Caligusselenecola sp. nov. (Siphonostomatoida, Caligidae) parasitic on the hairfin lookdown Selenebrevoortii (Gill) from the Gulf of California, Mexico, with some comments on Caritustolii Rangnekar, 1984.

Specimens of a caligid copepod (Siphonostomatoida) were found on the gills of the hairfin lookdown Selenebrevoortii (Gill) (Carangidae) from off Mazatlán, Sinaloa (north-western Mexico). This material represents a new species of Caligus, C.selenecola sp. nov., and is assigned to the diaphanus species group. Within this group, only C.kapuhili Lewis, 1967, C.laticaudus Shiino, 1960, C.macrurus Heller, 1865, and C.selenecola sp. nov., have been described with a reduced outer spine 1 on the second exopodal segment of leg 1. These four species can be readily separated by the relative length of the abdomen, and the presence/absence of a process on the myxal area of the female maxilliped, the sternal furca, the postantennal process, and the spiniform process on the basal antennary segment. A full description of the new species is given with some comments on Caritustolii Rangnekar, 1984.

Topology Testing and Demographic Modeling Illuminate a Novel Speciation Pathway in the Greater Caribbean Sea Following the Formation of the Isthmus of Panama.

Recent genomic analyses have highlighted the prevalence of speciation with gene flow in many taxa and have underscored the importance of accounting for these reticulate evolutionary processes when constructing species trees and generating parameter estimates. This is especially important for deepening our understanding of speciation in the sea where fast moving ocean currents, expanses of deep water, and periodic episodes of sea level rise and fall act as soft and temporary allopatric barriers that facilitate both divergence and secondary contact. Under these conditions, gene flow is not expected to cease completely while contemporary distributions are expected to differ from historical ones. Here we conduct range-wide sampling for Pederson's cleaner shrimp (Ancylomenes pedersoni), a species complex from the Greater Caribbean that contains three clearly delimited mitochondrial lineages with both allopatric and sympatric distributions. Using mtDNA barcodes and a genomic ddRADseq approach, we combine classic phylogenetic analyses with extensive topology testing and demographic modeling (10 site frequency replicates x 45 evolutionary models x 50 model simulations/replicate = 22,500 simulations) to test species boundaries and reconstruct the evolutionary history of what was expected to be a simple case study. Instead, our results indicate a history of allopatric divergence, secondary contact, introgression, and endemic hybrid speciation that we hypothesize was driven by the final closure of the Isthmus of Panama and the strengthening of the Gulf Stream Current ~3.5 million years ago. The history of this species complex recovered by model-based methods that allow reticulation differs from that recovered by standard phylogenetic analyses and is unexpected given contemporary distributions. The geologically and biologically meaningful insights gained by our model selection analyses illuminate what is likely a novel pathway of species formation not previously documented that resulted from one of the most biogeographically significant events in Earth's history.

Basal levels of biochemical biomarkers in the freshwater prawn Palaemon argentinus and their alterations due to the exposure of both insecticides cypermethrin and spirotetramat.

