RESUMEN

Two bacteria, UG2_1T and UG2_2, were isolated from the gill tissues of the mangrove fiddler crab Cranuca inversa collected on the east coast of the Red Sea (Thuwal, Saudi Arabia). The cells are Gram-negative, rod-shaped, orange-pigmented, motile by gliding with no flagella, strictly aerobic, and grow at 20-37 °C (optimum, 28-35 °C), at pH 5.0-9.0 (optimum, pH 6.0-7.0), and with 1-11 % (w/v) NaCl (optimum, 2-4 %). They were positive for oxidase and catalase activity. Phylogenetic analysis based on 16S rRNA gene sequences indicated that isolates UG2_1T and UG2_2 belong to the genus Mangrovimonas, showing the highest similarity to Mangrovimonas spongiae HN-E26T (99.4 %). Phylogenomic analysis based on the whole genomes, independently using 49 and 120 concatenated genes, showed that strains UG2_1T and UG2_2 formed a monophyletic lineage in a different cluster from other type strain species within the genus Mangrovimonas. The genome sizes were 3.08 and 3.07 Mbp for UG2_1T and UG2_2, respectively, with a G+C content of 33.8 mol% for both strains. Values of average nucleotide identity and digital DNA-DNA hybridization between the strains and closely related species were 91.0 and 43.5 %, respectively. Chemotaxonomic analysis indicated that both strains had iso-C15 : 0 and iso-C15 : 1 G as dominant fatty acids, and the primary respiratory quinone was identified as MK-6. The major polar lipids comprised phosphatidylethanolamine, one unidentified glycolipid, one unidentified phospholipid, two unidentified aminolipids, and four unidentified lipids. Based on phylogenetic, phylogenomic, genome relatedness, phenotypic, and chemotaxonomical data, the two isolates represent a novel species within the genus Mangrovimonas, with the proposed name Mangrovimonas cancribranchiae sp. nov., and the type strain UG2_1T (=KCTC 102158T=DSM 117025T).

Asunto(s)

Técnicas de Tipificación Bacteriana , Composición de Base , Braquiuros , ADN Bacteriano , Ácidos Grasos , Branquias , Hibridación de Ácido Nucleico , Filogenia , ARN Ribosómico 16S , Análisis de Secuencia de ADN , ARN Ribosómico 16S/genética , Ácidos Grasos/análisis , ADN Bacteriano/genética , Océano Índico , Animales , Branquias/microbiología , Braquiuros/microbiología , Arabia Saudita , Humedales , Vitamina K 2/análogos & derivados , Vitamina K 2/análisis , Fosfolípidos/análisis

RESUMEN

Anthropogenic activities have reduced ecotones between the ocean and land, which is likely to threaten the population of brackish-water brachyuran crabs. To assess the current status of these crabs, we examine the population genetic structures of three semi-terrestrial brachyuran crabs widely distributed along the coast of the Japan and to clarify factors determining their genetic structures. We collected 184 Orisarma dehaani, 252 Chiromantes haematocheir, and 151 Helice tridens crabs from 36 localities of the Japanese archipelago. Genome-wide SNP data from these crabs were analyzed using MIG-seq. Bayesian clustering of STRUCTURE and DAPC analysis were used to identify genetically disturbed populations and to visualize genetic differentiation between local populations. Genetic population structure showed clear differentiation between populations on the Pacific coast of the Tohoku region and on other Japanese coasts in O. dehaani, but not in C. haematocheir or H. tridens. The inbreeding coefficient of O. dehaani was significantly higher on the Pacific coast of the Tohoku region compared to other Japanese coasts. C. haematocheir and H. tridens had homogeneous genetic structures along the Japanese coast, but showed genetic differentiation of a local population at their range limits. Thus, O. dehaani showed little gene flow and clear genetic differentiation between populations in the Tohoku Pacific region and those on other Japanese coasts due to ocean currents. Although such a regional differentiation was not found in C. haematocheir and H. tridens, one population of C. haematocheir was genetically isolated at the edge of its distribution range and likely vulnerable to environmental changes.

