Gruna do Pedro Cassiano (“Pedro Cassiano cave”), Serra do Ramalho karst area, Carinhanha municipality, Bahia state, Brazil; A. Cave surroundings showing the limestone outcrops and the dried vegetation, sparse and altered by human impacts; B. Cave entrance.; C. Cave gallery showing the small subterranean drainage; D. Detail of the drainage with the apparatus of water extraction; E. Submerged roots, microhabitat of Idiopyrgus spp.; F. Detail of the microhabitat of Idiopyrgus spp., showing thinner roots; G. Xangoniscus aff. aganju, an amphibious troglobitic isopod that co-exists with Idiopyrgus spp.; H. Trichomycterus rubbioli, a cave catfish that co-exists with Idiopyrgus spp.