The aim of this study was to evaluate the sensitivity of the prawn Palaemon argentinus to the pyrethroid cypermethrin (CYP) and the tetramic acid spirotetramat (STM). These treatments were compared with prawns collected at a reference site to define their basal physiological state. Initially, physicochemical parameters and several pollutants at the selected site were analyzed. The LC50-96 h was determined in adult prawns. Then, prawns were exposed for 96 h to sublethal concentrations of CYP (0.0005 µg/l) and STM (0.44 mg/l) to evaluate the effects on some biochemical endpoints. A treatment combining both pesticides was also added at 5 % of these values. Controls with and without solvent (acetone) were included. The LC50-96 h values were 0.005 µg/l and 4.43 mg/l for CYP and STM, respectively. Moreover, some biomarkers linked to oxidative and energy metabolism were analyzed in the hepatopancreas and muscle of both essayed prawns and those at the basal state. The STM caused a significant decrease in total protein content (32 %) in contrast to the increase of protein carbonyl content (71 %) (p < 0.05). Also, glutathione S-transferase (52 %) and catalase (61 %) activities in the hepatopancreas of exposed prawns were higher compared to both the control and state basal groups (p < 0.05). In muscle, only a significant decrease in the lactate content (69 %) was caused by STM (p < 0.05). In addition, CYP caused a significant increase in the lactate dehydrogenase activity (110 %) in muscle and triacylglycerol content (73 %) in the hepatopancreas (p < 0.05). The integrated biomarker index (IBRv2) analysis showed that STM caused greater damage than CYP. Besides, the combined treatment showed an antagonistic interaction between both insecticides. The differential response of biomarkers to both CYP and STM exposure with respect to their basal levels shows a high sensitivity of P. argentinus demonstrating its potential role as a bioindicator organism.

Infestation of Lithodes santolla by Eremitione tuberculata: spatial and temporal variations in parasite prevalence and effect on host growth.

The southern king crab (SKC) Lithodes santolla is a crustacean parasitised by the bopyrid Eremitione tuberculata. This study aimed to analyse spatial and temporal variations in E. tuberculata prevalence in the juvenile SKC population of San Jorge Gulf (SJG) and adjacent waters (Argentine Patagonia), and evaluate the effects of the parasite on SKC juveniles to improve our understanding of its impact as a disease on SKC health condition. Moult increment and body weight were compared between parasitised and unparasitised individuals. The prevalence of E. tuberculata in SKC juveniles varied both spatially and temporally. In the south of SJG, the prevalence was 54.5% (n = 11). Temporal prevalence analysis revealed values lower than 17.4% in mid SJG during May and September 2015. No significant differences were observed in E. tuberculata prevalence between sexes or among seasons. Eremitione tuberculata had a negative effect on SKC growth (lower body dry mass, moult increment and relative increment rate) in parasitised individuals. We hypothesised that the higher prevalence of E. tuberculata in the south SJG could be attributed to the retention of parasite larvae and the presence of the frontal system in this part of the gulf. The temporal variations could reflect host mortality. Our results suggest that bopyrid infestation may have a more important role than previously believed in the dynamics of the SKC population in mid-Patagonia.

Biodiversity of macroalgae-associated invertebrates in the marine protected area of Alcatrazes archipelago, southeastern Brazil / Biodiversidade de invertebrados associados a macroalgas na área marinha protegida do Arquipélago de Alcatrazes, sudeste do Brasil

Abstract This study describes and illustrates the biodiversity of macroinvertebrates associated to Sargassum and Dictyota seaweed habitats in the Alcatrazes archipelago, the largest Marine Protected Area (MPA) in the state of São Paulo, southeast Brazil. Assemblages were sampled during the summers of 2018, 2019 and 2020 and winter of 2018 at two sites on the main island. Macroalgae containing the associated fauna were collected at approximately 10 meters deep, with six samples at each site and in each sampling campaign. Sargassum fronds prevailed during summer collections, whilst were absent in the winter campaigns, when Dictyota was the most frequent seaweed. Among invertebrates, 32 species were exclusively found on summer months, associated to Sargassum beds, while 12 species were only registered on winter collection, in association with Dictyota. In total, 91 species were identified, belonging to 60 families, 19 orders, 7 classes and 3 phyla, including Arthropoda (Malacostraca and Pycnogonida), Mollusca (Gastropoda, Bivalvia and Polyplacophora), and Echinodermata (Ophiuroidea and Echinoidea). Among the 91 species found, 73 species are new records for the Alcatrazes archipelago marine area, thus revealing the expressive invertebrate biodiversity living in association with macroalgae beds in that area, which has still been little explored. No significant difference in species diversity was found between the two sites of Alcatrazes. In addition, few specimens of two invasive species were found: Perna perna (Mollusca: Bivalvia) and Ophiothela mirabilis (Echinodermata: Ophiuroidea), which underscores the importance of monitoring different habitats within MPAs to check for possible changes in the fauna over the years. As far as our knowledge, this is the first illustrated inventory of the seaweed-associated macroinvertebrate fauna within the Alcatrazes Archipelago, one of the largest MPAs in the Brazilian coast; besides unravelling its notorious biodiversity, this can act as a reference for future monitoring of local coastal diversity.

