Helminth parasites of garter snakes and mud turtles from several localities of the Mesa Central of Mexico

Between 1996 and 1998, 212 specimens of aquatic snakes, the Mexican garter snake Thamnophis eques (77) and the black-bellied garter snake Thamnophis m elanogaster (135), and 71 Mexican mud turtles Kinosternon hirtipes were col lected in 7 localities along the Mesa Central of Mexico. We identified 22 s pecies of helminths from these reptiles. Nematodes represented the most div erse group of helminths in these hosts, with 13 of the 22 species collected (59%). Next were digeneans with 5 species, cestodes with 2, and monogenean s and acanthocephalans with 1 each. In total, 17 new host and 48 new locali ty records were obtained. Ten of the 22 species infect reptiles accidentall y since they frequently occur in sympatric species of freshwater fishes or amphibians, and 12 species are considered common members of the helminth pa rasite communities of these reptiles. Previous reports of all helminth spec ies found are summarized, and biogeographical affinities of helminths are d iscussed.