Contribution to the knowledge of Brazilian troglobitic Pseudoscorpiones (Arachnida): description of Pseudochthonius lubueno sp. nov. (Chthoniidae) from Serra do Ramalho karst area, state of Bahia, Brazil

Pseudochthonius lubuenosp. nov., a new obligatory cave-dwelling pseudoscorpion species is described from Gruna da Altina cave, the fifth species of the genus in the region of Serra do Ramalho karst area, southwestern Bahia, Brazil. This genus occurs in South and Central America, sub-Saharan central Africa, and in the Arabian Peninsula. The new species can be identified by the following combination of characters: eyes or eyespots absent, coxa I with two and coxa II with 4-5 coxal spines, without microdenticles on the fixed pedipalpal finger, rallum with five blades, ratio ist-est/ist-esb = 1.9. With this new description, the genus now includes 15 species from Brazil: P. biseriatus Mahnert, 2001, P. brasiliensis Beier, 1970, P. diamachi Prado & Ferreira, 2023, P. gracilimanus Mahnert, 2001, P. heterodentatus Hoff, 1946, P. homodentatus Chamberlin, 1929, P. koinopoliteia Prado & Ferreira, 2023, P. lubueno sp. nov., P. orthodactylus Muchmore, 1970, P. olegario Schimons ky, 2022, P. pali Prado & Ferreira, 2023, P. ramalho Assis, Schimonsky & Bichuette, 2021, P. ricardoi Mahnert, 2001, P. strinatii Beier, 1969 and P. tuxeni Mahnert, 1979. The new species shows troglomorphic characteristics such as the depigmentation of the carapace and the absence of eyes. In addition, illustrations, diagnoses, an identification key for cave-dwelling species of the genus, and distribution maps for all Brazilian species of Pseudochthonius are provided.