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Sample records for brachyura cancridae capturadas

  1. The complete mitochondrial genome of red frog crab Ranina ranina (Crustacea: Decapoda: Brachyura: Raninidae).

    PubMed

    Cheng, Jiao; Jiang, Wei; Shi, Huafeng; Sha, Zhongli

    2016-01-01

    Although the brachyuran nature of Raninoidea is widely accepted, there is no consensus over the precise position of the Raninoidea within Brachyura. Long PCR and primer walking methods are employed to determine the first complete mitochondrial genome (mitogenome) sequence of raninoidian crab, Ranina ranina. It is a circular double-stranded DNA molecule of 15,563 base pairs (bp) in length with a standard set of 22 transfer RNA genes (tRNAs), 2 ribosomal RNA genes (rRNAs), 13 protein-coding genes (PCGs) as well as a putative non-coding control region. The gene order is substantially consistent with that of the pancrustacean ground pattern with the tRNA(His) gene rearrangement. The basal placement of R. ranina in the phylogenetic tree integrated with a similar genomic organization to ancestral pancrustacea confirmed the primitive position of R. ranina in the Brachyura.

  2. Mimulus Stimpson, 1860, a junior synonym of Pugettia Dana, 1851 (Decapoda: Brachyura: Majoidea: Epialtidae).

    PubMed

    Wicksten, Mary K; Stachowicz, John J

    2013-01-01

    William Stimpson (1860) established Mimulus (Brachyura: Majoidea: Epialtidae), with a single species, Mfoliatus. Rathbun (1894) placed the genus in synonymy with Pugettia Dana, 18951, but subsequent authors have considered Mimulus to be a valid genus. Genetic evidence and re-examination of the morphology indicate that M. foliatus belongs to a clade of majoid crabs consisting of species of Pugettia. We therefore consider Mimulus to be a junior synonym of Pugettia. We provide a list of all species of Pugettia.

  3. Evolutionary history of true crabs (Crustacea: Decapoda: Brachyura) and the origin of freshwater crabs.

    PubMed

    Tsang, Ling Ming; Schubart, Christoph D; Ahyong, Shane T; Lai, Joelle C Y; Au, Eugene Y C; Chan, Tin-Yam; Ng, Peter K L; Chu, Ka Hou

    2014-05-01

    Crabs of the infra-order Brachyura are one of the most diverse groups of crustaceans with approximately 7,000 described species in 98 families, occurring in marine, freshwater, and terrestrial habitats. The relationships among the brachyuran families are poorly understood due to the high morphological complexity of the group. Here, we reconstruct the most comprehensive phylogeny of Brachyura to date using sequence data of six nuclear protein-coding genes and two mitochondrial rRNA genes from more than 140 species belonging to 58 families. The gene tree confirms that the "Podotremata," are paraphyletic. Within the monophyletic Eubrachyura, the reciprocal monophyly of the two subsections, Heterotremata and Thoracotremata, is supported. Monophyly of many superfamilies, however, is not recovered, indicating the prevalence of morphological convergence and the need for further taxonomic studies. Freshwater crabs were derived early in the evolution of Eubrachyura and are shown to have at least two independent origins. Bayesian relaxed molecular methods estimate that freshwater crabs separated from their closest marine sister taxa ~135 Ma, that is, after the break up of Pangaea (∼200 Ma) and that a Gondwanan origin of these freshwater representatives is untenable. Most extant families and superfamilies arose during the late Cretaceous and early Tertiary.

  4. Deep-Sea decapod crustaceans (Caridea, Polychelida, Anomura and Brachyura) collected from the Nikko Seamounts, Mariana Arc, using a remotely operated vehicle "Hyper-Dolphin".

    PubMed

    Komai, Tomoyuki; Tsuchida, Shinji

    2014-01-01

    Samples and images of deep-water benthic decapod crustaceans were collected from the Nikko Seamounts, Mariana Arc, at depths of 520-680 m, by using the remotely operate vehicle "Hyper-Dolphin", equipped with a high definition camera, digital camera, manipulators and slurp gun (suction sampler). The following seven species were collected, of which three are new to science: Plesionika unicolor n. sp. (Caridea: Pandalidae), Homeryon armarium Galil, 2000 (Polychelida: Polychelidae), Eumunida nikko n. sp. (Anomura: Eumunididae), Michelopagurus limatulus (Henderson, 1888) (Anomura: Paguridae), Galilia petricola n. sp. (Brachyura: Leucosiidae), Cyrtomaia micronesica Richer de Forges & Ng, 2007 (Brachyura: Inachidae), and Progeryon mus Ng & Guinot, 1999 (Brachyura: Progeryonidae). Affinities of these three new species are discussed. All but H. armarium are recorded from the Japanese Exclusive Economic Zone for the first time. Brief notes on ecology and/or behavior are given for each species. PMID:24870636

  5. Deep-Sea decapod crustaceans (Caridea, Polychelida, Anomura and Brachyura) collected from the Nikko Seamounts, Mariana Arc, using a remotely operated vehicle "Hyper-Dolphin".

    PubMed

    Komai, Tomoyuki; Tsuchida, Shinji

    2014-02-11

    Samples and images of deep-water benthic decapod crustaceans were collected from the Nikko Seamounts, Mariana Arc, at depths of 520-680 m, by using the remotely operate vehicle "Hyper-Dolphin", equipped with a high definition camera, digital camera, manipulators and slurp gun (suction sampler). The following seven species were collected, of which three are new to science: Plesionika unicolor n. sp. (Caridea: Pandalidae), Homeryon armarium Galil, 2000 (Polychelida: Polychelidae), Eumunida nikko n. sp. (Anomura: Eumunididae), Michelopagurus limatulus (Henderson, 1888) (Anomura: Paguridae), Galilia petricola n. sp. (Brachyura: Leucosiidae), Cyrtomaia micronesica Richer de Forges & Ng, 2007 (Brachyura: Inachidae), and Progeryon mus Ng & Guinot, 1999 (Brachyura: Progeryonidae). Affinities of these three new species are discussed. All but H. armarium are recorded from the Japanese Exclusive Economic Zone for the first time. Brief notes on ecology and/or behavior are given for each species.

  6. Comparative analyses of olfactory systems in terrestrial crabs (Brachyura): evidence for aerial olfaction?

    PubMed

    Krieger, Jakob; Braun, Philipp; Rivera, Nicole T; Schubart, Christoph D; Müller, Carsten H G; Harzsch, Steffen

    2015-01-01

    Adaptations to a terrestrial lifestyle occurred convergently multiple times during the evolution of the arthropods. This holds also true for the "true crabs" (Brachyura), a taxon that includes several lineages that invaded land independently. During an evolutionary transition from sea to land, animals have to develop a variety of physiological and anatomical adaptations to a terrestrial life style related to respiration, reproduction, development, circulation, ion and water balance. In addition, sensory systems that function in air instead of in water are essential for an animal's life on land. Besides vision and mechanosensory systems, on land, the chemical senses have to be modified substantially in comparison to their function in water. Among arthropods, insects are the most successful ones to evolve aerial olfaction. Various aspects of terrestrial adaptation have also been analyzed in those crustacean lineages that evolved terrestrial representatives including the taxa Anomala, Brachyura, Amphipoda, and Isopoda. We are interested in how the chemical senses of terrestrial crustaceans are modified to function in air. Therefore, in this study, we analyzed the brains and more specifically the structure of the olfactory system of representatives of brachyuran crabs that display different degrees of terrestriality, from exclusively marine to mainly terrestrial. The methods we used included immunohistochemistry, detection of autofluorescence- and confocal microscopy, as well as three-dimensional reconstruction and morphometry. Our comparative approach shows that both the peripheral and central olfactory pathways are reduced in terrestrial members in comparison to their marine relatives, suggesting a limited function of their olfactory system on land. We conclude that for arthropod lineages that invaded land, evolving aerial olfaction is no trivial task.

  7. Comparative analyses of olfactory systems in terrestrial crabs (Brachyura): evidence for aerial olfaction?

    PubMed Central

    Krieger, Jakob; Braun, Philipp; Rivera, Nicole T.; Schubart, Christoph D.; Müller, Carsten H.G.

    2015-01-01

    Adaptations to a terrestrial lifestyle occurred convergently multiple times during the evolution of the arthropods. This holds also true for the “true crabs” (Brachyura), a taxon that includes several lineages that invaded land independently. During an evolutionary transition from sea to land, animals have to develop a variety of physiological and anatomical adaptations to a terrestrial life style related to respiration, reproduction, development, circulation, ion and water balance. In addition, sensory systems that function in air instead of in water are essential for an animal’s life on land. Besides vision and mechanosensory systems, on land, the chemical senses have to be modified substantially in comparison to their function in water. Among arthropods, insects are the most successful ones to evolve aerial olfaction. Various aspects of terrestrial adaptation have also been analyzed in those crustacean lineages that evolved terrestrial representatives including the taxa Anomala, Brachyura, Amphipoda, and Isopoda. We are interested in how the chemical senses of terrestrial crustaceans are modified to function in air. Therefore, in this study, we analyzed the brains and more specifically the structure of the olfactory system of representatives of brachyuran crabs that display different degrees of terrestriality, from exclusively marine to mainly terrestrial. The methods we used included immunohistochemistry, detection of autofluorescence- and confocal microscopy, as well as three-dimensional reconstruction and morphometry. Our comparative approach shows that both the peripheral and central olfactory pathways are reduced in terrestrial members in comparison to their marine relatives, suggesting a limited function of their olfactory system on land. We conclude that for arthropod lineages that invaded land, evolving aerial olfaction is no trivial task. PMID:26713228

  8. Muscular anatomy of the legs of the forward walking crab, Libinia emarginata (Decapoda, Brachyura, Majoidea).

    PubMed

    Vidal-Gadea, A G; Belanger, J H

    2009-05-01

    Decapod crustaceans have been the focus of neuroethological studies for decades. With few exceptions, however, their musculature remains scarcely described. We study the neuroethology of legged locomotion in the portly spider crab, Libinia emarginata (Brachyura, Majoidea), which preferentially walks forward. Majoid crabs are thought to be among the first to have adopted the crab form (carcinification) from lobster-like ancestors, making them interesting subjects for comparative and phylogenetic studies. The radial arrangement of the legs around the thorax, coupled with its unidirectional walking modality makes L. emarginata a good candidate for the presence of anterior and posterior limb specializations. Here we describe the complete muscular anatomy of all the pereopods of L. emarginata and compare our findings with other decapods described in the literature. The number of proximal muscle bundles differs between the anterior and posterior pereopods of L. emarginata. We describe an intersegmental bundle of the flexor muscle similar to the one present in distantly related, forward walking macruran species. The behavioral repertoire, amenability to experimental investigations, and phylogenetic position make spider crabs useful species for the study of the neural control of legged locomotion. To our knowledge, this is the first instance of a complete description and comparison of the musculature in all the locomotor appendages of one species.

  9. Local distribution and abundance of Cardisoma guanhumi Latreille, 1928 (Brachyura: Gecarcinidae) in southern Brazil.

    PubMed

    Oliveira-Neto, J F; Batista, E; Metri, R; Metri, C B

    2014-02-01

    The blue land crab, Cardisoma guanhumi Latreille, 1828 (Brachyura: Gecarcinidae) is officially included in the list of over-exploited species in Brazil, although still abundantly found in the state of Santa Catarina, the southern limit of its distribution. This species was found in forested areas, gardens, and grassy areas, including crabs with carapace width larger than 80mm. The existence of this population with these characteristics is surprising, since there is only one official record of the species in the southern region. The objectives of this study are to estimate the abundance and occupation patterns of C. guanhumi in this region. Correlations with conservation were discussed. The absolute abundance of crabs in the middle of summer activity was established for an area of 100,000 m2. A smaller area was mapped and divided into sampling units for statistical analyses. We distributed approximately 240 crabs in a forested area of about 3,000 m2 and 150 crabs in grassy areas (90,000 m2). The statistical test of Kruskal-Wallis test showed that there are significant differences between the sizes of the openings of the galleries inside the forest and that located in grassy areas. In the forest, the openings tend to be much larger. Burrows were found at a distance of 150 metres from the channel. The number of galleries was higher in the forested area, although the burrows were more densely grouped in grassy areas. Although C. guanhumi seems to be adjusting well to changes caused by human occupation, small forested areas are more conducive to growth and conservation of this species.

  10. The complete mitogenome of the hydrothermal vent crab Xenograpsus testudinatus (Decapoda, Brachyura) and comparison with brachyuran crabs.

    PubMed

    Ki, Jang-Seu; Dahms, Hans-Uwe; Hwang, Jiang-Shiou; Lee, Jae-Seong

    2009-12-01

    In this study, we analyzed the complete mitochondrial (mt) genome of a hydrothermal vent crab Xenograpsus testudinatus (Decapoda: Brachyura) obtained from the hydrothermal vents off Kueishantao Island, Taiwan, which extend from the deep sea Okinawa Trench. The mitogenome of X. testudinatus was 15,796 bp in length and contained the same 37 genes (e.g. 2 rRNAs, 22 tRNAs, and 13 PCGs) found in other metazoan mitogenomes. Analysis of the structural mt gene order in X. testudinatus revealed that the 13 PCGs, excluding a translocation of ND6-Cyt b cluster, were similarly ordered when compared to the pancrustacean ground pattern; however the tRNAs were severely rearranged. Phylogenetic analysis of decapod mitogenomes showed that the molecular taxonomy of the vent crab was in accordance with its morphological systematics. Together, these findings suggest that the vent crab studied here has little mitochondrial genetic variation when compared with morphologically defined conspecifics from other marine habitats.

  11. Biochemical and physiological responses after exposure to microcystins in the crab Chasmagnathus granulatus (Decapoda, Brachyura).

    PubMed

    Dewes, L J; Sandrini, J Z; Monserrat, J M; Yunes, J S

    2006-10-01

    Microcystins are usually the predominant cyanotoxins present in both drinking and recreational waters after cyanobacterial blooms. Their classic toxic effect is hepatotoxicity through inhibition of serine/threonine phosphatases. However, recent studies also reported oxidative stress generation and disruption of ion regulation in aquatic organisms after microcystins exposure. In the present study, aqueous extracts of Microcystis aeruginosa were administered to the estuarine crab Chasmagnathus granulatus (Decapoda, Brachyura) by gavage in variable doses (from 34 to 860 microg kg(-1)) and exposure times (6, 12, and 72 h). A control group was exposed to saline solution. Analyzed variables included oxygen consumption, lipid peroxidation (LPO), enzyme activities (glutathione S-transferases or GST; alanine aminotransferase or ALT; aspartate aminotransferase or AST; and lactate dehydrogenase or LDH), glycogen, and microcystins content. Oxygen consumption increased in organisms exposed for 12h to 860 microg kg(-1) of microcystins and a similar result was observed after 72 h at doses equal to or higher than 34 microg kg(-1). LPO levels increased in doses equal to or higher than 34 microg kg(-1) after 72 h. GST and LDH activities increased after 12 h (at a dose of 860 microg kg(-1)), but ALT and AST activities remained unaltered in all experimental conditions. Glycogen content decreased after 72 h exposure at doses equal to or higher than 172 microg kg(-1). After 12h of exposure to 860 microg kg(-1) of microcystins, the concentration found in the hepatopancreas of C. granulatus was 13.17+/-0.56 microg kg(-1). In crabs exposed to doses higher than 172 microg kg(-1) during 72 h this value raised to 32.14+/-4.12 microg kg(-1). The obtained results indicated that microcystins exposure led the tissue to an oxidative stress condition (high LPO levels), at least in part favored by the augment of oxygen consumption, altering the glycogen metabolism. GST responses were only observed

  12. Relative growth of Acantholobulus schmitti (Rathbun, 1930) (Crustacea, Brachyura, Panopeidae) at Guaratuba Bay, southern Brazil.

    PubMed

    Frigotto, S F; Marochi, M Z; Masunari, S

    2013-11-01

    A study on the relative growth of the crab Acantholobulus schmitti (Rathbun, 1930) (Decapoda, Brachyura, Panopeidae) was performed with allometric techniques. The species is associated with lanterns used for oyster farming at Guaratuba Bay, southern Brazil. Crabs were obtained from five lanterns from March through December 2009. The following morphological characteristics were measured: the carapace width (CW), the height and length of the major cheliped propodus (LPH and LPL), the width of the female abdomen at the base of the 4th somite (AW) and the length of the male gonopod (GL). A total of 1,004 individuals of A. schmitti were measured, of which 451 were males, 323 non-ovigerous females and 230 ovigerous females. The CW of the males varied from 1.87 to 11.86 mm, that of non-ovigerous females from 1.44 to 8.77 mm and that of ovigerous females from 4.09 to 11.12 mm. The plot of LPH against CW showed a mean inflection point at 3.67 mm CW for the males. This result indicated that male crabs are juvenile below this value and adult above it. For the females, the corresponding inflection point occurred at 3.36 mm CW in the plot of AW against CW. These results, CW x LPH and CW x AW, highlight the importance of chelae enlargement at the onset of maturation in males. Similarly, the widening of the abdomen in females is required to accommodate egg clutches during the reproductive period. Heterochely was recorded in both sexes. Right-handed crabs were more frequent than left-handed ones, with percentages of 75.8% in males and 82.7% in females. The population of A. schmitti from Guaratuba Bay becomes sexually mature at an earlier age than A. schmitti from the coast of São Paulo state. The lanterns used in oyster farming furnish a safe habitat in which these crabs can spend their entire benthic life.

  13. Male internal reproductive structures of European pea crabs (Crustacea, Decapoda, Brachyura, Pinnotheridae): vas deferens morphology and spermatozoal ultrastructure.

    PubMed

    Becker, Carola; Klaus, Sebastian; Tudge, Christopher C

    2013-11-01

    Pea crabs of the subfamily Pinnotherinae (Pinnotheridae) have a high investment in reproduction and an outstanding reproductive output, probably as an adaptation to the required increase in reproductive rate due to the pinnotherids small size and their parasitic, host-dependant way of life. In the present study, we investigate the male internal reproductive structures and the ultrastructure of spermatozoa of Pinnotheres pisum and Nepinnotheres pinnotheres by histological methods and both scanning- and transmission electron microscopy. In the Brachyura, the male internal reproductive systems generally consist of paired testes and corresponding vasa deferentia where spermatozoa develop and mature. Spermatozoal ultrastructure of the investigated pinnotherids conforms to the thoracotreme type, however, N. pinnotheres has an accessory opercular ring and a periopercular rim, neither of which are present in spermatozoa of P. pisum. Spermatozoa are enclosed within spermatophores in the secretory proximal vas deferens. Two types of secretions were observed in P. pisum and N. pinnotheres: an electron dense substance secreted in the proximal vas deferens involved in spermatophore formation, and large electron-luscent vesicles constituting the seminal plasma in the medial and distal vas deferens. The medial vas deferens is strongly widened compared to other brachyurans to purpose storing spermatophores embedded in seminal plasma. Tubular appendices, which produce and store large amounts of seminal plasma, arise from the distal region of the vas deferens. The appendices extend into the ventral cephalothorax and also in the first pleomere. The latter being an exceptional location for reproductive structures among male brachyurans.

  14. Short- and long-term, salinity-induced modulation of V-ATPase activity in the posterior gills of the true freshwater crab, Dilocarcinus pagei (Brachyura, Trichodactylidae).

    PubMed

    Firmino, Kelly Cristina Silva; Faleiros, Rogério Oliveira; Masui, Douglas Chodi; McNamara, John Campbell; Furriel, Rosa Prazeres Melo

    2011-09-01

    To better understand the biochemical mechanisms underlying anisosmotic extracellular regulation in the freshwater Brachyura, we kinetically characterized the V-ATPase from the posterior gills of Dilocarcinus pagei, acclimated for 10days to salinities up to 21‰. Specific activity was highest in fresh water (26.5±2.1U mg(-1)), decreasing in 5‰ to 21‰, attaining 3-fold less at 15‰. Apparent affinities for ATP and Mg(2+) respectively increased 3.2- and 2-fold at 10‰, suggesting expression of different isoenzymes. In a 240-h time-course study of exposure to 21‰, maximum specific activity decreased 2.5- to 4-fold within 1 to 24h while apparent affinities for ATP and Mg(2+) respectively increased by 12-fold within 24h and 2.4-fold after 1h, unchanged thereafter. K(I) for bafilomycin A(1) decreased 150-fold after 1h, remaining constant up to 120h. This is the first kinetic analysis of V-ATPase specific activity in crustacean gills during salinity acclimation. Our findings indicate active gill Cl(-) uptake by D. pagei in fresh water, and short- and long-term down-regulation of V-ATPase-driven ion uptake processes during salinity exposure, aiding in comprehension of the biochemical adaptations underpinning the establishment of the Brachyura in fresh water.

  15. Significance of the sexual openings and supplementary structures on the phylogeny of brachyuran crabs (Crustacea, Decapoda, Brachyura), with new nomina for higher-ranked podotreme taxa.

    PubMed

    Guinot, Danièle; Tavares, Marcos; Castro, Peter

    2013-01-01

    The patterns of complexity of the male and female sexual openings in Brachyura, which have been the source of uncertainties and conflicting opinions, are documented, together with a study of the morphologies of the coxal and sternal gonopores in both sexes, penises, spermathecae, and gonopods. The vulvae, male gonopores and penises are described among selected taxa of Eubrachyura, and their function and evolution examined in the context of a wide variety of mating behaviours. The location of female and male gonopores, the condition of the penis (coxal and sternal openings and modalities of protection), and related configurations of thoracic sternites 7 and 8, which are modified by the intercalation of a wide sternal part (thoracic sternites 7 and 8) during carcinisation, show evidence of deep homology. They represent taxonomic criteria at all ranks of the family-series and may be used to test lineages. Of particular significance are the consequences of the posterior expansion of the thoracic sternum, which influences the condition, shape, and sclerotisation of the penis, and its emergence from coxal (heterotreme) to coxo-sternal, which is actually still coxal (heterotreme), in contrast to a sternal emergence (thoracotreme). The heterotreme-thoracotreme distinction results from two different trajectories of the vas deferens and its ejaculatory duct via the P5 coxa (Heterotremata) or through the thoracic sternum (Thoracotremata). Dissections of males of several families have demonstrated that this major difference not only affects the external surface (perforation of the coxa or the sternum by the ejaculatory duct) but also the internal anatomy. There is no evidence for an ejaculatory duct passing through the articular membrane between the P5 coxa and the thoracic sternum in any Brachyura, even when the sternal male gonopore is very close to the P5 coxa. Trends towards the coxo-sternal condition are exemplified by multistate characters, varying from a shallow

  16. Transisthmian differentiation in the tree-climbing mangrove crab Aratus H. Milne Edwards, 1853 (Crustacea, Brachyura, Sesarmidae), with description of a new species from the tropical eastern Pacific.

    PubMed

    Thiercelin, N; Schubart, C D

    2014-05-02

    The tree-climbing mangrove crab Aratus pisonii (H. Milne Edwards, 1837) (Brachyura, Sesarmidae) is considered to have a transisthmian distribution, due to its presence in mangroves of the Western Atlantic as well as the Eastern Pacific. We here present evidence, based on the morphologies of male gonopods and on genetic data, that populations from these two coastlines are morphologically and genetically distinct and require the description of a new species, Aratus pacificus n. sp., as the sister-species of Aratus pisonii. The corresponding speciation event can be regarded as the outcome of differentiation following the closure of the Isthmus of Panama. As these coastal brackish species were probably among the last ones to become separated, the speciation can thus be dated to a time frame of no more than 3.1 million years.

  17. Names and publication dates of the Brachyura in F.É. Guérin (Guérin-Méneville) (Crustacea: Decapoda).

    PubMed

    Low, Martyn E Y; Ng, Peter K L; Evenhuis, Neal L

    2013-11-12

    The names and dates of the publications of Brachyura of Guérin (Guérin-Méneville from 1836) are reviewed, and previously unidentified or overlooked names are identified. Several identical new names used in multiple publications by Guérin (also under the name Guérin-Méneville), and others that appeared in the same year necessitated the accurate determination of publication dates to establish priority. The authorships of three names should be credited to Guérin (1832): Gecarcinus lateralis (Gecarcinidae), Halimus aries (Majidae), and Libinia spinosa (Epialtidae), the first previously attributed to Fréminville (1835), the last two to H. Milne Edwards (1834). The overlooked genus- and species-group names Cyclocarcinus pinnotheroides Guérin-Méneville, 1838, are determined to be senior subjective synonyms of the genus- and species-group names Hapalonotus reticulatus (De Man, 1879) (Pilumnidae). Applying Article 23.9.1 of the International Code of Zoological Nomenclature, precedence is reversed between the genus-group names and the correct name is Hapalonotus pinnotheroides (Guérin-Méneville, 1838). Current and widespread use of the genus-group name Thalamita Latreille, 1829 (31 March) (Portunidae) is threatened by the overlooked Thalamites Guérin, 1829 (21 March), and the precedence of the names is also reversed to maintain usage of the former. The genus-group name Eurypodius Guérin (Inachidae) is shown to have been established in 1828, not 1825. Included is a complete bibliography of the publications in which Guérin (also under Guérin-Méneville) established new names for Brachyura, with their accurate publication dates.

  18. Characteristics and fate of the spermatozoa of Inachus phalangium (Decapoda, Majidae): description of novel sperm structures and evidence for an additional mechanism of sperm competition in Brachyura.

    PubMed

    Rorandelli, Rocco; Paoli, Francesco; Cannicci, Stefano; Mercati, David; Giusti, Fabiola

    2008-03-01

    Various aspects of the reproductive anatomy of the spider crab Inachus phalangium are investigated utilizing light and electron microscopy. Spermatozoal ultrastructure reveals the presence of a glycocalyx in the peripheral region of the periopercular rim, never recorded before in crustacean sperm cells. Sperm cell morphological traits such as semi-lunar acrosome shape, centrally perforate and flat operculum, and absence of a thickened ring, are shared only with Macropodia longirostris, confirming a close phylogenetic relationship of these species and their separation from the other members of the family Majidae. Spermatozoa are transferred to females inside spermatophores of different sizes, but during ejaculate transfer, larger spermatophores might be ruptured by tooth-like structures present on the ejaculatory canal of the male first gonopod, releasing free sperm cells. Such a mechanism could represent the first evidence of a second form of sperm competition in conflict with sperm displacement, the only mechanism of sperm competition known among Brachyura, enabling paternity for both dominant and smaller, non-dominant, males. In addition, we propose several hypotheses concerning the remote and proximal causes of the existence of large seminal receptacles in females of I. phalangium. Among these, genetically diverse progeny, reduction of sexual harassment and phylogenetic retention seem the most plausible, while acquisition of nutrients from seminal fluids, demonstrated in other arthropods, and suggested by previous studies, could be discarded on the basis of the presented data.

  19. Structural and biochemical correlates of Na+,K+-ATPase driven ion uptake across the posterior gill epithelium of the true freshwater crab, Dilocarcinus pagei (Brachyura, Trichodactylidae).

    PubMed

    Furriel, Rosa Prazeres Melo; Firmino, Kelly Cristina Silva; Masui, Douglas Chodi; Faleiros, Rogério Oliveira; Torres, Antonio Hernandes; McNamara, John Campbell

    2010-10-01

    To better comprehend the structural and biochemical underpinnings of ion uptake across the gills of true freshwater crabs, we performed an ultrastructural, ultracytochemical and morphometric investigation, and kinetically characterized the Na(+),K(+)-ATPase, in posterior gill lamellae of Dilocarcinus pagei. Ultrastructurally, the lamellar epithelia are markedly asymmetrical: the thick, mushroom-shaped, proximal ionocytes contain elongate mitochondria (41% cell volume) associated with numerous (≈14 µm² membrane per µm³cytoplasm), deep invaginations that house the Na(+),K(+)-ATPase, revealed ultracytochemically. Their apical surface is amplified (7.5 µm² µm⁻²)) by stubby evaginations whose bases adjoin mitochondria below the subcuticular space. The apical membrane of the thin, distal ionocytes shows few evaginations (1.6 µm² µm⁻²), each surrounding a mitochondrion, abundant in the cytoplasm below the subcuticular space; basolateral invaginations and mitochondria are few. Fine basal cytoplasmic bridges project across the hemolymph space, penetrating into the thick ionocytes, suggesting ion movement between the epithelia. Microsomal Na(+),K(+)-ATPase specific activity resembles marine crabs but is ≈5-fold less than in species from fluctuating salinities, and freshwater shrimps, suggesting ion loss compensation by strategies other than Na(+) uptake. Enzyme apparent K(+) affinity attains 14-fold that of marine crabs, emphasizing the relevance of elevated K(+) affinity to the conquest of fresh water. Western blotting and biphasic ouabain inhibition disclose two α-subunit isoforms comprising distinct functional isoenzymes. While enzyme activity is not synergistically stimulated by NH(4) (+) and K(+), each increases affinity for the other, possibly assuring appropriate intracellular K(+) concentrations. These findings reveal specific structural and biochemical adaptations that may have allowed the establishment of the Brachyura in fresh water.

  20. A new species of fiddler crab from the Ogasawara (Bonin) Islands, Japan, separated from the widely-distributed sister species Uca (Paraleptuca) crassipes (White, 1847) (Crustacea: Decapoda: Brachyura: Ocypodidae).

    PubMed

    Shih, Hsi-Te; Komai, Tomoyuki; Liu, Min-Yun

    2013-12-10

    A new species of fiddler crab (Brachyura: Ocypodidae), Uca boninensis sp. nov., is described from the Ogasawara (Bonin) Islands, Japan. The new species has previously been identified with the widely distributed U. crassipes (White, 1847), from which it differs by having a slightly differently shaped carapace, and relatively stouter male first gonopods (G1). The recognition of the new species is also supported by differences in the mitochondrial cytochrome oxidase I (COI) and control region (CR) genes. U. boninensis sp. nov., appears to be endemic to the Ogasawara Islands, and as the only known population is small, urgent conservation measures are needed for its protection. Our study brings the total number of the Japanese fiddler crab species to 12.

  1. Comparative brain architecture of the European shore crab Carcinus maenas (Brachyura) and the common hermit crab Pagurus bernhardus (Anomura) with notes on other marine hermit crabs.

    PubMed

    Krieger, Jakob; Sombke, Andy; Seefluth, Florian; Kenning, Matthes; Hansson, Bill S; Harzsch, Steffen

    2012-04-01

    The European shore crab Carcinus maenas and the common hermit crab Pagurus bernhardus are members of the sister taxa Brachyura and Anomura (together forming the taxon Meiura) respectively. Both species share similar coastal marine habitats and thus are confronted with similar environmental conditions. This study sets out to explore variations of general brain architecture of species that live in seemingly similar habitats but belong to different major malacostracan taxa and to understand possible differences of sensory systems and related brain compartments. We examined the brains of Carcinus maenas, Pagurus bernhardus, and three other hermit crab species with immunohistochemistry against tyrosinated tubulin, f-actin, synaptic proteins, RF-amides and allatostatin. Our comparison showed that their optic neuropils within the eyestalks display strong resemblance in gross morphology as well as in detailed organization, suggesting a rather similar potential of processing visual input. Besides the well-developed visual system, the olfactory neuropils are distinct components in the brain of both C. maenas and P. bernhardus as well as the other hermit crabs, suggesting that close integration of olfactory and visual information may be useful in turbid marine environments with low visibility, as is typical for many habitats such as, e.g., the Baltic and the North Sea. Comparing the shape of the olfactory glomeruli in the anomurans showed some variations, ranging from a wedge shape to an elongate morphology. Furthermore, the tritocerebrum and the organization of the second antennae associated with the tritocerebrum seem to differ markedly in C. maenas and P. bernhardus, indicating better mechanosensory abilities in the latter close to those of other Decapoda with long second antennae, such as Astacida, Homarida, or Achelata. This aspect may also represent an adaptation to the "hermit lifestyle" in which competition for shells is a major aspect of their life history. The shore

  2. Comparative brain architecture of the European shore crab Carcinus maenas (Brachyura) and the common hermit crab Pagurus bernhardus (Anomura) with notes on other marine hermit crabs.

