Characterization of anuran fauna inside caves in Brazil

Abstract

The natural underground environment has unique characteristics when compared to surface environments. These environments feature a reduced complexity food web that includes organisms such as anuran amphibians. This study examines the occurrence of Neotropical anurans in Brazilian caves, utilizing taxonomic, geographic, geological, and environmental data extracted from the scientific literature. A total of 247 anuran records were found in caves across 18 scientific papers covering a 42-years period (from 1980 to 2022). Of these, 177 records (71.6%) displayed the anurans identified to the species level (54 species), with the families Leptodactylidae (13 species; 24.1%), Hylidae (12; 22.2%), and Bufonidae (10; 18.5%) being the most frequently recorded. The anuran records were predominant in the states of Minas Gerais (81 records; 34.8%) and São Paulo (35; 15.0%). The Atlantic Forest had the highest number of records (78; 33.5%), followed by ecotonal zones between the Atlantic Forest and Cerrado (43; 18.5%). Environmental information was scarce in the consulted records, with only 12 providing detail about the cave light zone where the anuran was found (nine in the entrance zone) and 63 indicating the presence/absence of water bodies. Carbonaceous (109; 46.8%) and ferruginous (76; 33.9%) lithology predominated among the caves considered. The low number of sampled caves (55 caves; 0.24%) compared to the total number of caves registered in Brazil (23,278 caves) underscores a knowledge gap regarding Neotropical anurans use of subterranean habitats.