The Bythocytheridae Sars, 1866 is one of the oldest families of cytheroidean Ostracoda, with a fossil record dating back to the Silurian. During the Cenozoic this family became one of the main constituents of the deep-sea ostracod faunas, with some taxa reaching wide geographic distribution. Bythocytherids are, therefore, important for the understanding of evolution and paleobiogeography in marine Ostracoda. The main purpose of this paper is to present a study of the tribes Bythocytherini Sars, 1926 and Jonesini Schornikov, 1981 through the analysis of 47 sediment samples collected from 12 sites in the Rio Grande Rise and adjacent areas. The 11 species herein recorded are attributed to the genera Bythocythere Sars, 1866 (four species), Bythoceratina Hornibrook, 1952 (two species), Retibythere Schornikov, 1981 (two species), Rhombobythere Schornikov, 1982b (two species), and Ruggieriella Colalongo and Pasini, 1980 (one species). The occurrence of the bythocytherid species in the study area seems strongly influenced by the bathymetry, being more abundant in the shallowest site (~1,250 m) and absent beyond 3,000 m water depth.

ABSTRACT Scleropactidae are one of the most abundant families of Oniscidea, comprising 28 genera. Within this family, the genus Circoniscus includes 13 species, of which four are troglobitic. We herein describe the fifth troglobitic species of the genus, which represents the first species described from the largest limestone cave of the Brazilian Amazon, Paraíso cave. Circoniscus paradisus sp. nov. differs from the troglobitic species by the presence of schisma on pereonite 1 in all specimens, antennula with 2+9 aesthetascs, distal margin of male pleopod 1 exopod elongated, and pereonites epimera inner face with continuous ridge. Additionally, we provide ecological notes, habitat description, and the conservation status for the newly described species.

Abstract The present study reports the first zoogeographical record of the squat lobster Munidopsis lauensis Baba and de Saint Laurent, 1992 from a cold-seep site in the Krishna-Godavari Basin (Bay of Bengal), Northern Indian Ocean. Molecular analysis of the partial mitochondrial gene coding for cytochrome C oxidase subunit I (COI mtDNA), and mitochondrial 16S ribosomal RNA (16S rRNA) validated its identity. The present observation extends its geographical distribution to the Northern Indian Ocean. Additionally, molecular barcodes (COI) were generated for Munidopsis scobina Alcock, 1894, Munidopsis wardeni Anderson, 1896, and Shinkaia crosnieri Baba and Williams, 1998 collected from the Indian Exclusive Economic Zone.

Abstract The talitrid Cryptorchestia garbinii is a terrestrial and riparian European amphipod, distributed throughout the continent and well-known as a recent invader of the shores and banks of many water bodies. In the last decades, the species significantly expanded its range in the Balkans. First records of this species in Serbia are presented here and include descriptions of the habitats. The species was found at several localities alongside the Danube at the Iron Gates. The species was first observed in the Serbian section of the river in 2017. Abundance at this time was very high indicating that colonization almost certainly occurred much earlier. We discuss possible reasons why the species was not detected in Serbia before, as well as probable ways of its arrival and spread. Even though C. garbinii is the eighth allochthonous amphipod detected in Serbia, it is the first semiterrestrial representative, and also, the first one from the infraorder Talitrida recorded in the country.

The study investigated the population parameters of the shrimp Xiphopenaeus spp. (commonly known as seabob shrimp) in Anchieta, south coast of the state of Esprito Santo, Brazil, focusing on reducing the sampling effort. Shrimp were collected between February 2013 and February 2015. Individuals were measured, analyzed for sex and stage of reproductive development. In total, 1,564 individuals were analyzed in Anchieta, 534 males (74 juveniles and 460 adults) and 663 females (88 juveniles and 575 adults), and 367 individuals were not identified to sex or maturity. Significant differences were observed in shrimp abundance, with higher catches at the shallowest sampling point and associated with the type of substrate (silt+clay), while in the rainy season (September to March) and dry season (April to August) there were no significant differences. Despite this, greater abundances were found in the rainy season. The sex ratio was 0.80: 1. Carapace length ranged from 5.7 to 28.9 mm, with larger sizes recorded for females, as well as a larger size at first maturation than males, 12.86 and 11.60 mm respectively. All stages of development of the seabob shrimp were observed at the sampling points and periods, which represents a pattern of continuous reproduction and recruitment of the species in the area. Considering the sample size used, which is comparatively smaller than other studies, all estimates confirm current knowledge about the biology of the species and provide robust data on the seabob shrimp off the Anchieta coast, which are necessary for management and conservation.

