The genus Alloniscus Dana, 1854 includes 23 known species occurring exclusively in littoral habitats. The genus has never been recorded from the Atlantic coastal region of the Americas. This work describes the new species Alloniscus buckupi n. sp. from João Pessoa, Paraíba, Brazil, and provides the first record of the genus from the Atlantic coastal region.

All species of Brazilian terrestrial isopod known up to date, including references and distribution information, are listed. The list comprises 189 valid species, 135 of which are endemic to the country, 22 are recorded also from other countries in the Americas, 20 are introduced, and 12 have circumtropical or pantropical distributions.

The genus Pectenoniscus Andersson, 1960 currently presents two described species, one epigean, Pectenoniscus angulatus Andersson, 1960, from Nova Teutônia municipality, Santa Catarina state (Southern Brazil) and the hypogean Pectenoniscus liliae Campo-Filho, Bichuette and Taiti, 2019, found in two caves in the Serra do Ramalho karst area (Carinhanha municipality), Bahia state (northeastern Brazil). Recent surveys in karstic areas of Minas Gerais and Bahia revealed six new cave species from this genus, which are herein described. Two species occur in Minas Gerais state in the transition between the biomes Cerrado (Brazilian savannah) and Caatinga (mesophytic and xeromorphic forests): Pectenoniscus montalvaniensis n. sp. from Abrigo da Ema cave (Montalvânia municipality) and Pectenoniscus juveniliensis n. sp. from Gruta do Tabuleirinho cave (Juvenilia municipality). The other four species were found in Bahia state, in Caatinga biome: Pectenoniscus iuiuensis n. sp. from Baixa da Fortuna cave (Iuiu municipality); Pectenoniscus carinhanhensis n. sp. from three caves in Serra do Ramalho (Carinhanha municipality); Pectenoniscus santanensis n. sp. from Gruta do Padre cave (Santana municipality); and Pectenoniscus morrensis n. sp. from Gruta dos Brejões cave (Morro do Chapéu municipality). Aside from the taxonomic descriptions, we provide ecological notes for each described species, as well as an identification key for Pectenoniscus.

In the present work, five new species of Xangoniscus are described, increasing to eight the number of the known troglobitic species for the genus. Xangoniscus species can be distinguished from each other by the shape of pleonites epimera, the number and size of aesthetascs in the distal article of antennula, the modifications on pereopods, the shape of male pleopods and the proportion between uropod rami. Species from this genus are known for the states of Minas Gerais and Bahia with Xangoniscus aganju representing the northernmost occurrence, and X. lundi n. sp. and X. dagua n. sp. the southernmost occurrences. Of the six caves where specimens were collected, four are not registered in the national speleological database, what points to all the potential to yet be discovered regarding number of cavities and the associated biodiversity in Brazil. Some of the here mentioned type localities are not located inside protected areas, therefore exposing the species to risks related to the adjacent land use and consequent influence on water table level and input of food resources. The contribution of this work with descriptions of new troglobitic species provides support to consider them as plausible candidates to be assessed in the next list of threatened species as well as to elaborate conservation actions for the species, the caves where they inhabit and the surrounding landscape.

To date, approximately 190 species of terrestrial isopods are known from Brazil and only 14 are considered troglobiotic. After the examination of a large collection from caves in Bambuí and Una geomorphological areas, along the states of Bahia, Minas Gerais and Goiás, two new troglobiotic species were recognized. Pectenoniscus liliae Campos-Filho, Bichuette & Taiti sp. n. (Styloniscidae) is described from Serra do Ramalho karst area, and Benthana xiquinhoi Campos-Filho, Bichuette & Taiti sp. n. (Philosciidae) from sandstone caves of Chapada Diamantina region. The latter constitutes the second troglomorphic species of the genus. Xangoniscus aganju (Styloniscidae) is also recorded from two caves in the Serra do Ramalho karst area. The systematic position of Iuiuniscus iuiuensis is briefly discussed and Venezillo congener (Armadillidae) is redescribed from São Domingos karst area.

Two new species of Hyalella from Brazil are described. Hyalella veredae sp. n. shows the following characters: eyes reduced or absent in some specimens; antenna 1 and antenna 2 of similar size, and a curved seta on the inner ramus of male uropod 1. Hyalella formosa sp. n. is characterized by the absence of eyes, antenna 1 longer than antenna 2 and a curved seta on the inner ramus of male uropod 1. The species were found on caves located in two private properties, both under the impact of agricultural activities, which demonstrates a potential threat to these subterranean environments.