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1.
Sci Rep ; 12(1): 7508, 2022 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-35525848

RESUMO

Collective movement may emerge if coordinating one's movement with others produces a greater benefit to oneself than can be achieved alone. Experimentally, the capacity to manoeuvre simulated groups in the wild could enable powerful tests of the impact of collective movement on individual decisions. Yet such experiments are currently lacking due to the inherent difficulty of controlling whole collectives. Here we used a novel technique of experimentally simulating the movement of collectives of social hermit crabs (Coenobita compressus) in the wild. Using large architectural arrays of shells dragged across the beach, we generated synchronous collective movement and systematically varied the simulated collective's travel direction as well as the context (i.e., danger level). With drone video from above, we then tested whether focal individuals were biased in their movement by the collective. We found that, despite considerable engagement with the collective, individuals' direction was not significantly biased. Instead, individuals expressed substantial variability across all stimulus directions and contexts. Notably, individuals typically achieved shorter displacements in the presence of the collective versus in the presence of the control stimulus, suggesting an impact of traffic. The absence of a directional bias in individual movement due to the collective suggests that social hermit crabs are individualists, which move with a high level of opportunistic independence, likely thanks to the personal architecture and armour they carry in the form of a protective shell. Future studies can manipulate this level of armour to test its role in autonomy of movement, including the consequences of shell architecture for social decisions. Our novel experimental approach can be used to ask many further questions about how and why collective and individual movement interact.


Assuntos
Anomuros , Animais , Humanos , Movimento
2.
Zootaxa ; 5093(2): 195-217, 2022 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-35390810

RESUMO

Ghost shrimps collected from the Indian Exclusive Economic Zone by the Fishery Oceanographic Research Vessel Sagar Sampada during two cruises in the eastern (105 metres depth) and southeastern Arabian Sea (101 and 326 metres depth) were studied. One male, identified as Guyanacaris keralam sp. nov. of the Axiidae, differs from its congeners in the unique armature of the rostrum, gastric region of carapace, pleonal pleural margins, dorsal margins of cheliped fingers, ventral margin of second pereopod merus, and lateral margins of telson; the presence of corneous spines on the propodi and dactyli of third and fourth pereopods, and the relative sizes of the ocular peduncles, antennular peduncle, scaphocerite and cheliped fingers. Guyanacaris K. Sakai, 2011 is re-diagnosed based on the presence of short supraocular spine and post-cervical carina on carapace, dentate margins of first two pleonal pleura, third to fifth pleura with angular to straight posterior margins, antennal scaphocerite with mesial spine at base, and presence of male first pleopod 1. Bruceaxius thailandensis K. Sakai, 2015 is tentatively retained in Bruceaxius K. Sakai, 2011, owing to absence of mesial spine at the base of scaphocerite, tuberculate upper margins of carpus, propodus and dactylus of major cheliped, and tri-segmented appendix masculina on male second pleopod. In addition, two males, diagnosed herein as Paragourretia galathea (K. Sakai, 2017) of the Ctenochelidae, differ from the holotype female only in the relative length of the terminal antennular article and the presence of a distomedian spinule on the telson, of all the features.


Assuntos
Anomuros , Besouros , Decápodes , Distribuição Animal , Estruturas Animais , Animais , Feminino , Índia , Masculino
3.
Zootaxa ; 5104(4): 593-599, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-35391016

RESUMO

A new species of KeroplatidaeChetoneura lagangnsis sp. n. from Lagang cave in Sarawak, Borneo is described and illustrated based on a single male specimen. An identification key to the species of the genus Chetoneura Colless is provided. A distribution map of the five known species of Chetoneura is presentedCh. cavernae Colless, Ch. shennonggongensis Amorim Niu, Ch. oligoradiata (Papp), Ch. davidi evk, Hippa Burdikov and Ch. lagangensis Kazandzhieva Bechev, sp. n.