    PubMed

    Krieger, Jakob; Sombke, Andy; Seefluth, Florian; Kenning, Matthes; Hansson, Bill S; Harzsch, Steffen

    2012-04-01

    The European shore crab Carcinus maenas and the common hermit crab Pagurus bernhardus are members of the sister taxa Brachyura and Anomura (together forming the taxon Meiura) respectively. Both species share similar coastal marine habitats and thus are confronted with similar environmental conditions. This study sets out to explore variations of general brain architecture of species that live in seemingly similar habitats but belong to different major malacostracan taxa and to understand possible differences of sensory systems and related brain compartments. We examined the brains of Carcinus maenas, Pagurus bernhardus, and three other hermit crab species with immunohistochemistry against tyrosinated tubulin, f-actin, synaptic proteins, RF-amides and allatostatin. Our comparison showed that their optic neuropils within the eyestalks display strong resemblance in gross morphology as well as in detailed organization, suggesting a rather similar potential of processing visual input. Besides the well-developed visual system, the olfactory neuropils are distinct components in the brain of both C. maenas and P. bernhardus as well as the other hermit crabs, suggesting that close integration of olfactory and visual information may be useful in turbid marine environments with low visibility, as is typical for many habitats such as, e.g., the Baltic and the North Sea. Comparing the shape of the olfactory glomeruli in the anomurans showed some variations, ranging from a wedge shape to an elongate morphology. Furthermore, the tritocerebrum and the organization of the second antennae associated with the tritocerebrum seem to differ markedly in C. maenas and P. bernhardus, indicating better mechanosensory abilities in the latter close to those of other Decapoda with long second antennae, such as Astacida, Homarida, or Achelata. This aspect may also represent an adaptation to the "hermit lifestyle" in which competition for shells is a major aspect of their life history. The shore

  3. Phylogenetics of Cancer crabs (Crustacea: Decapoda: Brachyura).

    PubMed

    Harrison, M K; Crespi, B J

    1999-07-01

    We used morphological, mitochondrial DNA sequence, paleontological, and biogeographical information to examine the evolutionary history of crabs of the genus Cancer. Phylogenies inferred from adult morphology and DNA sequence of the cytochrome oxidase I (COI) gene were each well resolved and well supported, but differed substantially in topology. Four lines of evidence suggested that the COI data set accurately reflected Cancer phylogeny: (1) in the phylogeny inferred from morphological data, each Atlantic species was sister taxon to an ecologically similar Pacific species, suggesting convergence in morphology; (2) a single trans-Arctic dispersal event, as indicated by the phylogeny inferred from COI, is more parsimonious than two such dispersal events, as inferred from morphology; (3) test and application of a maximum likelihood molecular clock to the COI data yielded estimates of origin and speciation times that fit well with the fossil record; and (4) the tree inferred from the combined COI and morphology data was closely similar to the trees inferred from COI, although notably less well supported by the bootstrap. The phylogeny inferred from maximum likelihood analysis of COI suggested that Cancer originated in the North Pacific in the early Miocene, that the Atlantic species arose from a North Pacific ancestor, and that Cancer crabs invaded the Atlantic from the North Pacific 6-12 mya. This inferred invasion time is notably prior to most estimates of the date of submergence of the Bering Strait and the trans-Arctic interchange, but it agrees with fossil evidence placing at least one Cancer species in the Atlantic about 8 mya. PMID:10381321

  4. Spermatogenesis of the spider crab Maja brachydactyla (Decapoda: Brachyura).

    PubMed

    Simeó, Carles G; Kurtz, Kathryn; Chiva, Manel; Ribes, Enric; Rotllant, Guiomar

    2010-04-01

    This study describes spermatogenesis in a majid crab (Maja brachydactyla) using electron microscopy and reports the origin of the different organelles present in the spermatozoa. Spermatogenesis in M. brachydactyla follows the general pattern observed in other brachyuran species but with several peculiarities. Annulate lamellae have been reported in brachyuran spermatogenesis during the diplotene stage of first spermatocytes, the early and mid-spermatids. Unlike previous observations, a Golgi complex has been found in mid-spermatids and is involved in the development of the acrosome. The Golgi complex produces two types of vesicles: light vesicles and electron-dense vesicles. The light vesicles merge into the cytoplasm, giving rise to the proacrosomal vesicle. The electron-dense vesicles are implicated in the formation of an electron-dense granule, which later merges with the proacrosomal vesicle. In the late spermatid, the endoplasmic reticulum and the Golgi complex degenerate and form the structures-organelles complex found in the spermatozoa. At the end of spermatogenesis, the materials in the proacrosomal vesicle aggregate in a two-step process, forming the characteristic concentric three-layered structure of the spermatozoon acrosome. The newly formed spermatozoa from testis show the typical brachyuran morphology.

  5. Sperm ultrastructure of the spider crab Maja brachydactyla (Decapoda: Brachyura).

    PubMed

    Simeó, Carles G; Kurtz, Kathryn; Rotllant, Guiomar; Chiva, Manel; Ribes, Enric

    2010-04-01

    This study describes the morphology of the sperm cell of Maja brachydactyla, with emphasis on localizing actin and tubulin. The spermatozoon of M. brachydactyla is similar in appearance and organization to other brachyuran spermatozoa. The spermatozoon is a globular cell composed of a central acrosome, which is surrounded by a thin layer of cytoplasm and a cup-shaped nucleus with four radiating lateral arms. The acrosome is a subspheroidal vesicle composed of three concentric zones surrounded by a capsule. The acrosome is apically covered by an operculum. The perforatorium penetrates the center of the acrosome and has granular material partially composed of actin. The cytoplasm contains one centriole in the subacrosomal region. A cytoplasmic ring encircles the acrosome in the subapical region of the cell and contains the structures-organelles complex (SO-complex), which is composed of a membrane system, mitochondria with few cristae, and microtubules. In the nucleus, slightly condensed chromatin extends along the lateral arms, in which no microtubules have been observed. Chromatin fibers aggregate in certain areas and are often associated with the SO-complex. During the acrosomal reaction, the acrosome could provide support for the penetration of the sperm nucleus, the SO-complex could serve as an anchor point for chromatin, and the lateral arms could play an important role triggering the acrosomal reaction, while slightly decondensed chromatin may be necessary for the deformation of the nucleus.

  6. Cymonomid crabs of the MAINBAZA Expedition (Decapoda: Brachyura).

    PubMed

    Ahyong, Shane T

    2014-06-23

    Cymonomid crabs collected from the Mozambique Channel off Madagascar by the 2011 MAINBAZA Expedition are reported. Two species of Cymonomus A. Milne Edwards, 1880, are represented, of which one is new to science and the other, C. valdiviae Lankester, 1903, is rediscovered, being previously known only from the holotype. Three species of Cymonomidae are now known from the western Indian Ocean, including C. trifurcus Stebbing, 1920, from South Africa. 

  7. New species of Latreillopsis Henderson, 1888 (Brachyura: Homolidae) and Neopalicus Moosa & Serène, 1981 (Brachyura: Palicidae) from the Hawaiian Islands.

    PubMed

    Castro, Peter; Naruse, Tohru

    2014-01-01

    Two new species of brachyuran crabs belonging to Latreillopsis Henderson, 1888 (Homolidae) and Neopalicus Moosa & Serène, 1981 (Palicidae) respectively are described from Maui, Hawai'i. The new species of Latreillopsis is distinguished from its nine congeners by a granular carapace and pereopods, a triangular G1, and by the distinctive ornamentation of its carapace and third maxillipeds; the new species of Neopalicus from its three congeners by the presence of three triangular anterolateral teeth, absence of extensions on the outer margins of the P3 and P4 propodi, dentate inner margins of the P3, P4 dactyli, and absence of ridges on the female abdomen. Also listed is Latreillia metanesa Williams, 1982 (Latreilliidae), recorded for the first time from the archipelago since its description from Albatross material collected in 1902. PMID:24870630

  8. New species of Latreillopsis Henderson, 1888 (Brachyura: Homolidae) and Neopalicus Moosa & Serène, 1981 (Brachyura: Palicidae) from the Hawaiian Islands.

    PubMed

    Castro, Peter; Naruse, Tohru

    2014-02-10

    Two new species of brachyuran crabs belonging to Latreillopsis Henderson, 1888 (Homolidae) and Neopalicus Moosa & Serène, 1981 (Palicidae) respectively are described from Maui, Hawai'i. The new species of Latreillopsis is distinguished from its nine congeners by a granular carapace and pereopods, a triangular G1, and by the distinctive ornamentation of its carapace and third maxillipeds; the new species of Neopalicus from its three congeners by the presence of three triangular anterolateral teeth, absence of extensions on the outer margins of the P3 and P4 propodi, dentate inner margins of the P3, P4 dactyli, and absence of ridges on the female abdomen. Also listed is Latreillia metanesa Williams, 1982 (Latreilliidae), recorded for the first time from the archipelago since its description from Albatross material collected in 1902.

  9. Phylogeography, cave invasion and diversification of the Philippine Sundathelphusa (Decapoda: Brachyura: Parathelphusidae)

    NASA Astrophysics Data System (ADS)

    Husana, D.; Haga, T.; Kase, T.; Yamamuro, M.

    2010-12-01

    Availability of resources influences the opportunistic characters of animals to migrate and colonize a specific habitat while the organism’s geographic isolation causes speciation and diversification. Stable isotope signatures (δ13C and δ15N) elucidate the nutrient source of cavernicolous animals. Mitochondrial DNA sequences of the large subunit rRNA (16S rRNA) revealed multiple colonizations of caves by the genus Sundathelphusa as well as its phylogenetic relationships. Overall molecular phylogeny of the freshwater crabs recovered one major clade of the Philippine Sundathelphusa consisting nine clusters/subclades distributed to various regions in the archipelago. Molecular clock estimation based on the substitution rate of 0.88% per million years established for the grapsid crab genus Sesarma suggested that the diversification of Sundathelphusa species in the Philippines could have started during the late Miocene epoch ca. 5.92 mya. Speciation events coincide with the timing of the eustatic sea level fluctuation and geologic changes in the Philippine archipelago. The sea level fluctuation and subsequent geologic changes must have caused geographic isolation of the species. This appears to be the most plausible explanation for the high diversity of Sundathelphusa species in the Philippines where its congeners inhabit a wide range of habitats, ranging from epigean to hypogean domain.

  10. Prediction of Scylla olivacea (Crustacea; Brachyura) peptide hormones using publicly accessible transcriptome shotgun assembly (TSA) sequences.

    PubMed

    Christie, Andrew E

    2016-05-01

    The aquaculture of crabs from the genus Scylla is of increasing economic importance for many Southeast Asian countries. Expansion of Scylla farming has led to increased efforts to understand the physiology and behavior of these crabs, and as such, there are growing molecular resources for them. Here, publicly accessible Scylla olivacea transcriptomic data were mined for putative peptide-encoding transcripts; the proteins deduced from the identified sequences were then used to predict the structures of mature peptide hormones. Forty-nine pre/preprohormone-encoding transcripts were identified, allowing for the prediction of 187 distinct mature peptides. The identified peptides included isoforms of adipokinetic hormone-corazonin-like peptide, allatostatin A, allatostatin B, allatostatin C, bursicon β, CCHamide, corazonin, crustacean cardioactive peptide, crustacean hyperglycemic hormone/molt-inhibiting hormone, diuretic hormone 31, eclosion hormone, FMRFamide-like peptide, HIGSLYRamide, insulin-like peptide, intocin, leucokinin, myosuppressin, neuroparsin, neuropeptide F, orcokinin, pigment dispersing hormone, pyrokinin, red pigment concentrating hormone, RYamide, short neuropeptide F, SIFamide and tachykinin-related peptide, all well-known neuropeptide families. Surprisingly, the tissue used to generate the transcriptome mined here is reported to be testis. Whether or not the testis samples had neural contamination is unknown. However, if the peptides are truly produced by this reproductive organ, it could have far reaching consequences for the study of crustacean endocrinology, particularly in the area of reproductive control. Regardless, this peptidome is the largest thus far predicted for any brachyuran (true crab) species, and will serve as a foundation for future studies of peptidergic control in members of the commercially important genus Scylla.

  11. Etisus evamuellerae, a new xanthid crab (Decapoda, Brachyura) from the Middle Miocene of Austria and Hungary

    PubMed Central

    Hyžný, M.; van Bakel, B.W.M.; Guinot, D.

    2015-01-01

    On the basis of several carapaces, a new species of xanthid crab, Etisus evamuellerae, is described from the Middle Miocene of the Vienna (Austria) and Great Hungarian basins. It differs from the coeval xanthids, Xantho moldavicus and Pilodius vulgaris, in having a distinctly protruding front and comparatively longer carapace. Contrary to those two species, the new one makes up for just a small percentage in the decapod crustacean assemblages studied. PMID:25983383

  12. Functional anatomy of the fiddler crab compound eye (Uca vomeris: Ocypodidae, Brachyura, Decapoda).

    PubMed

    Alkaladi, Ali; Zeil, Jochen

    2014-04-15

    We describe the structural organization of the ommatidium in the compound eye of the fiddler crab, Uca vomeris, at both the light- and the electron-microscopy levels. We pay particular attention to the organization of the optical system, the retinular cells, the rhabdom, and of pigment cells. Although the fiddler crab compound eye is of the apposition type, typical for Brachyuran crabs, we identify a number of novel, functionally relevant aspects of ommatidial organization that have not previously been described. The flat corneal facet lenses provide the main focusing power and therefore must contain a gradient of refractive index. Each ommatidium has the typical set of eight retinular cells, with a distal retinular cell R8 lying close to the proximal tip of the crystalline cone. R8 is shaped into four lobes, which are separated by proximal extensions of the four crystalline cone cells and of distal extensions of retinular cells R1-R7. The microvilli in the R8 rhabdom are not aligned in a uniform direction, while the microvilli of the main rhabdom show the typical crustacean pattern of alternating bands of horizontally (R3, R4, R7) and vertically aligned microvilli (R1, R2, R5, R6). We describe in detail the distribution and structural properties of screening pigment granules in the two types of pigment cells and in the retinular cells in the equatorial eye. We discuss the functional significance of this fine-structural organization of the fiddler crab compound eye in relation to visual processing and visual ecology. PMID:24114990

  13. [Fishery and biometrics of genus Calappa crabs (Brachyura: Calappidae) in northeastern Venezuela].

    PubMed

    Alió, José J; Marcano, Luis A; Altuve, Douglas E

    2005-01-01

    The box crabs, genus Calappa, are important crab species landed by the industrial trawl fleet in Venezuela. These crabs have a wide distribution in the country, from the Gulf of Venezuela to the Orinoco River, but major landings take place in such gulf, near Margarita Island and northern Sucre State. Average annual landing in the eastern region was 69 t during 1970-2001, with a maximum of 221 t. For this study a sample of 2 398 box crabs was collected by observers on board of industrial trawl vessels, which operated in eastern Venezuela from 1994 to 2000. Three species were found in the landings, Calappa sulcata and C. flammea. each represented 47% of the sample, and C. nitida, which accounted for 5% of the sample. Sex ratio was strongly biased towards males in C. sulcata (2.8:1) and in C. flammnea (1.9:1). while it was only slightly biased in C. nitida (1.4:1). Due to its large size, C. sulcuta is of great commercial interest, with average weight 290 g and a maximum weight of 720 g: C. flammea showed an average weight of 140 g and a maximum weight of 418 g, while C. nitida is the smallest species, with average weight 46 g and maximum weight not beyond 113 g. Box crabs were captured by day and night in similar proportions, and were found in a wide depth range, from a few meters to 126 m deep; however, the largest captures were obtained in the interval 38 - 54 m. Regressions between weight of chelae and total weight were linear, and significantly different between sexes. The relation between total weight and carapace width was allometric, with a power exponent ca. three in C. sulcata, and less than three in C. flamea and C. nitida. Females of C. sulcata and C. nitida showed power exponents significantly smaller than males. Since claws are removed from the animal to be commercialized, while the rest of the animal is returned alive to the sea, for practical purposes a common equation among species and sexes to convert claws weight into total body weight is: total weight - 3 x claws weight. The relationship between catch per unit of effort (CPUE) and effort did not show a significantly decreasing trend, but landings follow the effort trend, with a decreasing tendency in recent years. No mature females were found in any of the three species, thus there could be reproductive migrations towards deeper waters from October to January, when abundance of crabs is lower in the study area. It is recommended that the practice of exploiting only one claw, returning the rest of the animal alive to the sea, should be promoted among fishers, while the removal of claws from female crabs should be avoided. PMID:17354456

  14. Population structure and reproductive biology of the fiddler crab Uca inversa (Hoffman, 1874) (Brachyura: Ocypodidae)

    NASA Astrophysics Data System (ADS)

    Litulo, Carlos

    2005-05-01

    The population structure and reproductive biology of Uca inversa (Hoffman) were studied in Mozambique for the first time. Crabs were randomly sampled on monthly basis during low tide periods from January to December 2002 at Costa do Sol mangrove, Maputo Bay, southern Mozambique. A total of 1131 crabs was obtained, of which 518 (45.8%) were males, 322 non-ovigerous females (29.3%) and 281 (24.8%) ovigerous females, respectively. The present population presents non-normal size frequency distributions, with males reaching greater size than females. The overall sex ratio (M:F) (1:0.84) was significantly different from the 1:1 ratio. Ovigerous females were present throughout the year and the embryonic development showed synchrony with the gonadosomatic index, in which females carrying eggs close to hatching were more abundant when the gonadosomatic index reached minimum values in the population. Egg number increases with female size. Juvenile recruitment was also continuous with high proportion of young recruits being recorded in winter, probably due to the high reproductive activity displayed in summer. U. inversa exhibits a rapid embryonic cycle accompanied by a rapid larval development and settlement in the study area.

  15. Revision of the spider crab genus Sargassocarcinus Ward, 1936 (Crustacea: Brachyura: Epialtidae).

    PubMed

    Ng, Peter K L; Lin, Chia-Wei; Naruse, Tohru

    2016-09-09

    The Western Pacific epialtid genus Sargassocarcinus Ward, 1936, is revised. The genus had been regarded as monotypic but is here shown to contain three species: S. sublimis (Rathbun, 1916), S. cristatus (Balss, 1924), and S. foliatus Ward, 1936 (type species). The many unusual characters possessed by Sargassocarcinus are figured and discussed; and diagnostic features of the three species are clarified. The taxonomy of the three species and aspects of their ecology are discussed. Sargassocarcinus species are found free-living on coral rubble habitats and not associated with macrophytic algae.

  16. The male copulatory system of European pea crabs (crustacea, brachyura, pinnotheridae).

    PubMed

    Becker, Carola; Türkay, Michael; Brandis, Dirk

    2012-11-01

    The male copulatory system of the European pinnotherid species Pinnotheres pisum, Pinnotheres pectunculi, and Nepinnotheres pinnotheres was investigated by gross morphology, scanning electron microscopy, histological methods, and confocal laser scanning microscopy. The brachyuran copulatory system is consistently formed by paired penes and two pairs of abdominal appendages, the gonopods, functioning in sperm transfer. In pinnotherids, the long first gonopods transfer the sperm mass into the female ducts. The first gonopod has the ejaculatory canal inside that opens both basally and distally. The second gonopod is solid, short, and conical. During copulation, the penis and the second gonopod are inserted into the basal lumen of the first gonopod. While the penis injects the sperm mass, the second gonopod functions in the transport of spermatozoa inside the ejaculatory canal toward its distal opening. The second gonopod is adapted for the sealing of the tubular system in the first gonopod by its specific shape and the ability to swell. Longitudinal cuticle foldings of the second gonopod hook into structures inside the first gonopod. The second gonopod can interact with the penis during copulation by a flexible flap separating the lumina in which the second gonopod and the penis are inserted. PMID:22930541

  17. Differential toxicity of copper, zinc, and lead during the embryonic development of Chasmagnathus granulatus (Brachyura, Varunidae).

    PubMed

    Lavolpe, Mariano; Greco, Laura López; Kesselman, Daniela; Rodríguez, Enrique

    2004-04-01

    Ovigerous females of the estuarine crab Chasmagnathus granulatus were exposed to copper (0.01 and 1 mg/L), zinc (0.05, 1, and 10 mg/L), or lead (0.01 and 1 mg/L) during early, late, or whole embryonic development. None of the assayed heavy metals produced a significant mortality of females, neither a decrease in the number of hatched larvae nor a decrease in the egg incubation time, but several morphological abnormalities were detected in hatched larvae. The abnormalities were classified in three categories: eye, body pigmentary, and body morphological abnormalities. Those larvae with eye and body pigmentary abnormalities, particularly those involving retinal pigments and chromatophores, showed the highest incidence by exposure to the assayed metals. In addition, embryos were more susceptible to copper and zinc during the late period of development, whereas the effect of lead was greater during the early period of embryogenesis. Some teratogenic effects observed in C. granulatus embryos exposed to heavy metals, particularly the hypertrophy and hypopigmentation of eyes observed in the laboratory at a lead concentration as low as that reported for the natural environment, could be considered as sensitive biomarkers for this kind of pollutant. PMID:15095892

  18. A new species of Naxia Latreille, 1825 (Brachyura: Majidae) from deep water off Brazil.

    PubMed

    Tavares, Marcos; Poore, Gary C B

    2014-09-11

    A new species of spider crab, Naxia atlantica n. sp., is described and illustrated from deep waters off São Paulo (southeastern Brazil). The new species can be separated from its congeners by a suite of characters including shapes of the propodi of the walking legs, rostrum and basal antennal article. This is the first record of the genus outside southern Australia and New Zealand. 

  19. Mass spectrometric characterization of the neuropeptidome of the ghost crab Ocypode ceratophthalma (Brachyura, Ocypodidae).

    PubMed

    Hui, Limei; D'Andrea, Brandon T; Jia, Chenxi; Liang, Zhidan; Christie, Andrew E; Li, Lingjun

    2013-04-01

    The horn-eyed ghost crab Ocypode ceratophthalma is a terrestrial brachyuran native to the Indo-Pacific region, including the islands of Hawaii. Here, multiple mass spectrometric platforms, including matrix-assisted laser desorption/ionization time-of-flight/time-of-flight tandem mass spectrometry (MALDI-TOF/TOF MS) and nanoflow liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (nanoLC-ESI-Q-TOF MS/MS), were used to characterize the neuropeptidome of this species. In total, 156 peptide paracrines/hormones, representing 15 peptide families, were identified from the O. ceratophthalma supraesophageal ganglion (brain), eyestalk ganglia, pericardial organ and/or sinus gland, including 59 neuropeptides de novo sequenced here for the first time. Among the de novo sequenced peptides were isoforms of A-type allatostatin, B-type allatostatin, FMRFamide-like peptide (FLP), orcokinin, orcomyotropin and RYamide. Of particular note, were several novel FLPs including DVRAPALRLRFamide, an isoform of short neuropeptide F, and NRSNLRFamide, the orcokinins NFDEIDRSGYGFV and DFDEIDRSSFGFH, which exhibit novel Y for F and D for N substitutions at positions 10 and 1, respectively, and FDAYTTGFGHS, a member of the orcomyotropin family exhibiting a novel Y for F substitution at position 4. Taken collectively, the set of peptides described here represents the largest number of neuropeptides thus far characterized via mass spectrometry from any single crustacean, and provides a framework for future investigations of the physiological roles played by these molecules in this species.

  20. Effects of zinc on molting and body weight of the estuarine crab Neohelice granulata (Brachyura: Varunidae).

    PubMed

    Beltrame, María Ornela; De Marco, Silvia G; Marcovecchio, Jorge E

    2010-01-01

    The semiterrestrial burrowing crab Neohelice granulata is one of the main inhabitants of the supratidal and intertidal zones of brackish salt marshes, estuaries and coastal lagoons from South America's Atlantic littoral. A large population of this species spreads out Mar Chiquita coastal lagoon (in Argentina) and its corresponding wetlands, and is considered as a key species within this system. Since high values of dissolved heavy metals (including Zn) have been recently reported within Mar Chiquita coastal lagoon, with levels unusually higher than those from other coastal systems within Argentina, it has been explored that the existence of a risk of environmental conditions endanger these populations. So, juveniles of this estuarine crab were experimentally exposed to increasing concentrations of dissolved Zn (i.e., 0, 0.5 and 1 mg Zn(2+)L(-1)) during six months, the time involved between two successive molts; in addition, both the size and weight reached after each molt were also studied in this assay. It can be concluded that zinc can be toxic to crabs only at high concentrations. Considering that levels up to 1 mg ZnL(-1) were recently reported in Mar Chiquita coastal lagoon waters, the potential occurrence of mean chronic effects on the crab population within the coastal lagoon is discussed.

  1. Physiology and morphology of sustaining and dimming neurons of the crab Chasmagnathus granulatus (Brachyura: Grapsidae).

    PubMed

    Berón de Astrada, Martín; Tuthill, John C; Tomsic, Daniel

    2009-08-01

    In crustaceans, sustaining (SN) and dimming (DN) neurons are readily identified by their distinct responses to a light pulse. However, morphological identification and electrophysiological characterization of these neurons has been achieved only in the crayfish. This study provides a description of SNs and DNs in a second crustacean species, the crab Chasmagnathus. SNs and DNs of the crab arborize extensively in the medulla and the axons project to the midbrain. Upon a light pulse, SNs depolarize and increase the firing rate while DNs hyperpolarize and reduce firing. These responses are highly consistent and their magnitudes depend on the intensity of the light pulse. When stimulated with a wide-field motion grating, SNs respond with a modulation of the membrane potential and spike frequency. We also characterized the responses of these neurons to a rotating e-vector of polarized light. SNs show the maximum depolarization when the e-vector approaches vertical. In contrast, DNs show maximal depolarization to near horizontal e-vector orientations. The semi-terrestrial crab and the crayfish inhabit unique light environments and exhibit disparate visual behaviors. Yet, we found that the location, morphology and physiology of SNs and DNs of the crab are nearly identical to those described in the crayfish.

  2. A new genus and species of freshwater crab from Madagascar (Decapoda, Brachyura, Potamoidea, Potamonautidae).

    PubMed

    Meyer, Kirstin S; Cumberlidge, Neil; Koppin, Jennifer C

    2014-11-12

    A new genus and species of freshwater crab is described from Madagascar. The new species is morphologically closest to the three species of the genus Foza Reed & Cumberlidge, 2006, but can easily be distinguished by having a completely smooth carapace with an unarmed anterolateral margin and a mandible with a distinctly shortened anterior lobe. This unusual suite of characters is sufficient to warrant the recognition of a new monotypic genus to accommodate this species.

  3. Foregut morphology and ontogeny of the spider crab Maja brachydactyla (Brachyura, Majoidea, Majidae).

    PubMed

    Castejón, Diego; Rotllant, Guiomar; Ribes, Enric; Durfort, Mercè; Guerao, Guillermo

    2015-09-01

    We describe the morphology of the foregut of the spider crab Maja brachydactyla Balss, 1922, from first larval stage to adult, with detailed stage-specific documentation using light and scanning electron microscopy. A total of 40 ossicles have been identified in the foregut of adults of M. brachydactyla using Alizarin-Red staining. The morphological pattern of the ossicles and gastric mill is very similar to other Majoidea species with only a few variations. The foregut of the zoeae stages appeared as a small and simple cavity, with a cardio-pyloric valve that separates the stomach into cardiac and pyloric regions. The pyloric filter is present from the first zoea, in contrast to the brachyuran species which have an extended larval development. Calcified structures have been identified in the cardio-pyloric valve and pyloric region of the zoeal stages. The most significant changes in foregut morphology take place after the metamorphosis from ZII to megalopa, including the occurrence of the gastric mill. In the megalopa stage, the foregut ossicles are recognizable by their organization and general morphology, but are different from the adult phase in shape and number. Moreover, the gastric teeth show important differences: the cusps of the lateral teeth are sharp (no molariform); the dorsal tooth have a small, dentate cusp (not a well-developed quadrangular cusp); and the accessory teeth are composed of one sharp peak (instead of four sharp peaks). The gastric mill ontogeny from megalopa to adult reveals intermediate morphologies during the earlier juvenile stages. The relationship between gastric mill structures with food preferences and their contribution to the brachyuran phylogeny are briefly discussed.

  4. Functional anatomy of the fiddler crab compound eye (Uca vomeris: Ocypodidae, Brachyura, Decapoda).

    PubMed

    Alkaladi, Ali; Zeil, Jochen

    2014-04-15

    We describe the structural organization of the ommatidium in the compound eye of the fiddler crab, Uca vomeris, at both the light- and the electron-microscopy levels. We pay particular attention to the organization of the optical system, the retinular cells, the rhabdom, and of pigment cells. Although the fiddler crab compound eye is of the apposition type, typical for Brachyuran crabs, we identify a number of novel, functionally relevant aspects of ommatidial organization that have not previously been described. The flat corneal facet lenses provide the main focusing power and therefore must contain a gradient of refractive index. Each ommatidium has the typical set of eight retinular cells, with a distal retinular cell R8 lying close to the proximal tip of the crystalline cone. R8 is shaped into four lobes, which are separated by proximal extensions of the four crystalline cone cells and of distal extensions of retinular cells R1-R7. The microvilli in the R8 rhabdom are not aligned in a uniform direction, while the microvilli of the main rhabdom show the typical crustacean pattern of alternating bands of horizontally (R3, R4, R7) and vertically aligned microvilli (R1, R2, R5, R6). We describe in detail the distribution and structural properties of screening pigment granules in the two types of pigment cells and in the retinular cells in the equatorial eye. We discuss the functional significance of this fine-structural organization of the fiddler crab compound eye in relation to visual processing and visual ecology.

  5. Foregut morphology and ontogeny of the mud crab Dyspanopeus sayi (Smith, 1869) (Decapoda, Brachyura, Panopeidae).

    PubMed

    Castejón, Diego; Ribes, Enric; Durfort, Mercè; Rotllant, Guiomar; Guerao, Guillermo

    2015-01-01

    The morphology of the foregut of the Say's mud crab Dyspanopeus sayi was described in adults and larvae. The ossicle system was illustrated based on a staining method with Alizarin-Red. The gastric teeth and cardio-pyloric valve were dissected and examined using optical and scanning electron microscopy. In the adults, the morphology of ossicles and gastric teeth of D. sayi is very similar to the related species Rhithropanopeus harrisii. The foregut of first zoea (ZI) presented a functional cardio-pyloric valve while the filter press was lacking. The filter press was observed in the pyloric chamber from ZII. The most significant changes in morphology take place after metamorphosis from ZIV to megalopa, including the occurrence of the gastric mill. The organization and morphology of many megalopal foregut ossicles are recognizable in the adult phase, although the morphology of the gastric teeth differs from the morphology of adults. A correlation of gastric mill structures with food preferences and their contribution to the phylogeny are briefly discussed.

  6. Marine pollution effects on the southern surf crab Ovalipes trimaculatus (Crustacea: Brachyura: Polybiidae) in Patagonia Argentina.

    PubMed

    Lezcano, Aníbal Hernán; Rojas Quiroga, María Laura; Liberoff, Ana Laura; Van der Molen, Silvina

    2015-02-28

    We compared the carapace shape and thickness as well as the energy density of Ovalipes trimaculatus inhabiting areas comprising a gradient of marine pollution: high, moderate and undetected, in the Nuevo gulf (Patagonia Argentina). The carapace shape was evaluated by means of individual asymmetry scores (=fluctuating asymmetry) whereas the carapace thickness was assessed by measuring the carapace dry weight. The energy density was analyzed through its negative relationship with water content in muscle tissue. The individual asymmetry scores as well as the percentage of water content in muscle tissue were proportional to the marine pollution gradient, whereas the carapaces thickness did not differ among sampling sites. Our results are consistent with previous findings and demonstrate the direct effect of marine pollution on other taxa different from gastropods, cephalopods and polyplacophora and add to long-standing concerns about detrimental effects caused by marine pollution on the benthic community of the Nuevo gulf.

  7. Tritodynamia serratipes sp. nov., a new marine crab from Singapore (Crustacea: Decapoda: Brachyura: Macrophthalmidae).

    PubMed

    Anker, Arthur; Ng, Peter K L

    2014-06-30

    Tritodynamia serratipes sp. nov. is described based on a female specimen dredged on soft mud at a depth of 6.3-6.5 m, near Marina East, only a few kilometers from Singapore's city centre. The new species differs from all other species of Tritodynamia Ortmann, 1894 by a unique combination of morphological characters, including the posterior margin of the propodus of the second ambulatory leg armed with a row of particularly strong teeth, and the cutting edges of dactylus and pollex each proximally armed with two stout teeth. Tritodynamia serratipes sp. nov. is the second species of the genus described from tropical Asia.

  8. First complete mitochondrial genome of primitive crab Homologenus malayensis (Decapoda: Brachyura: Podotremata: Homolidae).

    PubMed

    Hui, Min; Liu, Yuan; Cui, Zhaoxia

    2016-01-01

    The taxonomy and phylogeny of brachyuran crabs, and particularly of the Podotremata, have been the subjects of controversy due to their morphological diversity and complexity. The first complete mitochondrial genome (mitogenome) sequence of primitive crab Homologenus malayensis has been determined. The mitogenome is 15,793 bp in length, with A + T content 71.7%. The gene content and order are consistent with those in typical brachyuran crabs. A putative control region of 883 bp is identified due to its position (between srRNA and tRNA(Ile)) and AT richness (75.5%). Notably, the control region in H. malayensis contains nine identical specific repeat units of 42 bp and 11 identical repeat units of 2 bp with a total length of 400 bp, which is different from other crabs. These results are expected to provide useful information on both genomics and the future phylogenetic study of primitive crabs.

  9. Paramoguai kavieng, a new genus and species of camptandriid crab from Papua New Guinea (Crustacea: Brachyura).

    PubMed

    Ahyong, Shane T

    2014-08-26

    Paramoguai kavieng is recognised as a new genus and species of camptandriid crab, recently discovered in Papua New Guinea. The new genus closely resembles Moguai Tan & Ng, 1999, from the western Pacific, sharing similar carapace and pereopod structure, but is distinguished chiefly by the fusion of the maxilliped 3 ischiomerus, features of the epistome and front, and position of the anterolateral margins of the carapace. The new genus is unique in the Camptandriidae Stimpson, 1858, in having an epistome with a bilobed buccal margin. Moguai pyriforme Naruse, 2005, from Japan, which differs from P. kavieng primarily in carapace ornamentation and gonopod morphology, is transferred to Paramoguai. 

  10. Evolution of freshwater crab diversity in the Aegean region (Crustacea: Brachyura: Potamidae).

    PubMed

    Jesse, Ruth; Grudinski, Melanie; Klaus, Sebastian; Streit, Bruno; Pfenninger, Markus

    2011-04-01

    The aim of this study was to estimate the influence of the palaeogeographic and climatic history of the Aegean region on the diversity of freshwater crabs of the genus Potamon and to test whether this area served as source or reservoir in species diversity. Necessary species delimitation was accomplished by phylogenetic analyses of the mitochondrial markers COX1 and ND1, partial 16S rRNA gene and the tRNALeu gene. We found 14 genetic lineages of which nine could be assigned to previously recognised species. Temporal estimates of the splitting pattern in the phylogeny of Potamon indicated that a combination of geological and climatic events influenced their diversification. Within Potamon, the lineages separated into a western group and an eastern group. This first split in the genus occurred approximately 8.3-5.5 Mya, thus possibly correlated with the Messinian salinity crisis. A likelihood approach to geographic range evolution suggested for most species, occurring in the Aegean area, an origin in the Middle East. Moreover, there were no insular endemics in the central Aegean archipelago, therefore low sea-levels during the Pleistocene glacial periods possibly enabled dispersal to these islands, but subsequent rise in sea-level did not cause speciation. Nevertheless, the diversification of most lineages occurred during the Pleistocene epoch thus coinciding with Quaternary fluctuations of the climate.

