Gathering morphological and molecular data for identifying two species of trematodes from the neotropical Vaillant's frog, (Amphibia: Ranidae) in the highlands of Chiapas, south-eastern Mexico.

Mexico possesses a large diversity of amphibians partly due to its complex topography and transitional position between the Nearctic and Neotropical biogeographical regions. However, its helminth parasite fauna has been relatively poorly studied. Specimens of the Vaillant's frog, (Brocchi) were sampled in the tropical rain forest of Nahá, in the Chiapas Highlands, and examined for parasites. Two trematode species were collected from their hosts; morphologically, specimens were allocated to the genera Caballero and Bravo-Hollis, 1949 and Looss, 1899, respectively. Individuals were sequenced for two molecular markers (the mitochondrial cytochrome oxidase gene, and the ribosomal gene 28S), and processed for morphological analyses, including scanning electron microscopy. The new evidence was not enough to accomplish the identification at species level of sp. due to the lack of sequence data from the type localities of Christian, 1970 and Caballero and Bravo-Hollis, 1949. Likewise, the newly generated data were useful to properly identify the adult specimens of lung flukes as Seely, 1906.