Amphibians and reptiles of the Transvolcanic Belt biogeographic province of Mexico: diversity, similarities, and conservation

The Transvolcanic Belt (TVB) of Mexico is a biogeographic province of significant biodiversity, acting as a transition zone between eastern and western Mexico. Using available literature, we collected species lists for amphibians and reptiles in Mexican states within the TVB biogeographic province, updating them with additional literature. The TVB is home to 427 native species of amphibians and reptiles, 154 amphibians and 273 reptiles, which represent 30.5% of the species of amphibians and reptiles in Mexico. The TVB also houses 50 endemic species, with 84 species listed by the IUCN. Threats include habitat destruction and pollution. The TVB shares a significant portion of its amphibian and reptile species with neighboring provinces, particularly the Sierra Madre Oriental and the Sierra Madre del Sur, suggesting a mixture of species from both eastern and western Mexico. Cluster analyses based on species composition reveal distinct groupings of provinces, with the TVB forming a cluster with the Sierra Madre Oriental, Veracruzan, and Sierra Madre del Sur for both amphibians and reptiles. Conservation assessments indicate that a significant proportion of the amphibian and reptile species in the TVB are at risk, primarily due to habitat loss from urbanization, agriculture, and pollution. Urgent conservation actions are needed to protect the unique herpetofauna of the TVB from further decline.