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The order Ingolfiellida (Crustacea, Peracarida) represents a small group of peracarid crustaceans, usually less than 3 mm long and comprising 53 species in several ecosystems worldwide. Previously, eight ingolfiellid species had been documented from the Intra-Americans Sea: one from the Gulf of Mexico and eastern Florida and seven from the Caribbean Sea, including the Bahamas. A new deep-sea species of Ingolfiella is described based on material collected from bathyal soft bottoms (2650 m depth) offshore Veracruz State, southern Gulf of Mexico. The new species can be differentiated as follows: accessory flagellum 2-articulate; antenna 2 flagellum 4-articulate; pereopods 5-6 with long curved seta on dactylus; rami of uropod 1 subequal in length; uropod 3 ramus longer than peduncle, unarticulated; pleopods 1-3 as long as pleonal segments; maxilla 1 inner plate with one tiny seta distally; mandible without palp; molar poorly developed; pleopods reduced; telson as a fleshy ovoidal lobe with two slender dorsal setae. A table and a map featuring the nine ingolfiellids recorded in the Gulf of Mexico, the Caribbean Sea, and eastern Florida are also provided. The new species increases the number of Ingolfiella species to 35 worldwide, representing the second record of ingolfiellids from the Gulf of Mexico. [ABSTRACT FROM AUTHOR]

The shallow Vrana Lake in Dalmatia, Croatia, is directly connected to the Adriatic Sea by the Prosika canal (0.85 km), constructed in the eighteenth century. The aim of this research was to examine the impacts of salinization on long-term changes in littoral macro-crustacean (Malacostraca) populations and assemblages in Vrana Lake and connecting canals. Benthic macroinvertebrates were sampled at seven sites during the period 2011–2020 (14 months) using a hand net (25 × 25 cm, 500 µm). During the study period, saltwater intrusions (strongest in 2012) through the Prosika Canal and site V4 caused increased salinization, resulting in a shift from normal oligohaline (0.5–5 PSU) to mesohaline (5–18 PSU) salinity. Out of a total of 18 macro-crustacean taxa identified, five widespread species—amphipods Echinogammarus stocki and Gammarus aequicauda, isopods Lekanesphaera hookeri and Proasellus coxalis, and decapod Palaemon antennarius constituted 91.6% of collected specimens (26,986). The first three brackish/marine species were significantly positively correlated with the average salinity 12 and 24 months before sampling. They disappeared or had very low abundance during the second low salinity phase (< 1–2 PSU), when freshwater/oligohaline P. coxalis and P. antennarius were the dominant macro-crustaceans. Two years of low salinity were needed for a strong population decline or disappearance of three brackish/marine species. Salinization is a major stressor in the Vrana Lake basin, and measures for its active control are urgently needed. The use of tested macro-crustacean metrics is recommended for future ecological monitoring as it could provide fast information about the effects of water management on aquatic biodiversity. [ABSTRACT FROM AUTHOR]

Malacostracans are significant in several environmental processes, making them a major biotic component in aquatic ecosystems. An investigation on the spatio-temporal variations in the diversity and abundance of malacostraca was carried out in the Kallada River for a period of two years from 2019 to 2021. The malacostracan community was represented by 35 species in 17 families and 4 orders during the investigation period. Decapods (24 species), amphipods (7 species), isopods, and tanaids (2 species each) were identified from the Kallada River. Seasonally, PoM (Post-monsoon) witnessed the presence of 33 species closely followed by PrM (Pre-monsoon) and MoN (Monsoon) with 32 species each. The amphipod species Melita zeylanica belonging to the family Melitidae dominated in terms of abundance throughout the study period. Diversity, richness, and dominance indices were increased from the upstream to downstream sites. Contrarily, the highest values of evenness were recorded the upstream and lowest recorded downstream. Diversity analysis values were maximum at downstream sites during the PrM season while the abundance was maximum during the PoM season. Multivariate tools such as CCA (canonical correspondence analysis) and hierarchical clustering were applied to investigate the co-existence of various malacostracan taxa and the relation between the species and water quality parameters. Similar feeding habits and water quality requirements allowed the co-occurrence of malacostracan species. CCA indicates the freshwater and estuarine influences on malacostracan diversity and abundance. The study also assessed the detrimental effects of sewage and municipal effluents on malacostraca at the midstream stations. However, the low diversity at the upstream stations was attributed to the natural environmental conditions. [ABSTRACT FROM AUTHOR]

