Taxonomic distinctness of the subterranean fauna from Peruaçu Caves National Park, state of Minas Gerais, Eastern Brazil

Abstract

Limiting factors of subterranean environments, high relative air humidity and, especially, permanent darkness, represent ecological filters for organisms and biodiversity patterns of surface and subterranean communities display wide disparities. Subterranean diversity and singularity are, thus, better expressed when the common presence of rare and endemic species are considered. Our study aimed to describe the diversity of the cave fauna from 14 caves from Peruaçu Caves National Park (PCNP), eastern Brazil. We analyzed the regional diversity using the index that includes the average taxonomic distinction (TD-Δ +, AvTD). We recorded 1,674 individuals belonging to 10 Classes and 237 morphotypes, 11 troglobitic and two troglomorphic and possible troglobites. Greatest species abundance (N=330) and richness (s=76) were recorded at Lapa do Cipó cave, followed by Gruta Olhos d’Água (N=330, s=71), which shows the highest TD value (Δ + = 90.18) in relation to the others, including the richest Lapa do Cipó (Δ + = 85.24), consequence of the several taxonomic units with large number of species. The below-expected values of TD (Δ + = 87.70) may indicate anthropic impacts on these communities. Our results demonstrate that Gruta Olhos d’ Água and Lapa do Cipó caves are the most important sites for the occurrence of endemic and troglobitic species and may be part of a complex system that should be considered for a more efficient conservation planning.