ransom, 1920; A. (P.) nana Ransom, 1920; Centrocestus formosanus (Nishigori, 1924); *Euhaplorchis californiensis Martin, 1950; Galactosomum pu ni Yamaguti, 1941; *Haplorchis pumilio (Looss, 1896); Heterophyidae gen. sp. ( 5 Haplorchoides sp. of Scholz and Vargas-VaÂ zquez, 1998); *Phocitremoides ovale Martin, 1950; and *Pygidiopsis pindoramensis (Travassos, 1929). Two of the above-listed species, C. formosanus and H. pumilio, have been introduced recently to Mexico, most probably from Asia with the imported thiarid snail Melanoides tuberculata (MuÈller). Metacercariae of heterophyid trematodes are among the most frequent and abundant parasites of ®sh in Mexico, in particular in its southeastern part.