Owing to the “Racovitzan impediment”, the groundwater fauna of most biogeographical regions is currently inadequately known, thus hampering our understanding of subterranean biodiversity and its protection. Based on an extensive bibliographical review accompanied by fieldwork to localize occurrence sites, a checklist of crustacean taxa reported to date from Sicilian groundwater is provided, and their distribution is described. Among the 63 taxa recorded to date, 43 belong to the class Copepoda (orders Cyclopoida and Harpacticoida), 15 to the class Malacostraca (orders Amphipoda, Bathynellacea, Isopoda, and Thermosbaenacea), and 5 to the class Ostracoda (order Podocopida). Conversely, to date, no representatives of the copepod order Calanoida nor species of the class Branchiopoda have been recorded from groundwater habitats on the island. Several taxa require accurate taxonomic revision or are yet to be formally described and are thus at present left in open nomenclature. Finally, the date of publication of several copepod and amphipod taxa is amended. A high incidence of stygobites (i.e., obligate groundwater dwellers) has been observed in malacostracans, whereas nearly half of the recorded copepods were non-stygobites. This pattern is mirrored by the incidence of endemic species, which is higher in malacostracans than in copepods. The only non-stygobitic crustacean species endemic to Sicily observed in the frame of present review is the asellid isopod Proasellus montalentii. The paucity of information currently available on the Sicilian groundwater ostracods prevents us from drawing conclusions regarding this crustacean group. The origin and composition of Sicilian groundwater crustacean fauna can be explained by considering three major faunal assemblages: the presence of ancient paleoendemic taxa, likely of Miocene origin, the colonization of the groundwater of the island during late Pliocene and Pleistocene land connections with peninsular Italy, and the direct colonization of these environments from the sea; no species of African origin have been discovered to date. Based on currently available data, the groundwater of southeastern Sicily hosts the highest species richness and some of the most biogeographically interesting taxa. Unfortunately, a progressive lowering and salinization of the local aquifers possibly due to climate change and its overexploitation threats this fauna, and several taxa are disappearing even before their discovery and description.

Christoph D. Schubart is remembered as an outstanding carcinologist who left behind an enormous scientific legacy and a huge collaborative network with scientists from all over the world. Throughout his career, Christoph was also able to compile an extremely valuable crustacean collection, including physical specimens, DNA extracts, and tissues of many thousands of specimens. After his sudden death in early 2023, these valuable collections have been transferred from the University of Regensburg to the Leibniz Institute of Biodiversity Change (LIB). Molecular samples are now housed at the LIB Biobank in Bonn (ZFMK), and the physical specimens are deposited at the LIB Crustacea Collection in Hamburg (ZMH). The collections include marine (70%), freshwater (25%) and terrestrial (5%) material from all over the world. A preliminary list of the taxa potentially included in the collections is provided herein, which includes approximately 375 genera, 104 families, nine orders, and two crustacean classes. This note aims to provide the first insights into the Schubart collections and to encourage the scientific community to use this resource extensively, preserving the scientific legacy of Christoph Schubart, thus inspiring new emerging questions on decapod research. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the seasonal distribution of the Malacostraca fauna in the Seyhan Basin by examining their relationship with some physicochemical parameters. Field studies were done in the spring, summer, and autumn of 2019 at 23 stations. As a result, 4302 individuals were examined, and 5 families (Niphargidae, Gammaridae, Palemonidae ve Potamidae) and 10 species belonging to the orders Amphipoda and Decapoda were recorded. Echinogammarus ischnus, Gammarus mladeni and G. pseudanatoliensis are the first records for this basin. According to the results of the Shannon-Wiener diversity (H) index, the highest diversity was calculated at station 11 in the spring (0.72), at station 22 (0.66) in the summer and autumn, the lowest diversity was recorded at station 3 in the spring (0.22) and autumn (0.05), and at station 1 in the summer (0.17). According to Shannon Evenness (E), the most balanced distribution was found at station 22 in the spring and summer (0.97), and at station 1 in the autumn (0.96). The stations with the lowest homogeneity were determined as at station 3 in the spring (0.22) and autumn (0.53), and at station 1 in the summer (0.59). According to the results of the clustering analysis, the highest similarity was observed between the 3rd and 5th stations (89%), while the 2nd station was determined to be the station with the lowest similarity, separating from all other stations. According to the Pearson correlation analysis, a significant negative correlation was observed between DO and temperature and total nitrogen, while a significant positive correlation was found between temperature and EC (P<0.01). When the water quality classes of the stations are examined according to the criteria of the Water Quality Regulation, stations have 1st (very clean) or 2nd (moderately polluted) class water quality. [ABSTRACT FROM AUTHOR]