Resumo Este estudo descreve e ilustra a biodiversidade de macroinvertebrados associados a habitats de macroalgas pardas marinhas dos gêneros Sargassum e Dictyota no Arquipélago de Alcatrazes, a maior Área Marinha Protegida (AMP) do estado de São Paulo, sudeste do Brasil. As assembleias foram amostradas durante os verões de 2018, 2019 e 2020 e no inverno de 2018 em dois locais na ilha principal. As macroalgas contendo a fauna associada foram coletadas a aproximadamente 10 metros de profundidade, com seis amostras em cada local e em cada campanha amostral. Frondes de Sargassum predominaram nas coletas de verão, enquanto estiveram ausentes nas campanhas de inverno, quando Dictyota foram predominantes. Entre os invertebrados, 32 espécies foram encontradas exclusivamente nos meses de verão, associadas aos bancos de Sargassum, enquanto 12 espécies foram registradas apenas na coleta de inverno, em associação com Dictyota. No total, foram identificadas 91 espécies, pertencentes a 60 famílias, 19 ordens, 7 classes e 3 filos, incluindo Arthropoda (Malacostraca e Pycnogonida), Mollusca (Gastropoda, Bivalvia e Polyplacophora) e Echinodermata (Ophiuroidea e Echinoidea). Das 91 espécies encontradas, 73 espécies são novos registos para a área marinha do arquipélago de Alcatrazes, revelando assim a expressiva biodiversidade de invertebrados que vivem em associação com bancos de macroalgas naquela área ainda pouco explorada. Nenhuma diferença significativa de diversidade de espécies foi encontrada entre os dois locais de Alcatrazes. Além disso, foram encontrados poucos exemplares de duas espécies invasoras: Perna perna (Mollusca: Bivalvia) e Ophiothela mirabilis (Echinodermata: Ophiuroidea), o que ressalta a importância do monitoramento de diferentes habitats dentro das AMPs para verificar possíveis alterações na fauna ao longo dos anos. Até onde sabemos, este é o primeiro inventário ilustrado da fauna de macroinvertebrados associados a algas marinhas no Arquipélago de Alcatrazes, uma das maiores AMPs da costa brasileira; além de desvendar a sua notória biodiversidade, pode servir de referência para futuro monitoramento da diversidade costeira local.

Preliminary analysis of benthos of northeast Coatepeque Lake, El Salvador / Análisis preliminar del bentos del noreste del lago de coatepeque, el salvador

RESUMEN El conocimiento de la biodiversidad acuática de ecosistemas lénticos es escaso en muchas regiones del mundo. Por ello, se consideró importante realizar evaluaciones preliminares de la fauna bentónica de poca profundidad en tres franjas subacuáticas de muestreo entre los 0 a 10 m en una zona rocosa del área noreste del lago de Coatepeque, El Salvador. Las familias más abundantes fueron Thiaridae (Gastropoda), Hyalellidae (Malacostraca, Amphipoda) y larvas de Coenagrionidae (Insecta, Odonata) entre la orilla y 2,5 m de profundidad. En los sedimentos finos (10 m) se encontró una riqueza de especies y abundancia reducida en comparación a los estratos menos profundos, así como una gran cantidad de conchas vacías de caracoles de la familia Thiaridae y cápsulas cefálicas de larvas de quironómidos (Insecta, Diptera).