  11. Diversity, endemism and conservation of the freshwater crabs of China (Brachyura: Potamidae and Gecarcinucidae).

    PubMed

    Cumberlidge, Neil; Ng, Peter K L; Yeo, Darren C J; Naruse, Tohru; Meyer, Kirstin S; Esser, Lara J

    2011-03-01

    China lies at the heart of the global center of freshwater crab diversity in tropical Asia, where the 2 most diverse families occur: Potamidae (505 species, 95 genera) and Gecarcinucidae (344 species, 59 genera). China stands out as the country with the highest species richness of freshwater crabs globally. Its fauna comprises 243 species in 37 genera and in 2 families, and species discovery is still progressing at a rapid pace. The vast majority of the species are distributed in southwest, south central and eastern China in the Oriental zoogeographical region. China also stands out as having a highly endemic freshwater crab fauna at the species level (96%) and at the genus level (78%). Although the recent International Union for the Conservation of Nature (IUCN) red list conservation assessment found only 6 out of 228 species (2%) to be threatened (5 potamids and 1 gecarcinucid), the majority (more than 75%) of Chinese species are regarded as data deficient, so the number of threatened species is likely to be a serious underestimate. Threats from increasing habitat destruction and pollution are a major concern due to the rapidly growing economy and massive developments taking place in China. There is therefore an urgent need for increased species exploration and for the development of a conservation strategy for China's threatened (and potentially threatened) endemic freshwater crab species.

  12. The male copulatory system of European pea crabs (crustacea, brachyura, pinnotheridae).

    PubMed

    Becker, Carola; Türkay, Michael; Brandis, Dirk

    2012-11-01

    The male copulatory system of the European pinnotherid species Pinnotheres pisum, Pinnotheres pectunculi, and Nepinnotheres pinnotheres was investigated by gross morphology, scanning electron microscopy, histological methods, and confocal laser scanning microscopy. The brachyuran copulatory system is consistently formed by paired penes and two pairs of abdominal appendages, the gonopods, functioning in sperm transfer. In pinnotherids, the long first gonopods transfer the sperm mass into the female ducts. The first gonopod has the ejaculatory canal inside that opens both basally and distally. The second gonopod is solid, short, and conical. During copulation, the penis and the second gonopod are inserted into the basal lumen of the first gonopod. While the penis injects the sperm mass, the second gonopod functions in the transport of spermatozoa inside the ejaculatory canal toward its distal opening. The second gonopod is adapted for the sealing of the tubular system in the first gonopod by its specific shape and the ability to swell. Longitudinal cuticle foldings of the second gonopod hook into structures inside the first gonopod. The second gonopod can interact with the penis during copulation by a flexible flap separating the lumina in which the second gonopod and the penis are inserted.

  13. Comparative reproductive effort and fecundity in the spider crabs, Leurocyclus tuberculosus and Libinia spinosa (Majoidea, Brachyura).

    PubMed

    González-Pisani, Ximena; Greco, Laura López

    2014-04-01

    A comparative analysis of reproductive effort, fecundity, and egg weight was conducted in two species of spider crabs, Leurocyclus tuberculosus and Libinia spinosa, during one-year period. Ovigerous females were collected from Patagonia-Argentina (42°56'S, 64°21'W) and were measured (CW = carapace width). Each egg brood was weighed, dried and the number of eggs (F = fecundity) counted. Scatterplots of relative fecundity (RF = F/CW) were submitted to regression analyses. Mean F and RF was calculated for each season to assess seasonal variation of reproductive intensity. Mean F was 35,000 eggs in L. tuberculosus and 30,000 eggs in L. spinosa, with these values being intermediate in comparison with other Majoidea. The RF was approximately 18% higher in L. tuberculosus that presented an average dry weight egg 45% less than L. spinosa. Although in both species F showed a positive correlation with CW, less than the 20% of the variation in the number of eggs could be explained by female's size, suggesting there are other factors that influence F. The proportion of body energy devoted to reproduction (reproductive effort), exhibited significant differences between species. In Leurocyclus tuberculosus reproductive activity is significantly different along the 12-month suggesting that the conditions for 'optimal' egg production change throughout the year. In Libinia spinosa mean fecundity did not reveal significant differences over seasons. These results are central in studies of life-history theory and in the development of life history models, as it is directly related to energy allocation and partitioning.

  14. Morphology of the female reproductive system of European pea crabs (Crustacea, Decapoda, Brachyura, Pinnotheridae).

    PubMed

    Becker, Carola; Brandis, Dirk; Storch, Volker

    2011-01-01

    Commensal pea crabs inhabiting bivalves have a high reproductive output due to the extension andfecundity of the ovary. We studied the underlying morphology of the female reproductive system in the Pinnotheridae Pinnotheres pisum, Pinnotheres pectunculi and Nepinnotheres pinnotheres using light microscopy and transmission electron microscopy (TEM). Eubrachyura have internal fertilization: the paired vaginas enlarge into storage structures, the spermathecae, which are connected to the ovaries by oviducts. Sperm is stored inside the spermathecae until the oocytes are mature. The oocytes are transported by oviducts into the spermathecae where fertilization takes place. In the investigated pinnotherids, the vagina is of the "concave pattern" (sensu Hartnoll1968): musculature is attached alongside flexible parts of the vagina wall that controls the dimension of its lumen. The genital opening is closed by a muscular mobile operculum. The spermatheca can be divided into two distinct regions by function and morphology. The ventral part includes the connection with vagina and oviduct and is regarded as the zone where fertilization takes place. It is lined with cuticle except where the oviduct enters the spermatheca by the "holocrine transfer tissue." At ovulation, the oocytes have to pass through this multilayered glandular epithelium performing holocrine secretion. The dorsal part of the spermatheca is considered as the main sperm storage area. It is lined by a highly secretory apocrine glandular epithelium. Thus, two different forms of secretion occur in the spermathecae of pinnotherids. The definite role of secretion in sperm storage and fertilization is not yet resolved, but it is notable that structure and function of spermathecal secretion are more complex in pinnotherids, and probably more efficient, than in other brachyuran crabs.

  15. [Fishery and biometrics of genus Calappa crabs (Brachyura: Calappidae) in northeastern Venezuela].

    PubMed

    Alió, José J; Marcano, Luis A; Altuve, Douglas E

    2005-01-01

    The box crabs, genus Calappa, are important crab species landed by the industrial trawl fleet in Venezuela. These crabs have a wide distribution in the country, from the Gulf of Venezuela to the Orinoco River, but major landings take place in such gulf, near Margarita Island and northern Sucre State. Average annual landing in the eastern region was 69 t during 1970-2001, with a maximum of 221 t. For this study a sample of 2 398 box crabs was collected by observers on board of industrial trawl vessels, which operated in eastern Venezuela from 1994 to 2000. Three species were found in the landings, Calappa sulcata and C. flammea. each represented 47% of the sample, and C. nitida, which accounted for 5% of the sample. Sex ratio was strongly biased towards males in C. sulcata (2.8:1) and in C. flammnea (1.9:1). while it was only slightly biased in C. nitida (1.4:1). Due to its large size, C. sulcuta is of great commercial interest, with average weight 290 g and a maximum weight of 720 g: C. flammea showed an average weight of 140 g and a maximum weight of 418 g, while C. nitida is the smallest species, with average weight 46 g and maximum weight not beyond 113 g. Box crabs were captured by day and night in similar proportions, and were found in a wide depth range, from a few meters to 126 m deep; however, the largest captures were obtained in the interval 38 - 54 m. Regressions between weight of chelae and total weight were linear, and significantly different between sexes. The relation between total weight and carapace width was allometric, with a power exponent ca. three in C. sulcata, and less than three in C. flamea and C. nitida. Females of C. sulcata and C. nitida showed power exponents significantly smaller than males. Since claws are removed from the animal to be commercialized, while the rest of the animal is returned alive to the sea, for practical purposes a common equation among species and sexes to convert claws weight into total body weight is: total weight - 3 x claws weight. The relationship between catch per unit of effort (CPUE) and effort did not show a significantly decreasing trend, but landings follow the effort trend, with a decreasing tendency in recent years. No mature females were found in any of the three species, thus there could be reproductive migrations towards deeper waters from October to January, when abundance of crabs is lower in the study area. It is recommended that the practice of exploiting only one claw, returning the rest of the animal alive to the sea, should be promoted among fishers, while the removal of claws from female crabs should be avoided.

  16. Leucosiid crabs (Crustacea: Decapoda: Brachyura) from Taiwan, with three new records.

    PubMed

    Shih, Yi-Jia; Ho, Ping-Ho; Chan, Tin-Yam

    2015-12-01

    Four leucosiid species from Taiwan are presented. Ebalia nudipes Sakai, 1963, with its male first gonopod figured for the first time. Galilia petricola Komai & Tsuchida, 2014, is recorded on the basis of a larger specimen, and distinguishing features with its only congener, G. narusei Ng & Richer de Forges, 2007, reappraised. Nursia rhomboidalis (Miers, 1879), previously known only from Japan, Korea, and mainland China, is also recorded from Taiwan. Myra fugax (Fabricius, 1798) is now formally recorded from Taiwan, and female characters identified to help separate the three known Taiwanese species of Myra.

  17. Ultrastructure of spermatozoa and spermatophores of old world freshwater crabs (Brachyura: Potamoidea: Gecarcinucidae, Potamidae, and Potamonautidae).

    PubMed

    Klaus, Sebastian; Schubart, Christoph D; Brandis, Dirk

    2009-02-01

    We investigated the ultrastructure of spermatozoa and spermatophores of 19 palaeotropical freshwater crab species [12 species of the Gecarcinucidae, 6 of the Potamidae (Potamiscinae), and 1 species of the Potamonautidae (Deckeniinae: Hydrothelphusini)]. The investigated Potamiscinae have densely packed coenospermic spermatophores with the exception of Thaiphusa sirikit and Johora singaporensis that exhibit cleistospermia. In contrast, in the Gecarcinucidae the spermatozoa are loosely embedded in a mucous matrix. The gecarcinucid and potamiscine sperm differ, furthermore, in acrosomal structure and size. The acrosome in the Gecarcinucidae is much smaller and spherical, while the larger acrosome in the Potamiscinae has the tendency to be depressed. In the Potamiscinae, an additional middle acrosomal zone evolved between the acrosome ray zone and the outer acrosomal zone. Within the Gecarcinucidae, a differentiation into two groups (Gecarcinucinae and Parathelphusinae) is not supported by the present spermatological data. The sperm morphology of Hydrothelphusa aff. madagascariensis (Potamonautidae: Deckeniinae) differs from Potamonautes sidneyi (Potamonautidae: Potamonautinae) in acrosomal size and shape, and in the absence of a periopercular rim. A closer relationship of Deckeniinae and Gecarcinucidae cannot be confirmed by spermatology.

  18. Leucosiid crabs from Papua New Guinea, with descriptions of eight new species (Crustacea: Decapoda: Brachyura).

    PubMed

    Galil, Bella S; Ng, Peter K L

    2015-10-06

    Twenty-five species of leucosiid crabs are reported from Madang Province, Papua New Guinea. Of these, seven are new to science: two each are included in Alox Tan & Ng, 1995 and Tanaoa Galil, 2003, and one each in Ryphila Galil, 2009, Seulocia Galil, 2005, and Urnalana Galil, 2005. Fifteen additional species are new records for Papua New Guinea: Alox rugosum (Stimpson, 1858), Ancylodactyla nana (Zarenkov, 1990), Arcania heptacantha De Man, 1907, Heterolithadia fallax (Henderson, 1893), Hiplyra longimana (A. Milne Edwards, 1874), Myra curtimana Galil, 2001, M. digitata Galil 2004, Nursilia dentata Bell, 1855, Oreotlos etor Tan & Richer de Forges, 1993, Parilia major Sakai, 1961, Raylilia coniculifera Galil, 2001, R. uenoi (Takeda, 1995), Toru pilus (Tan, 1996), Urashima pustuloides (Sakai, 1961) and Leucosia rubripalma Galil, 2003. The new species are described and illustrated, and their affinities with allied taxa discussed. Colour photographs are provided for 20 species.

  19. Morphology and function of the female reproductive system of Ebalia tumefacta (Decapoda, Brachyura, Leucosiidae).

    PubMed

    Hayer, Sarah; Schubart, Christoph D; Brandis, Dirk

    2015-05-01

    In this article, the morphology and function of the female reproductive organs of Ebalia tumefacta were investigated using histological methods. While the vagina conforms to the concave type, the study reveals a new orientation of seminal receptacle compartments. The seminal receptacle consists of two chambers, which are oriented in anterior-posterior direction. This is in contrast to the dorso-ventral orientation of seminal receptacle chambers in all other known brachyuran crabs. The anterior chamber is lined by cuticle, whereas the posterior chamber is covered with a holocrine glandular epithelium. The oviduct connection is located ventrally, close to the opening of the vagina. The oviduct orifice is characterized by a transition of the epithelium lining of the oviduct to the seminal receptacle holocrine glandular epithelium. Special features are muscle fibers, which are attached to the oviduct orifice and to the sternal cuticle as well. The muscle fibers can be found exactly at that point where the oviduct opens into the seminal receptacle and are secondly attached to the sternum beneath. This musculature is newly described for Eubrachyuran crabs. This musculature can be interpreted as an important feature in the fertilization and egg-laying process in relation to supporting and controling the inflow of eggs into the seminal receptacle lumen. These new discoveries were compared to the known pattern of an Eubrachyuran seminal receptacle.

  20. Mass spectrometric characterization of the neuropeptidome of the ghost crab Ocypode ceratophthalma (Brachyura, Ocypodidae)

    PubMed Central

    Hui, Limei; D’Andrea, Brandon T.; Jia, Chenxi; Liang, Zhidan; Christie, Andrew E.; Li, Lingun

    2013-01-01

    The horn-eyed ghost crab Ocypode ceratophthalma is a terrestrial brachyuran native to the Indo-Pacific region, including the islands of Hawaii. Here, multiple mass spectrometric platforms, including matrix-assisted laser desorption/ionization time-of-flight/time-of-flight tandem mass spectrometry (MALDI-TOF/TOF MS/MS) and nanoflow liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (nanoLC-ESI-Q-TOF MS/MS), were used to characterize the neuropeptidome of this species. In total, 156 peptide paracrines/hormones, representing 15 peptide families, were identified from the O. ceratophthalma supraesophageal ganglion (brain), eyestalk ganglia, pericardial organ and/or sinus gland, including 59 neuropeptides de novo sequenced here for the first time. Among the de novo sequenced peptides were isoforms of A-type allatostatin, B-type allatostatin, FMRFamide-like peptide (FLP), orcokinin, orcomyotropin and RYamide. Of particular note, were several novel FLPs including DVRAPALRLRFamide, an isoform of short neuropeptide F, and NRSNLRFamide, the orcokinins NFDEIDRSGYGFV and DFDEIDRSSFGFH, which exhibit novel Y for F and D for N substitutions at positions 10 and 1, respectively, and FDAYTTGFGHS, a member of the orcomyotropin family exhibiting a novel Y for F substitution at position 4. Taken collectively, the set of peptides described here represents the largest number of neuropeptides thus far characterized via mass spectrometry from any single crustacean, and provides a framework for future investigations of the physiological roles played by these molecules in this species. PMID:23298572

  1. Marine pollution effects on the southern surf crab Ovalipes trimaculatus (Crustacea: Brachyura: Polybiidae) in Patagonia Argentina.

    PubMed

    Lezcano, Aníbal Hernán; Rojas Quiroga, María Laura; Liberoff, Ana Laura; Van der Molen, Silvina

    2015-02-28

    We compared the carapace shape and thickness as well as the energy density of Ovalipes trimaculatus inhabiting areas comprising a gradient of marine pollution: high, moderate and undetected, in the Nuevo gulf (Patagonia Argentina). The carapace shape was evaluated by means of individual asymmetry scores (=fluctuating asymmetry) whereas the carapace thickness was assessed by measuring the carapace dry weight. The energy density was analyzed through its negative relationship with water content in muscle tissue. The individual asymmetry scores as well as the percentage of water content in muscle tissue were proportional to the marine pollution gradient, whereas the carapaces thickness did not differ among sampling sites. Our results are consistent with previous findings and demonstrate the direct effect of marine pollution on other taxa different from gastropods, cephalopods and polyplacophora and add to long-standing concerns about detrimental effects caused by marine pollution on the benthic community of the Nuevo gulf. PMID:25293645

  2. Revision of the spider crab genus Sargassocarcinus Ward, 1936 (Crustacea: Brachyura: Epialtidae).

    PubMed

    Ng, Peter K L; Lin, Chia-Wei; Naruse, Tohru

    2016-01-01

    The Western Pacific epialtid genus Sargassocarcinus Ward, 1936, is revised. The genus had been regarded as monotypic but is here shown to contain three species: S. sublimis (Rathbun, 1916), S. cristatus (Balss, 1924), and S. foliatus Ward, 1936 (type species). The many unusual characters possessed by Sargassocarcinus are figured and discussed; and diagnostic features of the three species are clarified. The taxonomy of the three species and aspects of their ecology are discussed. Sargassocarcinus species are found free-living on coral rubble habitats and not associated with macrophytic algae. PMID:27615976

  3. Physiology and morphology of visual movement detector neurons in a crab (Decapoda: Brachyura).

    PubMed

    Berón de Astrada, M; Tomsic, D

    2002-08-01

    Although visually elicited behaviors have been extensively studied in crabs, their investigation at the neurophysiological level is scant. The present study is a physiological and morphological description of intracellularly recorded and dye injected visual movement detector neurons that respond to the same stimulus that elicits the escape response in the crab Chasmagnathus granulatus. The neurons were investigated in intact animals. The response of movement detector neurons to the danger stimulus (an object moving above the animal) consists of a strong discharge of action potentials frequently superimposed on noisy graded potentials, whereas the response to stationary changes in illumination is weak or undetectable. The response to the moving stimulus is relatively independent of the background intensity and of the contrast between target and background. Repeated presentations of the moving stimulus produce rapid habituation of the neural response. Some of the neurons also respond to mechanical stimulation. These physiological results coincide with those from early studies on visual movement detector fibers of crustaceans achieved by extracellular recordings. However, there are no previous morphological studies of these neurons. Intracellular injection with Lucifer Yellow revealed that these neurons in Chasmagnathus arborize extensively in the internal medulla and in the lateral protocerebrum. They have their somata located in the cell body cluster laying beneath the internal medulla. Their axons project centripetally across the protocerebral tract.

  4. An appraisal of Typilobus Stoliczka, 1871 (Crustacea, Brachyura, Leucosioidea), with description of a new family and genus.

    PubMed

    Artal, Pedro; Hyžný, Matúš

    2016-01-01

    Since its description, Typilobus Stoliczka, 1871, has become something like a catch-all taxon to accommodate fossil leucosioid crabs with uncertain affinities. As many as 17 species have been assigned to Typilobus, recorded from the Eocene to Miocene strata of Europe, Africa, and Asia. The re-examination of the type species, Typilobus granulosus Stoliczka, 1871, from the Miocene of Pakistan, has shown inconsistency in its description and published figures leading to the need of a revision of all species assigned to Typilobus. Typilobus boscoi Vía Boada, 1959, from the Middle Eocene of Spain, is revised and assigned to Folguerolesia n. gen. Characters present on ventral portions of male and female specimens differ from all known representatives of Leucosioidea, although the general morphology supports inclusion in this superfamily. A new family, Folguerolesiidae n. fam. is thus erected to accommodate Folguerolesia boscoi comb. nov., leading to recognition of three families of leucosioid crabs, including Iphiculidae and Leucosiidae. PMID:27395181

  5. Habitat-related differences in the pre-copulatory guarding and copulation behavior of Neohelice granulata (Brachyura, Grapsoidea, Varunidae)

    NASA Astrophysics Data System (ADS)

    Sal Moyano, María P.; Gavio, María A.; McLay, Colin L.; Luppi, Tomás

    2014-03-01

    Mating behavior strategies of brachyuran crabs are flexible depending on the habitat and social context. We evaluate pre-copulatory guarding in Neohelice granulata and describe the unusual copulatory behavior. Laboratory experiments were conducted to test whether factors such as male size, presence of burrows, a male-biased operational sex ratio (OSR) and female mating history affect the copulation duration in two different study areas. Females initiated a searching behavior approximately 20-26 h before they became receptive by assessing large male burrows and displaying a courtship behavior (“flirting”) in its entrance. Once the female entered inside the male burrow, pre-copulatory guarding was observed until the female became receptive and successful copulation occurred immediately after. This species shows some very unusual copulatory behavior involving eyestalk grasping not seen in any other varunid crab. The copulation duration was independent of male size and the presence of burrows, although it was dependent on the study area, the OSR and the female mating history. Thus, copulation duration is a flexible character in this species which varies with habitat and biological factors such as mating history and sex ratio.

  6. Biology of Grapsus grapsus (L innaeus, 1758) (Brachyura, Grapsidae) in the Saint Peter and Saint Paul Archipelago, Equatorial Atlantic Ocean

    NASA Astrophysics Data System (ADS)

    Freire, A. S.; Pinheiro, M. A. A.; Karam-Silva, H.; Teschima, M. M.

    2011-09-01

    Eleven expeditions were undertaken to the Saint Peter and Saint Paul Archipelago to study the reproductive biology of Grapsus grapsus, providing additional information on limb mutilation and carapace colour. MATURE software was used to estimate morphological maturity, while gonadal analyses were conducted to estimate physiological maturity. The puberty moult took place at larger size in males (51.4 mm of carapace length) than in females (33.8 mm), while physiological maturity occurred at a similar size in males (38.4 mm) and in females (33.4 mm). Above 50 mm, the proportion of red males increased in the population, indicating that functional maturity is also related to colour pattern. Small habitat and high local population density contributed to the high rate of cannibalism. The low diversity of food items, absence of predators of large crabs and high geographic isolation are the determinants of unique behavioural and biological characteristics observed in the G. grapsus population.

  7. The decapod fauna (Axiidea, Anomura, Brachyura) from the Late Pleistocene of Trumbacà, Reggio Calabria (Calabria, southern Italy)

    PubMed Central

    Garassino, Alessandro; Pasini, Giovanni; De Angeli, Antonio; Hyžný, Matúš

    2015-01-01

    We report a rich faunal assemblage from the Tyrrhenian (Late Pleistocene) of Trumbacà, located in the southern area of Reggio Calabria (Calabria, southern Italy). The only brachyuran reported to date from this locality is Ranilia constricta (A. Milne Edwards, 1880) by Vazzana (2008). The studied specimens have been assigned, as follows: ?Corallianassa sp., Dardanus arrosor (Herbst, 1796), Dardanus substriatus (A. Milne Edwards, 1861), Paguristes cf. P. syrtensis de Saint Laurent 1970, Anapagurus sp., Ranilia constricta (A. Milne Edwards, 1880), Ranina propinqua Ristori, 1891, Ebalia cf. E. deshayesi Lucas, 1846, Ilia nucleus (Linnaeus, 1758), Medorippe lanata (Linnaeus, 1767), Calappa granulata (Linnaeus, 1758), Pisa armata (Latreille, 1803), Derilambrus cf. D. angulifrons (Latreille, 1825), Atelecyclus undecimdentatus (Herbst, 1783), Carcinus sp., Pilumnus hirtellus (Linnaeus, 1761), and Xantho cf. X. incisus (Leach, 1814). The studied assemblage enlarges our knowledge on the evolution of the Mediterranean decapod faunas. PMID:26689358

  8. Integrative Taxonomic Study of the Purse Crab Genus Persephona Leach, 1817 (Brachyura: Leucosiidae): Combining Morphology and Molecular Data.

    PubMed

    Magalhães, Tatiana; Robles, Rafael; Felder, Darryl L; Mantelatto, Fernando L

    2016-01-01

    Marine crabs of the genus Persephona Leach, 1817 are restricted to American waters of the western Atlantic and eastern Pacific Oceans. Subfamilial assignment of this taxon has varied between authors and its species composition remain in question. We conducted a comparative study based on morphology and molecular phylogenetics for all ten recognized species of Persephona, along with Iliacantha hancocki. We tested whether Persephona finneganae, P. lichtensteinii, and P. crinita represent a single species as suggested by some authors; whether specimens identified as P. punctata, P. mediterranea, and P. aquilonaris warrant treatment as separate species; and whether I. hancocki should be regarded as a junior synonym of P. subovata. Diagnostic morphological characters (of the carapace, chelipeds, and third maxillipeds) were used along with gonopod (male first pleopod 1) features and live coloration. The 16S rRNA and the Cytochrome Oxidase I (COI) (DNA barcoding) mitochondrial genes were used as molecular markers. Both morphological and molecular analyses revealed that putative specimens of P. crinita from Brazil and those assigned to P. finneganae were no different from specimens presently assignable to P. lichtensteinii. P. finneganae is regarded as a junior synonym of P. lichtensteinii, and we apply P. crinita only to specimens we examined from the Gulf of Mexico. Specimens from Brazil previously reported as P. crinita are herewith concluded to represent P. lichtensteinii. Additionally, P. townsendi is a junior synonym of P. orbicularis, Iliacantha hancocki is concluded to be a junior synonym of P. subovata, while P. aquilonaris and P. mediterranea are found to represent separate species. On the basis of our revisions, eight species of Persephona are considered valid, and the reported distribution for P. crinita is restricted.

  9. Morphology of the first zoeal stages of five species of the portunid genus Callinectes (Decapoda, Brachyura) hatched at the laboratory.

    PubMed

    Mantelatto, Fernando L; Reigada, Alvaro L D; Gatti, Aline C R; Cuesta, José A

    2014-05-23

    The genus Callinectes Stimpson, 1860 currently consists of 16 species, six of which are reported in Brazilian coast. In the present study, the first zoeal stages of Callinectes bocourti, C. danae, C. exasperatus, C. ornatus and C. sapidus from Brazil were obtained from ovigerous females. The morphological and meristic characters of all these larval stages are described and illustrated. Those of C. bocourti, C. danae and C. sapidus are redescribed and compared with the previous descriptions, and differences are listed. Larval characters of these species were examined for interspecific differences, as well as larval features to distinguish the genus Callinectes within Portunidae. In addition, other portunid genera and species with a known first zoeal stage are compared, with special attention to those species present in the same geographical area. Our findings concord with some previous molecular studies, and we discuss the complexity within the group. PMID:24862577

  10. Yuebeipotamon calciatile, a new genus and new species of freshwater crab from southern China (Crustacea, Decapoda, Brachyura, Potamidae).

    PubMed

    Huang, Chao; Shih, Hsi-Te; Mao, Si Ying

    2016-01-01

    A new genus and species of freshwater crab, Yuebeipotamon calciatile gen. n., sp. n., is described from southern China. While the carapace features are superficially similar to species of Sinopotamon Bott, 1967, Longpotamon Shih, Huang & Ng, 2016, and Tenuilapotamon Dai, Song, Li, Chen, Wang & Hu, 1984, the new genus possesses a distinctive combination of carapace, ambulatory leg, male thoracic sternal, male abdominal, and gonopodal characters that distinguish it from these and other genera. Molecular evidence derived from the mitochondrial 16S rDNA supports the establishment of a new genus. PMID:27667941

  11. Folk classification of the crabs and swimming crabs (Crustacea – Brachyura) of the Mamanguape river estuary, Northeastern – Brazil

    PubMed Central

    Ferreira, Emmanoela N; da S Mourão, José; Rocha, Pollyana D; Nascimento, Douglas M; da S Q Bezerra, Dandara Monalisa Mariz

    2009-01-01

    Background Folk taxonomy is a sub-area of ethnobiology that study the way of how traditional communities classify, identify and name their natural resources. The work present was undertaken in two traditional communities (Barra de Mamanguape and Tramataia). The objective of this study was investigate the ethnobiological classification of the local crabs and swimming crabs used by the crustaceous gatherers of the Mamanguape River Estuary (MRE), Paraíba State, Brazil. Methods The methodology used here involved a combination of qualitative methods (open interviews, semi-structured interviews, direct observations, guided tours, surveys, and interviews in synchronic and diachronic situations that crossed-checked and repeated identifications) and quantitative methods (Venn diagram). A total of 32 men and women were interviewed in the two communities. Specimens of the local crustaceans were collected and identified by the harvesters themselves, subsequently fixed in formalin, conserved in 70% ethyl alcohol, identified using appropriate specialized literature, and then deposited in the laboratory of the Zoology Department of the University State of Paraiba. Results The crustaceous gatherers we studied were observed to group crustaceans according to their similarities and differences, producing a hierarchical classification system containing four levels of decreasing taxonomic order: unique beginner, life-form, generic, and specific. A sequential and/or semantic system classification system that is used to classify the ontogeny of the female swimming crab was also identified. Of the nine folk generics identified, 44.5% were monotypic. 55.5% were polytypic and were subdivided into 15 folk specifics. An identification key was elaborated with the data obtained about the folk polytypics generics. Conclusion The detailed knowledge concerning the crabs and swimming crabs revealed by the MRE crustaceous gatherers demonstrates that these people detain a vast knowledge concerning these marine resources. This local knowledge provides a rich but little-known source of information that will aid future ecological and/or zoological studies in the region that will be indispensable for producing management plans to help guarantee the sustainability of these local natural resources. PMID:19671153

  12. Reproductive biology of the Suez Canal spider crab Schizophrys aspera (H. Milne Edwards, 1834: Crustacea: Brachyura: Majidae)

    PubMed Central

    El-Serehy, Hamed A.; Al-Rasheid, Khaled A.; Ibrahim, Nesreen K.; Al-Misned, Fahad A.

    2015-01-01

    A reproductive biology study of the spider crab Schizophrys aspera (H. Milne Edwards, 1834) was conducted in the Suez Canal from July 2012 to June 2013. The annual sex ratio (Male:Female) of S. aspera was female biased with values of 1:1.25. Out of the four ovarian development stages of this crab, two stages were observed in the Suez Canal throughout the whole year. The ovigerous crab’s carapace width varied from 28 to 52 mm. This crab species can spawn during most of the year in the canal water, with a peak during late spring and early winter. The fecundity of ovigerous females ranged between 2349 and 13600 eggs with a mean of 5494 ± 1486 eggs. Female crabs that reached sexual maturity exhibited a minimum carapace width varying between 22 and 46 mm, and fifty percentage of all ovigerous females showed a carapace width of 36 mm. PMID:26587008

  13. The Opportunity for Post-Copulatory Sexual Selection in the Ectoparasitic Pea Crab, Dissodactylus primitivus (Brachyura: Pinnotheridae)

    PubMed Central

    2015-01-01

    Pea crabs, Dissodactylus primitivus, inhabit multiple echinoid (heart urchin) hosts. Male and female crabs move among hosts in search for mates, and both sexes mate multiple times, creating opportunities for post-copulatory sexual selection. For such selection to occur, only a fraction of the males who succeed in mating can also succeed in siring progeny. Jossart et al. 2014 used 4 microsatellite loci to document parentage and mating frequencies of both sexes in D. primitivus. From these data we identified the mean and variance in female offspring numbers, as well as the proportions of the female population that were gravid and not bearing offspring. We next identified the proportions of the male population who had (1) mated and sired offspring, (2) mated but failed to sire offspring, and (3) failed to mate altogether. We used these results to estimate the opportunity for selection on males and females in terms of mate numbers and offspring numbers, and estimated the sex difference in the opportunity for selection (i.e., the opportunity for sexual selection) using both forms of data. We then partitioned the total variance in male fitness into pre- and post-copulatory components and identified the fraction of the total opportunity for selection occurring in each context. Our results show that the opportunity for selection on each sex was of similar magnitude (0.69–0.98), consistent with this polyandrogynous mating system. We also found that 37% of the total opportunity for sexual selection on males occurred within the context of post-copulatory sexual selection. However, the fraction of the total opportunity for selection that was due to sexual selection, estimated using both mate numbers and offspring numbers, was 9% and 23% respectively. Thus, we further reduced our estimate of the opportunity for post-copulatory sexual selection in D. primitivus to less than 10% of the total opportunity for selection (0.37 of 0.09 and 0.23 = 0.03 and 0.09). Our results provide the first estimate of the maximum possible strength of post-copulatory sexual selection in crustaceans using this approach. PMID:26701316

  14. The taxonomy of Speodromia platyarthrodes (Stebbing, 1905) (Crustacea: Brachyura), an unusual dromiid crab endemic to South Africa.

    PubMed

    Ng, Peter K L

    2016-05-16

    The poorly known dromiid crab Speodromia platyarthrodes (Stebbing, 1905), endemic to South Africa, is redescribed and figured. Speodromia is unique among dromiids in possessing a large cavity on the anterior part of the sub-branchial region, which is believed to be associated with respiration. The systematics of the genus is discussed and is confirmed to be a member of Dromiinae De Haan, 1833, s. str.

  15. A new species of Macrophthalmus Desmarest, 1823 (Crustacea: Decapoda: Brachyura: Macrophthalmidae) from Taiwan, with notes on four new records.