Crabs are a large subtaxon of the Arthropoda, the most diverse and species-rich metazoan group. Several outstanding questions remain regarding crab diversification, including about the genomic capacitors of physiological and morphological adaptation, that cannot be answered with available genomic resources. Physiologically and ecologically diverse Anomuran porcelain crabs offer a valuable model for investigating these questions and hence genomic resources of these crabs would be particularly useful. Here, we present the first two genome assemblies of congeneric and sympatric Anomuran porcelain crabs, Petrolisthes cinctipes and Petrolisthes manimaculis from different microhabitats. Pacific Biosciences high-fidelity sequencing led to genome assemblies of 1.5 and 0.9 Gb, with N50s of 706.7 and 218.9 Kb, respectively. Their assembly length difference can largely be attributed to the different levels of interspersed repeats in their assemblies: The larger genome of P. cinctipes has more repeats (1.12 Gb) than the smaller genome of P. manimaculis (0.54 Gb). For obtaining high-quality annotations of 44,543 and 40,315 protein-coding genes in P. cinctipes and P. manimaculis , respectively, we used RNA-seq as part of a larger annotation pipeline. Contrarily to the large-scale differences in repeat content, divergence levels between the two species as estimated from orthologous protein-coding genes are moderate. These two high-quality genome assemblies allow future studies to examine the role of environmental regulation of gene expression in the two focal species to better understand physiological response to climate change, and provide the foundation for studies in fine-scale genome evolution and diversification of crabs. [ABSTRACT FROM AUTHOR]

The key points of the main evolutionary line of Articulata, leading from polychaetes to insects, are considered. The far-reaching similarity of the most primitive insects, jumping bristletails, with malacostracans, especially syncarids, leaves no doubt about the origin of the former directly from the latter. The similarity of mayfly nymphs to bristletails indicates that the evolution of Pterygota began with amphibiotic Palaeoptera. Myriapods are secondarily simplified descendants of early hexapods, having lost the division of the body into the thorax and abdomen and other ancestral characters due to transition to a cryptic lifestyle. Entognathous hexapods illustrate the initial stages of myriapodization of bristletails. Following Sharov, insect ancestry can be traced back into deep time via crustaceans to trilobitomorphs, Megacheira, and further to the most ancient arthropods, dinocarids—with grasping antennae but without walking legs! Many structural features of arthropods were formed in Polychaeta—the most primitive Articulata. The group most similar to arthropods are scale worms (Aphroditacea). By analogy with myriapods and entognaths, lobopods and non-arthropodan Ecdysozoa should be interpreted as side branches, which emerged from the dinocarid root of Arthropoda and simplified their body plans. Transformations of body plans occurred through heterochronies and heterotopies (including gamoheterotopies). [ABSTRACT FROM AUTHOR]

This present paper presents an inventory of benthic Malacostraca in the Gulf of Oran. The softbottom crustacean fauna was studied between February 2021 and September 2021. Samples were collected from 8 coastal stations. The class Malacostraca was represented with 2 subclasses, Eumalacostraca and Phyllocarida. Sixty-one species and 290 individuals belonging to seven crustacean orders (Amphipoda, Decapoda, Isopoda, Tanaidacea, Mysida, Lophogastrida and Leptostraca) were identified. Amphipoda were represented with the highest number of species (36) followed by Decapoda (11) and Isopoda (6). Tanaidacea and Mysida were poorly represented, with 3 and 2 species, respectively. Lophogastrida and Leptostraca were both represented by only one species. Among the crustaceans encountered, Ampelisca was the most dominant genus. The present inventory indicates that the carcinological fauna in the Gulf of Oran is less diversified than it is in other zones that have been studied on the Algerian coast (Gulf of Arzew, Bay of Bou-Ismail, and Bay of Algiers). [ABSTRACT FROM AUTHOR]

Based on newly collected material from the Iraqi coast, the status of the common intertidal snapping shrimp, Alpheus lobidens De Haan, 1849 species complex, is discussed. Based on several morphological characteristics as well as the color pattern, the material examined herein strongly supports the validity of A. lobidens. [ABSTRACT FROM AUTHOR]

The clade Pancrustacea, comprising crustaceans and hexapods, is the most diverse group of animals on earth, containing over 80% of animal species and half of animal biomass. It has been the subject of several recent phylogenomic analyses, yet relationships within Pancrustacea show a notable lack of stability. Here, the phylogeny is estimated with expanded taxon sampling, particularly of malacostracans. We show small changes in taxon sampling have large impacts on phylogenetic estimation. By analyzing identical orthologs between two slightly different taxon sets, we show that the differences in the resulting topologies are due primarily to the effects of taxon sampling on the phylogenetic reconstruction method. We compare trees resulting from our phylogenomic analyses with those from the literature to explore the large tree space of pancrustacean phylogenetic hypotheses and find that statistical topology tests reject the previously published trees in favor of the maximum likelihood trees produced here. Our results reject several clades including Caridoida, Eucarida, Multicrustacea, Vericrustacea, and Syncarida. Notably, we find Copepoda nested within Allotriocarida with high support and recover a novel relationship between decapods, euphausiids, and syncarids that we refer to as the Syneucarida. With denser taxon sampling, we find Stomatopoda sister to this latter clade, which we collectively name Stomatocarida, dividing Malacostraca into three clades: Leptostraca, Peracarida, and Stomatocarida. A new Bayesian divergence time estimation is conducted using 13 vetted fossils. We review our results in the context of other pancrustacean phylogenetic hypotheses and highlight 15 key taxa to sample in future studies. [ABSTRACT FROM AUTHOR]