ABSTRACT The knowledge of aquatic biodiversity in lentic ecosystems is scarce in many regions of the world. Therefore, it was considered important to accomplish preliminary assessments of benthic fauna associated with low depths in three sampling subaquatic fringes between 0 and 10 m on a rocky shore along the northeast area of Coatepeque Lake, El Salvador. The most abundant families were Thiaridae (Gastropoda), Hyalellidae (Malacostraca, Amphipoda), and Coenagrionidae (Insecta, Odonata) from the edge to a depth of 2,5 m. A reduced species richness and abundance were found in fine sediments (10 m) in comparison to shallower strata, as well as a lot of empty shells of the Thiaridae family and cephalic capsules of chironomid larvae (Insecta, Diptera).

Microplastic contamination in the freshwater shrimp Macrobrachium amazonicum in Itacoatiara, Amazonas, Brazil.

The present study analyzed the presence of microplastics (MPs) in the shrimp Macrobrachium amazonicum, which is an economically important food that is consumed in several regions of the Brazilian Amazon. A total of 600 specimens of M. amazonicum were captured at two sampling sites (urban and rural area). A total of 2597 MP particles were recorded in the shrimps, with a significant difference between the two sites. The presence of MPs in the body parts also differed significantly. No significant difference was found between MPs abundance and sex of the shrimps. The size of the MPs did not differ significantly between the collection sites and between the body parts. Dark blue fiber-type MPs were the most abundant. A positive correlation was observed between the abundance of MPs and the total weight of shrimps. Raman spectroscopy identified the dark blue fibers as polypropylene and the FTIR technique identified the light blue fragments as nylon. The results indicate that the presence of MPs in the M. amazonicum shrimp is associated with the capture sites near the urban area and is present in the diet of the Amazonian population that regularly consumes this crustacean in traditional dishes.

Aversive memory conditioning induces fluoxetine-dependent anxiety-like states in the crab Neohelice granulata.

The interactions between memory processes and emotions are complex. Our previous investigations in the crab Neohelice led to an adaptation of the affective extension of sometimes opponent processes (AESOP) model. The model proposes that emotions generate separate emotive memory traces, and that the unfolding of emotional responses is a crucial component of the behavioral expression of reactivated memories. Here, we show that an aversive conditioning, that used changes in an innate escape response to an aversive visual stimulus, induced an emotional behavior that endured beyond the stimuli: the aversive memory training built an anxiety-like state evaluated in a dark/light plus-maze. We found that, after the training session, crabs displayed aversion to maze light areas, and an increased time immobilized in the dark zones of the maze, an anxiety-like behavior induced by stressors or physiological conditions in other crustaceans. The training-dependent anxiety-like behavior was blocked by pretraining administration of fluoxetine, suggesting an underlying serotonin-dependent phenomenon. We hypothesize that this training-induced anxiety-like state generates a separate emotive memory trace that is reinstated and crucial for the modulation of memory expression once the memory is reactivated.

Genetic variation and cryptic lineage among the sergestid shrimp Acetes americanus (Decapoda).

The taxonomic status of the sergestid shrimp, Acetes americanus, has been questioned for several decades. No specific study has been performed thus far to resolve the incongruences. This species has a wide geographical range in the western Atlantic and is represented by two formally accepted subspecies: Acetes americanus carolinae, distributed in North America, and Acetes americanus americanus, present in South America. However, there are regions where the coexistence of both subspecies has been reported, such as Central America. This study aimed to genetically compare specimens of A. a. americanus collected in South America with A. a. carolinae sampled in North America to check for possible differences and the existence of more than one subspecies of A. americanus on the Brazilian coast. Based on the sequences of two informative markers, the cytochrome oxidase I region (COI) and 16S rRNA, phylogenetic reconstruction demonstrated well-defined clades with high support values, reinforcing the idea that A. a. americanus is genetically different from A. a. carolinae. Our hypothesis was corroborated as the specimens collected in Brazil were divided into two distinct lineages: the first composed of A. a. americanus sensu stricto (Brazil 1) and the second by Acetes americanus (Brazil 2). The three groups evidenced in the haplotype network were the same as those observed in the phylogenetic tree. The morphometric character (height/length of the thelycum) was effective in distinguishing A. a. Brazil 1 from A. a. carolinae. However, more detailed and conclusive studies comprising other characteristics to propose and describe a possible new entity are necessary. To the best of our knowledge, for the first time, the results of this study provide some insights into the taxonomic status of the sergestid shrimp A. americanus in the western Atlantic.