Assuntos
Anomuros , Dípteros , Distribuição Animal , Estruturas Animais , Animais , Bornéu , Masculino , Nematóceros
4.
Zootaxa ; 5091(4): 587-597, 2022 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-35391227

RESUMO

The new porcellanid crab Polyonyx deezi n. sp. is described on the basis of two specimens from Okinawa Island, Ryukyu Islands, southwestern Japan. The new species belongs to the P. sinensis group and may be closest to P. socialis Werding Hiller, 2019 in the comparatively broad proportions of the carpi of the chelipeds and meri of the ambulatory legs. However, P. deezi n. sp. is immediately distinguished from all other congeners by the median branchial margins of the carapace being bluntly angular and produced laterally and the dorsal surfaces of the carapace and chelipeds with distinct protuberances. The occurrence of P. deezi n. sp. from coral reefs may be unusual in species of the P. sinensis group because many of the known species have been recorded from estuaries or coastal embayments. An identification key to the Indo-West Pacific species of the Polyonyx sinensis group is provided.


Assuntos
Anomuros , Decápodes , Distribuição Animal , Exoesqueleto , Animais , Japão
5.
Zootaxa ; 5091(2): 301-329, 2022 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-35391248

RESUMO

Deep-water king crabs of the genus Paralomis White, 1856 collected during three cruises of the Fishery Oceanographic Research Vessel Sagar Sampada in the western Bay of Bengal (528777 m depths), one cruise in the eastern Bay of Bengal off Great Nicobar Island (337 m depth), and four cruises in the southeastern Arabian Sea (3151245 m) were identified. They are referred to Paralomis ceres Macpherson, 1989, recorded for the first time from Indian waters and P. indica Alcock Anderson, 1899, reported for the first time from the Bay of Bengal and the Andaman Sea. In addition, this study reports the morphological variability among the P. indica populations in the shape of the carapace and dorsal rostral spines, nature of the branchial and cardiac regions and abdominal marginal spines, and the relative lengths of pereopods 24. Mitochondrial Cytochrome oxidase I (594 base pairs) and 16S rRNA (503 bp) gene sequences of P. ceres and P. indica (602 and 497 bp, respectively) revealed that they formed distinct lineages. A key to the Indian Ocean species of Paralomis is provided.


Assuntos
Anomuros , Animais , Índia , RNA Ribossômico 16S , Água
6.
Zootaxa ; 5099(5): 563-585, 2022 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-35391396

RESUMO

We describe three new species of hermit crab of the pagurid genera, Catapagurus A. Milne-Edwards, 1880, Nematopagurus A. Milne-Edwards Bouvier, 1892 and Pagurixus Melin, 1939, on the basis of material collected during the scientific cruise to the Northern Mariana Islands conducted by the U.S. National Oceanographic and Atmospheric Administration (NOAA) in 2015. Catapagurus tenuilamina n. sp., referred to the C. ensifer Henderson, 1893 species group, appears close to C. granulatus Edmondson, 1951, but differs from the latter in the more slender ultimate article of the antennular peduncle, more slender dactyli of pereopods 2 and 3, and the possession of two dorsal subdistal spines in the meri of the pereopods. Nematopagurus marianicus n. sp. resembles N. gardineri Alcock, 1905 and N. lewinsohni Trkay, 1986, but is distinguished from the latter two by the characteristic dense setation on the upper part of the left cheliped carpus and by the elongate dactyli of pereopods 2 and 3 that lack a row of bristle-like setae on the dorsal margins. Pagurixus eminens n. sp. is referred to the P. boninensis Melin, 1939 species group and appears closest to P. annulus Komai Poupin, 2013, but is differentiated from the latter in the shape and ornamentation of the right coxa of pereopod 5 in the male as well as details of the colour pattern on the chelipeds and ambulatory legs. Partial sequences of the mitochondrial 16S rRNA gene from the three new species were sequenced and deposited in the GenBank database for future genetic and phylogenetic study.


Assuntos
Anomuros , Distribuição Animal , Animais , Masculino , Micronésia , Filogenia , RNA Ribossômico 16S
7.
Zootaxa ; 5093(4): 493-500, 2022 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-35391472

RESUMO

A new species of hermit crab, Diogenes matabiru, is described and illustrated on the basis of the specimens collected from mangrove environment in the eastern Lombok Island, Indonesia. This new species is related to D. pallescens Whitelegge, 1897 but differs in the shape of cheliped, telson and coloration in life. A key to the species of the genus Diogenes from Indonesia is also provided.


