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. described sp nov Iuiu Carinhanha State Brazil such deforestation andor or realm Additionally D Rurópolis environments

Abstract Spelunconiscus Campos-Filho, Araujo and Taiti, 2014 is a monotypic genus of the family Styloniscidae represented by a troglobitic species, Spelunconiscus castroi Campos-Filho, Araujo and Taiti, 2014, from the cave MOC-32, in the state of Minas Gerais, southeastern Brazil. New representatives of this family were found in three additional caves, which revealed a new species, Spelunconiscus septemlacuum sp. nov., from Taboa and Tatuzinhos caves and a new occurrence for the type-species in Retiro cave. The original diagnosis of Spelunconiscus is emended due to the discovery of a spur-like structure in the male pereopod VII ischium, as well as some supplementary traits that have not been previously considered. Spelunconiscus septemlacuum sp. nov. differs from S. castroi in the number of articles of the antennal flagellum, in the proportion between this flagellum and 5th article of peduncle of antenna, in the size of maxilliped endite, in the morphology of male pleopod II and in body size. A discussion is provided for both taxonomic and ecological concerns.

Abstract 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.

Abstract The reproductive aspects of populations are important determinants of their ability to maintain themselves throughout time. In the case of amphipods from the genus Hyalella Smith, 1874, the reproductive period is easily determined by the presence of ovigerous females and pre-copula pairs in the population. This study evaluated the fecundity, pairing patterns and reproduction period of Hyalella carstica Bastos-Pereira and Bueno, 2012 in a karst environment in the West of Minas Gerais, Brazil. Monthly, from April, 2010 to April, 2011, amphipods were sampled using a hand net with 15 cm diameter and 250 µm mesh size. In the laboratory, animals were sexed and measured, and the ovigerous state of females was evaluated. Couples in pre-copula and ovigerous females were found throughout the year, with the exception of the dry months (September−November). During drought, the stream's superficial water dried out, and only a few refuges for the population remained. Although couples were found in all months with a water flow, a higher number of unpaired males and females was found after the dry season. In all months, ovigerous females were more abundant than non-ovigerous, and the relationship between head length and the number of eggs in the marsupium was positive. Most eggs were in the first developmental stage, although all other stages were found before the dry season. Considering the frequency of pre-copula pairs, as well as ovigerous females, the reproduction in this H. carstica population seems to be continuous throughout the year, without a distinct peak.

To the present 57 species of Hyalella were described for Americas, 15 of them found in Brazil, which is among the most diverse countries for this genus. This work aims to describe a new Hyalella species with benthic habits which is found in a water source on Southeastern Brazil. It is mainly characterized by a wide truncated process formed near the dactylus insertion on gnathopod 2, besides both coxal and sternall gills present on pereonits 2 to 7. This work improves the knowledge on biodiversity about Hyalella species.