Mitochondrial genomes of the land hermit crab Coenobita clypeatus (Anomura: Paguroidea) and the mole crab Emerita talpoida (Anomura: Hippoidea) with insights into phylogenetic relationships in the Anomura (Crustacea: Decapoda).

The infraorder Anomura is a species-rich clade of decapod crustaceans recognized by its remarkable disparity in terms of morphology, anatomy, ecology, physiology, and behavior. This study assembled and characterized the complete mitochondrial genomes of two anomuran species, the hermit crab Coenobita clypeatus and the mole crab Emerita talpoida. The AT-rich mitochondrial genomes of C. clypeatus and E. talpoida are 16,469 bp and 15,810 bp long, respectively, and are composed of 13 protein-coding genes (PCGs), two ribosomal RNA genes, and 22 transfer RNA genes. A 1,390 bp and 553 bp long intergenic space is assumed to be the D-loop in C. clypeatus and E. talpoida, respectively. Mitochondrial synteny in C. clypeatus is identical to that reported in other congeneric hermit crabs while synteny in E. talpoida is identical to that described for the confamilial mole crab Stemonopa insignis. No major differences occur between the studied species and their respective congeneric / cofamilial species in terms of nucleotide composition and codon usage profiles of PCGs. Selective pressure analysis in PCGs, rarely conducted in anomuran crabs, indicate that all these mitochondrial PCGs experience purifying selection and that this purifying selection is stronger in some (i.e., cox family genes and cob) compared to other PCGs (e.g., atp8). Most of the tRNA genes exhibited a typical 'cloverleaf' secondary structure with few exceptions in the two studied species. In C. clypeatus, tRNA-Ser1 lacks the thymine pseudouracil cytosine (TΨC) loop while tRNA-Phe and tRNA-Tyr each exhibit a deletion of the dihydroxyuridine (DHU) loop but not the arm. In turn, in E. talpoida, tRNA-Phe and tRNA-Arg exhibit a deletion of the DHU loop but not the arm while tRNA-Ser1 lacks the TΨC arm. A phylogenomic analysis based on translated PCGs confirms the monophyly of the infraorder Anomura and retrieves most/all relationships at the superfamily and family level previously reported for anomurans. The analysis supports the monophyletic status of the families Albuneidae, Lithodidae, Coenobitidae, and Porcellanidae. In turn, the superfamily Paguroidea, and the families Paguridae and Diogenidae are polyphyletic.

Validation of Chronocancer camilosantanai† Santana, Tavares, Martins, Melo & Pinheiro (Crustacea, Decapoda, Brachyura) from the Romualdo Formation, Araripe Sedimentary Basin, Brazil

Santana et al. (2022) described a new genus and species of fossil crab, Chronocancer camilosantanai, from carbonate concretions of the Romualdo Formation of the Araripe Sedimentary Basin. The journal in which the description appeared was published online only and the new name did not include a ZooBank registration number (LSID), as required for validation of new names in electronic-only publications. The present note serves to validate the name Chronocancer camilosantanai by fulfilling the ICZN conditions for nomenclatural availability. The date and authorship of the specific name, accordingly, are those of this note, not Santana et al. (2022).(AU)

Effect of biological and anthropogenic habitat sounds on oxidative stress biomarkers and behavior in a key crab species.