Assuntos
Anomuros , Animais , Indonésia
8.
Mol Phylogenet Evol ; 171: 107467, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35351636

RESUMO

The exceptional hidden diversity included in the squat lobster genus Phylladiorhynchus and its wide bathymetric and geographic range make it an interesting group to thoroughly study its evolutionary history. Here we have analyzed the entire currently known species diversity of Phylladiorhynchus using an integrative approach that includes morphological and molecular characters. The aim was to establish whether depth range (bathymetry) has played a role in their morphological and molecular evolution and in their diversification pathways. Phylogenetic analyses recovered the genus as monophyletic and as the sister group of Coralliogalathea, conforming with current systematic hypotheses, although their placement in a monophyletic Galatheidae is doubted. All the analyzed species represent well-supported lineages, structured in ten clades, correlated in most part with the morphological phylogeny. The reconstruction of ancestral habitat showed that the most recent common ancestor of Phylladiorhynchus most likely lived in shallow water environments. The divergence time estimation analyses dated the origin of the genus back to the Upper Jurassic, preceding the origin of all the other galatheoid lineages. Morphological analyses suggested that species from deeper waters exhibit greater morphological divergences and lower genetic divergences in comparison to species from shallower waters. In Phylladiorhynchus, the colonization of deeper waters has taken place independently multiple times since the Lower-Cretaceous. Our reconstruction of ancestral habitat suggests that shallow water ancestors might show an acceleration in the molecular rate of evolution and a slowdown in the rates of morphological evolution in comparison to deep sea lineages. However, although lineages from shallow and deep sea habitats show slight differences in diversification trends, bathymetry does not significantly affect the diversification rate in Phylladiorhynchus according to our diversification analyses.


Assuntos
Anomuros , Decápodes , Animais , Decápodes/genética , Evolução Molecular , Filogenia , Água
9.
Food Microbiol ; 104: 103973, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35287802

RESUMO

The red king crab (RKC, Paralithodes camtschaticus) and snow crab (SC, Chionoecetes opilio) are valuable decapods that can undergo live holding (LH) in onshore facilities before either live export or processing into two cooked-frozen sections (i.e., clusters). This study investigated the effect of the LH time (up to two months without feeding) and temperature (5│10 °C for RKC; 1│5 °C for SC) on the total viable psychrotrophic count (TVCP) and Pseudomonas spp. in the leg meat of cooked RKC and SC. The effect of freezing after cooking was also evaluated. The counts were determined during storage at 4 °C after cooking on the clusters undergoing either immediate refrigeration (IR) or 24-month frozen storage before refrigeration (FBR). In the RKC cooked leg meat, the LH temperature significantly affected the TVCP, with LH at 10 °C leading to higher counts, while the Pseudomonas spp. levels were mainly influenced by the freezing, with lower levels in FBR samples compared to their IR counterparts. In the SC cooked leg meat, the LH conditions did not significantly affect the counts, which were instead significantly lowered by the freezing. From an industrial and commercial standpoint, it can be concluded that LH of RKC at high temperature (10 °C) led to a shorter microbial shelf-life of cooked RKC clusters, with the clusters undergoing FBR showing longer microbial shelf-life than their IR counterparts. By contrast, with the mild cooking regime applied, the LH time and temperature of SC had a lower influence on the microbial shelf-life of cooked SC clusters than that given by the choice of the storage type (IR or FBR) after cooking.


Assuntos
Anomuros , Braquiúros , Animais , Culinária , Carne/análise , Refrigeração
10.
Parasite ; 29: 9, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35191831

RESUMO

The morphology of cystacanths and adults of Profilicollis altmani (Perry, 1942) Van Cleave, 1947 (Polymorphidae) were studied from the Pacific mole crab Emerita analoga (Stimpson) (Crustacea, Hippidae) and Belcher's gull Larus belcheri (Vigors) (Aves, Laridae), respectively, in Peru. Comparative morphometrics with accounts of other populations of P. altmani from elsewhere off the Pacific and Atlantic coasts of North and South America revealed marked intraspecific population variations. We report scanning electron micrographs (SEM) of new features, not before noted or captured in line drawings by earlier observers. We further present microscope images that reveal internal details not previously reported or possible to see with SEM. Energy dispersive X-ray analysis (EDXA) revealed unusual patterns in the chemistry of proboscis hooks especially the high sulfur and diminished phosphorous and calcium in hook tips and low sulfur and high levels of phosphorous and calcium at mid hooks. The size and shape of all hooks of the cystacanths are reported for the first time. Histopathological studies in L. belcheri from Peru are also included. Cystacanths of P. altmani from California were also analyzed for molecular patterns and compared with other sequences reported from other locations. The molecular data and the analysis of our new sequences of cytochrome oxidase I (COI) showed that haplotypes of P. altmani had low genetic variation; the species is not geographically structured, and within its clade no monophyletic group is formed.


