Helminth parasites in Chaunus marinus and Cranopis valliceps (Anura: Bufonidae) from Lagunas Yalahau, Yucatan, Mexico.

Eight helminth taxa were found parasitizing Chaunus marinus (n = 40) and Cranopsis valliceps (n = 40) from the Parque Estatal Lagunas Yalahau, Yucatan, Mexico. Seven taxa (2 digeneans: Langeronia macrocirra, Mesocoelium monas; 1 acanthocephalan: Oncicola sp.; 3 nematodes: Rhabdias füleborni, Aplectana itzocanensis, Cruzia morleyi; and a nematode larva) were found in C. marinus, while 4 taxa (all nematodes: Rhabdias fuelleborni, Aplectana itzocanensis, Ozwaldocruzia sp., and a nematode larva) were present in C. valliceps. Nematodes, particularly A. iztocanensis, showed high prevalence, mean abundance, and mean intensity values for both species of amphibians. The occurrence of R. fuelleborni, M. monas, L. macrocirra, and C. morleyi in these amphibians from the Yucatan Peninsula confirms their neotropical distribution, while the presence of A. itzocanensis increases its geographical distribution, suggesting a preference by neotropical, rather than neartic areas.