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DM domain genes are a group of transcription factors that are integral to sexual development and its evolution in metazoans. Their functions and regulatory mechanisms are not well understood in Malacostraca (crabs and crayfish) while these sex regulators have been widely identified in the past decade. In this study, the Dmrt family was investigated in the decapod crab, Eriocheir sinensis. We find that most members of the EsDmrt family begin to enrich around the juvenile 1 stage. In reproductive organs, EsDsx1, EsDsx2, EsiDMY and EsiDmrt1a highly express in the male-specific androgenic gland (AG), while EsDmrt-like, EsDsx-like, EsDmrt11E, and EsiDmrt1b show relatively high expression in testis. Also, we find the highly aberrant expression of EsiDMY and EsiDmrt1a in the chimeric AG, strongly indicating their function in AG development. Moreover, RNA interference of EsDsx1, EsiDMY, and EsiDmrt1a results in a significant decrease in transcription of the Insulin-like androgenic hormone (IAG), respectively. Our findings suggest that Dmrt genes in E. sinensis primarily function in male sexual differentiation, especially in AG development. Besides, this study identifies two unique groups of Dmrt genes in Malacostraca: Dsx and iDmrt1. In Malacostraca Dsx, we uncover a cryptic mutation in the eight zinc motif-specific residues, which were firmly believed to be invariant across the Dmrt family. This mutation sets the Malacostraca Dsx apart from all the other Dmrt genes and implies a different way of transcriptional regulation. Genes from the iDmrt1 group show phylogenetical limitation to the malacostracan species and underwent positive selection, suggesting their highly specialized gene function to this class. Based on these findings, we propose that Dsx and iDmrt1 in Malacostraca have developed unique transcriptional regulation mechanisms to facilitate AG development. We hope that this study would contribute to our understandings of sexual development in Malacostraca and provide new insights into the evolutionary history of the Dmrt family. [ABSTRACT FROM AUTHOR]

Within Malacostraca, legs are diversified variously throughout the groups. Most conspicuous is the transformation of anterior thoracopods, especially the first, into maxillipeds involved in feeding. However, the concept of a maxilliped is not precise, because it relates to a vague combination of morphological and functional deviation from a locomotory limb. Although general homology of the first thoracopod (maxilliped or not) is beyond doubt, special homology (synapomorphy) of the anteriormost maxillipeds remains uncertain. For better insights, we studied the musculature and exoskeletal structures of the first thoracopods in Anaspidacea, Euphausiacea, Lophogastrida, Mysida and Stygiomysida, using three-dimesional reconstruction of laser scanning microscopy and micro-computed tomography data. Our analysis shows high muscular and skeletal complexity of the first thoracopods. We herein reject the term 'maxilliped' for Anaspidacea and Euphausiacea, because their first thoracopods differ little from the posterior limbs, although specific correspondences between these taxa might represent synapomorphies. The 'mysidacean maxilliped' is morphologically well derived from the posterior thoracopods and appears synapomorphic for the mysidacean subtaxa. A comparison with other Peracarida additionally shows correspondences indicating a homologous 'peracaridan maxilliped'. In contrast, we consider the peracaridan maxilliped not to be homologous to the decapodan maxilliped. As a distinction, we propose the term 'unguiped' for the peracaridan first thoracopod. [ABSTRACT FROM AUTHOR]

The aim of the study was to identify the species of the Malacostraca distributed in the estuarine habitats of the eastern part of the Black Sea of Turkey using both morphological and molecular data. Samples were collected from 11 stations in 2019–2020. Fifteen species were found. Eleven of them were identified based on sequences of COI gene region published in the GenBank and morphological differences. These were Echinogammarus foxi, Jassa marmorata, Dexamine cf. thea, Gammarellus angulosus, Amphithoe ramondi, Monocorophium insidiosum, Idotea balthica, Eriphia verrucosa, Pilumnus spinulosus, Pachygrapsus marmoratus and Palaemon elegans. Futher four species, i.e. Gammarus crinicornis, Lekanesphaeroma monodi, Pisidia bluteli and Tanais dulongi, were identified based on morphological data only. Due to the rapid degradation of the DNA of Malacostraca individuals and insufficient or partially incorrect information in the Genbank, genetic comparisons of some species could not be implemented. In order to solve this problem, it is discussed that species-specific primers have to be developed in future studies. [ABSTRACT FROM AUTHOR]

Los crustáceos eufausiáceos constituyen un grupo de 86 especies, conocidas como krill, que en general presentan una distribución muy amplia en todos los océanos, desde las aguas superficiales hasta los grandes abismos marinos. De ellos, 34 han sido citados para las aguas que circundan al archipiélago cubano. Sin embargo, son casi desconocidos en Cuba. La presente guía permite determinar las ocho especies que se han recolectado hasta el presente, con la consulta de las claves ilustradas originales que se ofrecen.

