A littoral treasure trove: a comprehensive assessment of the herpetofauna of Sainte Luce, southeastern Madagascar

Madagascar supports one of the grandest herpetological assemblages on Earth, with a highly species-rich fauna characterized by great diversity within specific families, and extremely high levels of endemism. The island, a biodiversity hotspot of global importance, is also experiencing rapid environmental decline. Thus, understanding presentday biodiversity is crucial for developing effective conservation measures. Despite severe fragmentation, Sainte Luce in southeast Madagascar retains some of the most intact examples of littoral forest remaining on the island. The area is known to support a diverse herpetological community, yet previous species identifications have been based predominantly on morphological characters. Given the rapid increase of described species for within both amphibians and non-avian reptiles in recent decades, a modern appraisal of herpetological diversity using modern gene-based analytical tools was essential amidst the ongoing environmental decline. We collected new genetic material from 86.8% of amphibian and reptile species across the Sainte Luce littoral environment. Various techniques including visual encounter surveys, pitfall traps, artificial tree bark refugia, and microhabitat searches were employed to locate species. Taxonomic identifications were based on an integrative approach combining morphological character assessment and molecular analysis. In this study, we increase the number of confirmed species to 76 distinct taxa, generate or retrieved molecular data for 68 of these taxa (21 amphibians and 47 reptiles), and identify 13 (6 amphibians and 7 reptiles) candidate species. Our results emphasize the critical role that littoral forest fragments play in providing refuge for biodiversity in Madagascar.