Descriptions of five new species of the salamander genus Chiropterotriton (Caudata: Plethodontidae) from eastern Mexico and the status of three currently recognized taxa

Predicting genetic biodiversity in salamanders using geographic, climatic, and life history traits

The geographic distribution of genetic variation within a species reveals information about its evolutionary history, including responses to historical climate change and dispersal ability across various habitat types. We combine genetic data from salamander species with geographic, climatic, and life history data collected from open-source online repositories to develop a machine learning model designed to identify the traits that are most predictive of unrecognized genetic lineages. We find evidence of hidden diversity distributed throughout the clade Caudata that is largely the result of variation in climatic variables. We highlight some of the difficulties in using machine-learning models on open-source data that are often messy and potentially taxonomically and geographically biased.

A new arboreal Pseudoeurycea (Caudata: Plethodontidae) from the Sierra de Zongolica, Veracruz, Mexico

We describe a new species of plethodontid salamander of the genus Pseudoeurycea from the Sierra de Zongolica, Veracruz, Mexico. The new species is distinguished from all other species in the genus by morphological and genetic features and by coloration. Based on a mtDNA phylogeny, the new species belongs to the Pseudoeurycea juarezi group and is most closely related to P. ruficauda from the Sierra Mazateca in northern Oaxaca. The newly described salamander increases the number of species of plethodontid salamanders from Veracruz to 43 and those recognized from Mexico to 140.

Tadpole soup: Chinantec caldo de piedra and behavior of Duellmanohyla ignicolor larvae (Amphibia, Anura, Hylidae)

Although amphibian consumption by humans has been reported globally, this practice is not well studied despite its direct implications to the decline of amphibian populations. The International Union for Conservation of Nature (IUCN) recognizes the need to document the use and trade of species to be considered in assessing their extinction risk. Here the consumption of Duellmanohyla ignicolor tadpoles is documented. It is a micro endemic species categorized as Near Threatened (NT) consumed in a traditional dish called “caldo de piedra” (stone soup) prepared by the Chinantec people (Tsa Ju Jmí’) in Oaxaca, Mexico. Through conversations with local people and stream monitoring, the behavior of tadpoles of this species was documented and aspects of their exploitation and habitat use described. Places where caldo de piedra is still consumed were determined and using a spatial analysis with Geographic Information Systems, the distribution of the species in relation to those localities was analyzed. A number of other areas where tadpoles of this species might also occur and be exploited is predicted. In conclusion, the school behaviour, surface feeding, and the preference for deeper waterbodies that these tadpoles exhibit makes them vulnerable to being caught in large quantities. As they are consumed locally, are not commercialized, and the species distribution range is wider than caldo de piedra consumption, this implies a low risk for their populations. However, the tadpoles’ reliance on streams with depths x̄ = 60 cm and flux x̄ = 0.65 m/s reduces the availability of sites for their optimal development.

A new species of the genus Tylototriton (Urodela, Salamandridae) from western Thailand

We describe a new species of the newt genus Tylototriton from Umphang Wildlife Sanctuary, Tak Province, western Thailand based on molecular and morphological evidence and named here as Tylototritonumphangensissp. nov. The new species is assigned to the subgenus Tylototriton and differs from other species in having dark-brown to blackish-brown body and limbs, truncate snout, prominent antero-medial ends of the expansion of the dentary bones, laterally protruding quadrate regions, indistinct and small rib nodules, a well-segmented vertebral ridge, and rough dorsolateral bony ridges, which are steeper anterior, and curved medially at the posterior ends. The molecular data show that Tylototritonumphangensissp. nov. differs from T.uyenoi sensu stricto by a 5% genetic sequence divergence of the mitochondrial NADH dehydrogenase subunit 2 region gene. The new species and T.uyenoi are both endemic to Thailand, distributed along the Northwest Thai (Dawna) Uplands of Indochina. To clarify the species boundary between Tylototritonumphangensissp. nov. and T.uyenoi, additional field research is needed in adjacent areas. Tylototritonumphangensissp. nov. is restricted to evergreen hill forests in Umphang Wildlife Sanctuary. We suggest that the new species should be classified as Endangered (EN) in the IUCN Red List.

Research on helminths from Mexican amphibians: gaps, trends, and biases

We present a taxonomic, spatial, and thematic overview of the current state of knowledge on helminth parasites of Mexican amphibians. Sixty-six host species have been studied so far, representing 17.5% of the amphibian species distributed in Mexico. A total of 139 nominal species of helminths - 68 platyhelminths, 62 nematodes, three acanthocephalans, three annelids (hirudineans), and three arthropods (pentastomids) - have been recorded parasitizing these hosts. Most taxa found in larval stages have not been identified at the species level. The gastrointestinal nematode Aplectana itzocanensis exhibits the broadest host range, while the bladder fluke Gorgoderina attenuata and A. itzocanensis show the widest geographic distribution. Our analysis of helminthological studies evidenced gaps and biases on research efforts that have been devoted to relatively few host species, regions, and approaches. Most helminthological records come from two species, the cane toad Rhinella marina and the Montezuma's frog Lithobates montezumae, and most studies have focused on describing the helminth fauna of a host species in a particular location or on the description of new helminth species. The highest proportion of records corresponds to the Veracruzan biogeographic province, and helminth richness is significantly correlated with host richness and with total amphibian richness by biogeographic province. Only three provinces (Yucatan Peninsula, Pacific Lowlands, and Baja Californian) have positive, yet still low helminth species discovery effort. Based on our findings, we recommend pursuing research approaches unexplored in Mexico and we provide guidelines to improve research on helminths parasitizing amphibians.

Two extremely rare new species of fossorial salamanders of the genus Oedipina (Plethodontidae) from northwestern Ecuador

We describe two new species of salamanders of the genus Oedipina, subgenus Oedopinola, from two localities on the northwestern foothills of Ecuador, at elevations between 921 and 1,067 m. These are the southernmost members of the genus. We examined different museum collections and we found just three specimens of Oedipina from Ecuador, obtained throughout the history of herpetological collections in the country. We identify two of the three specimens as new species, but refrain from assigning a specific identity to the third, pending further study. Oedipina villamizariorum sp. n. is a medium-sized member of the genus, with a narrow, relatively pointed head and blunt snout; dorsolaterally oriented eyes, moderate in size; and digits that are moderately long and having pointed tips. Oedipina ecuatoriana sp. n., somewhat larger, has a narrow head and broadly rounded snout; this new species differs from all known Oedipina by the distinctive presence of paired prefrontal bones and a reduced phalangeal formula: 0-0-1-0; 0-1-2-1-1. We provide detailed descriptions of the osteology of both new species. Finally, we present a phylogenetic hypothesis for the genus, including one of the two new species, based on partial sequences of mitochondrial DNA.