The production of wild crustacean larvae is crucial to Bangladesh's emerging shellfish industry. In the coastal zone of the northern Bay of Bengal, Bangladesh, environmental parameters and geographical and seasonal distribution patterns of the Malacostracan plankton stage (Subphylum: Crustacea) were studied. Plankton samples were collected from the surface using a bongo net. During the sampling period, four groups were identified: shrimp larvae, krill, crab zoea, and mantis shrimp larvae. Among them, almost 63% of krill were recorded, followed by shrimp larvae (21.1%), crab zoea (12.4%), and mantis shrimp larvae (3.4%). In addition, krill was the most abundant group at each station and season. One-way ANOVA was conducted to identify significant variation (P<0.05) in the mean larval abundance of crab zoea, shrimp larvae, krill, and mantis shrimp larvae based on the season of each group. A significant difference was observed among shrimp larvae, crab zoea, and mantis shrimp larvae during the season. However, krill abundance was not significantly different between seasons. Univariate analysis of correlations between stations and the abundance of crustacean groups was performed. Pairwise comparisons of mean anbundance showed significant variations between the identified four groups and three stations (Naf, Bakkhali and Rezu Khal estuaries). However, only the mean abundance of krill varied significantly with all the four stations (P<0.05). These results suggest that the abundance of Malacostracan crustaceans did not depend on stations; rather, their abundance varied significantly within seasons in the northern Bay of Bengal. [ABSTRACT FROM AUTHOR]

Chaetophiloscia hastata Verhoeff, 1928 is recorded from Saskhori limestone quarry (Mtskheta municipality, eastern Georgia). This is the first confirmed record of the genus and species for the Georgian isopod fauna. The species is fully illustrated to facilitate its identification. [ABSTRACT FROM AUTHOR]

To determine the Amphipoda (Crustacea) fauna of the inland waters of Western Anatolia, Marmara and the Turkish Thrace Region, field studies were conducted between May 2014 and March 2019. Sevenfieldstudieswereconducted.Samplingswereconductedat291localitiesandamphipodspecimens were found at 127 of them. As a result, 11 amphipod species (Echinogammarus stockiG.Karaman,1970,Gammarusaequicauda(G.Karaman,1970),GammarusanatoliensisSchellen-berg,1937,GammarusarduusG.Karaman,1975,GammarusbalcanicusSchäferna,1923,Gam-marusdorsosetosusMateus amp;Mateus,1990,GammarusgonensisÖzbek,2016,Gammarus komareki Schäferna, 1923, Gammarus lacustris G.O. Sars, 1863, Gammarus pulex pulex (Linnaeus, 1758), Gammarus uludagi G.S. Karaman, 1975) were determined. The new records can be listed as: E. stocki for Ekinanbarı, G. anatoliensis for Uşak, G. arduus for Bolu and Düzce, G. balcanicus for Kocaeli and Sakarya, G. dorsosetosus for Bolu, G. gonensis for Istanbul and Manisa, G. komarekifor Düzce and Kocaeli, G. lacustris for Istanbul, G. pulex pulex for Bolu, Kırklareli, Kocaeli, Sakarya and Uşak, and G. uludagi for Aydın, Bilecik, Sakarya and Yalova provinces. The observed morpho-logical features and the detailed drawings of the determined taxa are presented. Additionally, a map showing the distribution of the obtained species is also given.

The article provides information on amphipods found on two islands of the Lesser Kuril Chain collected during the period from 4 to 19 August 2013 in the framework of the 49th South Kuril Marine Expedition. A detailed morphological description of prophliantin amphipod Guernea ezoensis Ishimaru, 1987 — the species which has not been presented from Russian waters until now — is provided. The South Kuril specimens differ slightly from the original and accumulative descriptions. The article briefly discusses the issues of intraspecific morphological variability.

Abstract The natural history and conservation status of the West Indian endemic freshwater crabs of the genus Epilobocera are poorly known. Several species have restricted distributions and apparently specific ecological requirements, which make them particularly vulnerable to anthropogenic threats. Epilobocera capolongoi is known to occur exclusively in mountain streams and rivers above 300 m elevation in the Guamuhaya Massif, central Cuba. In addition to the publication with the original description, there is only one paper exclusively on this species, which reported it as being preyed upon by a heron and recorded it from some additional localities in the vicinity of Topes de Collantes, provinces of Cienfuegos and Sancti Spíritus. Epilobocera capolongoi is herein reported from Pico San Juan Ecological Reserve and Lomas de Banao Ecological Reserve, which expands its geographic range to about 60 km and its elevation to 1,000 m. The species was found living sympatric with the congeneric Epilobocera cubensis poliorcetes in Lomas de Banao Ecological Reserve, but apparently there exists some habitat segregation between them. Some phenotypic characters important to distinguish both species are described, some basic data on their natural history are provided, and an assessment of the conservation status of E. capolongoi following current IUCN criteria is made.

