Filogeografia de Rowlandius potiguar Santos, Ferreira & Buzzato, 2013 (Arachnida: Schizomida: Hubbardiidae) nas cavernas da Caatinga

Abstract

Most of the caves in the State of Rio Grande do Norte (RN) are located in the limestones of the Jandaíra Formation, in the Caatinga. This region is considered to be of high biospeleological relevance, as it holds a high species richness and species adapted to underground environments. Among them are the arachnids of the order Schizomida, also known as the short-tailed whip scorpion, represented by Rowlandius potiguar, a species recorded in 30 caves in western RN. This wide distribution may suggest it is a troglophilic species that eventually colonized caves throughout the Jandaíra Formation, or a complex of troglobite species, as detected in other invertebrates in the region. To answer this question through a phylogeographic approach, we collected these schizomids in 12 caves of their known distribution, including the Casa de Pedra cave, which is the southernmost record of Rowlandius in RN, in the Jucurutu formation. We also report 14 new distribution records for the group in the region. Phylogeographic and phylogenetic analyses, using the molecular markers mitochondrial cytochrome C oxidase I and nuclear rDNA 28s, indicated that R. potiguar is a species complex, with two possible new species, one restricted to the Casa de Pedra cave (Rowlandius sp. n.2), and one from thirteen caves (Rowlandius sp.n.1). The latter is also supported by morphological characters of the female internal genitalia and the shape of the terminal flagellum at the end of the male abdomen. Furthermore, phylogeographic analyses detected a structure of five populations for R. potiguar and three for Rowlandius sp.n.1. These lineages occur in allopatry and did not present a defined distribution pattern. We also highlight that the species identified in the complex are protected in conservation areas, such as the Furna Feia National Park, in Baraúna, and the Cavernas de Martins Natural Monument, in Martins. However, it is important to highlight that there are vulnerable populations in the municipalities of Governador Dix-Sept Rosado and Felipe Guerra. With this, we propose updating the taxonomy and geographic distribution of R. potiguar, and also discovered that the schozomid species richness in the Caatinga in higher than supposed originally.