TITLE: Évaluation comparative de la morphologie de Profilicollis altmani (Acanthocephala, Polymorphidae) de crustacés et d'oiseaux de rivage au Pérou, en particulier l'analyse élémentaire des crochet (EDXA), l'imagerie SEM, l'histopathologie et le profil moléculaire. ABSTRACT: La morphologie des cystacanthes et des adultes de Profilicollis altmani (Perry, 1942) Van Cleave, 1947 (Polymorphidae) a été étudiée, respectivement, à partir du crustacé Emerita analoga (Stimpson) (Crustacea, Hippidae) et du Goéland Siméon Larus belcheri (Vigors) (Aves, Laridae), au Pérou. La morphométrie comparative avec des données d'autres populations de P. altmani d'autres localités au large des côtes du Pacifique et de l'Atlantique de l'Amérique du Nord et du Sud a révélé des variations intraspécifiques marquées des populations. Nous rapportons des nouvelles observations de microscopie électronique à balayage, non notées auparavant ou non capturées dans des dessins au trait par des observateurs antérieurs. Nous présentons en outre des images au microscope qui révèlent des détails internes qui n'ont pas été signalés auparavant ni possibles à voir avec MET. L'analyse aux rayons X à dispersion d'énergie (EDXA) a révélé des modèles inhabituels dans la chimie des crochets de la trompe, en particulier la teneur élevée en soufre et une diminution du phosphore et du calcium dans les pointes des crochets et des niveaux faibles en soufre et en phosphore et en calcium au milieu des crochets. La taille et la forme de tous les crochets des cystacanthes sont décrites pour la première fois. Des études histopathologiques sur L. belcheri du Pérou sont également incluses. Les cystacanthes de P. altmani de Californie ont également été analysés pour les modèles moléculaires et comparés à d'autres séquences rapportées d'autres endroits. Les données moléculaires et l'analyse de nos nouvelles séquences de cytochrome oxydase I (COI) ont montré que les haplotypes de P. altmani avaient une faible variation génétique. L'espèce n'est pas structurée géographiquement, et au sein de son clade aucun groupe monophylétique n'est formé.


Assuntos
Acantocéfalos , Anomuros , Helmintíase Animal , Animais , Aves , Elétrons , Peru , Raios X
11.
Sci Rep ; 12(1): 2675, 2022 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-35177734

RESUMO

Life at hydrothermal vent sites is based on chemosynthetic primary producers that supply heterotrophic microorganisms with substrates and generate biomass for higher trophic levels. Often, chemoautotrophs associate with the hydrothermal vent megafauna. To investigate attached bacterial and archaeal communities on deep-sea squat lobsters, we collected ten specimens from a hydrothermal vent in the Guaymas Basin (Gulf of California). All animals were identified as Munidopsis alvisca via morphological and molecular classification, and intraspecific divergence was determined. Amplicon sequencing of microbial DNA and cDNA revealed significant differences between microbial communities on the carapaces of M. alvisca and those in ambient sea water. Major epibiotic bacterial taxa were chemoautotrophic Gammaproteobacteria, such as Thiotrichaceae and Methylococcaceae, while archaea were almost exclusively represented by sequences affiliated with Ca. Nitrosopumilus. In sea water samples, Marine Group II and III archaea and organoheterotrophic Alphaproteobacteria, Flavobacteriia and Planctomycetacia were more dominant. Based on the identified taxa, we assume that main metabolic processes, carried out by M. alvisca epibiota, include ammonia, methane and sulphide oxidation. Considering that M. alvisca could benefit from sulphide detoxification by its epibiota, and that attached microbes are supplied with a stable habitat in proximity to substrate-rich hydrothermal fluids, a mutualistic host-microbe relationship appears likely.


