Phylogeography of troglobitic arthropods from the western of Jandaíra formation, northeastern of Brazil: evolution and biological connectivity in subterranean environments as a basis for conservation actions
Caves, Caatinga, DNA barcode, Lineages delimitation, Endangered species, Conservation status
Caves have historically attracted attention due to troglobites, exclusively subterranan organisms that often have restricted distribution and high levels of endemism. Paleoclimatic events have been pointed out as the main responsible for the origin of troglobitic species, and the west of the Jandaíra formation, northeast of Brazil, combines the occurrence of extensive karst areas, huge concentration of caves and subterranean aquifers in a region that is currently semi-arid and with a history of paleoclimatic changes (including oceanic transgressions and regressions). This region is recognized due to the richness and concentration of troglobitic species, some of which (isopods, amphipods and planthoppers) have a relatively wide distribution in geologically and hydrologically distinct areas. Through phylogenetic and phylogeographic analyzes, we aim to assess the patterns of genetic variation of these taxa, investigate possible cryptic diversity and delimit operational taxonomic units (OTU’s), as well as indicate the factors that possibly influenced their diversification. In addition, we aim to assess the conservation status of each of the lineages and identify priority areas for their conservation. With the exception of Cirolanidae sp.1, the other taxa showed extensive diversity of cryptic lineages and, in addition to the identification of three OTU’s for Cirolanidae sp.2 and five for Potiberaba, K. troglobia probably consists of a complex with six other cryptic species, distributed according to microbasins (aquatic taxa) and outcrops (Kinnapotiguara). Only a small portion of the lineages are found in protected areas, while the majority occur in areas exposed to several anthropic threats and can be considered endangered: Cirolanidae sp.1 was categorized as Vulnerable, while Cirolanidae sp.2 has one Least Concern (LC) and two Critically Endangered (CR) lineages. For Potiberaba, there are two LC, one Endangered (EN, P. porakuara) and two CR lineages, and, for Kinnapotiguara, there are four EN and three CR (including K. troglobia) lineages. Two priority areas were identified for the conservation of these lineages, with emphasis on the region of Abreu stream microbasin and Rosário outcrop, in Felipe Guerra municipality, which harbor half (eight, six of which are endemic) of the identified lineages. The Rosário outcrop can be considered a new hotspot of subterranean biodiversity.