RESUMEN

Brachyuran crabs are ecologically and economically important macrofauna in mangrove habitats. However, they are exposed to various contaminants, including plastics, which bioaccumulate in relation to their feeding modes. Setiu Wetlands is a unique place on the east coast of Peninsular Malaysia where different ecosystems such as mangroves, lagoon, beaches, etc., are duly connected and influencing each other. In recent years, the shifted river mouth has threatened these wetlands, causing severe hydrodynamic changes in the lagoon, especially in the core mangrove zone. The present study tested microplastics (MPs) contamination in the mangroves through brachyuran crabs as indicators. Three sampling sites, namely Pulau Layat, Kampung Pengkalan Gelap, and Pulau Sutung were chosen. The four abundant crab species Parasesarma eumolpe, Metaplax elegans, Austruca annulipes, and Scylla olivacea, which display different feeding behaviours were collected from all sites covering the dry (Feb-Mar 2021) and the wet (Dec 2021-Jan 2022) seasonal periods. There were significant differences in the seasonal abundance of MPs among crab species. The highest accumulation of MPs in the crab stomachs in the dry season could be linked to subdued water circulation and poor material dispersion. Besides the lower MPs in the wet period due to improved water exchange conditions, its significant presence in the stomachs of S. olivacea indicates the role of its feeding behaviour as a carnivore. In addition, the micro-Fourier transform infrared spectroscopy (micro-FTIR) revealed the widespread occurrence of polymers such as rayon and polyester in all species across the sites. Given the fact that crabs like S. olivacea are commercially important and the ones contaminated with MPs can cause detrimental effects on the local community's health, further managerial actions are needed to assure sustainable management of the Setiu Wetlands.

RESUMEN

The shallow-water hydrothermal vent system of Kueishan Island has been described as one of the world's most acidic and sulfide-rich marine habitats. The only recorded metazoan species living in the direct vicinity of the vents is Xenograpsus testudinatus, a brachyuran crab endemic to marine sulfide-rich vent systems. Despite the toxicity of hydrogen sulfide, X. testudinatus occupies an ecological niche in a sulfide-rich habitat, with the underlying detoxification mechanism remaining unknown. Using laboratory and field-based experiments, we characterized the gills of X. testudinatus that are the major site of sulfide detoxification. Here sulfide is oxidized to thiosulfate or bound to hypotaurine to generate the less toxic thiotaurine. Biochemical and molecular analyses demonstrated that the accumulation of thiosulfate and hypotaurine is mediated by the sodium-independent sulfate anion transporter (SLC26A11) and taurine transporter (Taut), which are expressed in gill epithelia. Histological and metagenomic analyses of gill tissues demonstrated a distinct bacterial signature dominated by Epsilonproteobacteria. Our results suggest that thiotaurine synthesized in gills is used by sulfide-oxidizing endo-symbiotic bacteria, creating an effective sulfide-buffering system. This work identified physiological mechanisms involving host-microbe interactions that support life of a metazoan in one of the most extreme environments on our planet.

Asunto(s)

Braquiuros , Respiraderos Hidrotermales , Animales , Tiosulfatos , Sulfuros/toxicidad , Braquiuros/fisiología , Bacterias

RESUMEN

A neuropeptide (Sco-CHH-L), belonging to the crustacean hyperglycemic hormone (CHH) superfamily and preferentially expressed in the pericardial organs (POs) of the mud crab Scylla olivacea, was functionally and structurally studied. Its expression levels were significantly higher than the alternative splice form (Sco-CHH) in the POs, and increased significantly after the animals were subjected to a hypo-osmotic stress. Sco-CHH-L, but not Sco-CHH, significantly stimulated in vitro the Na+, K+-ATPase activity in the posterior (6th) gills. Furthermore, the solution structure of Sco-CHH-L was resolved using nuclear magnetic resonance spectroscopy, revealing that it has an N-terminal tail, three α-helices (α2, Gly9-Asn28; α3, His34-Gly38; and α5, Glu62-Arg72), and a π-helix (π4, Cys43-Tyr54), and is structurally constrained by a pattern of disulfide bonds (Cys7-Cys43, Cys23-Cys39, and Cys26-Cys52), which is characteristic of the CHH superfamily-peptides. Sco-CHH-L is topologically most similar to the molt-inhibiting hormone from the Kuruma prawn Marsupenaeus japonicus with a backbone root-mean-square-deviation of 3.12 Å. Ten residues of Sco-CHH-L were chosen for alanine-substitution, and the resulting mutants were functionally tested using the gill Na+, K+-ATPase activity assay, showing that the functionally important residues (I2, F3, E45, D69, I71, and G73) are located at either end of the sequence, which are sterically close to each other and presumably constitute the receptor binding sites. Sco-CHH-L was compared with other members of the superfamily, revealing a folding pattern, which is suggested to be common for the crustacean members of the superfamily, with the properties of the residues constituting the presumed receptor binding sites being the major factors dictating the ligand-receptor binding specificity.

