10 research outputs found

    Some Observations of Morphology and Behavior of a Hyperbenthic Misophrioid Copepod

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    The locomotion, feeding, excretion, and oviposition of a member of the copepod family Misophriidae were observed based on a live specimen collected from a sandy bottom at a depth of 52 m off Nagannu Island, Okinawa, Japan. This species is related to Arcticomisophria MartĂ­nez Arbizu and Seifried, 1996 in the armature of leg 1, but the fifth leg is much more reduced. The combination of morphological characters strongly suggests that it represents an undescribed genus. The maxillipeds played a major role in attaching to the bottom and in crawling, while the antennae and mandibular palps were involved in slow swimming along the bottom. It fed on small-sized cultured phytoplankters, and excreted numerous fecal pellets. The female carried 4-5 eggs of 0.09 mm diameter that were loosely attached to the urosome. Nearly complete nuclear 18S and 28S rRNA gene sequences and a partial mitochondrial cytochrome c oxidase subunit 1 (CO1) gene sequence were obtained and are made available for future phylogenetic and systematic work

    The World Amphipoda Database: history and progress

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    We provide an overview of the World Amphipoda Database (WAD), a global species database that is part of the World Register of Marine Species (WoRMS). Launched in 2013, the database contains entries for over 10,500 accepted species names. Edited currently by 31 amphipod taxonomists, following WoRMS priorities, the WAD has at least one editor per major group. All accepted species are checked by the editors, as is the authorship available for all of the names. The higher classification is documented for every species and a type species is recorded for every genus name. This constitutes five of the 13 priorities for completion, set by WoRMS. In 2015, five LifeWatch grants were allocated for WAD activities. These included a general training workshop in 2016, together with data input for the superfamily Lysianassoidea and for a number of non-marine groups. Philanthropy grants in 2019 and 2021 covered more important gaps across the whole group. Further work remains to complete the linking of unaccepted names, original descriptions, and environmental information. Once these tasks are completed, the database will be considered complete for 8 of the 13 priorities, and efforts will continue to input new taxa annually and focus on the remaining priorities, particularly the input of type localities. We give an overview of the current status of the order Amphipoda, providing counts of the number of genera and species within each family belonging to the six suborders currently recognized

    Genetic contributors to risk of schizophrenia in the presence of a 22q11.2 deletion

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    Schizophrenia occurs in about one in four individuals with 22q11.2 deletion syndrome (22q11.2DS). The aim of this International Brain and Behavior 22q11.2DS Consortium (IBBC) study was to identify genetic factors that contribute to schizophrenia, in addition to the ~20-fold increased risk conveyed by the 22q11.2 deletion. Using whole-genome sequencing data from 519 unrelated individuals with 22q11.2DS, we conducted genome-wide comparisons of common and rare variants between those with schizophrenia and those with no psychotic disorder at age ≄25 years. Available microarray data enabled direct comparison of polygenic risk for schizophrenia between 22q11.2DS and independent population samples with no 22q11.2 deletion, with and without schizophrenia (total n = 35,182). Polygenic risk for schizophrenia within 22q11.2DS was significantly greater for those with schizophrenia (padj = 6.73 × 10−6). Novel reciprocal case–control comparisons between the 22q11.2DS and population-based cohorts showed that polygenic risk score was significantly greater in individuals with psychotic illness, regardless of the presence of the 22q11.2 deletion. Within the 22q11.2DS cohort, results of gene-set analyses showed some support for rare variants affecting synaptic genes. No common or rare variants within the 22q11.2 deletion region were significantly associated with schizophrenia. These findings suggest that in addition to the deletion conferring a greatly increased risk to schizophrenia, the risk is higher when the 22q11.2 deletion and common polygenic risk factors that contribute to schizophrenia in the general population are both present

    A new species of Hyalella from the High Andes of Ecuador (Crustacea, Amphipoda, Hyalellidae)

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    Hyalella cajasi sp. n. is described from high altitude shallow water lakes in southern Ecuador. This is the second representative of the genus recorded in the country after H. meinerti. The new species shares with nine South American species of the genus the display of a smooth, non-processiferous body, a male first uropod with a modified curved robust seta on the endopod, and six pairs of sternal gills. The new taxon can be distinguished from these species based on the presence/absence of eyes; relative length of antenna 1 with respect to antenna 2; presence/absence of short pointed robust seta distally on palp of maxilla 1; number of pappose setae proximally on medial margin of inner lobe of maxilla 2; elongation and curvature of the modified robust seta of endopod of male uropod 1; relative length of ramus of uropod 3 with respect to protopod; and armature and outline of telson, among other features. It seems to be a high-altitude endemic to the Cajas Massif in Azuay Province, being replaced in the same area at lower altitudes by H. meinerti

    A new marine interstitial Psammogammarus (Crustacea, Amphipoda, Melitidae) from Gura Ici Island, off western Halmahera (North Moluccas, Indonesia), and an overview of the genus

