A new troglobitic palpigrade from Central Brazil, with notes on a new opisthosomal character (Arachnida: Palpigradi) Author Souza, Maysa F. V. R. Centro de Estudos em Biologia Subterrânea, Setor de Biodiversidade Subterrânea, Departamento de Ecologia e Conservação, Universidade Federal de Lavras, Lavras, MG. CEP 37200 - 000, Brazil. Author Mayoral, Jaime 0000-0002-8813-6804 Department of Biological Sciences, Florida International University, 11200 S. W. 8 th Street, Miami, FL, 33199, USA. & Grupo de Investigación Protección Vegetal de Cultivos, CITE II-B, Universidad de Almería, 04120, Almería, Spain. jgmayoral @ hotmail. com; https: // orcid. org / 0000 - 0002 - 8813 - 6804 jgmayoral@hotmail.com Author Ferreira, Rodrigo L. 0000-0003-3288-4405 Centro de Estudos em Biologia Subterrânea, Setor de Biodiversidade Subterrânea, Departamento de Ecologia e Conservação, Universidade Federal de Lavras, Lavras, MG. CEP 37200 - 000, Brazil. & drops @ ufla. br; https: // orcid. org / 0000 - 0003 - 3288 - 4405 drops@ufla.br text Zootaxa 2020 2020-11-04 4869 4 493 514 journal article 9071 10.11646/zootaxa.4869.4.2 f6e526b5-da1b-4f42-8ed5-0c70704d67fb 1175-5326 4418840 2E986EF1-29C0-4F43-8672-86128D8CC360 Taxonomy of E. audax Eukoenenia audax shows affinity with other Brazilian troglobitic palpigrades and with the edaphic species E. improvisa Condé, 1979 from French Guiana . The absence of one esp seta on IVbta and the chaetotaxy of tergites II–VI ( t 1 , t 2 , s ) are shared with E. maquinensis , E. spelunca , E. sagarana , E. cavatica , E. neytiri , E. jequitinhonha , E. navi , E. eywa , E . ibitipoca , E. igrejinha , E. improvisa , E. magna , E. lundi , E. jequitai and E. virgemdalapa (in these three last species, seta gla is also absent on bta IV). The number of setae on sternites IV–VI ( a 1 , a 2 , s ) in the new species is also similar to those in most of the species previously mentioned, except E. maquinensis , E. sagarana and E. igrejinha ( Condé 1979a ; Souza & Ferreira 2010 , 2011b , 2012a , 2012b , 2016 , 2018 , 2019a , 2019b , 2020 ). The chaetotaxy of the female genitalia is similar to that of E. navi , E. eywa , E. neytiri , E. magna , E. lundi and E. jequitinhonha (some species have an asymmetrical or unknown condition). However, the chaetotaxy of the male genitalia is only shared with E. sagarana and E. lundi ( Souza & Ferreira 2012a , 2016 , 2018 , 2020 ). The new species shares a similar coxal formula with E. navi , E. eywa , E. neytiri and E. magna . The general chaetotaxy of palp and leg I also resembles that of those species, as well as that of E. ibitipoca and E. igrejinha , but there are some differences. For instance, the number of setae on trochanter of leg I is 11 in Eukoenenia audax and 13 for all other species. In addition, E. audax carries 9n on ta3 of the pedipalp while E. navi , E. eywa and E. neytiri carry 11n setae, E. ibitipoca carries 13n and E. magna and E. igrejinha have 8n. On the other hand, E. audax , E. ibitipoca , E. magna and E. igrejinha have a forked seta ( fs ) on bta2 of leg I, but it is absent in E. navi , E. eywa and E. neytiri ( Souza & Ferreira 2018 , 2019a , 2019b , 2020 ). Eukoenenia audax can be differentiated from all South American species and from most palpigrades described to date by the presence of a single deutotritosternal seta. This character state is only shared with E. deleta Condé, 1992 from Thailand and E. vargovitshi Christian, 2014 from the Western Caucasus. A more detailed comparison with E. deleta is not possible since only two specimens were captured: an adult female that was lost before its description and an immature A on which the description of the species was based ( Condé 1992 ). E. vargovitshi differs from the new species in almost all other characters, i.e . number of setae on propeltidium (7 + 7 vs . 10 + 10), number of blades in lateral organs (9–11 vs . 3), number of setae on IVbta (6 vs . 4) and different ventral chaetotaxy on sternites IV–VI (Christian 2014). In addition to the deutotritosternal chaetotaxy, the position of the seta r on IVbta (distal to the insertion of the pair esd ) and the number of blades in the lateral organs ( 9–11 in adults) are unique characters among Brazilian palpigrades. The number of propeltidial setae is also distinctive in the new species. While most species of palpigrades carry 10 + 10 setae on the propeltidium, Eukoenenia audax carries 7 + 7. This character is shared with only 7 other species of Eukoenenia : E. maquinensis , E. sagarana , E. navi , E. eywa , E. neytiri and E. magna from Brazil , and with E. naxos Condé, 1989 from Greece ( Condé 1989 ; Souza & Ferreira 2010 , 2012a , 2018 , 2020 ). The presence of 2 thickened setae ( a 1 , a 2 ) and one seta ( s ) on sternites IV–VI relates the new species with some other Brazilian species, as discussed above, but also with E. improvisa Condé, 1979 , E . lyrifer Condé, 1992 , E. pauli Condé, 1979 and E. thais Condé, 1988 . All these other species have a different deutotritosternal setae formula (1 vs . 5–7), number of setae on propeltidium (7 + 7 vs . 10 + 10) and smaller legs, i.e . IVbta 215–238 vs . 62–117 (Note: for E. thais Condé reported two values for IVbta, 117 and 223) ( Condé 1979a , 1979b ; 1988 ; 1992 ).