Soundscapes are characterized by a combination of natural and anthropogenic sounds. This study evaluated the stress effect of biological and anthropogenic sounds characterizing a Man and Biosphere UNESCO wetland, by assessing the protein content, oxidative biomarkers, and behavior of a key crab species (Neohelice granulata), through a tank-laboratory experiment. Biological sounds corresponded to predators of N. granulata (fish and crustacean stimuli), while anthropogenic ones belonged to motorboat passages (boat stimulus). Biochemical results showed differences depending on the sound stimuli used and the crab tissue analyzed. Protein content was higher in hemolymph when crabs were exposed to fish and boat stimuli, and in gills when exposed to boat stimulus. The enzymatic activity in hemolymph showed a decreased GST (fish stimulus) and CAT (fish and boat stimuli) activity, in hepatopancreas a higher GST (crustacean stimulus) and CAT (crustacean and boat stimuli) activity was found, and in gills a higher CAT activity was also observed (crustacean and boat stimuli). Lipid peroxidation was higher only in hemolymph (fish and crustacean stimuli). Protein oxidation was higher in gills (fish stimulus) and hepatopancreas (crustacean stimulus). Behavioral analysis demonstrated that the crab locomotion activity diminished when exposed to diverse sound stimuli. Thus, both sound sources caused physiological and behavioral stress in this species. The results contribute important data to be used in the development of management plans considering the habitat importance in terms of biodiversity, the ecosystem services provided and the role of the studied species.

Holothuriophilus trapeziformis Nauck, 1880 (Decapoda: Pinnotheridae) from the Pacific coast of Mexico: taxonomic revision based on integrative taxonomy.

BACKGROUND: Holothuriophilus trapeziformis Nauck, 1880 is a holothurian-dweller pinnotherid crab representing one of the two species of the genus distributed along the Pacific coast of Mexico and Chile, respectively. While the parasitic ecological interaction with its host is well established, the morphology of the male remains unknown, and DNA information for the species is not available. Furthermore, the only morphological trait separating both species of the genus is subjective and corresponds to the presence or absence of a gap between the fingers of the chelae. Our goal is to complete and clarify the taxonomic status of H. trapeziformis and describe the male morphology with the use of the integrative taxonomy, providing additional characters to differentiate this species. METHODS: We collected new biological material in the Pacific coast of Mexico including the topotypes. We also reviewed material from national collections to integrate morphology (based on a complete and detailed description and illustration of the species using light microscopy), ecological data (based on the identification of the host and the place where it was located within the host), and the mtCOI gene information (commonly known as DNA barcode) to differentiate Holothuriophilus trapeziformis from other related crabs. RESULTS: This species presents marked sexual dimorphism only in the primary sexual characters. For the first time we describe morphological variability of traditionally stable characters. In addition to the gap between the fingers of the chelae, Holothuriophilus trapeziformis differs from H. pacificus (Poeppig, 1836) by their ornamentation, the shape of the male abdomen, and the gonopod. Cytocrome Oxidase 1 gene (COI) distance divergence was >3% between both Holothuriophilus species forming a clear clade. DNA barcoding indicates only one taxon, with a maximum divergence of 2.2%. All the specimens have the same Barcode Index Number (BIN; BOLD: ADE9974). All the hosts for H. trapeziformis were identified as Holothuria (Halodeima) inornata Semper, 1868; the presence of the crab in the host's coelomic cavity was confirmed, and for the first time we found it within the intestine. The geographical distribution is the Pacific coast of Mexico. Based on the data presented here, the taxonomic status of Holothuriophilus trapeziformis is now complete.