Asunto(s)

Proteínas de Artrópodos , Braquiuros , Hormonas de Invertebrados , Proteínas del Tejido Nervioso , Neuropéptidos , Receptores de Péptidos/metabolismo , Secuencia de Aminoácidos , Animales , Proteínas de Artrópodos/química , Proteínas de Artrópodos/genética , Proteínas de Artrópodos/metabolismo , Braquiuros/genética , Braquiuros/metabolismo , Hormonas de Invertebrados/química , Hormonas de Invertebrados/genética , Hormonas de Invertebrados/metabolismo , Modelos Moleculares , Familia de Multigenes , Proteínas del Tejido Nervioso/química , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/metabolismo , Neuropéptidos/química , Neuropéptidos/genética , Neuropéptidos/metabolismo , Pericardio/metabolismo , Unión Proteica , Dominios Proteicos , Relación Estructura-Actividad

RESUMEN

We first reported the complete mitochondrial genome of Tenuilapotamon latilum kaiyangense (Decapoda: Brachyura: Potamoidea). The genome is 19,294 bp in length, including 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes, and a control region. The whole mitochondrial genome is characterized by the apparent AT bias (74.19%). This research provides DNA data for further researches on population genetics and phylogenetics.

RESUMEN

We report the complete mitochondrial genome of Bottapotamon lingchuanense for the first time, which is found to be 17,612 base pairs in length, and contains 13 protein-coding genes (PCGs), 2 ribosomal RNA (rRNA) genes, 22 transfer RNA (tRNA), and 1 non-coding AT-rich region known as the D-loop. In addition, the mitogenome has 17 intergenic regions ranging from 1 to 1512 bp in length. The mitochondrial genome of B. lingchuanense is the first mitochondrial genome under the genus Bottapotamon, providing DNA data for species identification, enriching the species diversity of Brachyura. The maximum-likelihood (ML) tree and Bayesian inference (BI) tree based on the 13 PCGs of mitochondrial genome of Brachyura species showed similar topologies with high confidence, and the analysis results were consistent with the current mainstream classification system. The results indicating that B. lingchuanense is closely related to Neilupotamon sinense, Sinopotamon, and Tenuilapotamon, and it is likely to be derived from them.

RESUMEN

A variety of reoviruses have been described in crustacean hosts, including shrimp, crayfish, prawn, and especially in crabs. However, only one genus of crustacean reovirus - Cardoreovirus - has been formally recognized by ICTV (International Committee on Taxonomy of Viruses) and most crustacean reoviruses remain unclassified. This arises in part from ambiguous or incomplete information on which to categorize them. In recent years, increased availability of crustacean reovirus genomic sequences is making the discovery and classification of crustacean reoviruses faster and more certain. This minireview describes the properties of the reoviruses infecting crustaceans and suggests an overall classification of brachyuran crustacean reoviruses based on a combination of morphology, host, genome organization pattern and phylogenetic sequence analysis.

Asunto(s)

Crustáceos/virología , Reoviridae/clasificación , Animales , Filogenia , Reoviridae/genética

RESUMEN

Algal reefs are one of the world's rare and poorly understood ecosystems. They are mainly distributed in the Mediterranean Sea, but one notable exception-an intertidal algal reef ecosystem in northwestern Taiwan-stretches for 27 km along the coast of Taoyuan, making it probably the largest algal reef coast found in shallow water. Despite the reef's rarity and striking characteristics, the coastal land that it is part of has undergone a series of developments and is now surrounded by industrial parks. Brachyuran crabs are one of the most abundant and visible groups of organisms in the intertidal zone. In the present study, we investigated the brachyuran crab community in this reef to provide a more detailed record of brachyuran crab species compositions in this intertidal algal reef ecosystem and illustrate the characteristics of this understudied ecosystem by comparing its species diversity and abundance with three natural variables- sampling time, tidal level, and season-in a wildlife refuge and north of the refuge. Two methods were used in the study: a qualitative method (to determine the species richness) and a quantitative method (to estimate the population density). We identified a total of 52 brachyuran species from 13 families in the habitats. The highest species richness was found in Datan G2, north of the wildlife refuge. The crab species composition in this algal reef is different from its compositions in coral and rocky reefs. Our analysis indicated that the species abundance is affected by multiple factors, and a single investigation is not enough to reflect the true population density of brachyuran crabs on this reef. In addition, we found that the sites outside the wildlife refuge were in much better condition than those in the wildlife refuge, and should therefore be included in the wildlife refuge. In particular, Datan, located north of the wildlife refuge, had the highest species richness, and the area's species composition was different from that of the nearby wildlife refuge. Thus, we strongly recommend that a) the Datan area be protected to maintain this high crab diversity and b) further research be performed to better understand brachyuran crab biology in the intertidal algal reef ecosystem.

