Three new troglobitic Coarazuphium (Coleoptera, Carabidae, Zuphiini) species from a Brazilian hotspot of cave beetles: exploring how the environmental attributes of caves drive ground-beetle niches

Three new species of troglobitic beetles of the genus Coarazuphium are described from specimens collected in iron ore caves in the Flona de Carajás in Brazil, doubling the number of known species for the Carajás region. The new species of Coarazuphium are morphologically similar to the already described species from the same region and are distributed in a small geographic range. From all Coarazuphium species of the region, including the new ones, two stand out, C. spinifemur and C. xingusp. nov., which are the smallest Coarazuphium species. Both species have shorter legs and antennae when compared to the others. The main characteristic that differentiates C. xikrinsp. nov. and C. kayaposp. nov. from the other two species from the Carajás region, C. tapiaguassu and C. amazonicum, is that the new species have more numerous setigerous punctures dorsally on the head. With the three new species added to the six already described congeners, the area of intense mining of the Carajás region includes the highest diversity of obligatory cave-dwelling beetles in Brazil, representing a hotspot of cave beetles. Coarazuphium xikrinsp. nov. and C. amazonicum co-occur in some of the caves of the Carajás region, which is possible due to putative niche differentiation between the species. These findings highlight the importance of maintaining legal provisions that ensure the preservation of caves, especially those most relevant regarding physical and biotic aspects, which is crucial for the conservation of Brazilian subterranean biodiversity.