Abstract A new podocerid amphipod, Leipsuropus seisuiae sp. nov., from 338-340 m depth in the Kumano Sea, Japan, Northwestern Pacific, is described. This is the deepest record of any Leipsuropus species. Leipsuropus seisuiae sp. nov. is distinguished from four other congeneric species in having: i) pereonites 2-5 each with five narrow spiniform projections on tergal plate, ii) one dorsal tubercle on the telson, and iii) one small, proximal, denticulate projection on gnathopod-2 palmar margin. A key to males of the species of Leipsuropus is provided.

We describe a new tanaidid species, Zeuxo molybi sp. n., from Kominato, Chiba, Japan. Zeuxo molybi closely resembles the Japanese congener Zeuxo ezoensis, but differs in having (1) the pereopod-1 carpus without dorsodistal spiniform setae; (2) two or three ventrodistal simple setae on the pereopod-1 propodus in females, and three or four in males; and (3) the pereopod-6 propodus with four or five flattened denticulate setae. The two species also differ in the pattern of dorsal pigmentation on the carapace. Kimura 2-parameter distances between the two species were 15.6–16.9% for the cytochrome c oxidase subunit I (COI) gene and 2.8% for the 18S rRNA gene; the former value is much greater than intraspecific distances previously reported for Z. ezoensis (0–1.5%), confirming our conclusion from morphology that Z. molybi and Z. ezoensis are not conspecific. In a COI-based maximum-likelihood phylogenetic tree, the Japanese taxa Z. molybi, Z. ezoensis, and Z. cf. normani did not form a clade. [ABSTRACT FROM AUTHOR]

Abstract Environmental DNA (eDNA) analysis from water samples is a promising new method to identify both targeted species and whole communities of aquatic organisms. However, the current literature regarding eDNA shedding rates primarily focuses on fish and most decay rate constants are reported for warm sunlit waters. Here, we conducted experiments to investigate how eDNA shedding differs between animal forms and how long eDNA can persist in waters of varying temperature and light conditions. We designed quantitative PCR assays for one fish (mummichog, Fundulus heteroclitus), one crustacean (grass shrimp, Palaemon spp.), and two scyphomedusae (moon jelly, Aurelia aurita and nettle, Chrysaora spp.) to estimate eDNA shedding and decay rates. We found that shedding rates were highly variable for all organisms, but grass shrimp had the lowest shedding rate. We quantified eDNA decay rate constants at 6, 15, and 23°C and found that decay rate constants of mummichog and grass shrimp were larger at higher temperatures, while those of scyphomedusae did not show clear temperature dependence. We also found that higher‐order decay models with tails fit the data better than first‐order log‐linear models, suggesting temporal variability in eDNA decay rates. Results indicate that different animal forms shed different types of eDNA, impacting both shedding and decay rates. These findings fill critical knowledge gaps regarding variation in eDNA shedding and decay across animal forms under a range of realistic marine temperature conditions. These data will be useful for interpreting field studies that utilize eDNA to investigate ocean habitats that are otherwise difficult to access.

We report Afroapseudes cretacicus n. gen., n. sp. (Tanaidacea Dana, 1849; Apseudomorpha Sieg, 1980) from the Upper Cretaceous (Cenomanian-Turonian) of the Gara Sbaa layers (southeastern Morocco). The new species is considered as a possible lineage between the Jurassic and the more recent Paleogene Apseudomorpha, partially covering the wide gap of tanaidacean fossil records between Mesozoic and Cenozoic forms. At the same time, this results to be the first fossil record of a tanaidacean from Africa, enlarging the scarce knowledge on the real diversity and distribution of this poorly reported crustacean group during the geological times. [ABSTRACT FROM AUTHOR]

A new species of Leptostraca, Sarsinebalia agoensis sp. nov., from Ago Bay, Japan is described from specimens found at a depth of 120 m. The new species differs from other known Sarsinebalia species as follows: the compound eye has three distal lobes; the anterior margin of the first antennal segment has one distal process covered with setae; and the lateral margin of pleopod 1 exopod bears 5--6 simple, robust spines. A taxonomic key to all species of Sarsinebalia is also provided. [ABSTRACT FROM AUTHOR]