Diversity of Collembola and occurrence of Talitroides sylvaticus in a Pinus elliottii Engelm afforestation

A 52-year-old pine forest is characterized as an environment with low plant diversity and large accumulation of allelopathic litter with poor nutrient content. Collembola is sensitive to environmental conditions and may have difficulties living in these forests. This study aimed (1) to evaluate the abundance and richness of Collembola in the soil of a 52-year-old pine afforestation with different moisture contents; and (2) to identify the landhopper sampled unintentionally. For sampling, pitfall traps were set up for four days, in areas of a Pinus elliottii afforestation with high and low soil moisture located at the Universidade Federal de Santa Maria. Collembola specimens were counted and identified to family and genus level. The total abundance of springtails was greater in the low soil moisture area. The genera Desoria and Lepidocyrtus, and specimens of the family Onychiuridae were more abundant in low soil moisture, meanwhile, the genus Ceratophysella was more abundant in the high soil moisture. The landhopper Talitroides sylvaticus was sampled unintentionally by traps set up in the soil with higher moisture and calcium content. Six genera of Collembola and the landhopper T. sylvaticus were identified in soil of a P. elliottii afforestation and their distribution is influenced by soil moisture.(AU)

Female reproduction-specific proteins, origins in marine species, and their evolution in the animal kingdom.

The survival of a species largely depends on the ability of individuals to reproduce, thus perpetuating their life history. The advent of metazoans (i.e. pluricellular animals) brought about the evolution of specialized tissues and organs, which in turn led to the development of complex protein regulatory pathways. This study sought to elucidate the evolutionary relationships between female reproduction-associated proteins by analyzing the transcriptomes of representative species from a selection of marine invertebrate phyla. Our study identified more than 50 reproduction-related genes across a wide evolutionary spectrum, from Porifera to Vertebrata. Among these, a total of 19 sequences had not been previously reported in at least one phylum, particularly in Porifera. Moreover, most of the structural differences between these proteins did not appear to be determined by environmental pressures or reproductive strategies, but largely obeyed a distinguishable evolutionary pattern from sponges to mammals.

A checklist of species of the family Zoothamniidae (Ciliophora: Peritrichia), symbionts of crustaceans.

Eight genera are included in the family Zoothamniidae, and at the present the data of the epibiotic species on crustaceans is not updated. Thus, the main goal of the present work is to provide the checklist of zoothamniids worldwide reported as associated to several groups of crustaceans, including some data of their geographic distribution, and also to provide the complete list of species of this peritrich group. We obtained all available data of family Zoothamniidae and checked their taxonomic status. Then we provided the complete list of species including those reported as epibionts on crustacean hosts. We obtained 156 species included in eight genera of Zoothamniidae, being 85 species recorded as symbionts on 86 species of hosts. Genus Zoothamnium contained the higher number (56) of epibiotic species on crustaceans, and genus Pseudohaplocaulus has not been reported for any crustacean. The reviewed data highlights the concentration of records in Europe, and stands out the need to amplify sampling and studies in the Southern Hemisphere. The main groups of crustaceans infested by zoothamniids are the amphipods, isopods and decapods.

Two new species of emTypton/em Costa, 1844 from tropical American waters, with taxonomic notes on emT. tortugae/em McClendon, 1911 and a new record of br /emT. granulosus/em Ayón-Parente, Hendrickx amp; Galvan-Villa, 2015 (Decapoda: Caridea: Palaemonidae).

Two new species of the palaemonid shrimp genus Typton Costa, 1844 are described based on material from Panama and Mexico. Both species are closely related to T. tortugae McClendon, 1911, a species originally described from the Dry Tortugas, off southern Florida, USA, and later scarcely recorded from other western Atlantic localities, from Bermuda to Mexico and Brazil. Some clarification and additional illustrations are provided for the type material of T. tortugae. Typton jonkayei sp. nov., is described based on material from fouling-encrusting communities dominated by sponges, growing on submerged roots of the red mangrove, Rhizhophora mangle L., in Bocas del Toro, Caribbean coast of Panama. This new species differs from T. tortugae in several morphological details, for instance, on the minor and major chelipeds (second pereiopods), telson, uropod, frontal margin and ambulatory pereiopods. Typton cousteaui sp. nov. is described based on a single ovigerous female dredged in the southern Gulf of California off Baja California Sur, Mexico, previously reported as T. tortugae. This new taxon seems to represent a true cryptic species with no significant morphological divergence from the allopatrically isolated T. tortugae, except for slight morphometric differences. In addition, T. granulosus Ayón-Parente, Hendrickx Galvan-Villa, 2015 is recorded from the Pacific coast of Panama, based on material collected in the Coiba Archipelago. Some taxonomic, distributional and ecological remarks are provided for T. granulosus and the closely related T. serratus Holthuis, 1951.