Assuntos
Anomuros/microbiologia , Archaea , Bactérias , Microbiota , Animais , Archaea/classificação , Archaea/crescimento & desenvolvimento , Bactérias/classificação , Bactérias/crescimento & desenvolvimento , Água do Mar/microbiologia
12.
J Comp Neurol ; 530(9): 1399-1422, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34843626

RESUMO

The primary olfactory centers of metazoans as diverse as arthropods and mammals consist of an array of fields of dense synaptic neuropil, the olfactory glomeruli. However, the neurochemical structure of crustacean olfactory glomeruli is largely understudied when compared to the insects. We analyzed the glomerular architecture in selected species of hermit crabs using immunohistochemistry against presynaptic proteins, the neuropeptides orcokinin, RFamide and allatostatin, and the biogenic amine serotonin. Our study reveals an unexpected level of structural complexity, unmatched by what is found in the insect olfactory glomeruli. Peptidergic and aminergic interneurons provide the structural basis for a regionalization of the crustacean glomeruli into longitudinal and concentric compartments. Our data suggest that local olfactory interneurons take a central computational role in modulating the information transfer from olfactory sensory neurons to projection neurons within the glomeruli. Furthermore, we found yet unknown neuronal elements mediating lateral inhibitory interactions across the glomerular array that may play a central role in modulating the transfer of sensory input to the output neurons through presynaptic inhibition. Our study is another step in understanding the function of crustacean olfactory glomeruli as highly complex units of local olfactory processing.


Assuntos
Anomuros , Neurônios Receptores Olfatórios , Animais , Interneurônios , Mamíferos , Neurópilo/metabolismo , Bulbo Olfatório , Condutos Olfatórios/metabolismo
13.
Artigo em Inglês | MEDLINE | ID: mdl-34655763

RESUMO

Red king crab (Paralithodes camtschaticus) and snow crab (Chionoecetes opilio) are deep-sea crustaceans widely distributed in the North Pacific and Northwest Atlantic Oceans. These giant predators have invaded the Barents Sea over the past decades, and climate-driven temperature changes may influence their distribution and abundance in the sub-Arctic region. Molting and growth in crustaceans are strongly affected by temperature, but the underlying molecular mechanisms are little known, particularly in cold-water species. Here, we describe multiple regulatory factors in the two high-latitude crabs by developing de novo transcriptomes from the molting gland (Y-organ or YO) and eye stalk ganglia (ESG), in addition to the hepatopancreas and claw muscle of red king crab. The Halloween genes encoding the ecdysteroidogenic enzymes were expressed in YO, and the ESG contained multiple neuropeptides, including molt-inhibiting hormone (MIH), crustacean hyperglycemic hormone (CHH), and ion-transport peptide (ITP). Both crabs expressed a diversity of growth-related factors, such as mTOR, AKT, Rheb and AMPKα, and stress-responsive factors, including multiple heat shock proteins (HSPs). Temperature effects on the expression of key regulatory genes were quantified by qPCR in adult red king crab males kept at 4 °C or 10 °C for two weeks during intermolt. The Halloween genes tended to be upregulated in YO at high temperature, while the ecdysteroid receptor and several growth regulators showed tissue-specific responses to elevated temperature. Constitutive and heat-inducible HSPs were expressed in an inverse temperature-dependent manner, suggesting that adult red king crabs can acclimate to increased water temperatures.


Assuntos
Anomuros , Braquiúros , Animais , Braquiúros/genética , Gânglios , Genes Reguladores , Masculino , Muda/genética , Temperatura , Transcriptoma
14.
Braz. j. biol ; 82: e230147, 2022. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1153479