To determine the Amphipoda (Crustacea) fauna of the inland waters of Western Anatolia, Marmara and the Turkish Thrace Region, field studies were conducted between May 2014 and March 2019. Seven field studies were conducted. Samplings were conducted at 291 localities and amphipod specimens were found at 127 of them. As a result, 11 amphipod species (Echinogammarus stocki G. Karaman, 1970, Gammarus aequicauda (G. Karaman, 1970), Gammarus anatoliensis Schellenberg, 1937, Gammarus arduus G. Karaman, 1975, Gammarus balcanicus Schäferna, 1923, Gammarus dorsosetosus Mateus & Mateus, 1990, Gammarus gonensis Özbek, 2016, Gammarus komareki Schäferna, 1923, Gammarus lacustris G.O. Sars, 1863, Gammarus pulex pulex (Linnaeus, 1758), Gammarus uludagi G.S. Karaman, 1975) were determined. The new records can be listed as: E. stocki for Ekinanbarı, G. anatoliensis for Uşak, G. arduus for Bolu and Düzce, G. balcanicus for Kocaeli and Sakarya, G. dorsosetosus for Bolu, G. gonensis for Istanbul and Manisa, G. komareki for Düzce and Kocaeli, G. lacustris for Istanbul, G. pulex pulex for Bolu, Kırklareli, Kocaeli, Sakarya and Uşak, and G. uludagi for Aydın, Bilecik, Sakarya and Yalova provinces. The observed morphological features and the detailed drawings of the determined taxa are presented. Additionally, a map showing the distribution of the obtained species is also given. [ABSTRACT FROM AUTHOR]

The current knowledge of Sicilian inland water decapod malacostracans is scarce and an updated synopsis on species distribution is lacking. Therefore, we reviewed the checklist and recent distribution of Sicilian inland water decapods based on published and unpublished records and novel observations with the aim of providing an exhaustive repository, also to be used as a sound baseline for future surveys. Overall, five native decapod species occur in the study area, i.e., the atyid shrimp Atyaephyra desmarestii, the palaemonid shrimps Palaemon adspersus, P. antennarius, and P. elegans, and the freshwater crab Potamon fluviatile, and their current local distributions are described. In addition, three alien species were recorded: the common yabby Cherax destructor and the red swamp crayfish Procambarus clarkii, strictly linked to inland waters, and the Atlantic blue crab Callinectes sapidus, a mainly marine species that can also colonise the lower stretches of rivers and coastal brackish waters. The collected data suggest the existence of a partial segregation of native versus non-native species, with the latter currently confined to coastal water bodies and the lower stretches of rivers. Moreover, the exclusively freshwater caridean A. desmarestii and P. antennarius show a parapatric distribution in the study area, which may suggest the existence of mutual exclusion phenomena. The results obtained raise some concerns about the effects of alien species on the native biota, and dedicated monitoring and management strategies should be implemented in order to better understand and mitigate their impact. [ABSTRACT FROM AUTHOR]

The Shelta Cave Crayfish (Orconectes sheltae) is a small, cave-obligate member of the genus Orconectes (family Cambaridae) endemic to a single cave system--Shelta Cave--in northwest Huntsville, Madison Co., Alabama, USA. Although never abundant, this stygobiont was regularly observed in the 1960s and early 1970s before the population and aquatic community in general at Shelta Cave collapsed likely in response to groundwater contamination and the loss of energetic inputs from a Grey Bat (Myotis grisescens) maternity colony that abandoned the cave after installation of a poorly designed cave gate. We conducted 20 visual surveys of aquatic habitats at Shelta Cave between October 2018 and July 2021. Although the aquatic community has not recovered, we did confirm the continued existence of O. sheltae, which had not been observed in 31 years, with observations of an adult female on 31 May 2019 and an adult male on 28 August 2020. We conducted the first phylogenetic analyses of O. sheltae and discovered that the species is most closely related to other geographically proximate stygobiotic crayfishes in the genus Cambarus in northern Alabama than members of the genus Orconectes. We advocate for recognition of this species as Cambarus sheltae to more accurately reflect evolutionary relationships of this single-cave endemic and offer recommendations for its management, conservation, and future research, as this species remains at high risk of extinction. [ABSTRACT FROM AUTHOR]

Aeger crassipes, a penaeid shrimp from the Late Triassic (Carnian) of Cave del Predil (Raibl), Italy and Polzberg, Austria is revisited. Based on the restudied original material of Bronn and Glaessner, the species is considered poorly defined. Moreover, because of lack of important taxo-nomic characters on the preserved fossils the species cannot be assigned confidently on the genus level. We therefore treat it in open nomenclature and simultaneously refuse to suggest possible relationship with a particular genus. The resulting binomen is "Genus? crassipes". Such treatment may be used for fossil penaeoid shrimps of uncertain affinities rather than classifying them in the "catch-all" or "waste-basket" genera. [ABSTRACT FROM AUTHOR]