    PubMed

    Teng, Shao-Jyun; Shih, Hsi-Te

    2015-12-18

    A new species of sentinel crab (family Macrophthalmidae), Macrophthalmus (Mareotis) purpureocheir sp. nov., from coral reefs is herein described from southern and eastern Taiwan. The new species can be distinguished from other species by a suite of characters, including the narrower and more convex carapace, the first anterolateral tooth protruding forward, the short and stout chelipeds, and the male first gonopod with short apical process, as well as the distinctive reddish purple chelae of the male. The identity of this new species is also supported by molecular evidence using the mitochondrial 16S rDNA and cytochrome oxidase subunit I (COI). Three additional species of Macrophthalmus, viz. M. crinitus Rathbun, 1913, M. definitus Adams & White, 1849, and M. milloti Crosnier, 1965, as well as Ilyograpsus paludicola (Rathbun, 1909) of the subfamily Ilyograpsinae Števčić, 2005, are also confirmed from Taiwan.

  16. Yuebeipotamon calciatile, a new genus and new species of freshwater crab from southern China (Crustacea, Decapoda, Brachyura, Potamidae).

    PubMed

    Huang, Chao; Shih, Hsi-Te; Mao, Si Ying

    2016-01-01

    A new genus and species of freshwater crab, Yuebeipotamon calciatile gen. n., sp. n., is described from southern China. While the carapace features are superficially similar to species of Sinopotamon Bott, 1967, Longpotamon Shih, Huang & Ng, 2016, and Tenuilapotamon Dai, Song, Li, Chen, Wang & Hu, 1984, the new genus possesses a distinctive combination of carapace, ambulatory leg, male thoracic sternal, male abdominal, and gonopodal characters that distinguish it from these and other genera. Molecular evidence derived from the mitochondrial 16S rDNA supports the establishment of a new genus.

  17. A new dromiid crab (Crustacea, Brachyura, Dromioidea) from the Upper Eocene of Huesca (Aragón, northern Spain).

    PubMed

    Artal, Pedro; Bakel, Barry W M Van; Domínguez, José L; Gómez, Guillermo

    2016-01-08

    A new genus and species of brachyuran crab from the Upper Eocene (Priabonian) strata in Basa Valley (Huesca, northern Spain) assignable to the superfamily Dromioidea, Basadromia longifrons n. gen., n. sp., adds to current knowledge of the morphological diversity and geographical-stratigraphical distribution of the superfamily. The main characters of the new form, such as the orbitofrontal construction with two median teeth and an rostral tooth situated in a lower plane, two minor frontal (inner orbital) teeth, well-marked cervical and branchial grooves, general carapace outline, and the shape and distribution of dorsal regions, confirm placement in Dromioidea. Unique features, such as the four conspicuous frontal teeth, lateral margins of carapace with small, subtle spines, the reduced length of the posterior margin, disposition of dorsal grooves, and peculiar shape and distribution of the dorsal regions (mainly protogastric and epibranchial), warrants the erection of a new genus and new species. In the absence of ventral features the new taxon is tentatively assigned to the family Dromiidae after detailed comparison with both fossil and extant members.

  18. Carcinoplax fasciata, a new species of deep-water goneplacid crab from southwestern India (Crustacea: Decapoda: Brachyura: Goneplacoidea).

    PubMed

    Ng, Peter K L; Kumar, Appukuttannair Biju

    2016-08-03

    A new species of Carcinoplax H. Milne Edwards, 1852 (family Goneplacidae) is described from southern India. Carcinoplax fasciata n. sp. is closest to C. specularis Rathbun, 1914, but can be distinguished by its different coloration in life as well as structures of the carapace surface, anterolateral armature, supraorbital margin, chela and male first gonopod.

  19. Parathelphusa pardus, a new species of lowland freshwater crab from swamps in central Sumatra, Indonesia (Crustacea: Brachyura: Gecarcinucidae).

    PubMed

    Ng, Peter K L; Riady, Rikhi; Windarti, Windarti

    2016-02-29

    A new species of gecarcinucid freshwater crab of the genus Parathelphusa H. Milne Edwards, 1853, is described from freshwater swamp habitats in Pekanbaru, Riau Province, in central-eastern Sumatra, Indonesia. Parathelphusa pardus sp. nov., has a very distinctive colour pattern, and in this respect, resembles P. maindroni (Rathbun, 1902) from Sumatra and Peninsular Malaysia; P. batamensis Ng, 1992, from Batam Island, Indonesia; P. reticulata Ng, 1990, from Singapore; and P. oxygona Nobili, 1901, from western Sarawak. It can be distinguished from these species and congeners by a suite of carapace, ambulatory leg, thoracic sternal and most importantly, male first gonopod characters.

  20. Reproductive Biology of the Blue Swimming Crab Portunus pelagicus (Brachyura: Portunidae) in East Lampung Waters, Indonesia: Fecundity and Reproductive Potential

    PubMed Central

    Zairion; Wardiatno, Yusli; Boer, Mennofatria; Fahrudin, Achmad

    2015-01-01

    The blue swimming crab Portunus pelagicus is an important catch species for many coastal villages along the Java Sea coastline, but little is known regarding its reproductive biology or stock status. We examined the batch fecundity of female crabs that were collected monthly at landing sites from June 2011 to May 2012, calculated the relationships with body size, egg mass and month of the year, and determined the size at which females became potentially reproductive in the population inhabiting East Lampung waters (western Java Sea). Fecundity values ranged from 229,468 to 2,236,355 (mean = 926,638±30,975 [±SE]). The fecundity was positively and linearly correlated with carapace width (CW), but the relationships with body weight and egg mass were best described by logarithmic regression. A peaked, temporally cyclical pattern in fecundity was observed, with a peak period that was significantly different (F = 226.36; df = 22, p<0.05) from March to May 2012. Reproductive females were within the 111.0–155.9 mm CW size range; significantly higher reproductive potentials (F = 14.59; df = 30, p<0.05) were found in females within the 126.0–130.9 mm CW size group. The current minimum legal size (MLS = 100 mm CW) is not an appropriate limit reference point, and a precautionary approach is needed for a sustainable harvesting strategy. Resetting the MLS to 115 mm CW would potentially provide adequate protection for spawning females and increase total egg production, thereby maintaining population productivity and enhancing resilience in the face of current fishing pressures. PMID:26019748

  1. A new species of Paracleistostoma De Man, 1895 (Crustacea: Decapoda: Brachyura: Camptandriidae) from Haikou, Hainan Province, China.

    PubMed

    Liu, Han Lun; Huang, Jian Rong

    2016-01-01

    A new species of Paracleistostoma De Man, 1895, P. meilanense n. sp. is reported from mangroves forests in Haikou, Hainan Province, China. The new species inhabits mud burrows in the upper intertidal zone and is sympatric with P. tomentosa Yang & Sun, 1993, and P. depressum De Man, 1895. The slender chelipeds as well as the characteristic morphology of the male first pleopod easily distinguishes the species from congeners.

  2. Out of the Sichuan Basin: Rapid species diversification of the freshwater crabs in Sinopotamon (Decapoda: Brachyura: Potamidae) endemic to China.

    PubMed

    Ji, Yongkun; Sun, Yufang; Gao, Wei; Chu, Kelin; Wang, Ruicong; Zhao, Qiang; Sun, Hongying

    2016-07-01

    Sinopotamon Bott, 1967 is the most speciose and widely distributed freshwater crab genus in East Asia. Our extensive sampling includes about 76% of the known Sinopotamon taxa, and nearly covers its entire distribution area. Based on mitochondrial cytochrome oxidase I (COI) and 16S rRNA, as well as nuclear 28S rRNA and histone H3, we reconstructed the Sinopotamon phylogeny using maximum likelihood and Bayesian approaches. The divergence time was estimated and multiple methods were used to conduct diversification analyses. The ancestral geographic distribution and character state were reconstructed. Three main clades (Clades I, II and III) that roughly correspond to their main geographic distribution ranges were recovered. Our results challenge the current view of the four major species groups based on the morphological differences in the male first gonopod (G1). The most recent common ancestor of Sinopotamon most likely originated from the Sichuan Basin and surrounding mountains (SBSM) and subsequently dispersed throughout central and eastern China. The exceptionally rapid, recent diversification was detected in Clade II. The high incidence of species-level non-monophyly found in Clade II can be explained by recent rapid radiation. Climatic changes, morphological innovations, range expansion and geographical heterogeneity may all contribute to the diversification in Sinopotamon. This study contributes to our knowledge on diversification of freshwater benthic macro-invertebrates in the East Asian inland ecosystem. PMID:27058122

  3. Receptivity of female Neohelice granulata (Brachyura, Varunidae): different strategies to maximize their reproductive success in contrasting habitats

    NASA Astrophysics Data System (ADS)

    Sal Moyano, María Paz; Luppi, Tomás; Gavio, María Andrea; Vallina, Micaela; McLay, Colin

    2012-12-01

    The extent of the receptive period may determine the mating strategies employed by female crabs to obtain mates. Here, we studied the receptivity of female Neohelice granulata (Dana, 1851) in the laboratory, including the form of the vulvae and the anatomy of the seminal receptacle (SR). We examined the factors that influence the duration of receptivity by comparing two populations inhabiting contrasting habitats: Mar Chiquita Coastal lagoon (MCL), which is an oligo-polyhaline estuary, and San Antonio Oeste (SAO), which is an eu-hyperhaline marine bay. Non-receptive females have immobile vulva opercula, while receptive females have mobile opercula. Histological sections of the SR showed that the degree of epithelium secretions was associated with the receptive stage of females, and they may be involved in the maintenance of viable sperm and in the dehiscence of spermatophores. The existence of a special tissue at the junction of the oviduct and the SR was described and proposed as an internal mechanism influencing the timing of ovulation. The duration of receptivity was dependent on the SR load and the capacity to lay eggs. Thus, females with empty SR exhibited longer receptivity and did not lay eggs, while those with full SR exhibited shorter receptivity and always laid eggs. Interpopulation differences showed that females from SAO had shorter receptivity and heavier SR and laid eggs more frequently than females from MCL. Based on our results, we suggest that N. granulata females can adjust the duration of their receptivity and control the moment of fertilization according to different internal mechanisms related to the morphology of the vulvae, the fullness of the SR and anatomical attributes of the SR. An important consequence of this control is greater sperm competition. The extent of the receptive period and the number of times that a female could become receptive in a single reproductive season may also depend on the habitat characteristics.

  4. A new species of freshwater crab of the genus Kingsleya Ortmann, 1897 (Crustacea: Brachyura: Pseudothelphusidae) from Amazonia, Brazil.

    PubMed

    Pedraza, Manuel; Tavares, Marcos

    2015-10-19

    A new species of freshwater crab, Kingsleya celioi, from the Brazilian Amazon (Pará State) is described and illustrated. The new species can be easily separated from their congeners by a suite of morphological characters, including the apical plate of the first gonopod large, widest medially in abdominal view, with single large spine-like outgrowth in midlength of mesial margin; distal, proximal lobes of apical plate unequal in size, distal lobe largest, tapering distally in lateral view.

  5. Reproduction and management of the mangrove crab Ucides cordatus (Crustacea, Brachyura, Ucididae) at Iguape, São Paulo, Brazil.

    PubMed

    Sant'Anna, Bruno S; Borges, Roberto P; Hattori, Gustavo Y; Pinheiro, Marcelo A A

    2014-09-01

    The mangrove crab Ucides cordatus is one of the most exploited crustaceans in Brazil. The present study investigated the breeding season of this species and the period of the "andada" phenomenon, when the crabs are active outside their burrows and perform agonistic behaviors. Furthermore related them to environmental factors, in a mangrove on the coast of Brazil, with inferences about management of this crab. The crabs reproduced from October through February. The "andada" occurred from November through February, with typical characteristics in the first two months, during the full and new moon periods, and was influenced positively by the air and soil temperature, luminosity, and tidal amplitude, and negatively by salinity. Based on the results of the present study, the period when the "andada" occurs in other parts of Brazil could be defined, which will aid in managing this fishery. For Iguape, state of São Paulo, Brazil, we suggest a legal off-season for both sexes in December or during the full and new moon, including January.

  6. Aletheiana tenella, a new genus and new species of freshwater hymenosomatid crab (Crustacea: Decapoda: Brachyura) from Central Sulawesi, Indonesia.

    PubMed

    Ng, Peter K L; Lukhaup, Christian

    2015-11-03

    A new genus and new species of free-living hymenosomatid crab, Aletheiana tenella, is described from Central Sulawesi, Indonesia. The two known Sulawesi hymenosomatid species, Cancrocaeca xenomorpha Ng, 1991, and Sulaplax ensifer Naruse, Ng & Guinot, 2008, are both from cave habitats. Aletheiana gen. nov. is most similar to Neorhynchoplax Sakai, 1938 (from freshwater and intertidal habitats in the Indo-West Pacific), and Sulaplax, but can be distinguished by its front possessing only one subventral rostral lobe, the base of the antenna is positioned between the base of the ocular peduncle and antennular fossa, the posterior margin of the epistome has two low, rounded median lobes, the merus of the third maxilliped is elongated, the ambulatory dactylus has a prominent subdistal spine, the cutting edges of the chela are armed with distinct teeth proximally, and the male abdomen is slender and elongate with the telson linguiform.

  7. A new species of troglobitic crab of the genus Stygothelphusa Ng, 1989, from Sarawak, Malaysia (Crustacea: Decapoda: Brachyura: Gecarcinucidae).

    PubMed

    Ng, Peter K L; Grinang, Jongkar

    2014-03-04

    A new species of cave crab, Stygothelphusa antu new species, is described from limestone formations in Temurang, Sarawak, Malaysia. The new species is the most highly adapted to a cavericolous lifestyle among the four known species of Stygothelphusa, having a pale body pigmentation, reduced eyes and elongated pereopods. In contrast, the other three species have normal eyes that almost completely fill the orbits. The new species also differs from its congeners by a number of carapace, pereopod and gonopod characters.

  8. Structure and variable numbers of tandem repeats (VNTRs) of the mitochondrial control region in mitten crab Eriocheir (Crustacean: Brachyura).

    PubMed

    Zhang, Daizhen; Ding, Ge; Wang, Guangyue; Tang, Boping; Sun, Hongying

    2011-11-01

    Mitochondrial control region was called "A + T-rich" region in invertebrate. In the study, the general organization of control region in mitten crab was divided into two major domains: high variable segment and conserved segment. Four conserved blocks (CSB1, CSB2, CSB3 and CSB4) and two tandem repeat sequences (RT1 and RT2) were defined in control region. There were 116 polymorphic sites and 84 parsimony information sites in 571 aligned sites of the high variable segment adjacent "tRNA-Gln", in which 58 stable variable sites were defined between E. j. sinensis and E. j. hepuensis. Conserved domain contained more than two similar repeat units, and length polymorphism of control region was due to the number difference between the two repeat units (RT1 and RT2). And length polymorphism was a common phenomenon for tandem repeat in control region in the study. Furthermore, a novel result showed the core nucleotide of RT2 in control region tandem repeat was C in E. j. hepuensis, but G in E. j. sinensis. It might be a rapid and cost-effective measure of seedlings differentiation in aquaculture.

  9. Thampramon tonvuthi, a new genus and new species of cavernicolous crab (Crustacea: Decapoda: Brachyura: Potamidae) from Thailand.

    PubMed

    Ng, Peter K L; Vidthayanon, Chavalit

    2013-01-01

    A new genus and species of potamid cavernicolous crab, Thampramon tonvuthi sp. nov., is described from Thailand. While superficially similar to Tiwaripotamon Bott, 1970, Phaibulamon Ng, 1992, and Nemoron Ng, 1996, the new genus possesses a unique combination of morphological characters including a distinctive carapace form, possession of a relatively long third maxilliped exopod, long ambulatory legs and a unique male first gonopod.

  10. A new species of sesarmid crab of the genus Chiromantes (Crustacea: Decapoda: Brachyura) from the Ogasawara Islands, Japan.

    PubMed

    Komai, Tomoyuki; Ng, Peter K L

    2013-01-01

    A new species of sesarmid crab, Chiromantes magnus, is described from the Ogasawara (Bonin) Is., Japan. The new species was previously confused with C. dehaani (H. Milne Edwards, 1853). The different carapace shape, proportionally longer ambulatory legs, large adult size and the distinct live coloration distinguish the new species from its two closest congeners, C. dehaani and C. neglectus (De Man, 1887). Available information indicates that C. magnus n. sp. is endemic to the Ogasawara Is.; there is no evidence of the occurrence of the true C. dehaani in the Ogasawara Is.

  11. The Opportunity for Post-Copulatory Sexual Selection in the Ectoparasitic Pea Crab, Dissodactylus primitivus (Brachyura: Pinnotheridae).

    PubMed

    Prather, Robert B; Shuster, Stephen M

    2015-01-01

    Pea crabs, Dissodactylus primitivus, inhabit multiple echinoid (heart urchin) hosts. Male and female crabs move among hosts in search for mates, and both sexes mate multiple times, creating opportunities for post-copulatory sexual selection. For such selection to occur, only a fraction of the males who succeed in mating can also succeed in siring progeny. Jossart et al. 2014 used 4 microsatellite loci to document parentage and mating frequencies of both sexes in D. primitivus. From these data we identified the mean and variance in female offspring numbers, as well as the proportions of the female population that were gravid and not bearing offspring. We next identified the proportions of the male population who had (1) mated and sired offspring, (2) mated but failed to sire offspring, and (3) failed to mate altogether. We used these results to estimate the opportunity for selection on males and females in terms of mate numbers and offspring numbers, and estimated the sex difference in the opportunity for selection (i.e., the opportunity for sexual selection) using both forms of data. We then partitioned the total variance in male fitness into pre- and post-copulatory components and identified the fraction of the total opportunity for selection occurring in each context. Our results show that the opportunity for selection on each sex was of similar magnitude (0.69-0.98), consistent with this polyandrogynous mating system. We also found that 37% of the total opportunity for sexual selection on males occurred within the context of post-copulatory sexual selection. However, the fraction of the total opportunity for selection that was due to sexual selection, estimated using both mate numbers and offspring numbers, was 9% and 23% respectively. Thus, we further reduced our estimate of the opportunity for post-copulatory sexual selection in D. primitivus to less than 10% of the total opportunity for selection (0.37 of 0.09 and 0.23 = 0.03 and 0.09). Our results provide the first estimate of the maximum possible strength of post-copulatory sexual selection in crustaceans using this approach.

  12. Molecular markers reveal only two mud crab species of genus Scylla (Brachyura: Portunidae) in Indian coastal waters.

    PubMed

    Mandal, Anup; Varkey, Mathews; Sobhanan, Sobha Pindaniyil; Mani, Anjali Kottayil; Gopalakrishnan, Achamveetil; Kumaran, Ganesh; Sethuramalingam, Arulraj; Srinivasan, Pandiarajan; Samraj, Yohannan Chellema Thampi

    2014-08-01

    The taxonomic ambiguity of the Indian mud crab (genus Scylla de Hann 1833) is still a cause of concern as several papers have been published with misleading identification. This is the first attempt to resolve the taxonomic uncertainty of the mud crab commonly available in Indian coastal waters using molecular genetic markers (ITS-1 and sequencing of COI gene) combined with traditional morphometry. Additionally, we developed a PCR method by which Indian mud crab species can be identified rapidly and effectively. The results clearly indicate that the green morph of the Indian mud crab is Scylla serrata and the brown morph is S. olivacea. The S. serrata commonly mentioned in the literature from India is S. olivacea; the S. tranquebarica noted by many Indian researchers should belong to S. serrata. Caution should be taken when interpreting or implementing the biological, molecular, and aquaculture data in the literature.

  13. A new species of Malayopotamon Bott, 1968 (Crustacea: Decapoda: Brachyura: Potamidae), a freshwater crab from northern Sumatra, Indonesia.

    PubMed

    Ng, Peter K L

    2014-02-28

    A new species of potamid freshwater crab, Malayopotamon weh sp. nov., is described from the island of Pulau Weh off northern Sumatra, Indonesia. The species superficially resembles three Sumatran species: M. batak Ng & Wowor, 1991, M. tobaense (Bott, 1968), and M. turgeo Ng & Tan, 1999, but can easily be distinguished by various carapace as well as gonopod characters.

  14. Cebudonus poppeorum, a new genus and new species of eumedonine crab (Crustacea: Decapoda: Brachyura: Pilumnidae) from the Philippines.

    PubMed

    Ng, Peter K L

    2014-06-12

    A new genus and new species of eumedonine crab, Cebudonus poppeorum, is described from the central Philippines. Superficially similar to Eumedonus H. Milne Edwards, 1834, Gonatonotus White, 1847, Zebrida White, 1847, Zebridonus Chia, Ng & Castro, 1995, and Tiaramedon Chia & Ng, 1998, Cebudonus n. gen. is easily characterised by possessing two long pseudorostral spines, a gently convex and unarmed dorsal carapace surface, elongated chelipeds that have the chela and merus unarmed and not cristate, elongated and slender ambulatory legs in which the merus is not cristate, a relatively narrow anterior male thoracic sternum, and a proportionately broader male abdomen. The general structure and colour pattern (with longitudinal stripes) suggests Cebudonus n. gen. is an obligate symbiont with echinoids.

  15. Taxonomy and ecology of the Cape Town Spider Crab, Macropodia falcifera (Stimpson, 1858) (Crustacea: Decapoda: Brachyura: Inachidae).

    PubMed

    Ng, Peter K L; Richer De Forges, Bertrand; Jones, Georgina

    2013-01-01

    The nomenclature and taxonomy of the Cape Town Spider Crab, Macropodia falcifera Stimpson, 1858, is treated. The species is rediagnosed and figured, and its ecology discussed. A key is also provided of the Indo-West Pacific species of Macropodia.

  16. Terrathelphusa secula, a new species of semiterrestrial freshwater crab (Crustacea: Brachyura: Gecarcinucidae) from Sabah, East Malaysia, Borneo.

    PubMed

    Ng, Peter K L; Tan, Leo W H

    2015-08-28

    A new species of semiterrestrial gecarcinucid freshwater crab, Terrathelphusa secula, is described from Danum Valley in Sabah, East Malaysia, eastern Borneo. In the form of its carapace, third maxilliped, and male second gonopod, it most closely resembles T. ovis Ng, 1997, and T. telur Ng, 1997, from eastern Sarawak and Brunei, respectively. It differs markedly from these and other congeners in its proportionately much wider carapace, and a male first gonopod that is strongly curved and sickle-shaped.

  17. Reproductive biology of the Suez Canal spider crab Schizophrys aspera (H. Milne Edwards, 1834: Crustacea: Brachyura: Majidae).

    PubMed

    El-Serehy, Hamed A; Al-Rasheid, Khaled A; Ibrahim, Nesreen K; Al-Misned, Fahad A

    2015-11-01

    A reproductive biology study of the spider crab Schizophrys aspera (H. Milne Edwards, 1834) was conducted in the Suez Canal from July 2012 to June 2013. The annual sex ratio (Male:Female) of S. aspera was female biased with values of 1:1.25. Out of the four ovarian development stages of this crab, two stages were observed in the Suez Canal throughout the whole year. The ovigerous crab's carapace width varied from 28 to 52 mm. This crab species can spawn during most of the year in the canal water, with a peak during late spring and early winter. The fecundity of ovigerous females ranged between 2349 and 13600 eggs with a mean of 5494 ± 1486 eggs. Female crabs that reached sexual maturity exhibited a minimum carapace width varying between 22 and 46 mm, and fifty percentage of all ovigerous females showed a carapace width of 36 mm.

  18. Effect of melatonin in the antioxidant defense system in the locomotor muscles of the estuarine crab Neohelice granulata (Decapoda, Brachyura).

    PubMed

    Geihs, Márcio Alberto; Vargas, Marcelo Alves; Maciel, Fábio Everton; Caldas, Sergiane Souza; Cruz, Bruno Pinto; Primel, Ednei Gilberto; Monserrat, José Maria; Nery, Luiz Eduardo Maia

    2010-03-01

    In vertebrates, many studies verified different effects of melatonin in the antioxidant defense system (ADS). In crustaceans, few studies have been conducted to verify this possibility. We verified the melatonin effects in the crab Neohelice granulata using low (0.002 and 0.02 pmol/crab) and high (2.0 and 20.0 pmol/crab) melatonin dosages in short-term (0.5h) and long-term (9.5h) experiments. We analyzed the antioxidant capacity against peroxyl radicals (ACAP), reactive oxygen species (ROS) concentration, levels of by products of lipid peroxidation (LPO), oxygen consumption (VO(2)), the activity of glutamate cysteine ligase (gamma-GCL) and catalase (CAT) and glutathione content (GSH). Finally, the effects of exogenous melatonin were verified in terms of melatonin and N(1)-acetyl-N(2)-formyl-5-methoxykynuramine (AFMK) content in the muscles of N. granulata. In short-term experiment and low dosages, melatonin increased the VO(2), gamma-GCL activity and GSH content (p<0.05) and decreased melatonin content (p<0.05) without effects in ROS, ACAP and LPO (p>0.05). Possibly, melatonin is acting in the ADS increasing its efficiency and/or acting in mitochondrial activity and/or through signaling muscles to increase its consumption. AFMK was only detected in the eyestalk and cerebroid ganglia. In high dosages melatonin effects decreased, possibly by the desensitization of their receptors. In long-term experiment, melatonin decreased ACAP (p<0.05), and CAT activity (p<0.05) in low dosages. In high dosages melatonin reduced VO(2) (p<0.05) and increased ACAP (p<0.05), possibly stimulating others components of the ADS. In conclusion, melatonin in the locomotor muscles of N. granulata affects the antioxidant/pro-oxidant balance in a time and dosage dependent manner.

  19. Effects of metal contamination in situ on osmoregulation and oxygen consumption in the mudflat fiddler crab Uca rapax (Ocypodidae, Brachyura).

    PubMed

    Capparelli, Mariana V; Abessa, Denis M; McNamara, John C

    2016-01-01

    The contamination of estuaries by metals can impose additional stresses on estuarine species, which may exhibit a limited capability to adjust their regulatory processes and maintain physiological homeostasis. The mudflat fiddler crab Uca rapax is a typical estuarine crab, abundant in both pristine and contaminated areas along the Atlantic coast of Brazil. This study evaluates osmotic and ionic regulatory ability and gill Na(+)/K(+)-ATPase activity in different salinities (<0.5, 25 and 60‰ S) and oxygen consumption rates at different temperatures (15, 25 and 35°C) in U. rapax collected from localities along the coast of São Paulo State showing different histories of metal contamination (most contaminated Ilha Diana, Santos>Rio Itapanhaú, Bertioga>Picinguaba, Ubatuba [pristine reference site]). Our findings show that the contamination of U. rapax by metals in situ leads to bioaccumulation and induces biochemical and physiological changes compared to crabs from the pristine locality. U. rapax from the contaminated sites exhibit stronger hyper- and hypo-osmotic regulatory abilities and show greater gill Na(+)/K(+)-ATPase activities than crabs from the pristine site, revealing that the underlying biochemical machinery can maintain systemic physiological processes functioning well. However, oxygen consumption, particularly at elevated temperatures, decreases in crabs showing high bioaccumulation titers but increases in crabs with low/moderate bioaccumulation levels. These data show that U. rapax chronically contaminated in situ exhibits compensatory biochemical and physiological adjustments, and reveal the importance of studies on organisms exposed to metals in situ, particularly estuarine invertebrates subject to frequent changes in natural environmental parameters like salinity and temperature.

  20. Complete sequence and characterization of mitochondrial genome in the swimming crab Portunus sanguinolentus (Herbst, 1783) (Decapoda, Brachyura, Portunidae).

    PubMed

    Meng, Xianliang; Jia, Fulong; Zhang, Xiaohui; Liu, Ping; Li, Jian

    2016-07-01

    The three-spot swimming crab Portunus sanguinolentus (Herbst, 1783) is a commercially important fishery species, widely distributed in the Indo-Pacific region. In this study, we present the complete mitochondrial genome of P. sanguinolentus. The genome is 16 027 bp in length with circular organization, encoding the standard set of 13 protein-coding genes, 22 tRNA genes, and two rRNA genes. The overall A + T content is 65.60%, which is lower than that of its congeneric species Portunus pelagicus and Portunus trituberculatus. The mitogenome carries 1254 bp of intergenic region constituting 7.82% of the genome, and six pairs of overlapping genes with the overlap size from 1 to 7 bp. The complete mitogenome sequence information of P. sanguinolentus would provide useful data for further studies on population genetics and molecular systematics.

  1. Internal anatomy and ultrastructure of the male reproductive system of the spider crab Maja brachydactyla (Decapoda: Brachyura).

    PubMed

    Simeó, C G; Ribes, E; Rotllant, G

    2009-10-01

    The morphology and function of the male reproductive system in the spider crab Maja brachydactyla, an important commercial species, is described using light and electron microscopy. The reproductive system follows the pattern found among brachyuran with several peculiarities. The testis, known as tubular testis, consists of a single, highly coiled seminiferous tubule divided all along by an inner epithelium into germinal, transformation, and evacuation zones, each playing a different role during spermatogenesis. The vas deferens (VD) presents diverticula increasing in number and size towards the median VD, where spermatophores are stored. The inner monostratified epithelium exocytoses the materials involved in the spermatophore wall formation (named substance I and II) and spermatophore storage in the anterior and median VD, respectively. A large accessory gland is attached to the posterior VD, and its secretions are released as granules in apocrine secretion, and stored in the lumen of the diverticula as seminal fluids. A striated musculature may contribute to the formation and movement of spermatophores and seminal fluids along the VD. The ejaculatory duct (ED) shows a multilayered musculature and a nonsecretory pseudostratified epithelium, and extrudes the reproductive products towards the gonopores. A tissue attached to the ED is identified as the androgenic gland.

  2. On the morphology of the central nervous system in larval stages of Carcinus maenas L. (Decapoda, Brachyura)

    NASA Astrophysics Data System (ADS)

    Harzsch, S.; Dawirs, R. R.

    1993-02-01

    We investigated the morphology of the central nervous system throughout the larval development of Carcinus maenas. For that purpose single larvae were reared in the laboratory from hatching through metamorphosis. Complete series of whole mout semithin sections were obtained from individuals of all successive larval stages and analysed with a light microscope. Morphological feature and spatial arrangement of discernable neural cell clusters, fibre tracts and neuropile are described and compared with the adult pattern. We found that most of the morphological features characterizing the adult nervous system are already present in the zoea-1. Nevertheless, there are marked differences with respect to the arrangement of nerve cell bodies, organization of cerebral neuropile, and disposition of ganglia in the ventral nerve cord. It appears that complexity of the central nervous neuropile is selectively altered during postmetamorphotic development, probably reflecting adaptive changes of sensory-motor integration in response to behavioural maturation. In contrast, during larval development there was little change in the overall structural organization of the central nervous system despite some considerable growth. However, the transition from zoea-4 to megalopa brings about multiple fundamental changes in larval morphology and behavioural pattern. Since central nervous integration should properly adapt to the altered behavioural repertoire of the megalopa, it seems necessary to ask in which respect synaptic rearrangement might characterize development of the central nervous system.

  3. Yuebeipotamon calciatile, a new genus and new species of freshwater crab from southern China (Crustacea, Decapoda, Brachyura, Potamidae)

    PubMed Central

    Huang, Chao; Shih, Hsi-Te; Mao, Si Ying

    2016-01-01

    Abstract A new genus and species of freshwater crab, Yuebeipotamon calciatile gen. n., sp. n., is described from southern China. While the carapace features are superficially similar to species of Sinopotamon Bott, 1967, Longpotamon Shih, Huang & Ng, 2016, and Tenuilapotamon Dai, Song, Li, Chen, Wang & Hu, 1984, the new genus possesses a distinctive combination of carapace, ambulatory leg, male thoracic sternal, male abdominal, and gonopodal characters that distinguish it from these and other genera. Molecular evidence derived from the mitochondrial 16S rDNA supports the establishment of a new genus.

  4. A new species of Fizesereneia Takeda & Tamura, 1980 (Crustacea: Brachyura: Cryptochiridae) from the Red Sea and Oman.

    PubMed

    Van Der Meij, Sancia E T; Berumen, Michael L; Paulay, Gustav

    2015-01-01

    A new species of cryptochirid crab, Fizesereneia panda van der Meij, is described and illustrated based on specimens collected from the scleractinian corals Lobophyllia cf. hemprichii and L. cf. corymbosa from the Farasan Banks, Farasan Islands, and the reefs off Thuwal in the Saudi Arabian Red Sea, and from Symphyllia recta from reefs in the Gulf of Oman. This is the second cryptochirid species with the Red Sea as type locality. It can be separated from its congeners by the subrectangular carapace, raised midline and the complete division of the carapace depressions, and reddish black colour pattern of these concavities in live specimens. This new species is the seventh assigned to Fizesereneia. A DNA barcode for the new species has been deposited in GenBank. PMID:25781848

  5. Two new species of Palapedia Ng, 1993 (Crustacea, Decapoda, Brachyura,
    Xanthidae) from the Persian Gulf.

    PubMed

    Naderloo, Reza

    2015-01-01

    Two new species of Palapedia Ng, 1993, are described based on material collected from Abu-Musa Island, Persian Gulf during the present study, from Bahrain by the 1937/38 Danish Expedition, and from the Saudi Arabian coast of the Persian Gulf by Michael Apel in 1992-1995. Palapedia persica n. sp. is distinguishable from its congeners by having distinctly large denticles on the upper margin of the palm and fingers of the chelae and anterior margin of the ambulatory dactyli, and by the markedly sickle-shaped dactylus of the ambulatory legs. Palapedia apeli n. sp. is similar to P. valentini Ng, 1993, and P. nitida (Stimpson, 1858), by having relatively smooth appendages. PMID:26250272

  6. A new species of Paracleistostoma De Man, 1895 (Crustacea: Decapoda: Brachyura: Camptandriidae) from Haikou, Hainan Province, China.