RESUMEN

Decapoda is one of the most diverse crustacean orders, and has become an important research subject. However, the phylogenetic relationships among the main lineages of Decapoda remain uncertain, especially in the order Brachyura. Herein, we sequenced the whole mitochondrial genome of V. litterata and constructed a phylogenetic tree to understand its phylogenetic relationships with other species. The results showed that the mitochondrial genome of V. litterata was generally similar to mitogenomes of Metazoa reported in the literature, with a size of 16,247 bp, 37 genes, and a control region. Both AT-skew and GC-skew were negative, indicating more abundant Cs and Ts than Gs and As. The gene arrangement of V. litterata is identical to those of Eriocheir hepuensis, Cyclograpsus granulosus, Hemigrapsus sanguineus, Helicana wuana, and Helice tientsinensis but differs from the pancrustacean ground pattern and typical arrangement of Brachyuran crabs. Phylogenetic reconstruction showed that V. litterata belongs to the Varunidae.

Asunto(s)

Braquiuros/clasificación , Filogenia , Animales , Braquiuros/genética , Genoma Mitocondrial , Polimorfismo Genético

RESUMEN

Potamiscus motuoensis is the only one freshwater crab species distributed in Yarlung Zangbo River Grand Canyon and its complete mitochondrial genome was obtained for the first time. The complete mitochondrial genome of P. motuoensis is 17,971 bp in length, including 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes, and 1 control region. In addition, the mitogenome has 19 noncoding regions ranging from 1 to 1396 bp in length. The report of the mitochondrial genome will enrich the species diversity of Yarlung Zangbo River Grand Canyon and provide data support for further research.

RESUMEN

The transition to terrestrial environments by formerly aquatic species has occurred repeatedly in many animal phyla and lead to the vast diversity of extant terrestrial species. The differences between aquatic and terrestrial habitats are enormous and involved remarkable morphological and physiological changes. Convergent evolution of various traits is evident among phylogenetically distant taxa, but almost no information is available about the role of symbiotic microbiota in such transition. Here, we suggest that intertidal and terrestrial brachyuran crabs are a perfect model to study the evolutionary pathways and the ecological role of animal-microbiome symbioses, since their transition to land is happening right now, through a number of independent lineages. The microorganisms colonizing the gut of intertidal and terrestrial crabs are expected to play a major role to conquer the land, by reducing water losses and permitting the utilization of novel food sources. Indeed, it has been shown that the microbiomes hosted in the digestive system of terrestrial isopods has been critical to digest plant items, but nothing is known about the microbiomes present in the gut of truly terrestrial crabs. Other important physiological regulations that could be facilitated by microbiomes are nitrogen excretion and osmoregulation in the new environment. We also advocate for advances in comparative and functional genomics to uncover physiological aspects of these ongoing evolutionary processes. We think that the multidisciplinary study of microorganisms associated with terrestrial crabs will shed a completely new light on the biological and physiological processes involved in the sea-land transition.

RESUMEN

The complete mitochondrial genome of Chinapotamon maolanense was obtained for the first time. The complete mitochondrial genome of C. maolanense is 17,130 bp in length, including 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes, and 1 control region. In addition, the mitogenome has 18 noncoding regions ranging from 1 to 1553 bp in length.

RESUMEN

In this study, we first obtained the complete mitochondrial genome of Neilupotamon xinganense (Decapoda: Brachyura: Potamoidea). The genome is 16,965 bp in length and typically consists of 37 genes (13 protein-coding genes, 22 tRNAs genes, two rRNAs genes, and one putative control region). In addition, the mitogenome has 20 non-coding regions ranging from 1 to 683 bp in length. This study provides DNA data for further researches on population genetics and phylogenetics.

RESUMEN

We report the complete mitochondrial genome of Sinolapotamon patellifer for the first time, which is found to be 16,547 base pairs in length, and contains 13 protein-coding genes (PCGs), two ribosomal RNA (rRNA) genes, 22 transfer RNA (tRNA), and one non-coding AT-rich region known as the D-loop. In addition, the mitogenome has 17 intergenic regions ranging from 1 to 1512 bp in length. The mitochondrial genome of S. patellifer is the first mitochondrial genome under the genus Sinolapamon, providing DNA data for species identification, enriching the species diversity of Brachyura, and providing a basis for further studies on population genetics and phylogenetics.