Biocoenosis of macrobenthic communities in relation to environmental and mangrove flora was studied in mangrove ecosystem of Cochin backwaters during 2010–2012 period. A total of 48 species in 45 genera belonging to 38 families of macrobenthos were collected with a mean numerical density of 1628 ± 2283 ind m−2. Malacostraca was the dominant taxa in terms of benthic density (55%) and diversity with 17 spp., then polychaeta (11 spp.), mollusca (9 spp.) and others (9 spp.). The dominant species were amphipods Idunella sp. (40,170 ind m−2), Cheiriphotis geniculata (34,169 ind m−2), polychaete Dendronereis aestuarina (38,808 ind m−2), tanaid Ctenapseudes chilkensis (29,419 ind m−2), bivalve Indosphenia kayalum (23,835 ind m−2) and oligochaete Tubificoides psuedogaster (16,946 ind m−2). The PCA and redundancy analysis revealed that the nature of the substratum determined by sediment texture, organic matter, total organic carbon, sediment nutrients were found to be an influencing factor in the differential distribution and community structure of macrobenthic organisms in mangroves of Cochin. Mangrove plant density also exhibited significant correlation with the density of macrofauna. This study has noted a decline in species composition as well as diversity and richness of macrobenthic fauna compared to the previous study notably polychaetes reported in 1993 in Cochin mangroves. Moreover, community structure exhibited significant change with newer associations of species especially opportunistic oligochaetes, corophiids and tanaids that are tolerant of various anthropogenic stressors. This change in community assemblage and biodiversity, thus demanding efficient management strategies for mangrove ecosystem through integrated planning, rehabilitation and periodic benthic faunal surveillance coupled with mangrove floral assessment. [ABSTRACT FROM AUTHOR]

The Indo-West Pacific emperor shrimp, Zenopontonia rex (Kemp, 1922) from the family Palaemonidae, was hitherto known as a peaceful symbiotic crustacean, feeding on very small organisms or detritus and other organic particles trapped in its varied hosts’ mucus. However, at two occasions in Indonesia, Z. rex was observed capturing and subduing relatively large and agile animals, representing completely new observations for the species’ diet and feeding behaviour. In the first case, Z. rex associated with the large chromodorid nudibranch Ceratosoma tenue Abraham, 1876 captured another palaemonid shrimp (Cuapetes sp.), only slightly smaller in size. In the second case, two individuals of Z. rex associated with a sea star, Echinaster luzonicus (Gray, 1840), were seen actively exploring the substrate under the star’s arms and one of them eventually captured and killed a juvenile/post-larval fish, probably a goby (Gobiidae). The second case represents one of the few in situ observations of a caridean shrimp killing a vertebrate. [ABSTRACT FROM AUTHOR]

Neural organization of mushroom bodies is largely consistent across insects, whereas the ancestral ground pattern diverges broadly across crustacean lineages resulting in successive loss of columns and the acquisition of domed centers retaining ancestral Hebbian-like networks and aminergic connections. We demonstrate here a major departure from this evolutionary trend in Brachyura, the most recent malacostracan lineage. In the shore crab Hemigrapsus nudus, instead of occupying the rostral surface of the lateral protocerebrum, mushroom body calyces are buried deep within it with their columns extending outwards to an expansive system of gyri on the brain’s surface. The organization amongst mushroom body neurons reaches extreme elaboration throughout its constituent neuropils. The calyces, columns, and especially the gyri show DC0 immunoreactivity, an indicator of extensive circuits involved in learning and memory.

The current knowledge of Sicilian inland water decapod malacostracans is scarce and an updated synopsis on species distribution is lacking. Therefore, we reviewed the checklist and recent distribution of Sicilian inland water decapods based on published and unpublished records and novel observations with the aim of providing an exhaustive repository, also to be used as a sound baseline for future surveys. Overall, five native decapod species occur in the study area, i.e., the atyid shrimp Atyaephyra desmarestii, the palaemonid shrimps Palaemon adspersus, P. antennarius, and P. elegans, and the freshwater crab Potamon fluviatile, and their current local distributions are described. In addition, three alien species were recorded: the common yabby Cherax destructor and the red swamp crayfish Procambarus clarkii, strictly linked to inland waters, and the Atlantic blue crab Callinectes sapidus, a mainly marine species that can also colonise the lower stretches of rivers and coastal brackish waters. The collected data suggest the existence of a partial segregation of native versus non-native species, with the latter currently confined to coastal water bodies and the lower stretches of rivers. Moreover, the exclusively freshwater caridean A. desmarestii and P. antennarius show a parapatric distribution in the study area, which may suggest the existence of mutual exclusion phenomena. The results obtained raise some concerns about the effects of alien species on the native biota, and dedicated monitoring and management strategies should be implemented in order to better understand and mitigate their impact.