The term hotspots of subterranean biodiversity has been used to define subterranean
habitats with an arbitrary cutoff of twenty or more obligate stygobitic and troglobitic
species. Until present, no hotspots of subterranean biodiversity had been identified
in South America. Thus, the objective of this work is to present the first two hotspots
of subterranean biodiversity in that continent. The two hotspots of subterranean biodiversity
are the Toca do Gonçalo cave (22 spp.) and Areias cave systems (28 spp.). The cave
species, some of them considered relict species, belong to the Platyhelminthes (1
sp.), Nemertea (1 sp.), Gastropoda (2 spp.), Amphipoda (2) Isopoda (7), Decapoda (1),
Collembola (5), Coleoptera (5), Ensifera (1), Sternorrhyncha (1), Zygentoma (1), Diplopoda
(6) Chilopoda (5) Araneae (2), Opiliones (1) Palpigradi (2), Pseudoscorpiones (4),
and Osteicthyes (2). Although both caves, together, have 50 troglobitic species, only
38% of these species are formally described. Both caves have perennial water bodies,
but terrestrial obligate cave invertebrates are dominant in number of species in both
systems (around 77%). While the Areias system is partially contained in a conservation
unit, Toca do Gonçalo cave is currently unprotected, although it certainly deserves
protection.