Cave-dwellers Diploexochus (Isopoda, Armadillidae): new species and new records of the genus from Brazil

Abstract

Two new species of Diploexochus are described. Diploexochus spinatus sp. nov. from Lapa do Honorato cave, located in the municipality of Iuiu, and Diploexochus obscurus sp. nov. from Água Escura I cave, located in the municipality of Carinhanha, both in the southwest of Bahia State, northeastern Brazil. Both species are likely to occur in caves due to anthropogenic impacts in the surrounding area (such as deforestation) and/or looking for the stable microclimatic conditions found in the subterranean realm. Additionally, D. echinatus is recorded in a cave in the municipality of Rurópolis, Pará State, northern Brazil. These represent the first records of the genus for subterranean environments.

Shedding light into Brazilian subterranean isopods (Isopoda, Oniscidea): expanding distribution data and describing new taxa

“…Several Armadillidae species belonging to other genera were incorrectly assigned to Diploexochus (see Schmalfuss 2003 for an overview). To date, the genus comprises three species exclusively distributed in South America, D. echinatus , D. obscurus Cardoso, Bastos-Pereira & Ferreira, 2023, and D. spinatus Cardoso, Bastos-Pereira & Ferreira, 2023 (Campos-Filho et al 2017; Cardoso et al 2023).…”

“…Diploexochus carrapicho Campos-Filho, López-Orozco & Taiti, n. sp. can be distinguished from the congeneric species in having the dorsal surface covered with spiny shaped tubercles and in the number and arrangement of the dorsal tubercles (see Campos-Filho et al 2017; Cardoso et al 2023). Moreover, it differs in having pereonite 2 epimera with ventral lobe directed outwards (vs downwards in D. echinatus and D. spinatus ), telson with distal margin slightly concave (vs distinctly concave in D. echinatus ; slightly convex in D. obscurus ; straight in D. spinatus ), mandibles with molar penicil semi-dichotomized (vs simple in all other species), and uropod protopod with distal part triangular (vs subrectangular in all other species).…”

“…In Brazil, more than 220 species of Oniscidea are known, of which 79 were recorded in caves. Among them, 38 are considered troglobites (obligatory cave-dwellers) and several are troglophiles (facultative cave-dwellers) (Trajano & Carvalho 2017; Campos-Filho et al 2018a, 2019, 2020, 2022a, b, c; Fernandez et al 2019; Cardoso et al 2020a, 2020b, 2021, 2022a, 2022b, 2023; Bastos-Pereira et al 2022). However, for some Oniscidea taxa, these subterranean categories were not properly assigned due to the lack of efficient sampling outside caves.…”