RESUMEN

Two brachyuran species of the families Dynonemidae and Iphiculidae are reported from red coral beds in northern Taiwan. The dynonemid Acanthodromia margarita (Alcock, 1899) has hitherto been reported from the Andaman Sea, Japan, and Philippines and the species is here recorded for the first time from Taiwan. A new species of iphiculid, Pariphiculus stellatussp. n., is also described. The new Pariphiculus, which also occurs in the Philippines, is superficially similar to P. agariciferus Ihle, 1918, a species known from Indonesia, Japan, Philippines, South China Sea, Taiwan, and Vanuatu, but can be distinguished by distinct carapace, pleonal and male first gonopod features.

RESUMEN

Confocal laser scanning microscopy is an excellent tool for nondestructive imaging of arthropods and can provide detailed information on morphology including fine surface detail. A methodology is presented here for the visualization by confocal microscopy of arthropods, using brachyuran crab zoeal stages as examples and postprocessing techniques derived from micro-CT protocols to improve the final images. This protocol is divided into description of the preprocessing steps (cleaning, staining, digesting and mounting), confocal laser scanning microscopy and data visualization using open-source, freeware programs ImageJ and Drishti. The advantages of using ImageJ to standardize stack data and Drishti for surface rendering are discussed. The methodology has been comprehensively tested using data acquired from all four brands of confocal microscope (Leica, Nikon, Olympus and Zeiss).

Asunto(s)

Artrópodos/anatomía & histología , Imagenología Tridimensional/métodos , Microscopía Confocal/métodos , Animales , Larva/anatomía & histología , Flujo de Trabajo

RESUMEN

Improving our understanding of species responses to environmental changes is an important contribution ecologists can make to facilitate effective management decisions. Novel synthetic approaches to assessing biodiversity and ecosystem integrity are needed, ideally including all species living in a community and the dynamics defining their ecological relationships. Here, we present and apply an integrative approach that links high-throughput, multicharacter taxonomy with community ecology. The overall purpose is to enable the coupling of biodiversity assessments with investigations into the nature of ecological interactions in a community-level data set. We collected 1195 gastropods and crabs in British Columbia. First, the General mixed Yule-coalescent (GMYC) and the Poisson Tree Processes (PTP) methods for proposing primary species-hypotheses based on cox1 sequences were evaluated against an integrative taxonomic framework. We then used data on the geographic distribution of delineated species to test species co-occurrence patterns for nonrandomness using community-wide and pairwise approaches. Results showed that PTP generally outperformed GMYC and thus constitutes a more effective option for producing species-hypotheses in community-level data sets. Nonrandom species co-occurrence patterns indicative of ecological relationships or habitat preferences were observed for grazer gastropods, whereas assemblages of carnivorous gastropods and crabs appeared influenced by random processes. Species-pair associations were consistent with current ecological knowledge, thus suggesting that applying community assembly within a large taxonomical framework constitutes a valuable tool for assessing ecological interactions. Combining phylogenetic, morphological and co-occurrence data enabled an integrated view of communities, providing both a conceptual and pragmatic framework for biodiversity assessments and investigations into community dynamics.

Asunto(s)

Biodiversidad , Braquiuros/clasificación , Exposición a Riesgos Ambientales , Gastrópodos/clasificación , Animales , Braquiuros/anatomía & histología , Braquiuros/genética , Colombia Británica , Gastrópodos/anatomía & histología , Gastrópodos/genética , Genética de Población , Análisis de Secuencia de ADN

RESUMEN

We report for the first time the complete mitochondrial genome of Sinopotamon xiushuiense, which is found to be 18,460 bp in length, and contains 13 protein-coding genes (PCGs), 2 ribosomal RNA (rRNA) genes, 22 transfer RNA (tRNA), and 1 non-coding region known as the D-loop. In addition, the mitogenome has 18 intergenic regions ranging from 1 to 1221 bp in length. The complete mitogenome of S. xiushuiense is the longest among brachyurans reported in GenBank before November 2015, and its AT content is slightly lower than that in Geotholphusa dehaani. The mitogenome data provides a basis for further studies on population genetics and phylogenetics.

RESUMEN

The Caribbean king crab Damithrax spinosissimus (former Mithrax spinosissimus) is a large brachyuran in the tropical and subtropical western Atlantic. This is the first report of the complete mitochondrial genome of D. spinosissimus, which was pyrosequenced by FLX 454 technology. The mtDNA encodes for 13 proteins, 22 tRNAs and 2 ribosomal RNAs. In addition, the coding sequences and gene synteny were similar to other previously reported mitogenomes of brachyuran.

Asunto(s)

Braquiuros/genética , Genoma Mitocondrial , Animales , Composición de Base/genética , Secuencia de Bases , ADN Mitocondrial/genética , Genes Mitocondriales , ARN de Transferencia/genética