    PubMed

    Liu, Han Lun; Huang, Jian Rong

    2016-01-01

    A new species of Paracleistostoma De Man, 1895, P. meilanense n. sp. is reported from mangroves forests in Haikou, Hainan Province, China. The new species inhabits mud burrows in the upper intertidal zone and is sympatric with P. tomentosa Yang & Sun, 1993, and P. depressum De Man, 1895. The slender chelipeds as well as the characteristic morphology of the male first pleopod easily distinguishes the species from congeners. PMID:27395229

  7. Local knowledge of traditional fishermen on economically important crabs (Decapoda: Brachyura) in the city of Conde, Bahia State, Northeastern Brazil

    PubMed Central

    2012-01-01

    Background This article records the traditional knowledge of crab gatherers in the city of Conde, in the North Coast Region of Bahia State, Northeastern Brazil. Methods Data on biological and ecological aspects of economically important brachyuran crustaceans have been obtained from semi-structured interviews and in loco observations conducted from September 2007 to December 2009. A total of 57 fishermen of both genders, aged between 10 and 78 years have been interviewed (individually or collectively) in different contexts; interviewees were asked about aspects such as external morphology, life cycle, trophic ecology, and spatial and temporal distribution of the major economically important brachyuran crustaceans in the region. Seven fishing communities were visited: Siribinha, Sítio do Conde, Poças, Ilha das Ostras, Cobó, Buri and Sempre Viva. Data were analyzed by comparing the information provided by participants with those from the specialized academic literature. Results The results show that artisanal fishermen have a wide ranging and well-grounded knowledge on the ecological and biological aspects of crustaceans. Crab gatherers of Conde know about growth and reproductive behavior of the animals they interact with, especially with regard to the three major biological aspects: “molt”, “walking dance” and “spawning”. Conclusion This knowledge constitutes an important source of information that should be considered in studies of management and sustainable use of fishery resources in the North Coast Region of Bahia State. PMID:22449069

  8. Yuebeipotamon calciatile, a new genus and new species of freshwater crab from southern China (Crustacea, Decapoda, Brachyura, Potamidae)

    PubMed Central

    Huang, Chao; Shih, Hsi-Te; Mao, Si Ying

    2016-01-01

    Abstract A new genus and species of freshwater crab, Yuebeipotamon calciatile gen. n., sp. n., is described from southern China. While the carapace features are superficially similar to species of Sinopotamon Bott, 1967, Longpotamon Shih, Huang & Ng, 2016, and Tenuilapotamon Dai, Song, Li, Chen, Wang & Hu, 1984, the new genus possesses a distinctive combination of carapace, ambulatory leg, male thoracic sternal, male abdominal, and gonopodal characters that distinguish it from these and other genera. Molecular evidence derived from the mitochondrial 16S rDNA supports the establishment of a new genus. PMID:27667941

  9. Integrative Taxonomic Study of the Purse Crab Genus Persephona Leach, 1817 (Brachyura: Leucosiidae): Combining Morphology and Molecular Data

    PubMed Central

    Magalhães, Tatiana; Robles, Rafael; Felder, Darryl L.

    2016-01-01

    Marine crabs of the genus Persephona Leach, 1817 are restricted to American waters of the western Atlantic and eastern Pacific Oceans. Subfamilial assignment of this taxon has varied between authors and its species composition remain in question. We conducted a comparative study based on morphology and molecular phylogenetics for all ten recognized species of Persephona, along with Iliacantha hancocki. We tested whether Persephona finneganae, P. lichtensteinii, and P. crinita represent a single species as suggested by some authors; whether specimens identified as P. punctata, P. mediterranea, and P. aquilonaris warrant treatment as separate species; and whether I. hancocki should be regarded as a junior synonym of P. subovata. Diagnostic morphological characters (of the carapace, chelipeds, and third maxillipeds) were used along with gonopod (male first pleopod 1) features and live coloration. The 16S rRNA and the Cytochrome Oxidase I (COI) (DNA barcoding) mitochondrial genes were used as molecular markers. Both morphological and molecular analyses revealed that putative specimens of P. crinita from Brazil and those assigned to P. finneganae were no different from specimens presently assignable to P. lichtensteinii. P. finneganae is regarded as a junior synonym of P. lichtensteinii, and we apply P. crinita only to specimens we examined from the Gulf of Mexico. Specimens from Brazil previously reported as P. crinita are herewith concluded to represent P. lichtensteinii. Additionally, P. townsendi is a junior synonym of P. orbicularis, Iliacantha hancocki is concluded to be a junior synonym of P. subovata, while P. aquilonaris and P. mediterranea are found to represent separate species. On the basis of our revisions, eight species of Persephona are considered valid, and the reported distribution for P. crinita is restricted. PMID:27099956

  10. Fatty acids dynamics during embryonic development in genus Uca (Brachyura: Ocypodidae), from the mangroves of Inhaca Island, Mozambique

    NASA Astrophysics Data System (ADS)

    Torres, Paulo; Penha-Lopes, Gil; Narciso, Luís; Macia, Adriano; Paula, José

    2008-11-01

    Variations in egg volume and fatty acid (FA) content through embryogenesis were evaluated in Uca species from Inhaca island, Mozambique. Egg volume increased 96.1%, 93.3%, 84.2%, 92.9%, 96.3%, respectively, in Uca annulipes, Uca inversa, Uca urvillei, Uca chlorophthalmus and Uca vocans ( p < 0.05). Fatty acid content decreased through embryogenesis, showing its importance as fuel during embryonic development. Major fatty acids were 16:0, 18:0, 16:1 n-7, 18:1 n-9, 18:1 n-7, 18:2 n-6, 20:5 n-3 and 20:4 n-3. Unsaturated fatty acids (UFA) and saturated fatty acids (SFA) were used up at a similar rate for U. annulipes and U. inversa contrarily to the other three species. Within the UFA, MUFA were more consumed than PUFA for all species except U. chlorophthalmus. The high values detected for fatty acid trophic markers (essential C 18 and C 20 PUFAs) and odd-numbered fatty acid suggest that Uca species occupy medium trophic level, primarily omnivores and scavengers/detritivores consuming algae common in the intertidal habitats. The fatty acid consumption pattern during embryonic development was essentially similar between species with some variation as expected, as FA content varies within species mainly due to female feeding ecology, nutritional and physiological conditions, differential demands on resource allocation and geographic and seasonal variations in embryonic development.

  11. Integrative Taxonomic Study of the Purse Crab Genus Persephona Leach, 1817 (Brachyura: Leucosiidae): Combining Morphology and Molecular Data.

    PubMed

    Magalhães, Tatiana; Robles, Rafael; Felder, Darryl L; Mantelatto, Fernando L

    2016-01-01

    Marine crabs of the genus Persephona Leach, 1817 are restricted to American waters of the western Atlantic and eastern Pacific Oceans. Subfamilial assignment of this taxon has varied between authors and its species composition remain in question. We conducted a comparative study based on morphology and molecular phylogenetics for all ten recognized species of Persephona, along with Iliacantha hancocki. We tested whether Persephona finneganae, P. lichtensteinii, and P. crinita represent a single species as suggested by some authors; whether specimens identified as P. punctata, P. mediterranea, and P. aquilonaris warrant treatment as separate species; and whether I. hancocki should be regarded as a junior synonym of P. subovata. Diagnostic morphological characters (of the carapace, chelipeds, and third maxillipeds) were used along with gonopod (male first pleopod 1) features and live coloration. The 16S rRNA and the Cytochrome Oxidase I (COI) (DNA barcoding) mitochondrial genes were used as molecular markers. Both morphological and molecular analyses revealed that putative specimens of P. crinita from Brazil and those assigned to P. finneganae were no different from specimens presently assignable to P. lichtensteinii. P. finneganae is regarded as a junior synonym of P. lichtensteinii, and we apply P. crinita only to specimens we examined from the Gulf of Mexico. Specimens from Brazil previously reported as P. crinita are herewith concluded to represent P. lichtensteinii. Additionally, P. townsendi is a junior synonym of P. orbicularis, Iliacantha hancocki is concluded to be a junior synonym of P. subovata, while P. aquilonaris and P. mediterranea are found to represent separate species. On the basis of our revisions, eight species of Persephona are considered valid, and the reported distribution for P. crinita is restricted. PMID:27099956

  12. The description of a new species of the Neotropical land crab genus Gecarcinus Leach, 1814 (Crustacea, Decapoda, Brachyura, Gecarcinidae)

    PubMed Central

    Perger, Robert; Wall, Adam

    2014-01-01

    Abstract In this contribution a new species of the land crab genus Gecarcinus Leach, 1814, from the Neotropical Pacific coast of South America is described and illustrated. In addition to its unique body color, Gecarcinus nobilii sp. n. is distinguished from congeners by a distinctly wider carapace front and differences in the shape of the infraorbital margin. The new species is not isolated from Gecarcinus populations from the Pacific coast of Central America by an insurmountable geographic barrier. Considering the closure of the Panamanian Isthmus as a calibration point for morphological divergence between the trans-isthmian mainland populations of Gecarcinus, the virtual lack of morphological differentiation (other than color) between them and the distinctness of G. nobilii sp. n. suggests that G. nobilii sp. n. evolved from a common ancestor before the Isthmus closed. PMID:25152688

  13. A molecular method for the detection of sally lightfoot crab larvae (Grapsus grapsus, Brachyura, Grapsidae) in plankton samples

    PubMed Central

    Ströher, Patrícia R.; Firkowski, Carina R.; Freire, Andrea S.; Pie, Marcio R.

    2011-01-01

    The decapod Grapsus grapsus is commonly found on oceanic islands of the Pacific and Atlantic coasts of the Americas. In this study, a simple, quick and reliable method for detecting its larvae in plankton samples is described, which makes it ideal for large-scale studies of larval dispersal patterns in the species. PMID:21931530

  14. Digestive strategies in two species of leaf-eating land crabs (Brachyura: Gecarcinidae) in a rain forest.

    PubMed

    Greenaway, P; Raghaven, S

    1998-01-01

    Two species of herbivorous land crabs from Christmas Island, Cardisoma hirtipes and Gecarcoidea natalis, overlap in both diet and distribution. This study compared the dietary preferences and digestive capabilities of these two species on a diet of leaf litter to establish the digestive strategies each adopts and the likely degree of competition for food. C. hirtipes preferred green to yellow or brown leaves of Ficus macrophylla in short-term food-choice experiments. Brown leaves were least favoured. G. natalis showed no preference for the different leaf types and in the field ate chiefly brown and decomposing leaf litter. When fed green leaves, C. hirtipes had a low food intake (4.5+/-0.36 g kg-1 d-1) and a short retention time for food, and the readily digestible components of the diet constituted greater than 84% of the dry matter assimilated. When fed brown leaves, the intake was increased 3.3 times, but retention time remained short, and assimilation coefficients for all nutrients were low. The readily digestible fraction of the diet made the chief contribution to dry matter assimilation (69%), and hemicellulose (19%) and cellulose (21%) were also significantly used. This pattern of food intake and assimilation contrasts with that for G. natalis, which had a low intake of brown leaves and a longer retention time associated with higher nutrient assimilation, particularly of complex polysaccharides. It is suggested that through their feeding preferences and habits, these two sympatric species use opposite ends of the leaf litter quality spectrum on Christmas Island.

  15. Characterization and sequence analysis of manganese superoxide dismutases from Brachyura (Crustacea: Decapoda): hydrothermal Bythograeidae versus littoral crabs.

    PubMed

    Marchand, J; Leignel, V; Moreau, B; Chénais, B

    2009-06-01

    Hydrothermal vent conditions are particular and organisms living in these environments may have developed detoxification mechanisms and/or genetic adaptations. In particular, physico-chemical conditions are thought to generate reactive oxygen species, highly toxic for organisms. The enzyme superoxide dismutase constitutes the first line of defense against oxidative damage. To improve our understanding of the environmental impacts exerted on the vent organisms, we have characterized the two manganese superoxide dismutase cDNAs (mitochondrial: mMnSOD and cytoplasmic: cMnSOD) of three members of the Bythograeidae (Bythograea thermydron, Cyanagraea praedator and Segonzacia mesatlantica), the only endemic crab family living in hydrothermal vents. In comparison, the isolation of manganese superoxide dismutase cDNAs was also carried out in several littoral crab families. MnSOD signatures were found in both sequences from each species studied, as well as different residues involved in metal coordination and protein activity. The phylogenetic analysis performed confirms the probable ancient duplication that gave rise to the two MnSODs (cMnSOD and mMnSOD). This study describes two potential distinct mMnSOD isoforms presenting particular peptide signals. Nevertheless, no sequence particularity that could support the hypothesis of a genetic adaptation was found in Bythograeidae's MnSODs compared to the other sequences. The mRNA expression analysis performed by real-time PCR on B. thermydron and S. mesatlantica compared to Cancer pagurus and Necora puber revealed a higher cMnSOD and mMnSOD mRNA expression in hydrothermal crabs compared to littoral crabs.

  16. On a collection of calappid crabs (Crustacea: Decapoda: Brachyura) from Fiji, with a description of a new species of Mursia.

    PubMed

    Galil, Bella S

    2013-11-07

    Seven species of calappid crabs were identified from material collected during four IRD-MNHN expeditions conducted in 1998 and 1999 in shallow and deep waters off Fiji. Six species are reported for the first time from the islands. One new species, Mursia murimura n. sp., is described and illustrated. The new species differs from the closely related M. diwata Galil & Takeda, 2004, with which it shares a stout, distally auriculated first male pleopod, by possessing much longer lateral carapacial and cheliped spines.

  17. Redescriptions of three species of freshwater crabs from the Democratic Republic of Congo, Central Africa (Brachyura: Potamoidea: Potamonautidae).

    PubMed

    Cumberlidge, Neil

    2015-06-16

    The taxonomy of three species of freshwater crabs from the Upper Congo River in the Democratic Republic of Congo, Potamonautes congoensis (Rathbun, 1921), P. langi (Rathbun, 1921), and P. stanleyensis (Rathbun, 1921), is revised based on examination of the holotypes. Updated diagnoses, illustrations, and distribution maps are provided for these species, and their conservation status is discussed.

  18. Out of the Sichuan Basin: Rapid species diversification of the freshwater crabs in Sinopotamon (Decapoda: Brachyura: Potamidae) endemic to China.

    PubMed

    Ji, Yongkun; Sun, Yufang; Gao, Wei; Chu, Kelin; Wang, Ruicong; Zhao, Qiang; Sun, Hongying

    2016-07-01

    Sinopotamon Bott, 1967 is the most speciose and widely distributed freshwater crab genus in East Asia. Our extensive sampling includes about 76% of the known Sinopotamon taxa, and nearly covers its entire distribution area. Based on mitochondrial cytochrome oxidase I (COI) and 16S rRNA, as well as nuclear 28S rRNA and histone H3, we reconstructed the Sinopotamon phylogeny using maximum likelihood and Bayesian approaches. The divergence time was estimated and multiple methods were used to conduct diversification analyses. The ancestral geographic distribution and character state were reconstructed. Three main clades (Clades I, II and III) that roughly correspond to their main geographic distribution ranges were recovered. Our results challenge the current view of the four major species groups based on the morphological differences in the male first gonopod (G1). The most recent common ancestor of Sinopotamon most likely originated from the Sichuan Basin and surrounding mountains (SBSM) and subsequently dispersed throughout central and eastern China. The exceptionally rapid, recent diversification was detected in Clade II. The high incidence of species-level non-monophyly found in Clade II can be explained by recent rapid radiation. Climatic changes, morphological innovations, range expansion and geographical heterogeneity may all contribute to the diversification in Sinopotamon. This study contributes to our knowledge on diversification of freshwater benthic macro-invertebrates in the East Asian inland ecosystem.

  19. Two new species of freshwater crabs of the genus Sundathelphusa Bott, 1969 (Decapoda: Brachyura: Gecarcinucidae) from caves in Luzon, Philippines.

    PubMed

    Husana, Daniel Edison M; Yamamuro, Masumi; Ng, Peter K L

    2014-06-17

    Two cave species of Sundathelphusa are described from a karst area in southern Luzon, Philippines. Both species have elongated ambulatory legs but the eyes and carapace pigmentation are well developed, indicating they are not troglobites. Sundathelphusa danae sp. nov. is superficially more similar to S. longipes (Balss, 1937) than to S. holthuisi Ng, 2010, which was described from the same locality. Sundathelphusa danae sp. nov. is distinguished from its closest congeners by its strongly convex anterolateral margin, more swollen branchial regions, possession of a complete frontal median triangle, laterally inflated subbranchial region and the more slender ambulatory legs. Sundathelphusa vienae sp. nov. is unusual among Sundathelphusa species in that its carapace is more quadrate, with the slender and almost straight male first gonopod tapered and having a pointed terminal segment. 

  20. New retroplumid crabs (Crustacea, Brachyura, Retroplumidae Gill, 1894) from the Eocene of Huesca (Aragón, Spain).

    PubMed

    Artal, Pedro; Van Bakel, Barry W M; Fraaije, René H B; Jagt, John W M

    2013-01-01

    Two new brachyurans assignable to the family Retroplumidae Gill, 1894, Serrablopluma diminuta n. gen., n. sp., and Gaudipluma bacamortensis n. gen., n. sp., from the Eocene of northern Spain (Huesca, Aragón), substantially enlarge our current knowledge of the morphological diversity of the family. The material, with well-preserved ventral surfaces, permits the erection of two new genera that can be referred to the family with confidence on the basis of the general carapace shape, narrow front, a reduced last pair of pereiopods and characteristic thoracic sternum (broad, trapezoidal sternites 3, 4, subrectangular sternites 5-7, sternite 8 conspicuously reduced and inclined). Serrablopluma diminuta n. gen., n. sp. co-occurs with two other retroplumids in the most diverse fossil assemblage of that family known to date.

  1. The leucosiid crabs described by Thomas Bell in 1855: original description and dates of publication (Crustacea: Decapoda: Brachyura).

    PubMed

    Lee, B Y; Low, Martyne E Y

    2013-01-01

    Thomas Bell proposed 37 species- and 5 genus-group names for the Leucosiidae in four publications that appeared in 1855. The version appearing in the Proceedings of the Linnean Society of London is the earliest of these publications and the first available description of these taxa.

  2. Reproductive Biology of the Blue Swimming Crab Portunus pelagicus (Brachyura: Portunidae) in East Lampung Waters, Indonesia: Fecundity and Reproductive Potential.

    PubMed

    Zairion; Wardiatno, Yusli; Boer, Mennofatria; Fahrudin, Achmad

    2015-04-01

    The blue swimming crab Portunus pelagicus is an important catch species for many coastal villages along the Java Sea coastline, but little is known regarding its reproductive biology or stock status. We examined the batch fecundity of female crabs that were collected monthly at landing sites from June 2011 to May 2012, calculated the relationships with body size, egg mass and month of the year, and determined the size at which females became potentially reproductive in the population inhabiting East Lampung waters (western Java Sea). Fecundity values ranged from 229,468 to 2,236,355 (mean = 926,638±30,975 [±SE]). The fecundity was positively and linearly correlated with carapace width (CW), but the relationships with body weight and egg mass were best described by logarithmic regression. A peaked, temporally cyclical pattern in fecundity was observed, with a peak period that was significantly different (F = 226.36; df = 22, p<0.05) from March to May 2012. Reproductive females were within the 111.0-155.9 mm CW size range; significantly higher reproductive potentials (F = 14.59; df = 30, p<0.05) were found in females within the 126.0-130.9 mm CW size group. The current minimum legal size (MLS = 100 mm CW) is not an appropriate limit reference point, and a precautionary approach is needed for a sustainable harvesting strategy. Resetting the MLS to 115 mm CW would potentially provide adequate protection for spawning females and increase total egg production, thereby maintaining population productivity and enhancing resilience in the face of current fishing pressures.

  3. Histological and histochemical analysis of the gonadal development of males and females of Armases rubripes (Rathbun 1897) (Crustacea, Brachyura, Sesarmidae).

    PubMed

    Santos, C M; Lima, G V; Nascimento, A A; Sales, A; Oshiro, L M Y

    2009-02-01

    The objective of this study was to provide information on the histological characteristics of the gonads of male and female Armases rubripes crabs, and to try to establish a relationship between the microscopic and macroscopic stages previously identified. Thirty-six crabs were collected by hand between February 2003 and January 2004 in banks of Spartina alterniflora on Sahy Beach in Mangaratiba, Rio de Janeiro state, Brazil. The histological analysis of the ovaries of A. rubripes demonstrated a gradual process of development of the oocytes. According to their cellular characteristics, five types of cells were distinguished: oogonia, oocyte I, oocyte II, oocyte III and oocyte IV. The ovaries showed four stages during gonadal activity: stage I (rudimentary), stage II (developing or maturing), stage III (developed or mature) and stage IV (resting). The results of the histochemical analyses showed that the ovaries vary according to the gonad development stage. The histological aspect of one section of the male gonad was always the same in all of the seminiferous tubules, where the lumen of these tubules always contained spermatozoa and/or spermatids. It was not possible to characterize the three stages of gonad development in the males. This agrees with previous reports in the literature. However, in the females there was a relationship between the gonad stages distinguished macroscopically and the results obtained through the histological and histochemical analysis, due to the presence of different cell types, as well as the lysis process and reabsorption of the oocytes in spent females.

  4. Histology and histochemistry of the intermoult integument in the ghost crab Ocypoda platytarsis (Milne-Edwards) (Crustacea: Brachyura).

    PubMed

    Devi, K R; Shyamasundari, K; Rao, K H

    1991-01-01

    The histological and histochemical aspects of the integument have been described and discussed during the intermoult period of Ocypoda platytarsis. Histological observations revealed that the cuticle comprises of four layers namely epicuticle, exocuticle, endocuticle and membranous layers. Various types of cells in the subepidermal tissue have also been elucidated.

  5. Parathelphusa pardus, a new species of lowland freshwater crab from swamps in central Sumatra, Indonesia (Crustacea: Brachyura: Gecarcinucidae).

    PubMed

    Ng, Peter K L; Riady, Rikhi; Windarti, Windarti

    2016-01-01

    A new species of gecarcinucid freshwater crab of the genus Parathelphusa H. Milne Edwards, 1853, is described from freshwater swamp habitats in Pekanbaru, Riau Province, in central-eastern Sumatra, Indonesia. Parathelphusa pardus sp. nov., has a very distinctive colour pattern, and in this respect, resembles P. maindroni (Rathbun, 1902) from Sumatra and Peninsular Malaysia; P. batamensis Ng, 1992, from Batam Island, Indonesia; P. reticulata Ng, 1990, from Singapore; and P. oxygona Nobili, 1901, from western Sarawak. It can be distinguished from these species and congeners by a suite of carapace, ambulatory leg, thoracic sternal and most importantly, male first gonopod characters. PMID:27394277

  6. A new species of Fizesereneia Takeda & Tamura, 1980 (Crustacea: Brachyura: Cryptochiridae) from the Red Sea and Oman.

    PubMed

    Van Der Meij, Sancia E T; Berumen, Michael L; Paulay, Gustav

    2015-03-16

    A new species of cryptochirid crab, Fizesereneia panda van der Meij, is described and illustrated based on specimens collected from the scleractinian corals Lobophyllia cf. hemprichii and L. cf. corymbosa from the Farasan Banks, Farasan Islands, and the reefs off Thuwal in the Saudi Arabian Red Sea, and from Symphyllia recta from reefs in the Gulf of Oman. This is the second cryptochirid species with the Red Sea as type locality. It can be separated from its congeners by the subrectangular carapace, raised midline and the complete division of the carapace depressions, and reddish black colour pattern of these concavities in live specimens. This new species is the seventh assigned to Fizesereneia. A DNA barcode for the new species has been deposited in GenBank.

  7. Carcinoplax fasciata, a new species of deep-water goneplacid crab from southwestern India (Crustacea: Decapoda: Brachyura: Goneplacoidea).

    PubMed

    Ng, Peter K L; Kumar, Appukuttannair Biju

    2016-01-01

    A new species of Carcinoplax H. Milne Edwards, 1852 (family Goneplacidae) is described from southern India. Carcinoplax fasciata n. sp. is closest to C. specularis Rathbun, 1914, but can be distinguished by its different coloration in life as well as structures of the carapace surface, anterolateral armature, supraorbital margin, chela and male first gonopod. PMID:27515615

  8. A new gall crab species (Brachyura, Cryptochiridae) associated with the free-living coral Trachyphyllia geoffroyi (Scleractinia, Merulinidae)

    PubMed Central

    van der Meij, Sancia E.T.

    2015-01-01

    Abstract A new species of gall crab is described from the free-living stony coral Trachyphyllia geoffroyi. Specimens were collected during field work in Lembeh Strait (Indonesia) and off Kudat (Malaysian Borneo). This new species, here named Lithoscaptus semperi sp. n., is the ninth species assigned to the genus. It can be separated from its congeners by not having the internal orbital angle extending beyond the external orbital angle, and by the stout female P2 merus with prominent distomesial projection. In addition, the carapace surface appears smooth, despite having small tubercles on the anterior half, and is without noticeable spines, other than those on the frontal margin. The distinctive carapace pattern in life is a diagnostic character in male specimens. PMID:25987871

  9. Osmoregulation in the terrestrial Christmas Island red crab Gecarcoidea natalis (Brachyura: Gecarcinidae): modulation of branchial chloride uptake from the urine.

    PubMed

    Taylor, H H; Greenaway, P

    2002-10-01

    Crabs generally produce urine iso-osmotic to their haemolymph, but terrestrial crabs are able to vary the composition of their final excretory fluid (termed P) postrenally, in the branchial chambers. Regulatory aspects of branchial urine processing were investigated in the Christmas Island red crab Gecarcoidea natalis acclimated to drinking either freshwater (FW crabs) or 70% seawater (SW crabs). FW crabs released dilute P (mean [Cl(-)] 8.8 mmol l(-1)). Drinking 70% seawater caused the mean [Cl(-)] of the P to rise to 376 mmol l(-1) over 5 days, approaching the haemolymph [Cl(-)]. FW crabs with saline-perfused branchial chambers absorbed chloride at a high rate (10 mmol kg(-1) h(-1)), and haemolymph [Cl(-)] increased at approximately 20 mmol l(-1) h(-1). SW crabs exhibited elevated haemolymph osmolalities and ion concentrations and zero branchial chloride uptake. FW crabs that were salt-loaded by branchial chamber perfusion over several hours downregulated, and eventually ceased, chloride uptake. The rate of downregulation, but not the initial chloride flux, was dependent on initial haemolymph [Cl(-)]. Intravascular infusion of NaCl caused immediate reduction in branchial [Cl(-)] of 80%. Crabs ingested and regurgitated the perfusion saline, supporting suggestions that reingestion of urine could conserve water and ions. Dopamine upregulated branchial chloride transport in G. natalis. This is consistent with the ion-regulatory effects of dopamine in euryhaline marine brachyurans but contrasts with its inhibitory effects in the terrestrial anomuran Birgus latro. Dopamine increased the rate of urine release in FW crabs. Urine composition appears to be unimportant in ionic regulation, except in the case of magnesium, levels of which were elevated in the urine of SW crabs.

  10. A new species of Neoliomera Odhner, 1925, from the western Pacific, and the first record of N. demani Forest & Guinot, 1961, from Taiwan (Crustacea: Decapoda: Brachyura: Xanthidae).

    PubMed

    Ho, P-H; Ng, Peter K L

    2014-01-01

    A new species of a strikingly coloured xanthid crab of the genus Neoliomera Odhner, 1925, is described from coral reefs in Guam, Taiwan, and the Hawaiian Islands. The new species is allied to N. pubescens (H. Milne Edwards, 1834), and N. demani Forest & Guinot, 1961, but differs in the form of the carapace armature, frontal margin, structure of the chela, proportions of the ambulatory merus and the form of the male first gonopod. Neoliomera demani is also recorded from Taiwan for the first time and aspects of its taxonomy are discussed.

  11. Results of the global conservation assessment of the freshwater crabs (Brachyura, Pseudothelphusidae and Trichodactylidae): The Neotropical region, with an update on diversity.

    PubMed

    Cumberlidge, Neil; Alvarez, Fernando; Villalobos, Jose-Luis

    2014-01-01

    The freshwater crabs of the Neotropics comprise 311 species in two families (Pseudothelphusidae and Trichodactylidae) and one or both of these families are found in all of the countries in the Neotropical region (except for Chile and some of the Caribbean islands). Colombia (102 species, 81% endemic) and Mexico (67 species, 95% endemic) are the biodiversity hotspots of freshwater crab species richness and country-level endemism for this region. The results of the IUCN Red List conservation assessments show that 34% of pseudothelphusids and 10% of trichodactylids have an elevated risk of extinction, 29% of pseudothelphusids and 75% of trichodactylids are not at-risk (Least Concern), and although none are actually extinct, 56% of pseudothelphusids and 17% of trichodactylids are too poorly known to assess (Data Deficient). Colombia (14 species), Venezuela (7 species), Mexico (6 species), and Ecuador (5 species) are the countries with the highest number of threatened species of Neotropical freshwater crabs. The majority of threatened species are restricted-range semiterrestrial endemics living in habitats subjected to deforestation, alteration of drainage patterns, and pollution. This underlines the need to prioritize and develop conservation measures before species decline to levels from which they cannot recover. These results represent a baseline that can be used to design strategies to save threatened Neotropical species of freshwater crabs. PMID:25561834

  12. Seasonal dynamics of the density of the crab larvae (Decapoda: Brachyura et Anomura) in Minonosok Bay of Pos'eta Bay (Peter the Great Bay, Sea of Japan)

    NASA Astrophysics Data System (ADS)

    Grigoryeva, N. I.

    2013-03-01

    As the materials for this project, we used data on the distribution of the larvae of the Asian paddle crab Charybdis japonicus (A. Milne-Edwards, 1861); the spider crabs Hyas coarctatus ursinus (= Hyas ursinus) (Rathbun, 1924), Pugettia quadridens (de Haan, 1839), and Pisoides bidentatus (H. Milne-Edwards, 1873); the samurai crab Paradorippe granulata (= Dorippe granulata) (de Haan, 1841); the pea crab Pinnixa rathbuni (Sakai, 1934); and the porcelain crab Pachycheles stevensii (Stimpson, 1858) in Minonosok Bay of Pos'eta Bay obtained during 2000-2002 and in 2004. The planktonic samples were collected from the last third of May to September. The greatest density of the larvae was observed in May, mid-June, late June-early July, and late July-early August. The greatest densities of the crab larvae and the decapod larvae ranged from 20.4 to 48.2 and from 88.4 to 245.3 specimens/m3. The schedule of the crab larvae's occurrence in the plankton is provided for the first time. The distribution of the density showed pronounced patchiness.

  13. The enigmatic life history of the symbiotic crab Tunicotheres moseri (Crustacea, Brachyura, Pinnotheridae): implications for its mating system and population structure.

    PubMed

    Hernández, J E; Bolaños, J A; Palazón, J L; Hernández, G; Lira, C; Baeza, J Antonio

    2012-12-01

    Resource-monopolization theory predicts the adoption of a solitary habit in species using scarce, discrete, and small refuges. Life-history theory suggests that temporarily stable parental dwellings favor extended parental care in species that brood embryos. We tested these two predictions with the symbiotic crab Tunicotheres moseri. This species exhibits abbreviated development and inhabits the atrial chamber of the scarce, structurally simple, long-lived, and relatively small ascidian Phalusia nigra in the Caribbean. These host characteristics should favor a solitary habit and extended parental care (EPC) in T. moseri. As predicted, males and females of T. moseri inhabited ascidians solitarily with greater frequency than expected by chance alone. The male-female association pattern and reverse sexual dimorphism (males < females) additionally suggests a promiscuous "pure-search" mating system in T. moseri. Also in agreement with theoretical considerations, T. moseri displays EPC; in addition to embryos, females naturally retain larval stages, megalopae, and juveniles within their brooding pouches. This is the first record of EPC in a symbiotic crab and the second confirmed record of EPC in a marine brachyuran crab. This study supports predictions central to resource-monopolization and life-history theories. PMID:23264474

  14. Molecular analysis of the commercial deep-sea crabs Chaceon ramosae and Chaceon notialis (Brachyura, Geryonidae) reveals possible cryptic species in the South Atlantic

    NASA Astrophysics Data System (ADS)

    Mantelatto, Fernando L.; Pezzuto, Paulo Ricardo; Masello, Arianna; Rossi Wongtschowski, Carmen Lucia Del Bianco; Silva Hilsdorf, Alexandre Wagner; Rossi, Natalia

    2014-02-01

    Deep-sea red crabs Chaceon ramosae and Chaceon notialis are commercially and ecologically important crustaceans in South Atlantic waters. With some overlapping occurring at the edge of the crabs' distribution, the fisheries are managed separately in Brazil and Uruguay, with some differences in the regulations, although the stock is supposedly shared between the two countries. To assess genetic information on these two species, we examined the nucleotide sequence of the mitochondrial 16S rDNA and CO1 mtDNA genes in samples from the southern region. We also compared these data to sequences from other congeners. The genetic analysis revealed a clear separation between C. notialis and C. ramosae. In addition, we detected the existence of at least two different groups within the species that is currently recognized as C. notialis. This might indicate the existence of cryptic species, leading us to speculate about the presence of two different taxonomic entities, although further research is needed to resolve this issue.