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    Psammogammarus wallacei sp. n. is described from the shallow marine interstitial of a sand and coral rubble beach on the Gura Ici islands (North Moluccas; Indonesia). This is the first record of this circum-tropical genus from SE Asia, with the geographically closest relative inhabiting the Ryukyu archipelago in Japan. The new species is highly distinctive by the display of sexual dimorphism on pleopod II, with the medial margin of the male proximal article of exopod provided with a comb of short, blunt curved spinules; no other representative of the genus is known to display sexually-dimorphic appendages aside of the gnathopods. The new species is also noteworthy by the outline of the palm margin of male gnathopod II, hardly excavated, and by showing a carpus broader than long. An overview of the genus Psammogammarus with 14 species to date is provided

    DNA barcodes, cryptic diversity and phylogeography of a W Mediterranean assemblage of thermosbaenacean crustaceans

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    We assess the occurrence of crypticism and analyse the phylogeography of a thermosbaenacean crustacean, the monodellid Tethysbaena scabra, endemic to the Balearic Islands (W Mediterranean). This species occurs only in mixohaline waters of coastal wells and caves adjacent to the seashore. We have used the mitochondrial DNA barcode region to assess its genetic population structure throughout the anchialine environment of the islands. Maximum likelihood phylogenetic analyses showed that the Balearic Tethysbaena and those from the NW Italian Peninsula form a monophyletic assemblage subdivided into several lineages. Cytochrome c oxidase subunit 1 (cox1) p-distances among the more divergent Mallorcan lineages are remarkably high and on par with those established between the formally described species T.scabra from Menorca and T.argentarii from Italy. This result and the application of the generalised mixed Yule coalescence model (GMYC) suggest that at least some of the Mallorcan lineages represent cryptic species. A clear-cut phylogeographic pattern is displayed by this anchialine assemblage: six of its seven lineages appear in allopatry, with the exception of a Mallorcan lineage limited to a single cave nested within the geographic range of another lineage. All lineages show a distribution reduced to a single cave or to short portions of coast not exceeding 60km in length. Our coalescence estimations suggest an early Tortonian (10.7Ma) origin for the Balearic+Italy Tethysbaena clade, an age that is largely prior to the onset of the eustatic oscillations associated with the Quaternary glaciations. Only the diversification that took place within some of the Mallorcan lineages could be coeval with the broad glacio-eustatic oscillations of the Quaternary

    World Register of marine Cave Species (WoRCS): a new Thematic Species Database for marine and anchialine cave biodiversity

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    Scientific exploration of marine cave environments and anchialine ecosystems over recent decades has led to outstanding discoveries of novel taxa, increasing our knowledge of biodiversity. However, biological research on underwater caves has taken place only in a few areas of the world and relevant information remains fragmented in isolated publications and databases. This fragmentation makes assessing the conservation status of marine cave species especially problematic, and this issue should be addressed urgently given the stresses resulting from planned and rampant development in the coastal zone worldwide. The goal of the World Register of marine Cave Species (WoRCS) initiative is to create a comprehensive taxonomic and ecological database of known species from marine caves and anchialine systems worldwide and to present this as a Thematic Species Database (TSD) of the World Register of marine Species (WoRMS). WoRCS will incorporate ecological data (e.g., type of environment, salinity regimes, and cave zone) as well as geographical information on the distribution of species in cave and anchialine environments. Biodiversity data will be progressively assembled from individual database sources at regional, national or local levels, as well as from literature sources (estimate: >20,000 existing records of cave-dwelling species scattered in several databases). Information will be organized in the WoRCS database following a standard glossary based on existing terminology. Cave-related information will be managed by the WoRCS thematic editors with all data dynamically linked to WoRMS and its team of taxonomic editors. In order to mobilize data into global biogeographic databases, a Gazetteer of the Marine and Anchialine Caves of the World will be established. The presence records of species could be eventually georeferenced for submission to the Ocean Biogeographic Information System (OBIS) and constitute an important dataset for biogeographical and climate change studies on marine caves and anchialine systems

    The World Amphipoda Database: history and progress

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    (IF 0.4; Q4)We provide an overview of the World Amphipoda Database (WAD), a global species database that is part of the World Register of Marine Species (WoRMS). Launched in 2013, the database contains entries for over 10,500 accepted species names. Edited currently by 31 amphipod taxonomists, following WoRMS priorities, the WAD has at least one editor per major group. All accepted species are checked by the editors, as is the authorship available for all of the names. The higher classification is documented for every species and a type species is recorded for every genus name. This constitutes five of the 13 priorities for completion, set by WoRMS. In 2015, five LifeWatch grants were allocated for WAD activities. These included a general training workshop in 2016, together with data input for the superfamily Lysianassoidea and for a number of non-marine groups. Philanthropy grants in 2019 and 2021 covered more important gaps across the whole group. Further work remains to complete the linking of unaccepted names, original descriptions, and environmental information. Once these tasks are completed, the database will be considered complete for 8 of the 13 priorities, and efforts will continue to input new taxa annually and focus on the remaining priorities, particularly the input of type localities. We give an overview of the current status of the order Amphipoda, providing counts of the number of genera and species within each family belonging to the six suborders currently recognized
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