Novo registro de Ctenorillo tuberosus (Budde–Lund, 1904) (Oniscidea, Armadilidae) para o Piauí

Abstract

Terrestrial isopods of the suborder Oniscidea are among the few groups of crustaceans adapted to terrestrial environments, with around 3,800 recognized species worldwide. These organisms possess important morphological and physiological adaptations, such as pleopodal lungs and a lipid cuticle, which have enabled their colonization of various habitats. In Brazil, terrestrial isopods of the family Armadillidae are represented by four genera, including Ctenorillo, whose species exhibit a high capacity for environmental adaptation. This study aimed to record the occurrence of the species Ctenorillo tuberosus Budde-Lund, 1904 in the state of Piauí, expanding its geographic distribution in Brazil. Collections were carried out by the GETOPI team between 2012 and 2016 at two distinct sites in the city of Picos-PI, and the specimens were preserved in 70% alcohol for sorting and morphological analysis. Taxonomic identification was based on the dissection of mouthparts, antennae, pereiopods, and pleopods, followed by comparison with specialized descriptions in the literature. Eleven lots containing specimens of the family Armadillidae were analyzed, all of which were identified as C. tuberosus. The species is characterized, among other features, by the presence of dorsal tubercles in series on the pereon, a specific arrangement of setae, and adapted mouthparts. Until now, this species had been recorded only in the states of Bahia and Ceará. Thus, this study reports for the first time C. tuberosus in Piauí, enriching knowledge about local biodiversity and the distribution of the family Armadillidae in northeastern Brazil, while also contributing to future research on Oniscidea in the region.