  15. A new species of sand crab Jonas Hombron & Jacquinot, 1846 (Crustacea:
    Decapoda: Brachyura: Corystidae) from the southeastern coast of India.

    PubMed

    Barathkumar, S; Das, N P I; Satpathy, K K

    2016-02-15

    A new species of sand crab of the genus Jonas Hombron & Jacquinot, 1846 (family Corystidae) is described from specimens collected from Kalpakkam, southeastern coast of India. Two other species, J. indicus (Chopra, 1935), and J. choprai Serène, 1971, have previously been recorded from this area. A detailed description of the new species is given and compared with the closely related J. formosae Balss, 1922, also from the Indo-West Pacific.

  16. A new species of Sunipea Griffin & Tranter, 1986 (Crustacea: Brachyura: Inachidae) and a redescription of Sunipea indicus (Alcock, 1895).

    PubMed

    Santana, William

    2015-12-03

    A new species of spider crab, Sunipea callistus, n. sp., from Cape Guardafui, Somali Republic, is described and illustrated. Sunipea indicus (Alcock, 1895) is also redescribed and figured. Sunipea callistus n. sp. differs from S. indicus in the structures of the carapace, third maxillipeds, thoracic sternum, male abdomen, and chelipeds. Despite a number of characteristics that separate both species, these differences are more pronounced in males and are less evident in females. A diagnosis for the genus is provided.

  17. Description of a new species of brooding spider crab in the genus Paranaxia Rathbun, 1924 (Brachyura: Majoidea), from northern Australia and Indonesia.

    PubMed

    Hosie, Andrew M; Hara, Ana

    2016-06-22

    A new species, Paranaxia keesingi sp. nov., is described based on specimens collected in northern Australia. The new species differs from its only congener, P. serpulifera (Guérin, 1832, in Guérin-Méneville 1829-1837), by several characters including carapace setation, sternal cavities, absence of a subhepatic spine, presence of a sharp spine on the posterodistal angle of the cheliped merus, relatively shorter chelipeds, and longer and more slender ambulatory legs. Morphological separation of the two species is supported by 12s rDNA sequence divergences of 7.4-8.2%. Like P. serpulifera, the newly described species exhibits direct development with females carrying juvenile individuals under the pleon. Both species are sympatric, but Paranaxia keesingi sp. nov. is found in deeper waters than P. serpulifera.

  18. Five new species of freshwater crabs of the genera Ghatiana Pati & Sharma, 2014, and Gubernatoriana Bott, 1970 (Crustacea, Decapoda, Brachyura: Gecarcinucidae Rathbun, 1904) from the Western Ghats, India.

    PubMed

    Pati, S K; Thackeray, T; Khaire, A

    2016-01-01

    Five new species of gecarcinucid freshwater crabs, Ghatiana atropurpurea n. sp., Ghatiana splendida n. sp., Gubernatoriana alcocki Pati n. sp., Gubernatoriana thackerayi Pati n. sp., and Gubernatoriana waghi Pati n. sp. are described from the Western Ghats in Maharashtra and Goa states of India. Ghatiana atropurpurea n. sp. can be differentiated from other species of Ghatiana Pati & Sharma, 2014 by the shape and colour of its carapace, and the sigmoid-shaped male first pleopod (G1). Ghatiana splendida n. sp. is separated from its congeners mainly by its long anterolateral margin of the carapace and short terminal article of the G1. Besides, the colour pattern (deep pink carapace and chelipeds, orange ambulatory legs) of G. splendida n. sp. is exceptional among its congeners. Gubernatoriana alcocki n. sp. is unique among species of Gubernatoriana Bott, 1970 due to its inwardly curved tip of the terminal article of the G1. The stout and cone-shaped terminal article of the G1 of G. thackerayi n. sp. is characteristic among its congeners. In addition, G. thackerayi n. sp. has a unique colouration amongst congeners (violet-red carapace and ambulatory legs, orange-red chelipeds). Gubernatoriana waghi n. sp. can be distinguished from its congeners by the quadrate-shaped carapace, narrow frontal margin, pointed tips of the cheliped fingers, short terminal article of the G1 and very short or vestigial terminal article of the male second pleopod (G2). The body colour (burnt orange carapace and ivory coloured chelipeds and ambulatory legs) of G. waghi n. sp. is also important to distinguish live crabs of the genus. Key to the species of Ghatiana and Gubernatoriana is provided. PMID:27394247

  19. A review of Chiromantes obtusifrons (Dana, 1851) (Decapoda: Brachyura: Sesarmidae), with descriptions of four new sibling-species from Christmas Island (Indian Ocean), Guam and Taiwan.

    PubMed

    Davie, Peter J F; Ng, Peter K L

    2013-01-01

    The identity of Chiromantes obtusifrons (Dana, 1851), previously considered widespread in the tropical West Pacific region to the eastern Indian Ocean, is revised and found to be a species-complex. Chiromantes obtusifrons is now considered endemic to the Hawaiian Is., and four new species are described from Guam, Taiwan and Christmas Island. Two species live sympatrically in Taiwan. Species separation is based on carapace and frontal shape and granulation, leg proportions, abdominal somite proportions, and distinctive live colouration.

  20. Changes during late-stage embryonic development from egg-juvenile to free-living hatchling in Chinese freshwater crab Sinopotamon yangtsekiense (Decapoda, Brachyura, Potamidae)

    NASA Astrophysics Data System (ADS)

    Xue, Junzeng; Liu, Yan; Cumberlidge, Neil; Wu, Huixian

    2013-05-01

    This study expands on recent reports that direct development in the Chinese potamid freshwater crab Sinopotamon yangtsekiense involves the completion of all brachyuran larval stages (nauplius, zoea, and megalopa) inside the egg case during embryonic development. Detailed studies of embryonic development in this species revealed the presence of an additional larval stage (the egg-juvenile) between the megalopa and the free-living hatchling crab. We described and compared the appendages of the head, thorax, and abdomen of the egg-juvenile with those of the hatchling crab in S. yangtsekiense. Significant differences were found between most of the appendages of these two stages with a soft exoskeleton in the egg-juvenile, no joint articulation, a slimmer appearance, and a lack of setae when compared with the newly emerged free-living hatchling crab. These modifications of the appendages are related to the confinement within the egg case of the egg-megalopa and egg-juvenile during direct development, and the need for the free-living hatchling freshwater crab to move, feed, and respire. In marine crabs, the megalopa gives rise to the first crab stage whereas in freshwater crabs the egg-juvenile follows the megalopa and immediately precedes the free-living first crab stage.

  1. Gonadal development in the freshwater crab Sylviocarcinus pictus (H. Milne Edwards, 1853) (Brachyura: Trichodactylidae) from the Guamá river, state of Pará, Brazil.

    PubMed

    Silva, Leiliane S; Martinelli-Lemos, Jussara M; Ferreira, Maria Auxiliadora P; Rocha, Rossineide M

    2012-09-01

    The development stages of male and female gonads in the freshwater crab Sylviocarcinus pictus (H. Milne Eduards, 1853) were described through macroscopic and microscopic (histology) examinations. The histological description was based on 40 specimens (20 each sex). Four gonadal development stages were found for females: immature, ripening, mature and spawned. The following female cells were found: ovogonia, oocytes in initial vitellogenesis, oocytes in advanced vitellogenesis, follicular cells and post-ovulatory follicles. Three development stages were found for males: immature, maturing and mature, with the indication of: spermatogonia, spermatocytes, spermatids, spermatozoids and spermatophores. These data suggest the pattern described in the literature. Size at sexual maturity was 32.3 mm of carapace width for males and 31.5 mm for females. The gonadal stages observed macroscopically by volume and color were validated through histological analysis and proved to be useful method for the rapid identification of sexual maturity in the species. The present study offers previously unpublished data on the reproductive biology of Sylviocarcinus pictus.

  2. The complete mitochondrial genome of the black mud crab, Scylla serrata (Crustacea: Brachyura: Portunidae) and its phylogenetic position among (pan)crustaceans.

    PubMed

    Jondeung, Amnuay; Karinthanyakit, Wirangrong; Kaewkhumsan, Jitlada

    2012-12-01

    The black mud crab, Scylla serrata (Forskål 1775), is the most economically important edible crab in South-East Asia. In the present study, the complete mitochondrial genome of black mud crab, S. serrata, was determined with the sequential polymerase chain reaction and primer walking sequencing. The complete mitochondrial genome was 15,721 bp in length with an A+T content of 69.2 % and contained 37 mitochondrial genes (13 protein coding genes (PCGs), 2 ribosomal RNA genes and 22 transfer RNA genes) and a control region (CR). The analysis of the CR sequence shows that it contains a multitude of repetitive fragments which can fold into hairpin-like or secondary structures and conserved elements as in other arthropods. The gene order of S. serrata mainly retains as the pancrustacean ground pattern, except for a single translocation of trnH. The gene arrangement of S. serrata appears to be a typical feature of portunid crabs. Phylogenetic analyses with concatenated amino acid sequences of 12 PCGs establishes that S. serrata in a well-supported monophyletic Portunidae and is consistent with previous morphological classification. Moreover, the phylogenomic results strongly support monophyletic Pancrustacea (Hexapoda plus "Crustaceans"). Within Pancrustacea, this study identifies Malacostraca + Entomostraca and Branchiopoda as the sister group to Hexapoda, which confirms that "Crustacea" is not monophyletic. Cirripedia + Remipedia appear to be a basal lineage of Pancrustacea. The present study also provides considerable data for the application of both population and phylogenetic studies of other crab species.

  3. Discovery of a new genus and new species of Indo-West Pacific pilumnoidid crab from a semisubmersible oil platform (Crustacea: Brachyura: Pseudozioidea).

    PubMed

    Ng, Peter K L; Ahyong, Shane T

    2013-01-01

    A new genus and new species of pseudozioid crab of the family Pilumnoididae is described from a fouling community on a semisubmersible oil platform in Singapore that had been operating in the Timor Sea and South China Sea. Setozius incertus gen. et sp. nov. superficially resembles species of Pilumnus (Pilumnidae, Pilumnoidea) but has male first and second gonopod structures characteristic of the Pseudozioidea. The form of the carapace, male anterior thoracic sternum and male abdomen indicates that it should be classified in the Pilumnoididae. Setozius is the first member of the family to be recorded from the Indo-West Pacific; all other known pilumnoidids occur in the Atlantic and eastern Pacific.

  4. A new species of freshwater crab of the genus Microthelphusa Pretzmann, 1968 (Crustacea: Brachyura: Pseudothelphusidae) from the Amazon region of Guyana.

    PubMed

    Pedraza, Manuel; Tavares, Marcos

    2014-08-07

    A new species of freshwater crab, Microthelphusa furcifer, is described and illustrated from the Potaro-Siparuni Kuribrong River in the Guyana Shield (Amazon region of Guyana). The new species can be easily separated from its congeners by the morphology of the first gonopod. The first gonopod of Microthelphusa meansi Cumberlidge, 2007, is illustrated to clarify some aspects of its morphology. 

  5. The enigmatic life history of the symbiotic crab Tunicotheres moseri (Crustacea, Brachyura, Pinnotheridae): implications for its mating system and population structure.

    PubMed

    Hernández, J E; Bolaños, J A; Palazón, J L; Hernández, G; Lira, C; Baeza, J Antonio

    2012-12-01

    Resource-monopolization theory predicts the adoption of a solitary habit in species using scarce, discrete, and small refuges. Life-history theory suggests that temporarily stable parental dwellings favor extended parental care in species that brood embryos. We tested these two predictions with the symbiotic crab Tunicotheres moseri. This species exhibits abbreviated development and inhabits the atrial chamber of the scarce, structurally simple, long-lived, and relatively small ascidian Phalusia nigra in the Caribbean. These host characteristics should favor a solitary habit and extended parental care (EPC) in T. moseri. As predicted, males and females of T. moseri inhabited ascidians solitarily with greater frequency than expected by chance alone. The male-female association pattern and reverse sexual dimorphism (males < females) additionally suggests a promiscuous "pure-search" mating system in T. moseri. Also in agreement with theoretical considerations, T. moseri displays EPC; in addition to embryos, females naturally retain larval stages, megalopae, and juveniles within their brooding pouches. This is the first record of EPC in a symbiotic crab and the second confirmed record of EPC in a marine brachyuran crab. This study supports predictions central to resource-monopolization and life-history theories.

  6. A new species of false spider crab of the genus Elamena H. Milne Edwards, 1837 (Crustacea: Decapoda: Brachyura: Hymenosomatidae), from Davao Gulf, Philippines.

    PubMed

    Husana, Daniel Edison M; Kase, Tomoki; Mendoza, Jose Christopher E

    2013-02-22

    A new species of hymenosomatid crab of the genus Elamena H. Milne Edwards, 1837, is described from the island of Samal, in the Davao Gulf, Mindanao, southern Philippines. Elamena samalensis sp. nov. belongs to the Elamena truncata species-group and is most similar to E. simplidenta Ng & Chuang, 1996, in the general form of the carapace and in the presence of only one subdistal tooth on the ambulatory dactyli. It can be distinguished from this species, however, by its more projecting rostrum, relatively longer and more slender ambulatory legs, and by the pointed apex of the female pleotelson.

  7. Preservation of internal pleurites in a new palaeocorystid crab (Crustacea, Brachyura, Raninoidia) from the Cenomanian (Upper Cretaceous) of Poitou-Charentes, France.

    PubMed

    Van Bakel, Barry W M

    2013-01-01

    A new palaeocorystid crab, Joeranina houssineaui n. sp., is described from upper Cenomanian strata in southwest France, Being apparently derived from J. broderipii, the new species inhabited a sandier substrate environment than its predecessor. The incomplete holotype reveals portions of the internal pleurites, which are rarely seen in extinct crabs.

  8. Binhthuanomon vinhtan, a new genus and new species of semi-terrestrial freshwater crab (Crustacea: Decapoda: Brachyura: Potamidae) from south central Vietnam.

    PubMed

    Do, Van Tu; Le, Van Tho; Phan, Doan Dang

    2015-12-01

    A new genus and new species of semi-terrestrial crab of the family Potamidae, Binhthuanomon vinhtan n. sp., is described from south central Vietnam. The new genus is morphologically closest to Villopotamon Dang & Ho, 2003, and Balssipotamon Dang & Ho, 2008, in the shapes of the carapace and first gonopod but is easily distinguished by distinct carapace characteristics and gonopod 1 structures, and the habitat occupied.

  9. The identity of the Sarawak freshwater crab Parathelphusa oxygona Nobili, 1901, with description of a new species, Parathelphusa nobilii, from Western Kalimantan, Indonesia, Borneo (Crustacea: Brachyura: Gecarcinucidae).

    PubMed

    Ng, Peter K L

    2014-03-04

    The identity of the common lowland freshwater crab in western Sarawak, Borneo, East Malaysia, Parathelphusa oxygona Nobili, 1901 (family Gecarcinucidae), is clarified. The species is redescribed and figured, and its taxonomy discussed. Specimens from western Kalimantan, Borneo, Indonesia, which have been referred to P. oxygona are here referred to a new species, Parathelphusa nobilii. The new species can be differentiated from congeners by its relatively more swollen branchial regions of the carapace, wider and lower external orbital tooth, relatively more slender male abdomen and a straight male first gonopod. 

  10. Redescription of a poorly known epialtid crab Pugettia pellucens Rathbun, 1932 (Crustacea: Decapoda: Brachyura: Majoidea) and description of a new species from Sagami Bay, Japan.

    PubMed

    Ohtsuchi, Naoya; Kawamura, Tomohiko; Takeda, Masatsune

    2014-02-21

    A poorly known epialtid crab species, Pugettia pellucens Rathbun, 1932, is redescribed and a closely allied new species P. vulgaris n. sp. is described and illustrated on the basis of material from Sagami Bay, Japan. Pugettia pellucens was originally described as a subspecies of P. quadridens (De Haan, 1839), but it is confirmed that the taxon is distinct from P. quadridens. The superficially similar Pugettia vulgaris n. sp. can be distinguished from P. pellucens by several morphological characters. The new species is also similar to P. elongata Yokoya, 1933, and P. intermedia Sakai, 1938, but can also be separated by various carapace and gonopodal characters.

  11. The identification and distribution of progesterone receptors in the brain and thoracic ganglion in the mud crab Scylla paramamosain (Crustacea: Decapoda: Brachyura).

    PubMed

    Ye, Haihui; Huang, Huiyang; Song, Ping; Wang, Guizhong

    2010-11-01

    The existence of progesterone receptors (PR) in the Scylla paramamosain (mud crab) was studied using immunological techniques. By Western blotting, PR with an apparent molecular weight of 70 kDa is identified in both the brain and the thoracic ganglion. By immunohistochemistry, PR immunoreactive neurons are detected mainly in the protocerebrum, the subesophageal ganglion and the leg ganglion. PR immunoreactivity is localized mainly in the nuclei of these neurons, while only a few neurons show such activities in their cytoplasm. Our results provide evidence that progesterone modulates the neuroendocrine system mainly via nucleus receptors.

  12. Regulation by the exogenous polyamine spermidine of Na,K-ATPase activity from the gills of the euryhaline swimming crab Callinectes danae (Brachyura, Portunidae).

    PubMed

    Silva, E C C; Masui, D C; Furriel, R P M; Mantelatto, F L M; McNamara, J C; Barrabin, H; Leone, F A; Scofano, H M; Fontes, C F L

    2008-04-01

    Euryhaline crustaceans rarely hyporegulates and employ the driving force of the Na,K-ATPase, located at the basal surface of the gill epithelium, to maintain their hemolymph osmolality within a range compatible with cell function during hyper-regulation. Since polyamine levels increase during the adaptation of crustaceans to hyperosmotic media, we investigate the effect of exogenous polyamines on Na,K-ATPase activity in the posterior gills of Callinectes danae, a euryhaline swimming crab. Polyamine inhibition was dependent on cation concentration, charge and size in the following order: spermine>spermidine>putrescine. Spermidine affected K(0.5) values for Na(+) with minor alterations in K(0.5) values for K(+) and NH(4)(+), causing a decrease in maximal velocities under saturating Na(+), K(+) and NH(4)(+) concentrations. Phosphorylation measurements in the presence of 20 microM ATP revealed that the Na,K-ATPase possesses a high affinity site for this substrate. In the presence of 10 mM Na(+), both spermidine and spermine inhibited formation of the phosphoenzyme; however, in the presence of 100 mM Na(+), the addition of these polyamines allowed accumulation of the phosphoenzyme. The polyamines inhibited pumping activity, both by competing with Na(+) at the Na(+)-binding site, and by inhibiting enzyme dephosphorylation. These findings suggest that polyamine-induced inhibition of Na,K-ATPase activity may be physiologically relevant during migration to fully marine environments.

  13. The land crab Johngarthiaplanata (Stimpson, 1860) (Crustacea, Brachyura, Gecarcinidae) colonizes human-dominated ecosystems in the continental mainland coast of Mexico.

    PubMed

    Perger, Robert

    2014-01-01

    The land crab Johngarthiaplanata (Stimpson, 1860) has been reported from the Baja California Peninsula and several oceanic islands in the Eastern Pacific as well as inshore islands of the Mexican, Costa Rican and Colombian coast. However, the species has not been observed on the continental mainland, as it is likely that the high diversity of terrestrial predators/competitors make the establishment of mainland populations nearly impossible. In this contribution, several new records of this species that have been observed in urban areas along the continental Pacific coast of Mexico are reported. These records demonstrate that the presence of humans does not necessarily have a negative impact on land crab species. Indeed, the presence of humans may actually discourage the presence of native crab predators/competitors and hence increase the likelihood of a successful mainland settlement of land crab species that are otherwise island and peninsula restricted. The presence of Johngarthiaplanata is ecologically relevant for coastal forests because gecarcinid crabs significantly influence plant recruitment and Johngarthiaplanata is considerably larger than the mainland species Gecarcinusquadratus.

  14. Hemolymph ionic regulation and adjustments in gill (Na+, K+)-ATPase activity during salinity acclimation in the swimming crab Callinectes ornatus (Decapoda, Brachyura).

    PubMed

    Garçon, Daniela P; Masui, Douglas C; Mantelatto, Fernando L M; Furriel, Rosa P M; McNamara, John C; Leone, Francisco A

    2009-09-01

    We evaluate hemolymph osmotic and ionic regulatory abilities and characterize a posterior gill microsomal (Na+, K+)-ATPase from the marine swimming crab, Callinectes ornatus, acclimated to 21 per thousand or 33 per thousand salinity. C. ornatus is isosmotic after acclimation to 21 per thousand but is hyposmotic at 33 per thousand salinity; hemolymph ions do not recover initial levels on acclimation to 21 per thousand salinity but are anisoionic compared to ambient concentrations, revealing modest regulatory ability. NH4+ modulates enzyme affinity for K+, which increases 187-fold in crabs acclimated to 33 per thousand salinity. The (Na+, K+)-ATPase redistributes into membrane fractions of different densities, suggesting that altered membrane composition results from salinity acclimation. ATP was hydrolyzed at maximum rates of 182.6 +/- 7.1 nmol Pi min(-1) mg(-1) (21 per thousand) and 76.2 +/- 3.5 nmol Pi min(-1) mg(-1) (33 per thousand), with little change in KM values (approximately 50 micromol L(-1)). K+ together with NH4+ synergistically stimulated activity to maximum rates of approximately 240 nmol Pi min(-1) mg(-1). KI values for ouabain inhibition (approximately 110 micromol L(-1)) decreased to 44.9 +/- 1.0 micromol L(-1) (21 per thousand) and 28.8 +/- 1.3 micromol L(-1) (33 per thousand) in the presence of both K+ and NH4+. Assays employing various inhibitors suggest the presence of mitochondrial F0F1-, and K+- and V-ATPase activities in the gill microsomes.

  15. Multi-level biological responses in Ucides cordatus (Linnaeus, 1763) (Brachyura, Ucididae) as indicators of conservation status in mangrove areas from the western atlantic.

    PubMed

    Duarte, Luis Felipe de Almeida; Souza, Caroline Araújo de; Nobre, Caio Rodrigues; Pereira, Camilo Dias Seabra; Pinheiro, Marcelo Antonio Amaro

    2016-11-01

    There is a global lack of knowledge on tropical ecotoxicology, particularly in terms of mangrove areas. These areas often serve as nurseries or homes for several animal species, including Ucides cordatus (the uçá crab). This species is widely distributed, is part of the diet of human coastal communities, and is considered to be a sentinel species due to its sensitivity to toxic xenobiotics in natural environments. Sublethal damages to benthic populations reveal pre-pathological conditions, but discussions of the implications are scarce in the literature. In Brazil, the state of São Paulo offers an interesting scenario for ecotoxicology and population studies: it is easy to distinguish between mangroves that are well preserved and those which are significantly impacted by human activity. The objectives of this study were to provide the normal baseline values for the frequency of Micronucleated cells (MN‰) and for neutral red retention time (NRRT) in U. cordatus at pristine locations, as well to indicate the conservation status of different mangrove areas using a multi-level biological response approach in which these biomarkers and population indicators (condition factor and crab density) are applied in relation to environmental quality indicators (determined via information in the literature and solid waste volume). A mangrove area with no effects of impact (areas of reference or pristine areas) presented a mean value of MN‰<3 and NRRT>120min, values which were assumed as baseline values representing genetic and physiological normality. A significant correlation was found between NRRT and MN, with both showing similar and effective results for distinguishing between different mangrove areas according to conservation status. Furthermore, crab density was lower in more impacted mangrove areas, a finding which also reflects the effects of sublethal damage; this finding was not determined by condition factor measurements. Multi-level biological responses were able to reflect the conservation status of the mangrove areas studied using information on guideline values of MN‰, NRRT, and density of the uçá crab in order to categorize three levels of human impacts in mangrove areas: PNI (probable null impact); PLI (probable low impact); and PHI (probable high impact). Results confirm the success of U. cordatus species' multi-level biological responses in diagnosing threats to mangrove areas. Therefore, this species represents an effective tool in studies on mangrove conservation statuses in the Western Atlantic.

  16. Longitudinal distribution and lateral pattern of megalopal settlement and juvenile recruitment of Carcinus maenas (L.) (Brachyura, Portunidae) in the Mira River Estuary, Portugal

    NASA Astrophysics Data System (ADS)

    Silva, Inês C.; Dinis, Ana M.; Francisco, Sara M.; Flores, Augusto A. V.; Paula, José

    2006-08-01

    Settlement is a critical process in the life history of crabs, and thus affecting the abundance, distribution and structure of estuarine communities. The spatial pattern of settlement of megalopae of the shore crab Carcinus maenas along a longitudinal estuarine gradient (Mira River Estuary, Portugal) was examined, as well as its effects on the juvenile population. To measure megalopal settlement, four replicate collectors were deployed in six equally spaced stations along the estuarine axis. Juveniles were collected on the same locations with a quadrat randomly deployed on the substrate. To assess fine-scale megalopal settlement within a curved region of the estuary, replicate collectors were deployed on both margins along Moinho da Asneira curve. Megalopae settled differently along the six longitudinal points, with a tendency to attenuate their settlement upstream. Within the curved region, megalopae preferentially settled on the left margin collectors, probably due to the weaker velocity speeds felt on this margin. Concerning the overall juvenile density, there were significant differences among the stations distributed along the estuary, but they did no reflect a longitudinal dispersion attenuation pattern. Size-frequency distribution of the juvenile population showed that the average size is higher on the left margin. Recruits (carapace length between 1.0 mm and 3.4 mm) were more abundant on the upstream stations. Density of early juveniles (3.4 mm-6.5 mm) and juveniles (6.5 mm-10 mm) was more stable throughout the estuary axis than that of recruits. This distribution pattern may result from tidal excursion processes or mechanisms to avoid biotic interactions, such as predation and competition.

  17. Molt and reproduction enhancement together with hemolymph ecdysteroid elevation under eyestalk ablation in the female fiddler crab, Uca triangularis (Brachyura: Decapoda)

    NASA Astrophysics Data System (ADS)

    Supriya, Nagathinkal T.; Sudha, Kappalli; Krishnakumar, Velayudhannair; Anilkumar, Gopinathan

    2016-07-01

    We present the results of eyestalk extirpation experiments performed on the fiddler crab, Uca triangularis at seasons of molting and reproduction, with a view to have a better understanding of the regulatory mechanisms of these two highly energy-demanding processes. Bilateral eyestalk ablation resulted in precocious acceleration of both molting and reproduction, irrespective of the season at which each experiment was conducted. The rate of accelerated ovarian growth, however, was maximum if the eyestalk ablation was conducted during August-January, the breeding season in the wild, or in February-May (molting-reproductive season), wherein a section of the wild population would be engaged in molting and another section in breeding. The highest degree of precocious molt acceleration, on the other hand, was obtained during June-July when the population was primarily engaged in molting, but with no reproductive activity. The precocious oocyte maturation (due to de-eyestalking) was minimal in June-July. Significantly, the eyestalk ablation also resulted in a dramatic increase in the hemolymph ecdysteroid titer, revealing that a high ecdysteroid titer would have no restraining influence on vitellogenesis. No spawning was, however, observed among de-eyestalked females, even though their final oocyte size surpassed the size of the normal mature oocytes, implying that spawning is not exclusively under the control of eyestalk hormones. A comparative study performed on the vitelline components of the experimentals and the controls revealed that the precociously incorporated yolk under eyestalk ablation was biochemically impoverished. These results indicate that throughout the annual cycle, both the somatic and the reproductive growth of U. triangularis are under the influence of inhibitory principles from the eyestalks. It is also revealing that mere deprival of the inhibitory principles does not culminate into successful vitellogenesis. Arguably, the inhibitory influence from the eyestalks could be a prerequisite for normal healthy maturation of the oocytes and spawning.

  18. Multi-level biological responses in Ucides cordatus (Linnaeus, 1763) (Brachyura, Ucididae) as indicators of conservation status in mangrove areas from the western atlantic.

    PubMed

    Duarte, Luis Felipe de Almeida; Souza, Caroline Araújo de; Nobre, Caio Rodrigues; Pereira, Camilo Dias Seabra; Pinheiro, Marcelo Antonio Amaro

    2016-11-01

    There is a global lack of knowledge on tropical ecotoxicology, particularly in terms of mangrove areas. These areas often serve as nurseries or homes for several animal species, including Ucides cordatus (the uçá crab). This species is widely distributed, is part of the diet of human coastal communities, and is considered to be a sentinel species due to its sensitivity to toxic xenobiotics in natural environments. Sublethal damages to benthic populations reveal pre-pathological conditions, but discussions of the implications are scarce in the literature. In Brazil, the state of São Paulo offers an interesting scenario for ecotoxicology and population studies: it is easy to distinguish between mangroves that are well preserved and those which are significantly impacted by human activity. The objectives of this study were to provide the normal baseline values for the frequency of Micronucleated cells (MN‰) and for neutral red retention time (NRRT) in U. cordatus at pristine locations, as well to indicate the conservation status of different mangrove areas using a multi-level biological response approach in which these biomarkers and population indicators (condition factor and crab density) are applied in relation to environmental quality indicators (determined via information in the literature and solid waste volume). A mangrove area with no effects of impact (areas of reference or pristine areas) presented a mean value of MN‰<3 and NRRT>120min, values which were assumed as baseline values representing genetic and physiological normality. A significant correlation was found between NRRT and MN, with both showing similar and effective results for distinguishing between different mangrove areas according to conservation status. Furthermore, crab density was lower in more impacted mangrove areas, a finding which also reflects the effects of sublethal damage; this finding was not determined by condition factor measurements. Multi-level biological responses were able to reflect the conservation status of the mangrove areas studied using information on guideline values of MN‰, NRRT, and density of the uçá crab in order to categorize three levels of human impacts in mangrove areas: PNI (probable null impact); PLI (probable low impact); and PHI (probable high impact). Results confirm the success of U. cordatus species' multi-level biological responses in diagnosing threats to mangrove areas. Therefore, this species represents an effective tool in studies on mangrove conservation statuses in the Western Atlantic. PMID:27448958

  19. Results of the global conservation assessment of the freshwater crabs (Brachyura, Pseudothelphusidae and Trichodactylidae): The Neotropical region, with an update on diversity

    PubMed Central

    Cumberlidge, Neil; Alvarez, Fernando; Villalobos, Jose-Luis

    2014-01-01

    Abstract The freshwater crabs of the Neotropics comprise 311 species in two families (Pseudothelphusidae and Trichodactylidae) and one or both of these families are found in all of the countries in the Neotropical region (except for Chile and some of the Caribbean islands). Colombia (102 species, 81% endemic) and Mexico (67 species, 95% endemic) are the biodiversity hotspots of freshwater crab species richness and country-level endemism for this region. The results of the IUCN Red List conservation assessments show that 34% of pseudothelphusids and 10% of trichodactylids have an elevated risk of extinction, 29% of pseudothelphusids and 75% of trichodactylids are not at-risk (Least Concern), and although none are actually extinct, 56% of pseudothelphusids and 17% of trichodactylids are too poorly known to assess (Data Deficient). Colombia (14 species), Venezuela (7 species), Mexico (6 species), and Ecuador (5 species) are the countries with the highest number of threatened species of Neotropical freshwater crabs. The majority of threatened species are restricted-range semiterrestrial endemics living in habitats subjected to deforestation, alteration of drainage patterns, and pollution. This underlines the need to prioritize and develop conservation measures before species decline to levels from which they cannot recover. These results represent a baseline that can be used to design strategies to save threatened Neotropical species of freshwater crabs. PMID:25561834

  20. Resurrection of Rhynchoplax Stimpson, 1858, with the description of two new species from Japan and Australia (Crustacea: Decapoda: Brachyura: Hymenosomatidae).

    PubMed

    Komai, Tomoyuki; Poore, Gary C B

    2016-01-01

    Rhynchoplax Stimpson, 1858, is resurrected from synonymy with Halicarcinus White, 1846. Rhynchoplax hondai Takeda & Miyake, 1971, a species based on an immature female, is rediagnosed and two new species, R. magnetica n. sp. from northeastern Australia and R. minutula n. sp. from the Ryukyu Islands, Japan, are described. They differ from R. hondai in the shape of the rostrum, form of the subhepatic region and the armature of the pereopodal meri. All differ from the type species R. messor Stimpson, 1858, in having a longer and simple rostrum without supraocular pseudorostral spines and the absence of a postocular spine. PMID:27394510

  1. Redescription of Alox chaunos Galil & Ng, 2007 (Crustacea: Decapoda: Brachyura: Leucosiidae) new to Japan; with notes on the male characters of A. latusoides (Sakai, 1937).

    PubMed

    Ohtsuchi, Naoya; Kawamura, Tomohiko

    2016-01-01

    The leucosiid crab Alox chaunos Galil & Ng, 2007 is reported from Japan for the first time, and redescribed on the basis of specimens from the Ryukyu Islands. The taxonomy of this species is discussed, and comparisons are made with A. rugosum (Stimpson, 1858), A. uru Naruse & Ng, 2006, and A. liklik Galil & Ng, 2015. Alox somphos Tan & Ng, 1995, is excluded from the fauna of Japan, the original record actually based on a specimen of A. chaunos. Male characters of A. latusoides are also described for the first time to differentiate this species from A. chaunos. PMID:27394895

  2. The land crab Johngarthia planata (Stimpson, 1860) (Crustacea, Brachyura, Gecarcinidae) colonizes human-dominated ecosystems in the continental mainland coast of Mexico

    PubMed Central

    2014-01-01

    Abstract The land crab Johngarthia planata (Stimpson, 1860) has been reported from the Baja California Peninsula and several oceanic islands in the Eastern Pacific as well as inshore islands of the Mexican, Costa Rican and Colombian coast. However, the species has not been observed on the continental mainland, as it is likely that the high diversity of terrestrial predators/competitors make the establishment of mainland populations nearly impossible. In this contribution, several new records of this species that have been observed in urban areas along the continental Pacific coast of Mexico are reported. These records demonstrate that the presence of humans does not necessarily have a negative impact on land crab species. Indeed, the presence of humans may actually discourage the presence of native crab predators/competitors and hence increase the likelihood of a successful mainland settlement of land crab species that are otherwise island and peninsula restricted. The presence of Johngarthia planata is ecologically relevant for coastal forests because gecarcinid crabs significantly influence plant recruitment and Johngarthia planata is considerably larger than the mainland species Gecarcinus quadratus. PMID:25057257

  3. Semiterrestrial crabs of the genus Geosesarma De Man, 1892 (Crustacea, Brachyura, Sesarmidae) from western Borneo, Indonesia, with descriptions of three new species.