RESUMO

Abstract Metals and agrochemicals are among the main aquatic contaminants, being able to trigger oxidative stress in exposed organisms. The objective of this work was to evaluate the correlation between the level of oxidative stress biomarkers in Aegla crabs (Crustacea, Anomura) with (i) the set of metals present in the streams sediment and (ii) with land uses of three hydrographic basins. The study was carried out in streams (≤ 2nd order) of hydrographic basins in southern Brazil (Basins of Rio Suzana, Rio Ligeirinho-Leãozinho and Rio Dourado). In these streams were quantified the land uses and Cu, Cr, Cd, Fe, Mn and Zn concentrations in the sediment. The enzymes Catalase (CAT) and Glutathione Reductase (GR), as well as the level of membrane lipid peroxidation (TBARS), were analyzed in adult females. The PCA analysis showed that the distribution of metals was different between the basins. Cd, Cr and Fe were correlated positively with CAT and negatively with TBARS and GR. The Dourado basin had the lowest concentrations of these three metals and the highest levels of TBARS. However, in Dourado basin there is predominance of agriculture land use, and TBARS was positively correlated with agricultural land use. Besides in Dourado basin, GR activity was higher than in the others basins, indicating a compensatory response in relation to CAT inhibition. The basins of Suzana and Ligeirinho-Leãozinho rivers had lower TBARS values, which may be due to the induction of CAT in response to metals accumulated in sediment. In summary, this work indicates that in the basins with a higher concentration of toxic metals there is an adaptive response of CAT induction, which reduces TBARS in Aegla. On the other hand, in the basin with lower metallic contamination, TBARS occurrence was primarily influenced by agricultural land use.


Resumo Os metais e agroquímicos estão entre os principais contaminantes aquáticos, podendo desencadear estresse oxidativo em organismos expostos. O objetivo deste trabalho foi avaliar uma possível correlação entre o nível de biomarcadores de estresse oxidativo em Aegla (Crustacea, Anomura) com (i) o conjunto de metais presentes no sedimento e (ii) com os usos da terra, em três bacias hidrográficas distintas. O estudo foi realizado em riachos (≤ 2ª ordem) de bacias hidrográficas do Sul do Brasil (Bacias do Rio Suzana, do Rio Ligeirinho-Leãozinho e do Rio Dourado), as quais foram caracterizadas em função do percentual de usos da terra e do nível de Cu, Cr, Cd, Fe, Mn e Zn no sedimento. As enzimas Catalase (CAT) e Glutationa Redutase (GR), bem como o nível de peroxidação lipídica das membranas (TBARS), foram analisadas em fêmeas adultas. Uma análise de PCA mostrou que a distribuição de metais foi distinta entre as bacias. Cd, Cr e Fe no sedimento correlacionaram positivamente com a CAT e negativamente com TBARS e GR. Entretanto, a bacia do Dourado apresentou os menores níveis destes três metais e os maiores níveis de TBARS, o que pode ser justificado pelo predomínio da agricultura nesta bacia, já que o TBARS correlacionou positivamente com o percentual de uso agrícola. Nesta bacia, a atividade da GR foi mais alta do que nas outras, indicando uma resposta compensatória em relação a inibição da CAT. As bacias do rio Suzana e rio Ligeirinho-Leãozinho apresentaram valores menores de TBARS, o que pode decorrer da indução da CAT em função dos metais acumulados no sedimento. Em síntese, este trabalho indica que nas bacias com maior concentração de metais tóxicos ocorre uma resposta adaptativa de indução da CAT, o que reduz os níveis de TBARS em Aegla. Por outro lado, na bacia com menor contaminação metálica os níveis de TBARS foram primariamente influenciados pelo uso agrícola.


Assuntos
Animais , Feminino , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade , Metais Pesados/análise , Anomuros , Brasil , Biomarcadores/metabolismo , Monitoramento Ambiental , Estresse Oxidativo , Rios , Agricultura
15.
Zoolog Sci ; 38(6): 558-564, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34854287

RESUMO

This study investigated ovarian development and larval release in the hermit crab Clibanarius eurysternus, which inhabits the upper intertidal zone on Okinawa, Japan. Adult females were collected monthly and had a high gonadosomatic index (GSI) from May to October. Oocytes at vitellogenic stages were observed from May to October. Some females had post-ovulatory follicles in the ovary and embryos on the abdomen (ovigerous females) in June and August, suggesting active ovarian development and larval release during these months (breeding season). When adult females were collected weekly according to the lunar cycle, a high GSI with oocytes at the tertiary yolk globule stage in the ovaries was maintained in all lunar phases. Since post-ovulated follicles were seen in ovaries collected around the last quarter and new moons, darkness at night is needed for spawning. Ovigerous females exposed to stepwise changes in hydrostatic pressure exhibited significantly higher synchrony between larval release and high pressure at night from the last quarter moon to the new moon, suggesting the importance of the tidal amplitude cycle in larval release under non-moonlight conditions. We concluded that the continuity of synchronous spawning and larval release of C. eurysternus are repeated under darkness and high tide at night during the breeding season.