We propose a new species of the troglobitic genus Spelaeogammarus da Silva Brum, 1975, with data on its distribution, ecology, aspects of behavior, and conservation status. Spelaeogammarus ginae sp. nov. occurs in a single cave in the Serra do Ramalho karst area, of the northeastern Brazilian semi-arid region. We also provide new data on the distribution and conservation status of its congener, Spelaeogammarus spinilacertus Koenemann and Holsinger, 2000 that occurs in the upper phreatic aquifer inside caves from Chapada Diamantina domain. Both species occur in caves in the state of Bahia, northeastern Brazil.

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 Clausidium Kossman, 1874 is a genus of copepods that is found in subtropical to temperate coastal areas. All species of the genus occur on the bodies of mud shrimp of the families Callianassidae and Upogebiidae. Based on morphological data from light scanning and confocal laser scanning microscopy, there are four species of Clausidium copepod in Iran. In this study we address Clausidium iranensis Sepahvand, Kihara and Boxshall, 2019 and Clausidium persiaensis Sepahvand and Kihara, 2017 that were reported on the body of the burrowing shrimps Neocallichirus jousseaumei (Nobili, 1904) and Callianidea typa Milne Edwards, 1837, respectively. We undertook analyses of mitochondrial DNA gene sequences (CO1) to evaluate taxonomic status and taxonomic relationships of the Clausidium species. The result demonstrates that two major clades, with strong support, can be identified within the Clausidium copepods in the southern waters of Iran, representing distinct taxonomic entities at the species rank. Our data indicate that CO1 can be a powerful tool for species identification and delimitation. In the case of Clausidium copepods, the general utility of CO1 for taxonomic relationship inferences within a genus or a family is still under investigated. Our study adds the first genetic data from these copepods from the Persian Gulf and Gulf of Oman.

Abstract Deep-water brachyuran crabs collected from the Indian Exclusive Economic Zone by the Fishery Oceanographic Research Vessel “Sagar Sampada” in the southeastern Arabian Sea (50 m depth), southwestern Bay of Bengal (307 m depth), and in the vicinity of the Andaman and Nicobar Archipelagos (271-535 m depth) were studied. They are referred to Sphaerodromia kendalli (Alcock and Anderson, 1894) and Sphaerodromia nux Alcock, 1900 (family Dromiidae), Intesius brevipes sp. nov. (family Mathildellidae), Tunepugettia corbariae B.Y. Lee, Richer de Forges and P.K.L. Ng, 2019 (family Epialtidae), Cyrtomaia suhmii Miers, 1885 (family Inachidae), Chaceon alcocki Ghosh and Manning, 1993 (family Geryonidae), and Sphenomerides trapezioides (Wood-Mason, 1891) (family Trapeziidae). Sphaerodromia nux and T. corbariae are new records from Indian waters. The first male specimen of C. alcocki is reported, with a description of the male first gonopod. Intesius brevipes sp. nov. is the fifth species of the genus, differing from the four known congeners in the form and setation of the carapace, distinctly curved and granular anterolateral margins, and shorter pereopods with much slender merus and carpus articles.

Abstract Santaremicaris gen. nov. is proposed to accommodate Santaremicaris amazonensis sp. nov., a new species collected by Noodt from the hyporheic zone of the Amazonas River at Santarem, Brazil, and Parastenocaris santaremensis Noodt, 1963, which is redescribed and designated as the type species of the new genus. The new genus is recorded also from several localities of the Amazonian hydrographic basin. Santaremicaris gen. nov. is well supported by clear autapomorphies, e.g., 1) the absence of distal spinules on the endopod of the second swimming leg of the male, which is ornamented with strong outer spinules along the first 2/3 of the segment and armed with a long distal seta the insertion area of which covers almost the whole width of the segment; 2) the presence of a triangular, short and strongly sclerotized endopod on the fourth swimming leg of the male; and 3) the presence of a long and slim male fifth leg ending in a long distal spiniform process, with irregular margins, armed with only three setigerous elements on the outer margin, and reaching the middle of the subsequent urosomal segment or beyond it. The new genus is closely related to Murunducaris Reid, 1994, with males sharing conspicuous ornamentation on the inner margin of the first swimming leg basis, represented either by an enlarged spinule accompanied by minute accessory spinules or by a row of strong spinules. In addition, the males of both Murunducaris and Santaremicaris gen. nov. share an enlarged intercoxal sclerite with a median process on the fifth leg.