    PubMed

    Ng, Peter K L

    2015-11-24

    The poorly known semiterrestrial sesarmid crab, Geosesarma amphinome (De Man, 1899), from Kalimantan Barat in western Borneo, is redescribed and figured. Three other species from areas surrounding the town of Pontianak, are here described as new. Geosesarma ambawang sp. nov., G. pontianak sp. nov., and G. pylaemenes sp. nov. can be distinguished from congeners on Borneo and adjacent areas by their colours in life, form of the carapaces and ambulatory legs, and the structures of the male abdomens and first gonopods.

  4. Five new species of freshwater crabs of the genera Ghatiana Pati & Sharma, 2014, and Gubernatoriana Bott, 1970 (Crustacea, Decapoda, Brachyura: Gecarcinucidae Rathbun, 1904) from the Western Ghats, India.

    PubMed

    Pati, S K; Thackeray, T; Khaire, A

    2016-02-23

    Five new species of gecarcinucid freshwater crabs, Ghatiana atropurpurea n. sp., Ghatiana splendida n. sp., Gubernatoriana alcocki Pati n. sp., Gubernatoriana thackerayi Pati n. sp., and Gubernatoriana waghi Pati n. sp. are described from the Western Ghats in Maharashtra and Goa states of India. Ghatiana atropurpurea n. sp. can be differentiated from other species of Ghatiana Pati & Sharma, 2014 by the shape and colour of its carapace, and the sigmoid-shaped male first pleopod (G1). Ghatiana splendida n. sp. is separated from its congeners mainly by its long anterolateral margin of the carapace and short terminal article of the G1. Besides, the colour pattern (deep pink carapace and chelipeds, orange ambulatory legs) of G. splendida n. sp. is exceptional among its congeners. Gubernatoriana alcocki n. sp. is unique among species of Gubernatoriana Bott, 1970 due to its inwardly curved tip of the terminal article of the G1. The stout and cone-shaped terminal article of the G1 of G. thackerayi n. sp. is characteristic among its congeners. In addition, G. thackerayi n. sp. has a unique colouration amongst congeners (violet-red carapace and ambulatory legs, orange-red chelipeds). Gubernatoriana waghi n. sp. can be distinguished from its congeners by the quadrate-shaped carapace, narrow frontal margin, pointed tips of the cheliped fingers, short terminal article of the G1 and very short or vestigial terminal article of the male second pleopod (G2). The body colour (burnt orange carapace and ivory coloured chelipeds and ambulatory legs) of G. waghi n. sp. is also important to distinguish live crabs of the genus. Key to the species of Ghatiana and Gubernatoriana is provided.

  5. Crabs of the families Palicidae and Crossotonotidae (Crustacea, Decapoda, Brachyura, Palicoidea) from the Ogasawara Islands, Japan, with the description of a new species.

    PubMed

    Takeda, Masatsune; Tachikawa, Hiroyuki

    2015-01-10

    Four species of palicoid crabs, Neopalicus jukesii (White, 1847) and Rectopalicus ampullatus Castro, 2000 of the family Palicidae, and Crossotonotus spinipes (De Man, 1888) and a new species of Pleurophricus A. Milne-Edwards, 1873 of the family Crossotonotidae, are recorded from the Ogasawara Islands, Japan. Diagnostics for the new species are the protruded bilobed front, six subacute lobate teeth at each lateral margin of the carapace, six rounded lobes at the posterior margin of the carapace, a crested armature of the cheliped carpus, and the strongly depressed ambulatory legs, which readily distinguish it from its two congeners, P. cristatipes A. Milne-Edwards, 1873 known by two males from Australia and the Kai Islands in Indonesia, and P. longirostris (Moosa & Serène, 1981) known by a female from the Sunda Strait, Indonesia.

  6. A new genus and two new species of hymenosomatid crabs (Crustacea:Brachyura: Hymenosomatidae) from the southwestern Atlantic and eastern Australia.

    PubMed

    Tavares, Marcos; Santana, William

    2015-01-09

    A new genus, Teramnonotus n. gen., is erected for Elamena gordonae Monod, 1956. The new genus includes two new species, T. johnlucasi n. gen., n. sp. and T. monodi n. gen., n. sp., described herein from eastern Australia (Queensland) and the southwestern Atlantic (Brazil), respectively. Teramnonotus n. gen. superficially resembles Elamena H. Milne Edwards, 1837, and Trigonoplax H. Milne Edwards, 1853, of which it can be easily distinguished by a combination of characters: eyes and ocular peduncle, rostrum, carapace, thoracic sternite 8 and thoracic pleurite 8, and the inhalant water openings. The validity of the obscure species Elamena mexicana H. Milne Edwards, 1853, is not supported and it is synonymised with Halicarcinus planatus (Fabricius, 1775).

  7. Patterns of diversity, areas of endemism, and multiple glacial refuges for freshwater crabs of the genus Sinopotamon in China (Decapoda: Brachyura: Potamidae).

    PubMed

    Fang, Fang; Sun, Hongying; Zhao, Qiang; Lin, Congtian; Sun, Yufang; Gao, Wei; Xu, Juanjuan; Zhou, Junying; Ge, Feng; Liu, Naifa

    2013-01-01

    Previous research has shown that the geographical distribution patterns of freshwater fishes and amphibians have been influenced by past climatic oscillations in China resulting from Pleistocene glacial activity. However, it remains unknown how these past changes have impacted the present-day distribution of Chinese freshwater crabs. This work describes the diversity and endemism of freshwater crabs belonging to Sinopotamon, a highly speciose genus endemic to China, and evaluates its distribution in terms of topography and past climatic fluctuations. Species diversity within Sinopotamon was found to be concentrated in an area from the northeastern edge of the Yunnan-Guizhou Plateau to the Jiangnan Hills, and three areas of endemism were identified. Multiple regression analysis between current climatic variables and Sinopotamon diversity suggested that regional annual precipitation, minimum temperature in the coldest month, and annual temperature range significantly influenced species diversity and may explain the diversity patterns of Sinopotamon. A comparison of ecological niche models (ENMs) between current conditions and the last glacial maximum (LGM) showed that suitable habitat for Sinopotamon in China severely contracted during the LGM. The coincidence of ENMs and the areas of endemism indicated that southeast of the Daba Mountains, and central and southeastern China, are potential Pleistocene refuges for Sinopotamon. The presence of multiple Pleistocene refuges within the range of this genus could further promote inter- and intraspecific differentiations, and may have led to high Sinopotamon species diversity, a high endemism rate and widespread distribution.

  8. The land crabs of the Discoplax longipes A. Milne-Edwards, 1867 species group, with description of a new species from Guam (Crustacea: Decapoda: Brachyura: Gecarcinidae).

    PubMed

    Ng, Peter K L; Shih, Hsi-Te

    2015-06-30

    Specimens of the gecarcinid land crab Discoplax longipes A. Milne-Edwards, 1867, from the western Pacific, can be separated into two distinct groups on the basis of DNA (mitochondrial 16S rDNA and cytochrome oxidase subunit I) and structure of the male first gonopod. On the basis of this data, the material that occurs from the Loyalty Islands to French Polynesia is shown to be D. longipes s. str., whereas specimens from Guam are here referred to a new pseudocryptic species, D. michalis n. sp. The two species are described and figured; and a revised key to the long-legged Discoplax species is provided.

  9. Two new potamid crabs, Yuexipotamon arcophallus new genus, new species and Minutomon shanweiense new genus, new species, (Crustacea: Decapoda: Brachyura: Potamidae) from southern China.

    PubMed

    Huang, Chao; Mao, Si Ying

    2014-02-12

    Two new Chinese genera and species of freshwater crabs, Yuexipotamon arcophallus, new genus, new species, and Minutomon shanweiense, new genus, new species, are described from Zhaoqing City and Shanwei City, respectively. The former is superficially closest to Huananpotamon Dai & Ng, 1994, while the latter resembles Sinopotamon Bott, 1967, and Mediapotamon Dai, 1995. The two new genera, however, possess distinctive combinations of carapace, third maxilliped, male thoracic sternal and first gonopodal characters that easily distinguish them from other genera. Notes on the general biology of the two new species are also given.

  10. The nomenclatural status of the two "spiny-wristed" fiddler crabs: Uca spinicarpa Rathbun, 1900, and U. hesperiae Crane, 1975 (Crustacea: Brachyura: Ocypodidae).

    PubMed

    Rosenberg, Michael S

    2013-01-01

    A secondary homonymy is documented for Gelasimus [= Uca] tetragonon var. spinicarpa Kossmann, 1877 (a species from the Red Sea), and Uca spinicarpa Rathbun, 1900 (a species from the Gulf of Mexico). Although Kossmann's usage of the nomen spinicarpa has chronological priority, a reversal of precedence is required by Article 23.9 of the Code since Kossmann's use has not been applied as a valid name since the original publication in 1877, while Rathbun's use of the name has been applied over 50 times in the last half century. The species Kossmann was most likely referring to is today known as Uca hesperiae Crane, 1975, a name which may be retained in light of the reversal of precedence.

  11. Two new species of freshwater crabs of the genus Heterochelamon Türkay & Dai, 1997 (Crustacea: Decapoda: Brachyura: Potamidae) from Guangxi Zhuang Autonomous Region, southern China.

    PubMed

    Naruse, Tohru; Zhu, Chunchao; Zhou, Xianmin

    2013-01-01

    Heterochelamon tessellatum n. sp. and H. castanea n. sp. are described trom the Guangxi Zhuang Autonomous Region, southern China. Heterochelamon tessellatum n. sp. and H. castanea n. sp. are morphologically most similar to H. yangshuoense Türkay & Dai, 1997, and H. guangxiense Türkay & Dai, 1997, respectively. The new species can be differentiated from these allied species by differences in the shape of external orbital tooth, epibranchial tooth, and male first gonopod. The present study brings the number of Heterochelamon species to five. A key to species of the genus Heterochelamon is provided.

  12. A new species of decorator crabs, genus Menaethiops Alcock, 1895 (Crustacea: Decapoda: Brachyura: Majoidea: Epialthidae), from Abu-Musa Island, Persian Gulf, Iran.

    PubMed

    Naderloo, Reza

    2015-03-02

    Menaethiops abumusa n. sp. is closely similar to M. bicornis Alcock, 1985, and M. gadaniensis Kazmi & Tirmizi, 1999, regarding the relatively contiguous rostral spines. The new species is easily distinguishable from its two congeners by having distinctly round angles of orbital eaves and distally divergent rostral spines. Whereas in M. bicornis, and M. gadaniensis, the angles of orbital eaves are anteriorly produced and rostral spines are closely attached to each other along their entire length.  Other morphological differences include the carapace spination/granulation, basal antennal segments, and morphology of the male's first gonopod. Menaethiops gadaniensis was described from Gadani, Pakistan and was only known from the type locality, but is here recorded for the first time from the Gulf of Oman.

  13. Embryology of the spider crabs Leurocyclus tuberculosus (H. Milne-Edwards & Lucas 1842) and Libinia spinosa (H. Milne-Edwards 1834) (Brachyura, Majoidea).

    PubMed

    González-Pisani, Ximena; Gaspar Dellatorre, Fernando; López-Greco, Laura

    2013-01-01

    The embryonic development of the spider crabs Leurocyclus tuberculosus and Libinia spinosa was divided into five periods based on the differentiation of: (I) cleavage, (II) embryonic primordium, III) optic lobes, (IV) optic lobes pigmented and (V) chromatophores presence. Different traits such as spines, setae and telson morphology distinguish the two species from period III until hatching. Egg volume was greater in Leurocyclus tuberculosus than in Libinia spinosa. The duration of each period was different during development. Whereas in Leurocyclus tuberculosus period II (morphogenesis) is the longest, in Libinia spinosa the period IV is the longest. Complete embryonic development at 14'C lasted 36.7 +/- 3.1 days in Leurocyclus tuberculosus and 57.4 +/- 4.4 days in Libinia spinosa.

  14. Ontogeny of osmoregulation in embryos of intertidal crabs (Hemigrapsus sexdentatus and H. crenulatus, Grapsidae, Brachyura): putative involvement of the embryonic dorsal organ.

    PubMed

    Seneviratna, Deepani; Taylor, H H

    2006-04-01

    This study examined whether the existence of hyperosmotic internal fluids in embryos of euryhaline crabs (Hemigrapsus sexdentatus and H. crenulatus) in dilute seawater reflects osmotic isolation due to impermeability of the egg envelope, as proposed for other decapods, or active osmoregulation. When ovigerous crabs with eggs at gastrula stage were transferred from 100% seawater (osmolality 1000 mmol kg(-1)) to 50% seawater, embryogenesis and hatching of zoea were completed normally, but were delayed. Hatching failed if the transfer to 50% seawater occurred before gastrulation, and embryogenesis was abnormal in 25% seawater. In 100% seawater, embryos at all stages were internally hyperosmotic by 150-250 mmol kg(-1). On transfer to 50% seawater, osmolality initially decreased but remained 200-350 mmol kg(-1) hyperosmotic to the medium for several weeks until hatching. High efflux rates of tritium-labelled water (t((1/2)) 16-75 min) and (22)Na (t(1/2) 109-374 min) from H. crenulatus embryos were inconsistent with the osmotic isolation hypothesis. It is concluded that post-gastrula embryos were actively hyper-osmoregulating. The diffusional water permeability of the embryos decreased during development while the sodium efflux rate increased 10-fold. Very rapidly exchanging pools of water and sodium (t(1/2) a few seconds to minutes) probably corresponded to peri-embryonic fluid and implied that the egg envelope was a negligible barrier to diffusion of water and salts. Higher Na(+)/K(+)-ATPase activities in late embryos of H. crenulatus incubated in 50% seawater than in embryos incubated in full strength seawater were consistent with an acclimation response. An area of the embryonic surface located over the yolk in the region of the embryonic dorsal organ stained with AgNO(3). Staining appeared at gastrulation, persisted throughout development and was lost at hatching. Deposits of AgCl between the outer and inner membranes, identified by X-ray microanalysis, suggest that the dorsal organ was a site of chloride extrusion. A model for osmoregulation in post-gastrula embryos is proposed: osmotic uptake of water is balanced by excretion of water and salts via the dorsal organ and salt loss is balanced by active uptake over the general embryonic ectoderm.

  15. Reappraisal of species attributed to Halicarcinus White, 1846 (Crustacea: Decapoda: Brachyura: Hymenosomatidae) with diagnosis of four new genera and one new species from New Ireland, Papua New Guinea.

    PubMed

    Poore, Gary C B; Guinot, Danièle; Komai, Tomoyuki; Naruse, Tohru

    2016-01-01

    Species of Hymenosomatidae previously treated as species or junior synonyms of species of Halicarcinus White, 1846 are assigned to this and other genera. Halicarcinus is restricted to seven valid species; Rhynchoplax Stimpson, 1858, since 1980 synonymised with Halicarcinus, is now recognised with four species; four species are added to Micas Ng & Richer de Forges, 1996 (making five in total); and four new genera are erected: Culexisoma n. gen. (two species, one newly described), Lucascinus n. gen. (three species), Nasutoplax n. gen. (one species) and Stimpsoplax n. gen. (three species). The genera are distinguished primarily on features of the gonopod 1, interaction of the pleon with the thoracic sternal pleonal cavity, maxilliped 3, male cheliped, propodus-dactylus articulation of the ambulatory pereopods, and degree of fusion of the pleomeres. Species of Halicarcinus s.s. share a short trilobed rostrum, strongly curved gonopod 1 and free pleomeres. Some members of other genera may have a similar rostrum but typically have a long median projection with or without lateral angles or spines variously developed at the anterior margin of a supraocular eave. A lectotype of Hymenicus cookii Filhol, 1885 (now Halicarcinus cookii) is designated. A lectotype of Hymenosoma leachii Guérin, 1832, in Guérin-Méneville 1829-1837 (synonym of Halicarcinus planatus Fabricius, 1775) is selected in the interests of nomenclatural stability. Halicarcinus quoyi (H. Milne Edwards, 1853) is recognised as a senior synonym of the more widely used H. innominatus Richardson, 1949, which is itself a nomen nudum because it was erected without type designation. We also recognise Hymenicus marmoratus Chilton, 1882, as a junior synonym of Halicarcinus varius (Dana, 1851). Species of Rhynchoplax share a curved gonopod 1, falcate dactyli on pereopods 2-5 and fused pleomeres 3-4 in males and 3-5 in females. Species of Micas have a twisted gonopod 1 with the apex bent and only one or two subapical teeth on the dactylus of ambulatory legs. Culexisoma n. gen. is established for Halicarcinus ginowan Naruse & Komai, 2009, and a second species, Culexisoma niugini n. sp., from Papua New Guinea as type species. The genus is unique among these genera in having the male pleon not tightly engaging with the thoracic sternum, maxillipeds 3 not fully covering the buccal cavern and in having a strongly sexually dimorphic rostrum. Species of Lucascinus n. gen. share a male cheliped with 'nut-cracker'-like fingers and free pleomeres in both male and female. Nasutoplax n. gen. differs from others in the erect lateral profile of the rostrum and in gonopod 1 with an unusual subterminal spinulose projection on its posterior face. Stimpsoplax n. gen. has a gonopod 1 with a swollen base and a narrow strongly twisted distal part, tapering distally to a curved apex. Each genus is diagnosed, all species are tabulated, some discussed in more detail, and generic diagnostic characters are illustrated. PMID:27394509

  16. Patterns of Diversity, Areas of Endemism, and Multiple Glacial Refuges for Freshwater Crabs of the Genus Sinopotamon in China (Decapoda: Brachyura: Potamidae)

    PubMed Central

    Fang, Fang; Sun, Hongying; Zhao, Qiang; Lin, Congtian; Sun, Yufang; Gao, Wei; Xu, Juanjuan; Zhou, Junying; Ge, Feng; Liu, Naifa

    2013-01-01

    Previous research has shown that the geographical distribution patterns of freshwater fishes and amphibians have been influenced by past climatic oscillations in China resulting from Pleistocene glacial activity. However, it remains unknown how these past changes have impacted the present-day distribution of Chinese freshwater crabs. This work describes the diversity and endemism of freshwater crabs belonging to Sinopotamon, a highly speciose genus endemic to China, and evaluates its distribution in terms of topography and past climatic fluctuations. Species diversity within Sinopotamon was found to be concentrated in an area from the northeastern edge of the Yunnan-Guizhou Plateau to the Jiangnan Hills, and three areas of endemism were identified. Multiple regression analysis between current climatic variables and Sinopotamon diversity suggested that regional annual precipitation, minimum temperature in the coldest month, and annual temperature range significantly influenced species diversity and may explain the diversity patterns of Sinopotamon. A comparison of ecological niche models (ENMs) between current conditions and the last glacial maximum (LGM) showed that suitable habitat for Sinopotamon in China severely contracted during the LGM. The coincidence of ENMs and the areas of endemism indicated that southeast of the Daba Mountains, and central and southeastern China, are potential Pleistocene refuges for Sinopotamon. The presence of multiple Pleistocene refuges within the range of this genus could further promote inter- and intraspecific differentiations, and may have led to high Sinopotamon species diversity, a high endemism rate and widespread distribution. PMID:23308152

  17. Results of the global conservation assessment of the freshwater crabs (Brachyura, Pseudothelphusidae and Trichodactylidae): The Neotropical region, with an update on diversity.

    PubMed

    Cumberlidge, Neil; Alvarez, Fernando; Villalobos, Jose-Luis

    2014-01-01

    The freshwater crabs of the Neotropics comprise 311 species in two families (Pseudothelphusidae and Trichodactylidae) and one or both of these families are found in all of the countries in the Neotropical region (except for Chile and some of the Caribbean islands). Colombia (102 species, 81% endemic) and Mexico (67 species, 95% endemic) are the biodiversity hotspots of freshwater crab species richness and country-level endemism for this region. The results of the IUCN Red List conservation assessments show that 34% of pseudothelphusids and 10% of trichodactylids have an elevated risk of extinction, 29% of pseudothelphusids and 75% of trichodactylids are not at-risk (Least Concern), and although none are actually extinct, 56% of pseudothelphusids and 17% of trichodactylids are too poorly known to assess (Data Deficient). Colombia (14 species), Venezuela (7 species), Mexico (6 species), and Ecuador (5 species) are the countries with the highest number of threatened species of Neotropical freshwater crabs. The majority of threatened species are restricted-range semiterrestrial endemics living in habitats subjected to deforestation, alteration of drainage patterns, and pollution. This underlines the need to prioritize and develop conservation measures before species decline to levels from which they cannot recover. These results represent a baseline that can be used to design strategies to save threatened Neotropical species of freshwater crabs.

  18. Significant fluctuations in ecdysteroid receptor gene (EcR) expression in relation to seasons of molt and reproduction in the grapsid crab, Metopograpsus messor (Brachyura: Decapoda).

    PubMed

    Shyamal, Sharmishtha; Anilkumar, G; Bhaskaran, R; Doss, G P; Durica, D S

    2015-01-15

    Metopograpsus messor, a brachyuran crab inhabiting the estuaries of North Kerala (India), is a prolific breeder releasing approximately 14-16 broods a year. The present paper reports the sequence information on the DNA binding domain (C domain, DBD), linker (D domain) and ligand binding domain (E domain, LBD) of M. messor ecdysteroid receptor (MmEcR) gene, the first grapsid brachyuran crab EcR examined. We have also measured MmEcR transcript levels in the ovary and the hepatopancreas throughout the annual cycle, with special reference to seasons of molt and reproduction. MmEcR expression in both the tissues is found to be at its peak (P<0.05) in late premolt crabs (January/May, molt/reproduction season); the expression levels are lowest (P<0.05) during June/July, when the females would neither molt nor reproduce (season for molt/reproduction repose). Intermediate levels of expression were found during the breeding season (August/December). Interestingly, this pattern of gene expression is in concordance with the fluctuating ecdysteroid levels of the hemolymph and Y organ secretory activity. The significant levels of fluctuation in the ovarian expression of MmEcR strongly suggest the ovary as a potential target for ecdysteroid action. A season-wise comparison of the gene expression reveals that ovarian MmEcR transcript levels are higher in breeding crabs (August/December) than the non-breeding animals (June/July), implicating a possible ecdysteroid role in reproduction in M. messor.

  19. Morphology of the first zoeal stage of the commensal southwestern Atlantic crab Austinixa aidae (Righi 1967) (Brachyura: Pinnotheridae), hatched in the laboratory

    NASA Astrophysics Data System (ADS)

    Mantelatto, Fernando L.; Cuesta, José A.

    2010-12-01

    The first zoeal stage of the endemic southern Atlantic pinnotherid crab Austinixa aidae is described and illustrated based on laboratory-hatched material from ovigerous females collected from the upper burrows of the thalassinidean shrimp Callichirus major at Ubatuba, São Paulo, Brazil. The zoeae of Austinixa species can be distinguished from other pinnotherids and especially from zoeae of the closely related species of Pinnixa by the telson structure.

  20. Correct date and authorship of taxa of Middle American freshwater crabs described by Rodríguez & Smalley (1972) (not 1969) and included in Smalley (1970) (Crustacea: Decapoda: Brachyura: Pseudothelphusidae).

    PubMed

    Guinot, Danièle; Hendrickx, Michel E

    2014-01-01

    One subgenus and one genus of Pseudothelphusidae described by Gilberto Rodríguez and Alfred E. Smalley from Mexico have been erroneously referred to for over 40 years as variously described in 1968 and 1969. The review of the original publication indicates that these taxa were published in a journal dated 1969 that became available for distribution only in 1972. Smalley (1970), who believed that the original manuscript had been previously published, referred to some of these new taxa (i.e., Epithelphusa, E. mixtepensis, Tehuana and T. veracruzana) and provided sufficient information to make these names available in 1970, thus becoming the correct authorship for these four taxa. Therefore they must be referred to as "Rodríguez & Smalley in Smalley 1970". A list of all affected taxa with the correct publication date and authorship is given. A list of publications in which the taxa authored by Rodríguez and Smalley were erroneously referred to as published in 1969 is also provided. PMID:24989760

  1. Correct date and authorship of taxa of Middle American freshwater crabs described by Rodríguez & Smalley (1972) (not 1969) and included in Smalley (1970) (Crustacea: Decapoda: Brachyura: Pseudothelphusidae).

    PubMed

    Guinot, Danièle; Hendrickx, Michel E

    2014-06-24

    One subgenus and one genus of Pseudothelphusidae described by Gilberto Rodríguez and Alfred E. Smalley from Mexico have been erroneously referred to for over 40 years as variously described in 1968 and 1969. The review of the original publication indicates that these taxa were published in a journal dated 1969 that became available for distribution only in 1972. Smalley (1970), who believed that the original manuscript had been previously published, referred to some of these new taxa (i.e., Epithelphusa, E. mixtepensis, Tehuana and T. veracruzana) and provided sufficient information to make these names available in 1970, thus becoming the correct authorship for these four taxa. Therefore they must be referred to as "Rodríguez & Smalley in Smalley 1970". A list of all affected taxa with the correct publication date and authorship is given. A list of publications in which the taxa authored by Rodríguez and Smalley were erroneously referred to as published in 1969 is also provided.

  2. Sex-structure, depth distribution, intermoult period and reproductive pattern of the deep-sea red crab Chaceon affinis (Brachyura, Geryonidae) in two populations in the north-eastern Atlantic

    NASA Astrophysics Data System (ADS)

    Biscoito, Manuel; Freitas, Mafalda; Pajuelo, José G.; Triay-Portella, Raül; Santana, José I.; Costa, Ana L.; Delgado, João; González, José A.

    2015-01-01

    This work investigated the biology of Chaceon affinis in two isolated populations of the Atlantic Ocean, including depth distribution, sexual structure, reproductive patterns and intermoult period. Males were larger and heavier than females. Mean size decreased with depth for both males and females. The highest abundance was found at 600-799 m of depth for males and at 800-999 m depth stratum for females. The highest abundance of ovigerous females was found at the 800-999 m depth stratum. Of the different ovaries' colour or colour shades recorded, only six categories were histologically characterized. The presence of spermatophores in the spermatheca of females in carapace stages II and III suggests that spermatophores are viable and used during the intermoult period. The size at sexual maturity in females was estimated at 104.4-104.7 mm carapace width (CW) in Madeira, and 109.3-110.5 mm CW in the Canary Islands. Only three categories of testes were identified. Mature testes consisted in a large mass, with highly coiled vasa deferentia visible to the naked eye. The size at sexual maturity in males was estimated at 113.8 mm CW in Madeira and 118.9 mm CW in the Canaries. The relative growth of males showed significant changes along the ontogeny and size at which allometric growth changes, as an indicator of morphometric maturity, occurred between 103.2 and 103.6 mm CW in Madeira and between 111.4 and 113.1 mm CW in the Canaries. In females, size at which allometric growth changes was found for maximum width of fifth abdominal somite (AS5W) at 98.2 mm CW in Madeira and 103.0 mm CW in the Canaries. The size at maturity obtained for C. affinis indicates that the minimum landing size (MLS) should not be set smaller than 125 mm CW in Madeira and 130 mm CW in the Canaries. This conservative MLS, higher than length at functional maturity, would safeguard immature individuals until they reach the size at which they can contribute to the reproductive capacity of the population. Ovigerous females were observed from October to April in Madeira, and in all months in the Canaries. Moreover, the observation of berried females in the last developmental stage in all quarters of the year suggests that gonad maturation and release of larvae are asynchronous throughout the spawning season. A total of 138 crabs with CW between 96 and 154 mm were tagged off Madeira. Of these, nine were recovered in the same area, more than 900 days after tagging. Eight of the recaptures were females with a wide range of CW confirming intermoult periods exceeding three years with expected growth per moult of less than 20 mm CW.

  3. Calappid and leucosiid crabs (Crustacea: Decapoda: Brachyura) from Kerala, India, with the description of a new species of Mursia Desmarest, 1823, from the Arabian Sea and redescription of M. bicristimana Alcock & Anderson, 1894.

    PubMed

    Kumar, Biju A; Kumar, M Sushil; Galil, Bella S

    2013-12-13

    Eleven species of calappid and leucosiid crabs were identified from by-catch landed by trawlers at four fishing ports in Kerala, India that were surveyed in 2007 and supplemented by material obtained in January 2013. Four species are reported for the first time from India, six are new records for Kerala. The status of Mursia bicristimana Alcock & Anderson, 1894, is clarified and the species redescribed. A new species of Mursia is described from the Gulf of Aden, Arabian Sea. 

  4. On the genera Selwynia Borradaile, 1903, and Gandoa Kammerer, 2006,
    with descriptions of two new species from Papua New Guinea and French
    Polynesia (Crustacea: Decapoda: Brachyura: Aphanodactylidae).

    PubMed

    Ng, Peter K L; Rahayu, Dwi Listyo

    2016-01-01

    The taxonomy of the Indo-West Pacific aphanodactylid crabs Selwynia sibogae (Tesch, 1918) and S. edmondsoni (Rathbun, 1932) is discussed on the basis of the types, and both species are redescribed and figured. Two new species from Papua New Guinea and French Polynesia respectively, are described and compared with congeners. All are symbionts in polychaete tubes. A key to the genus Selwynia is also provided. The poorly known genus Gandoa Kammerer, 2006, is redescribed on the basis of the rediscovered the type species, Voeltzkowia zanzibarensis Lenz, 1905. The lectotype female of Pinnixa brevipes H. Milne Edwards, 1853, is examined and shown to be a senior subjective synonym of G. zanzibarensis. PMID:27394459

  5. Parapleisticantha Yokoya, 1933, a valid genus of deep-sea inachid spider crab from Japan and the Philippines (Crustacea: Decapoda: Brachyura: Majoidea), with the description of a new species.

    PubMed

    De Forges, Bertrand Richer; Ng, Peter K L; Ahyong, Shane T

    2013-01-01

    The inachid spider crab genus, Parapleisticantha Yokoya, 1933 [type species: Parapleisticantha japonica Yokoya, 1933] is removed from the synonymy of Pleistacantha Miers, 1879 [type species: Pleistacantha sanctijohannis Miers, 1879], and recognised as a valid genus. Parapleisticantha differs from Pleistacantha sensu stricto primarily by having a less spiny carapace, stouter and more inflated male chelipeds, and by lacking a slender subdistal process on the male first gonopod. We redescribe Parapleisticantha japonica based on the Japanese type material and describe as new a second species, Parapleisticantha ludivinae n. sp., recently discovered in the Philippines.

  6. Samadinia longispina, a new genus and species of deep-sea spider crab from the western Pacific, and a new species of Rochinia A. Milne-Edwards, 1875, from Papua New Guinea (Crustacea: Brachyura: Majoidea: Epialtidae).

    PubMed

    Ng, Peter K L; Richer De Forges, Bertrand

    2013-01-01

    A new genus, Samadinia n. gen., and new species, Samadinia longispina n. sp., of deep-water epialtid spider crab is described from French Polynesia and New Caledonia. The new genus is superficially similar to Rochinia A. Milne-Edwards, 1875, but can be distinguished by having the dorsal surface of the carapace covered with small, rounded granules (versus with long spines or strong tubercles), well developed hepatic and lateral branchial spines (versus relatively shorter and weaker), a prominently constricted male thoracic sternite 4 (versus relatively broader with less prominent or without median constriction) and a proportionally broader male abdomen. A new species of Rochinia, R. granulosa n. sp., is also described from Papua New Guinea. It is easily distinguished from congeners its small adult size, the presence of numerous relatively large granules on the carapace and a relatively short hepatic spine.

  7. Description of a new genus and a new species of gaeticine crab (Crustacea: Brachyura: Varunidae) from the Ryukyu Islands, and a review of Acmaeopleura Stimpson, 1858, and Sestrostoma Davie & N.K. Ng, 2007.

    PubMed

    Naruse, Tohru

    2015-01-01

    Acmaeopleura parvula Stimpson, 1858, the type species of the varunid Acmaeopleura Stimpson, 1858, is redescribed, and a neotype is designated. Examination of all three species of the gaeticine Sestrostoma Davie & N.K. Ng, 2007, revealed that, although the diagnostic characters of Sestrostoma proposed by the previous study are variable and mostly overlap with those of Acmaeopleura, they can still be distinguished from each other by the characters of the carapace, the thoracic sternite 2, the third maxillipeds, and the ambulatory legs. The subfamilial position of Acmaeopleura was assessed by comparing it with all gaeticine genera. Gaetice Gistel, 1848, the type genus of the subfamily, has a very characteristic structure of the third maxilliped and the anterior sternal plate, which are partially shared with Gopkittisak Naruse & Clark, 2009, Brankocleistostoma Števčić, 2011, Sestrostoma and Acmaeopleura in different combinations. The generic diagnostic characters of these four genera are unique among Varunidae and they are tentatively placed in Gaeticinae. A new genus and new species, which is allied to Sestrostoma but clearly distinguishable from all varunine genera, is described from Iriomote Island, Ryukyu Islands, Japan. PMID:25781740

  8. Acute toxicity of sodium nitrate, potassium nitrate, and potassium chloride and their effects on the hemolymph composition and gill structure of early juvenile blue swimmer crabs(Portunus pelagicus Linnaeus, 1758) (Decapoda, Brachyura, Portunidae).