Assuntos
Anomuros , Animais , Feminino , Japão , Larva , Ovário , Ovulação
16.
Sci Rep ; 11(1): 21833, 2021 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-34750431

RESUMO

Complete mitochondrial genomes (mitogenomes) can provide useful information for phylogenetic relationships, gene rearrangement, and molecular evolution. In this study, the complete mitogenomes of two hermit crabs, Dardanus arrosor and Dardanus aspersus, were sequenced for the first time and compared with other published mitogenomes of Paguroidea. Each of the two mitogenomes contains an entire set of 37 genes and a putative control region, but they display different gene arrangements. The different arrangements of the two mitogenomes might be the result of transposition, reversal, and tandem duplication/random loss events from the ancestral pancrustacean pattern. Genome sequence similarity analysis reveals the gene rearrangement in 15 Paguroidea mitogenomes. After synteny analysis between the 15 Paguroidea mitogenomes, an obvious rearranged region is found in D. aspersus mitogenome. Across the 13 protein-coding genes (PCGs) tested, COI has the least and ND6 has the largest genetic distances among the 15 hermit crabs, indicating varied evolution rates of PCGs. In addition, the dN/dS ratio analysis shows that all PCGs are evolving under purifying selection. The phylogenetic analyses based on both gene order and sequence data present the monophyly of three families (Paguridae, Coenobitidae, and Pylochelidae) and the paraphyly of the family Diogenidae. Meanwhile, the phylogenetic tree based on the nucleotide sequences of 13 PCGs shows that two Dardanus species formed a sister group with five Coenobitidae species. These findings help to better understand the gene rearrangement and phylogeny of Paguroidea, as well as provide new insights into the usefulness of mitochondrial gene order as a phylogenetic marker.


Assuntos
Anomuros/classificação , Anomuros/genética , Rearranjo Gênico , Genoma Mitocondrial , Animais , Uso do Códon , Evolução Molecular , Ordem dos Genes , Anotação de Sequência Molecular , Filogenia , Análise de Sequência de DNA , Especificidade da Espécie , Sintenia
17.
Zootaxa ; 5008(1): 1-159, 2021 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-34810473

RESUMO

The genus Phylladiorhynchus Baba, 1969 currently contains 11 species, all occurring in the shallow waters and on the continental shelf of the Indian and Pacific oceans. Recent expeditions in these oceans have resulted in the collection of numerous new specimens in need of analysis. We have studied this material using an integrative approach analysing both morphological and molecular (COI and 16S) characters. We describe 41 new species and resurrect three old names: P. integrus (Benedict, 1902) and P. lenzi (Rathbun, 1907), previously synonymized with P. pusillus (Henderson, 1885), and P. serrirostris (Melin, 1939), previously synonymized with P. integrirostris (Dana, 1852). Most species of the genus are described and illustrated. Some species are barely discernible on the basis of morphological characters but are highly divergent genetically. Species of Phylladiorhynchus are mainly distinguishable by the number of epigastric spines and lateral spines of the carapace, the shape and the armature of the rostrum, the number and pattern of the ridges on the carapace and pleon, the shape of thoracic sternite 3 and the armature of the P24 dactyli. A dichotomous identification key to all species is provided.


Assuntos
Anomuros , Expedições , Exoesqueleto , Animais
18.
Zootaxa ; 4999(4): 301-324, 2021 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-34810482