Six new epigean species of Caecidotea/ (Isopoda: Asellidae) distributed along the Trans-Mexican Volcanic Belt in Central Mexico.

Six new epigean freshwater species of the genus Caecidotea in Mexico are described. These species were collected in waterbodies located along the Trans-Mexican Volcanic Belt (TMVB) and the eastern slope of the country: Caecidotea buzwilsoni sp. nov., Caecidotea chicoensis sp. nov., Caecidotea alvarezi sp. nov., Caecidotea mintzita sp. nov., Caecidotea zacapuensis sp. nov., and one additional species Caecidotea villalobosi sp. nov. is described from the Papaloapan basin at the Atlantic Slope of Mexico. The taxonomic treatment for each species includes a detailed description, figures of characters of diagnostic importance and comments. We also provide an updated map of Caecidotea records in Mexico. This work substantially increases the number of epigean Caecidotea known to occur in Mexico to 11 species, a new total of 99 species described to North America.

Description of Paraxiopsis/ kensleyi/ n. sp., a new axiid lobster from the Gulf of Mexico (Crustacea: Decapoda: Axiidea).

A new species of axiid was discovered during sampling offshore deep banks on the middle continental shelf off Louisiana. Paraxiopsis kensleyi n. sp. appears to inhabit interstices and cavities of coralline algal rubble, rhodoliths, coral rubble, and other eroded calcareous substrates. Weakly separated from Eutrichocheles Wood-Mason, 1876 on the basis of morphology, present assignments of western Atlantic species to Paraxiopsis de Man, 1905 are regarded as provisional. The new species is described morphologically, and the coloration of freshly captured specimens is documented and compared to related species where possible. Coloration readily distinguishes mature specimens of the new species from Paraxiopsis spinipleura Kensley, 1996, with which it was initially confused. The diagnosis includes GenBank accession numbers for COI sequences to allow future molecular phylogenetic comparisons. Compared to regional species that share a similar dentation or spination on the submedian carina, the pleon of the new species is distinctive in the truncate ventral margin on pleura 2-4, as opposed to being broadly rounded or directed ventrally in an acutely triangular tip. The new species is the eighteenth species of Paraxiopsis worldwide and the ninth from western Atlantic waters, seven of which are now known to range into the Gulf of Mexico. An updated key to western Atlantic members of the genus is provided.

Macrobrachium/ Spence Bate, 1868 (Decapoda: Palaemonidae): New records, range extension and geographic distribution in the Northeastern Caatinga amp; Coastal Drainages, and São Francisco hydrographic ecoregions, Northeast of Brazil.

This study constitutes the most comprehensive effort ever done to assess the faunal diversity of the Macrobrachium genus within two ecoregions that encompass part of the northeastern Brazil: the Northeastern Caatinga Coastal Drainages, and the São Francisco (Lower-middle and Lower portions). Through sampling in several of their hydrographic basins, bibliographic research, and consulting scientific collections, our results reveal the occurrence of five species along these ecoregions: Macrobrachium acanthurus, M. amazonicum, M. carcinus, M. jelskii and M. olfersii. We also provide the first record of these species for several river basins in both ecoregions. Additionally, we confirm the occurrence of M. carcinus from Rio Grande do Norte State and provide updated distribution maps for each species in the studied area. This carcinofauna survey may form the basis for future evaluations of eventual anthropic impacts on biological diversity resulting from projects being implemented in these regions, which involve the São Francisco interbasin water transfer.