RESUMO

Morphological characters, as presently applied to describe members of the Paguristes tortugae Schmitt, 1933 species complex, appear to be of limited value in inferring phylogenetic relationships within the genus, and may have similarly misinformed understanding of relationships between members of this complex and those presently assigned to the related genera Areopaguristes Rahayu McLaughlin, 2010 and Pseudopaguristes McLaughlin, 2002. Previously undocumented observations of similarities and differences in color patterns among populations additionally suggest genetic divergences within some species, or alternatively seem to support phylogenetic groupings of some species. In the present study, a Maximum Likelihood (ML) phylogenetic analysis was undertaken based on the H3, 12S mtDNA, and 16S mtDNA sequences of 148 individuals, primarily representatives of paguroid species from the western Atlantic. This molecular analysis supported a polyphyletic Diogenidae Ortmann, 1892, although incomplete taxonomic sampling among the genera of Diogenidae limits the utility of this finding for resolving family level relationships. Several hypotheses regarding the evolutionary relationships among hermit crab genera were refuted by the Kishino-Hasegawa (KH). Shimodaira-Hasegawa (SH) and Approximately Unbiased (AU) tree topology tests, among them the hypothesis that Areopaguristes is monophyletic. A lack of support for the monophyly of Areopaguristes calls into question the phylogenetic validity of gill number for the differentiation of Paguristes, Areopaguristes, and Pseudopaguristes. The study was inconclusive with regard to the relationships among these three genera, but previously unknown diversity within both Paguristes and Areopaguristes was demonstrated. Existence of an undescribed species confounded under the name Paguristes tortugae Schmitt, 1933 was supported by genetics, morphology, and coloration. A second undescribed species with remarkable similarity to Areopaguristes hummi Wass, 1955 was discovered based on genetics and coloration.


Assuntos
Anomuros , Animais , Anomuros/genética , Deriva Genética , Filogenia
19.
Zootaxa ; 4996(2): 363-373, 2021 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-34810524

RESUMO

A new bopyrid, Pseudione chiesai n. sp., is herein described based on an ovigerous female and an adult male found in the right branchial chamber on a specimen of Munida spinosa Henderson, 1885. This parasite was collected in the Mar del Plata submarine canyon at 819 m depth during the expedition Talud Continental I carried out by the Argentine RV Puerto Deseado in 2012. P. chiesai n. sp. belongs to the Pseudione crels group sensu Bourdon (1972, 1976), which currently contains seven species, all of which have galatheoid crabs as hosts. P. chiesai n. sp. can be separated from the other species in the Pseudione crels group by the following combination of characters: (1) both sides of the body convex, (2) frontal lamina with a few, shallow indentations, (3) coxal plates 14 and tergal projections 14 with distinct irregular margins, mainly on the right side, (4) pereomeres 57 with single/branched lateral digitations, (5) maxilliped palp well-developed and setose, and (6) pleon with lateral plates 15 distally rounded and directed laterally. The taxonomic position of this new species is briefly discussed.


Assuntos
Anomuros , Braquiúros , Decápodes , Isópodes , Parasitos , Animais , Feminino , Masculino
20.
Zootaxa ; 5020(2): 257-287, 2021 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-34811002

RESUMO

Here we describe a new hornerid, Hornera currieae n. sp. (Bryozoa: Cyclostomatida) from bathyal depths across the New Zealand region. Colonies are irregular, finely branched fans attaining ~40 mm or more in height. Key characters include: (1) thick, semi-hyaline porcellanous skeleton; (2) loss or reduction of nervi (longitudinal striae) away from growing tips; (3) sparse, threadlike cancelli; and (4) small (6187 m), widely spaced autozooidal apertures. Diagnostic hornerid traits possessed by H. currieae n. sp. include vertical ancestrular tube, periancestrular budding of daughter zooids, and skeletal ultrastructure dominated by hexagonal semi-nacre grading to pseudofoliated fabric. The abfrontal incubation chamber develops from a cryptic tube arising from the frontally positioned aperture of the fertile zooid. We used SEM, micro-CT and electron backscatter diffractometry (EBSD) to investigate the ultrastructure and internal architecture of H. currieae n. sp. EBSD reveals that crystalline c-axes of laminated crystallites are perpendicular to skeletal walls. Threadlike cancelli, which traverse secondary calcification, connect autozooidal chambers to the colony-wide hypostegal cavity. Micro-CT reveals that abfrontal cancelli usually bend proximally towards the base, but turn distally towards reproductively active regions of the colony in synchrony with gonozooid development. The zone of affected cancelli extends for 47 branch internodes below the gonozooid. We assessed whether skeletal ultrastructure was similarly affected, but neither cancellus direction, nor gonozooid proximity, were predictive of the crystallite imbrication direction. We hypothesise that (1) hornerid cancelli are active conduits for colonial metabolite transport and (2) that changes in gradients of metabolites and/or reproductive morphogens within the hypostegal cavity affect cancellus morphogenesis. Potentially, H. currieae n. sp. skeletons may preserve a record of intra-colony metabolite translocation dynamics over time.


Assuntos
Anomuros , Briozoários , Animais
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