    PubMed

    Romano, Nicholas; Zeng, Chaoshu

    2007-09-01

    Various nutrients, including K+ and NO3-, are increasingly being discharged into aquatic systems via anthropogenic sources, which may impact marine organisms. The present study was conducted on blue swimmer crab (Portunus pelagicus) early juveniles to determine the acute toxicity of NaNO3, KNO3, and KCl; if a toxicity interaction exists between K+ and NO3-; the hemolymph Na+, K+, and Ca2+ changes; and the gill histopathological alterations following exposure to elevated NaNO3, KNO3, and KCl levels. A total of 20 replicate crabs were exposed to each of the five NaNO3, KNO3, and KCl concentrations for 96 h. After 96 h, the surviving crabs were sampled for hemolymph Na+, K+, and Ca2+ levels and fixed for histological examination of the anterior gills. The 96-h median lethal concentration of NaNO3-N, KNO3-N, KNO3-K, and KCl-K was 3,452, 112, 312, and 356 mg/L, respectively, for early P. pelagicus juveniles. The toxicity of NaNO3-N was significantly less (p < 0.01) than that of KNO3-N. Furthermore, at the same K+ levels, KNO3-K was significantly (p < 0.05) more toxic than KCl-K, indicating a toxicity interaction between K+ and NO3-. Following exposure to elevated KNO3 and KCl levels, the crabs had significantly higher (p < 0.01) hemolymph K+ levels compared to the control. Conversely, following exposure to elevated NaNO3 concentrations, the crabs had significantly higher (p < 0.01) hemolymph Na+ levels but significantly lower (p < 0.01) hemolymph K+ levels. Despite the markedly different hemolymph ionic changes following NaNO3 and KNO3/KCl exposure, the histopathological changes to the anterior gill lamellae of the crabs appeared to be similar, including lamellae swelling, epithelial thickening, pillar cell disruption, necrosis, and distortion.

  9. Gill-specific (Na(+), K(+))-ATPase activity and α-subunit mRNA expression during low-salinity acclimation of the ornate blue crab Callinectes ornatus (Decapoda, Brachyura).

    PubMed

    Leone, Francisco A; Garçon, Daniela P; Lucena, Malson N; Faleiros, Rogério O; Azevedo, Sergio V; Pinto, Marcelo R; McNamara, John C

    2015-08-01

    We evaluate (Na(+), K(+))-ATPase activity, and protein and gene expression of the α-subunit in posterior gills 6 and 7 of Callinectes ornatus, a euryhaline crab, during a 10-day acclimation period from seawater (33‰ S) to low salinity (21‰ S). (Na(+), K(+))-ATPase activity decreased within 1h after transfer to 21‰ S, values recovering by 24h and attaining a maximum of ≈180 nmol Pi min(-1) mg(-1) after 10 days (≈2.5-fold increase). (Na(+), K(+))-ATPase activity is ≈1.5-fold greater in gill 6 than in gill 7, independently of salinity. Relative expression of (Na(+), K(+))-ATPase α-subunit mRNA increased in both gills within 1- to 2-h exposure to low salinity, reaching an ≈8-fold maximum after 24-h exposure, decreasing slightly by 10 days acclimation to low salinity. This increase in α-subunit mRNA expression may underpin the increased (Na(+), K(+))-ATPase activity seen after 10 days acclimation to low salinity. Enzyme affinity for ATP was greater in gill 6 than in gill 7, in contrast to ouabain affinity that was greater in gill 7. Western blotting analysis identified a single immunoreactive band against the (Na(+), K(+))-ATPase α-subunit with an Mr of ≈105 kDa, independently of gill number and low salinity acclimation. Despite these differences, gills 6 and 7 appear to perform similar functions in salt uptake from the dilute medium. The partial cDNA sequence obtained for the gill (Na(+), K(+))-ATPase of C. ornatus (GenBank deposit KF056804) showed 97 to 91% identities with similar sequences from other portunid crab gills. The regulation of gill (Na(+), K(+))-ATPase activity during acclimation to low salinity is discussed.

  10. Na⁺,K⁺-ATPase activity in the posterior gills of the blue crab, Callinectes ornatus (Decapoda, Brachyura): modulation of ATP hydrolysis by the biogenic amines spermidine and spermine.

    PubMed

    Garçon, Daniela P; Lucena, Malson N; França, Juliana L; McNamara, John C; Fontes, Carlos F L; Leone, Francisco A

    2011-11-01

    We investigated the effect of the exogenous polyamines spermine, spermidine and putrescine on modulation by ATP, K⁺, Na⁺, NH₄⁺ and Mg²⁺ and on inhibition by ouabain of posterior gill microsomal Na⁺,K⁺-ATPase activity in the blue crab, Callinectes ornatus, acclimated to a dilute medium (21‰ salinity). This is the first kinetic demonstration of competition between spermine and spermidine for the cation sites of a crustacean Na⁺,K⁺-ATPase. Polyamine inhibition is enhanced at low cation concentrations: spermidine almost completely inhibited total ATPase activity, while spermine inhibition attained 58%; putrescine had a negligible effect on Na⁺,K⁺-ATPase activity. Spermine and spermidine affected both V and K for ATP hydrolysis but did not affect ouabain-insensitive ATPase activity. ATP hydrolysis in the absence of spermine and spermidine obeyed Michaelis-Menten behavior, in contrast to the cooperative kinetics seen for both polyamines. Modulation of V and K by K⁺, Na⁺, NH₄⁺ and Mg²⁺ varied considerably in the presence of spermine and spermidine. These findings suggest that polyamine inhibition of Na⁺,K⁺-ATPase activity may be of physiological relevance to crustaceans that occupy habitats of variable salinity.

  11. Calappid and leucosiid crabs (Crustacea: Decapoda: Brachyura) from Kerala, India, with the description of a new species of Mursia Desmarest, 1823, from the Arabian Sea and redescription of M. bicristimana Alcock & Anderson, 1894.

    PubMed

    Kumar, Biju A; Kumar, M Sushil; Galil, Bella S

    2013-01-01

    Eleven species of calappid and leucosiid crabs were identified from by-catch landed by trawlers at four fishing ports in Kerala, India that were surveyed in 2007 and supplemented by material obtained in January 2013. Four species are reported for the first time from India, six are new records for Kerala. The status of Mursia bicristimana Alcock & Anderson, 1894, is clarified and the species redescribed. A new species of Mursia is described from the Gulf of Aden, Arabian Sea.  PMID:25113495

  12. AN EARLY MIOCENE DEEP-WATER DECAPOD CRUSTACEAN FAUNULE FROM THE SLOVENIAN PART OF THE STYRIAN BASIN, AND ITS PALAEOENVIRONMENTAL AND PALAEOBIOGEOGRAPHICAL SIGNIFICANCE

    PubMed Central

    GAŠPARIČ, ROK; HYŽNÝ, MATÚŠ

    2015-01-01

    A new decapod crustacean faunule is described from the early Miocene of the Slovenian part of the Styrian Basin. The Ivnik Beds exposed at the Činžat locality contain seven species: Calliax michelottii (Axiidea: Callianassidae), Lepidophthalmus paratethyensis sp. nov. (Axiidea: Callianassidae), Jaxea kuemeli (Gebiidea: Laomediidae), Styrioplax exiguus (Brachyura: Chasmocarcinidae), Goneplax gulderi (Brachyura: Goneplacidae), Neopilumnoplax pohorjensis sp. nov. (Brachyura: Mathildellidae) and Retropluma slovenica sp. nov. (Brachyura: Retroplumidae). Numerous specimens of well-preserved Styrioplax exiguus permitted its redescription and re-assignment of its familial placement to Chasmocarcinidae. Neopilumnoplax pohorjensis sp. nov. constitutes the first fossil occurrence of the genus known to date. The decapod association, as well as other faunal elements, suggests low-energy deep-water depositional environment with epibathyal water depth of more than 125 m. The studied locality is situated in the Ribnica–Selnica graben filled with sediments once deposited in the Central Paratethys sea. Based on the affinities of decapod genera of the Central Paratethys and the Proto-Mediterranean, we conclude that the exchange of decapod faunas between these regions was probably regulated by an anti-estuarine circulation permitting an easier incursion of species from the Proto-Mediterranean into the Paratethys and simultaneous hindering the Paratethyan endemics (Styrioplax) from entering the Mediterranean. PMID:26689949

  13. Taphonomy and diversity of Middle Miocene decapod crustaceans from the Novohrad-Nógrad Basin, Slovakia, with remarks on palaeobiography

    PubMed Central

    Hyžný, Matúš; Hudáčková, Natália; Szalma, Štefan

    2016-01-01

    Decapod crustacean assemblages from the Middle Miocene (lower ‘Badenian’=Langhian) volcanoclastic Plášťovce Beds (Sebechleby Formation) in the Slovakian part of the Novohrad-Nógrad Basin comprise five species in five families (Callianassidae, Laomediidae, Munididae, Cancridae and Retroplumidae) and are dominated by the cancrid crab Tasadia carniolica (Bittner, 1884). Munida sp. constitutes the first record of this genus from Slovakia and the second from the European Neogene. Burrowing shrimp (Jaxea kuemeli Bachmayer, 1954) are associated with burrows tentatively attributed to this species. The occurrence of Retropluma slovenica Gašparič & Hyžný, 2014, previously recorded from the Lower Miocene of Slovenia, extends both the geographical distribution and stratigraphical range of the species. Differential decapod diversity at four localities in the Plášťovce area can be explained by collecting bias and palaeoenvironmental factors. The palaeosetting is interpreted as a muddy-bottom, nearshore zone with a water depth of approximately 100 m. Abundant articulated crabs suggest rapid burial. Third maxillipeds in open posture in some specimens may indicate respiratory stress of the animals, suggesting episodic events of rapid volcanoclastic flows responsible for killing crabs and promoting their preservation. Species composition of the decapod fauna of the Plášťovce Beds further strengthens similarities with Miocene faunas from the North Sea Basin. PMID:27499675

  14. The Decapod Crustacean Circulatory System: A Case That Is neither Open nor Closed

    NASA Astrophysics Data System (ADS)

    McGaw, Iain J.

    2005-02-01

    Historically, the decapod crustacean circulatory system has been classed as open. However, recent work on the blue crab, Callinectes sapidus, suggests the circulatory system may be more complex than previously described. Corrosion casting techniques were refined and used to map the circulatory system of a variety of crab species (order: Decapoda; family: Cancridae) to determine if the complexity observed in the blue crab was present in other species. Seven arteries arose from the single chambered heart. The anterior aorta, the paired anterolateral arteries, and the paired hepatic arteries exited from the anterior aspect of the heart. The small-diameter posterior aorta exited posteriorly from the heart. Exiting from the ventral surface of the heart, the sternal artery branched to supply the legs and mouthparts of the crab. These arteries were more complex than previously described, with arterioles perfusing all areas of the body. The arterioles split into fine capillary-like vessels. Most of these capillaries were blind ending. However, in several areas (antennal gland, supraesophageal ganglion) complete capillary beds were present. After passing through the capillary-like vessels, blood drained into a series of sinuses. However, rather than being arbitrary spaces as previously described, scanning electron micrographs showed the sinuses to be distinct units. Most of the sinuses formed a series of flattened membrane-bound lacunae. This complexity may qualify the decapod crustacean circulatory system as one that is "partially closed" rather than open.

  15. Contribution to the feeding ecology of the banded puffer fish Colomesus psittacus (Tetraodontidae) in north Brazilian mangrove creeks.

    PubMed

    Krumme, U; Keuthen, H; Saint-Paul, U; Villwock, W

    2007-08-01

    Stomach contents were examined from 102 banded puffer, Colomesus psittacus (Tetraodontidae), caught from intertidal mangrove creeks at diurnal neap tides between June and September, 1997 (early dry season) near Bragança (north Brazil). The study found that C. psittacus were specialized predators of Cirripedia (Balanus spp.) and Brachyuran crabs (Uca spp., Pachygrapsus gracilis) (mean: 58 and 38% by dry weight, respectively), emphasizing a short food chain in the mangrove system. Cirripedia and Brachyura dominated the diet in all size classes, however, the prey spectrum narrowed with fish size. The mean daily consumption of Cirripedia and Brachyura was 6.2% body weight of C. psittacus. On average C. psittacus consumed 100.3 g x ha(-1) x d(-1) of Cirripedia and 178.7 g x ha(-1) x d(-1) of Brachyura (wet weight). The predation on Brachyuran crabs--a significant driver of fluxes of organic matter and energy in the system--provides C. psittacus with an important ecological function in the mangrove food web. A plant-animal interaction is proposed where C. psittacus exerts a mutually beneficial cleaning function on the Aufwuchs (Cirripedia and associated epibiota) of Rhizophora mangle stilt roots. Our results and those of other studies suggest that C. psittacus encounter optimum foraging conditions in the mangrove at high inundations at daylight (spring tide-day) whereas darkness and low inundations are linked to poor foraging conditions (neap tide-night). The C. psittacus resource could be used as an alternative income in the region in terms of i) sustainable catch and filet processing for exports to East Asia, ii) developing certified aquaculture methods for breeding puffers for the aquarium trade.

  16. Contribution to the feeding ecology of the banded puffer fish Colomesus psittacus (Tetraodontidae) in north Brazilian mangrove creeks.

    PubMed

    Krumme, U; Keuthen, H; Saint-Paul, U; Villwock, W

    2007-08-01

    Stomach contents were examined from 102 banded puffer, Colomesus psittacus (Tetraodontidae), caught from intertidal mangrove creeks at diurnal neap tides between June and September, 1997 (early dry season) near Bragança (north Brazil). The study found that C. psittacus were specialized predators of Cirripedia (Balanus spp.) and Brachyuran crabs (Uca spp., Pachygrapsus gracilis) (mean: 58 and 38% by dry weight, respectively), emphasizing a short food chain in the mangrove system. Cirripedia and Brachyura dominated the diet in all size classes, however, the prey spectrum narrowed with fish size. The mean daily consumption of Cirripedia and Brachyura was 6.2% body weight of C. psittacus. On average C. psittacus consumed 100.3 g x ha(-1) x d(-1) of Cirripedia and 178.7 g x ha(-1) x d(-1) of Brachyura (wet weight). The predation on Brachyuran crabs--a significant driver of fluxes of organic matter and energy in the system--provides C. psittacus with an important ecological function in the mangrove food web. A plant-animal interaction is proposed where C. psittacus exerts a mutually beneficial cleaning function on the Aufwuchs (Cirripedia and associated epibiota) of Rhizophora mangle stilt roots. Our results and those of other studies suggest that C. psittacus encounter optimum foraging conditions in the mangrove at high inundations at daylight (spring tide-day) whereas darkness and low inundations are linked to poor foraging conditions (neap tide-night). The C. psittacus resource could be used as an alternative income in the region in terms of i) sustainable catch and filet processing for exports to East Asia, ii) developing certified aquaculture methods for breeding puffers for the aquarium trade. PMID:18094820

  17. The complete mitochondrial genomes of Umalia orientalis and Lyreidus brevifrons: The phylogenetic position of the family Raninidae within Brachyuran crabs.

    PubMed

    Shi, Guohui; Cui, Zhaoxia; Hui, Min; Liu, Yuan; Chan, Tin-Yam; Song, Chengwen

    2015-06-01

    The complete mitochondrial genome (mitogenome) sequences of two primitive crabs, Umalia orientalis and Lyreidus brevifrons (Decapoda: Brachyura: Raninidae) were determined. The mitogenomes of the two species are 15,466 and 16,112bp in length with AT content of 68.0% and 70.6%, respectively. Each genome contains 13 protein-coding genes (PCGs), two rRNA genes, and 22 tRNA genes. The gene arrangement of U. orientalis is the same with those reported for most brachyuran species. Nevertheless, the gene arrangement of L. brevifrons differs from that of U. orientalis in having an additional non-coding region. The newly found non-coding region is located between nad3 and trnA with 641bp in length. Its nucleotide composition and secondary structure are similar to the typical control region. In L. brevifrons, the secondary structures of trnS-AGN and trnI are significantly different from those in U. orientalis and other brachyuran species. The start codon for cox1 is ATG in all reported Eubrachyura mitogenomes, while a common start codon ACG is found in the Podotremata. Phylogenetic analyses for crustacean decapods based on the nucleotide and amino acid of 13 PCGs indicate that Homolidae is more primitive in Brachyura, and Raninidae is a sister group to Eubrachyura. This implies that Raninidae is closer to Eubrachyura than to Homolidae, and Podotremata may be a paraphyletic assemblage. The results also indicate that the subfamily Lyreidinae is closer to Notopodinae than to Ranininae within Raninidae. The novel mitogenome data provides useful information for refining the phylogenetic relationships within Brachyura.

  18. Libanasa kilomeni, a new species of East African Lutosinae (Orthoptera: Anostostomatidae).

    PubMed

    Hemp, Claudia; Johns, Peter M

    2015-01-01

    A new species of Libanasa, L. kilomeni, is described. In contrast to L. brachyura, an inhabitant of lowland wet to submontane forest along the Tanzanian coast and part of the Eastern Arc Mountains of Tanzania, this new species is found in montane forest in the North Pare Mountains. L. kilomeni n. sp. is restricted to a small forest reserve and due to forest clearing at lower elevations probably driven to its upper ecological border. Therefore this species is considered endangered and should be included in the IUCN red list. PMID:26624379

  19. Monomia calla, a new species of swimming crab (Decapoda, Portunidae)
    from Madagascar and the Philippines.

    PubMed

    Koch, Milan; Nguyen, Thanh Son; Ďuriš, Zdeněk

    2015-01-01

    A new species of portunid crab (Brachyura: Portunidae) from southern Madagascar and central Philippines is described. Monomia calla sp. nov. is most similar in morphology to M. lecromi (Moosa, 1996) from the Chesterfield Islands in the southwestern Pacific Ocean, and M. rubromarginata (Lanchester, 1900) from the South China Sea, Singapore, Malay Archipelago and the northern half of Australia. The new species can be easily distinguished from all congeners by the distinctive morphology of the male first gonopod. The number of species of the Indo-West Pacific genus Monomia now stands at 12.

  20. Survey of genome size in 28 hydrothermal vent species covering 10 families.

    PubMed

    Bonnivard, Eric; Catrice, Olivier; Ravaux, Juliette; Brown, Spencer C; Higuet, Dominique

    2009-06-01

    Knowledge of genome size is a useful and necessary prerequisite for the development of many genomic resources. To better understand the origins and effects of DNA gains and losses among species, it is important to collect data from a broad taxonomic base, but also from particular ecosystems. Oceanic thermal vents are an interesting model to investigate genome size in very unstable environments. Here we provide data estimated by flow cytometry for 28 vent-living species among the most representative from different hydrothermal vents. We also report the genome size of closely related coastal decapods. Haploid C-values were compared with those previously reported for species from corresponding orders or infraorders. This is the first broad survey of 2C values in vent organisms. Contrary to expectations, it shows that certain hydrothermal vent species have particularly large genomes. The vent squat lobster Munidopsis recta has the largest genome yet reported for any anomuran: 2C=31.1 pg=30.4x10(9) bp. In several groups, such as Brachyura, Phyllodocida, and Veneroida, vent species have genomes that clearly rank at the high end of published values for each group. We also describe the highest DNA content yet recorded for the Brachyura (coastal crabs Xantho pilipes and Necora puber). Finally, analysis of genome size variation across populations revealed unexpected intraspecific variation in the vent shrimp Mirocaris fortunata that could not be attributed simply to ploidy changes.

  1. Phylogenetics of the brachyuran crabs (Crustacea: Decapoda): the status of Podotremata based on small subunit nuclear ribosomal RNA.

    PubMed

    Ahyong, Shane T; Lai, Joelle C Y; Sharkey, Deirdre; Colgan, Donald J; Ng, Peter K L

    2007-11-01

    The true crabs, the Brachyura, are generally divided into two major groups: Eubrachyura or 'advanced' crabs, and Podotremata or 'primitive' crabs. The status of Podotremata is one of the most controversial issues in brachyuran systematics. The podotreme crabs, best recognised by the possession of gonopores on the coxae of the pereopods, have variously been regarded as mono-, para- or polyphyletic, or even as non-brachyuran. For the first time, the phylogenetic positions of the podotreme crabs were studied by cladistic analysis of small subunit nuclear ribosomal RNA sequences. Eight of 10 podotreme families were represented along with representatives of 17 eubrachyuran families. Under both maximum parsimony and Bayesian Inference, Podotremata was found to be significantly paraphyletic, comprising three major clades: Dromiacea, Raninoida, and Cyclodorippoida. The most 'basal' is Dromiacea, followed by Raninoida and Cylodorippoida. Notably, Cyclodorippoida was identified as the sister group of the Eubrachyura. Previous hypotheses that the dromiid crab, Hypoconcha, is an anomuran were unsupported, though Dromiidae as presently composed could be paraphyletic. Topologies constrained for podotreme monophyly were found to be significantly worse (P < 0.04) than unconstrained topologies under Templeton and S-H tests. The clear pattern of podotreme paraphyly and robustness of topologies recovered indicates that Podotremata as a formal concept is untenable. Relationships among the eubrachyurans were generally equivocal, though results indicate the majoids or dorippoids were the least derived of the Eubrachyura. A new high level classification of the Brachyura is proposed.

  2. Circular dichroism study of the hemocyanin thermostability

    NASA Astrophysics Data System (ADS)

    Nikolova Georgieva, Dessislava; Stoeva, Stanka; Abid Ali, Syed; Abbasi, Atiya; Genov, Nicolay; Voelter, Wolfgang

    1998-05-01

    Circular dichroism spectroscopy is used to investigate the thermostability of six arthropod hemocyanins (Hcs), representatives of the subphyla Crustacea (infraorder Brachyura) and Chelicerate (infraorders Xiphosura and Arachnida), and three molluscan Hcs from gastropod organisms. Melting points ( Tm) are determined from the temperature dependence of ellipticity of dioxygen-binding proteins from Maia squinado, Callinectes sapidus, Carcinus maenas, Limulus polyphemus, Buthus sindicus, Androctonus australis, Megathura crenulata, Haliotis tuberculata, and Rapana thomasiana. Both, arthropod and molluscan Hcs, are thermostable proteins with melting temperatures in the region 68-91°C. Binuclear dioxygen-binding sites contribute significantly to the thermostability and increase the Tm values of the apo-forms by 3-16°C. An elevated thermostability is observed in the case of the Limulus polyphemus Hc. One of the reasons is the high degree of hemocyanin oligomerization.

  3. Littoral decapods of Socorro Island, Revillagigedo Archipelago, Mexico.

    PubMed

    Mille-Pagaza, Silvia; Pérez-Chi, A; Sánchez-Salazar, M E

    2003-03-01

    Decapod community inhabiting the rocky littoral of eight bays from Socorro island, Revillagigedo Archipelago, was studied during March 1992. Samples were collected from one-square meter plots placed following transects drawn perpendicularly to the shoreline along the intertidal zone. Species richness and abundance were determined in each bay, as well as the similarity between bays using Morisita's index. Organisms collected belong to six families, 20 genera and 26 species of the Brachyura and Anomura infraorders. Xanthidae was the family with the highest number of species, and the highest species richness was recorded at the V. Lozano bay. Pachygrapsus transversus, Xanthodius cooksoni and Calcinus explorator were the most abundant species in nearly all localities. Dendrogram obtained define two groups of bays at a similarity level above 0.67, given the similarity in the crab's species richness and their abundance between bays in the island.

  4. A 150-million-year-old crab larva and its implications for the early rise of brachyuran crabs.

    PubMed

    Haug, Joachim T; Martin, Joel W; Haug, Carolin

    2015-03-09

    True crabs (Brachyura) are the most successful group of decapod crustaceans. This success is most likely coupled to their life history, including two specialised larval forms, zoea and megalopa. The group is comparably young, starting to diversify only about 100 million years ago (mya), with a dramatic increase in species richness beginning approximately 50 mya. Early evolution of crabs is still very incompletely known. Here, we report a fossil crab larva, 150 mya, documented with up-to-date imaging techniques. It is only the second find of any fossil crab larva, but the first complete one, the first megalopa, and the oldest one (other fossil ca. 110 mya). Despite its age, the new fossil possesses a very modern morphology, being indistinguishable from many extant crab larvae. Hence, modern morphologies must have been present significantly earlier than formerly anticipated. We briefly discuss the impact of this find on our understanding of early crab evolution.

  5. Descriptions and revised key to the eggcases of the skates (Rajiformes: Rajidae) and catsharks (Carcharhiniformes: Scyliorhinidae) of the British Isles.

    PubMed

    Gordon, Cat A; Hood, Ali R; Ellis, Jim R

    2016-01-01

    Updated descriptions and measurements for the eggcases of 10 rajiform and three scyliorhinid species occurring in the shelf seas around the British Isles are given, based on museum material, specimens collected during the 'Great Eggcase Hunt' (a Shark Trust recording project), and specimens obtained from fishery surveys. Quantitative data are given for Amblyraja radiata (n = 94), Dipturus batis (n = 24), D. cf. intermedia (n = 33), Leucoraja naevus (n = 94), Raja brachyura (n = 53), R. clavata (n = 52), R. microocellata (n = 57), R. montagui (n = 52), R. undulata (n = 52), Rostroraja alba (n = 5), Galeus melastomus (n = 7), Scyliorhinus canicula (n = 52) and S. stellaris (n = 58). An updated key for the identification of elasmobranch eggcases is provided, incorporating recent changes in skate taxonomy. PMID:27515657

  6. Chewing lice (Phthiraptera) from wild birds in Senegal, with descriptions of three new species of the genera Brueelia and Philopteroides.

    PubMed

    Najer, Tomáš; Sychra, Oldřich; Literák, Ivan; Procházka, Petr; Capek, Miroslav; Koubek, Petr

    2012-03-01

    A total of 170 wild birds from Senegal, belonging to 48 species and 9 orders, were searched for lice in 2005 and 2007. Chewing lice were found on 58 birds of 18 species and 5 orders (Columbiformes, Cuculiformes, Coraciiformes, Galliformes and Passeriformes). Twenty-two species of chewing lice of 13 genera were determined. Other nine samples of chewing lice that represent a new host-parasite association were determined at generic level only, because only one sex or nymph of these lice were found. Our records represent the first louse records from passerines Camaroptera brachyura (Cisticolidae), Chalcomitra senegalensis (Nectariniidae), Corvinella corvina (Laniidae), Laniarius barbarus (Malaconotidae), Prinia erythroptera (Cisticolidae) and Turdus pelios (Turdidae). Descriptions and illustrations are given for Brueelia chalcomitrae Najer et Sychra sp. nov. ex Chalcomitra senegalensis (Nectariniidae), Brueelia priniae Najer et Sychra sp. nov. ex Prinia subflava (Cisticolidae), and Philopteroides terpsiphoni Najer et Sychra sp. nov. ex Terpsiphone viridis (Monarchidae).

  7. Numerical density and biomass of macrobenthic animals living in the intertidal zone of Surinam, South America

    NASA Astrophysics Data System (ADS)

    Swennen, C.; Duiven, P.; Spaans, A. L.

    The macrobenthic fauna of all types of intertidal area of the Surinam coast, mainly mud flats, were briefly studied by coring. Crustaceans dominated; polychaetes and molluscs were poorly represented. The highest biomass values (32 to 37 g · m -2 ADW, mainly contributed by Uca maracoani) were found around high tide level, at the border of the mangrove forest. Just outside the Uca zone, on sheltered places also high values ( ca 20 g · m -2 ADW, mainly contributed by Tanaidacea) were found. In the middle and lower parts of the flats biomass was low (only a few g · m -2 or less), probably a result of the instability of the sediment. The following crustaceans not recorded previously for Surinam were found living in the intertidal clay and mud: Hexapanopeus schmitti, Cycloplax pinnotheroides, Pinnixa sayana (Brachyura), and Upogebia brasiliensis (Macrura).

  8. Molecular cloning and characterization of a heat shock protein 70 gene in swimming crab (Portunus trituberculatus).

    PubMed

    Cui, Zhaoxia; Liu, Yuan; Luan, Weisha; Li, Qianqian; Wu, Danhua; Wang, Shuangyan

    2010-01-01

    Hsp70 can stimulate cells of the innate immune system directly by acting as "danger"-signaling molecules. To understand the immune defense mechanisms of swimming crab Portunus trituberculatus (Decapoda: Brachyura: Portunidae), the cDNA of Hsp70 (designated PtHsp70) was cloned by the combination of homology cloning and rapid amplification of cDNA ends (RACE). The full-length PtHsp70 cDNA was 2195 bp, including an open reading frame (ORF) of 1950 bp encoding a polypeptide of 650 amino acids with estimated molecular mass of 71.1514 kDa and theoretical isoelectric point of 5.38. FASTA and BLAST analysis indicated that PtHsp70 should be an inducible cytosolic member of the Hsp70 family. The coding region of PtHsp70 was uninterrupted and four SNPs with 1133C/T, 1311C/T, 1551C/T and 1809 A/G were detected by direct sequencing of 20 genomic samples. Using fluorescent real-time quantitative PCR, the transcriptional expression of PtHsp70 showed a clear time-dependent response after challenge by Vibrio alginolyticus, the main causative agent of emulsification disease causing large mortality in P. trituberculatus. This is the first report on the expression of Hsp70 induced by pathogen stimulation in Brachyura. Phylogenetic analysis revealed that the inducible Hsp70s were divided into two groups in crab and PtHsp70 was clustered into the Hsp/Hsc group (Clade I) by maximum-likelihood (ML) and Bayesian inference (BI) methods. GAP repeat and GGMP motif of inducible Hsp70 gene in the crab species were only found in Clade I. PMID:19815077

  9. Crystallization and preliminary X-ray diffraction studies of trypsin-like proteases from the gastric fluid of the marine crab Cancer pagurus

    SciTech Connect

    Hehemann, Jan-Hendrik; Redecke, Lars; Saborowski, Reinhard; Betzel, Christian

    2007-03-01

    Two trypsins from the gastric fluid of the marine crab C. pagurus were purified and crystallized and X-ray data were collected to 0.97 and 3.2 Å resolution. The digestive fluid of the marine crab Cancer pagurus (Decapoda, Brachyura) contains highly stable proteases which display enhanced activity in aqueous mixtures of organic solvents. Three trypsins were isolated from the gastric fluid and two of them, C.p.TryII and C.p.TryIII, were purified to homogeneity by anion-exchange chromatography and crystallized by hanging-drop vapour diffusion. Diffraction data were collected at a synchrotron to 0.97 and 3.2 Å resolution, respectively. The crystal of C.p.TryII belongs to the orthorhombic space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 52.06, b = 62.00, c = 71.66 Å. Based on the Matthews coefficient, one protein molecule per asymmetric unit is suggested. In contrast, crystals of C.p.TryIII, which belong to the cubic space group P2{sub 1}3 with unit-cell parameters a = b = c = 215.4 Å, are assumed to contain 12 molecules per asymmetric unit.

  10. A Membrane-bound Hemoglobin from Gills of the Green Shore Crab Carcinus maenas*

    PubMed Central

    Ertas, Beyhan; Kiger, Laurent; Blank, Miriam; Marden, Michael C.; Burmester, Thorsten

    2011-01-01

    Most hemoglobins serve for the transport or storage of O2. Although hemoglobins are widespread in “entomostracan” Crustacea, malacostracans harbor the copper-containing hemocyanin in their hemolymph. Usually, only one type of respiratory protein occurs within a single species. Here, we report the identification of a hemoglobin of the shore crab Carcinus maenas (Malacostraca, Brachyura). In contrast to the dodecameric hemocyanin of this species, C. maenas hemoglobin does not reside in the hemolymph but is restricted to the gills. Immunofluorescence studies and cell fractioning showed that C. maenas hemoglobin resides in the membrane of the chief cells of the gill. To the best of our knowledge, this is the first time that a membrane-bound hemoglobin has been identified in eukaryotes. Bioinformatic evaluation suggests that C. maenas hemoglobin is anchored in the membrane by N-myristoylation. Recombinant C. maenas hemoglobin has a hexacoordinate binding scheme at the Fe2+ and an oxygen affinity of P50 = 0.5 Torr. A rapid autoxidation rate precludes a function as oxygen carrier. We rather speculate that, analogous to prokaryotic membrane-globins, C. maenas hemoglobin carries out enzymatic functions to protect the lipids in cell membrane from reactive oxygen species. Sequence comparisons and phylogenetic studies suggested that the ancestral arthropod hemoglobin was most likely an N-myristoylated protein that did not have an O2 supply function. True respiratory hemoglobins of arthropods, however, evolved independently in chironomid midges and branchiopod crustaceans. PMID:21118803

  11. Phylogenetic and morphometric differentiation reveal geographic radiation and pseudo-cryptic speciation in a mangrove crab from the Indo-West Pacific.

    PubMed

    Ragionieri, Lapo; Fratini, Sara; Vannini, Marco; Schubart, Christoph D

    2009-09-01

    The presence of boundaries to dispersal has been recently documented for many Indo-West Pacific (IWP) species with planktonic propagules and a widespread distribution. We studied the phylogeography of the mangrove crab Neosarmatium meinerti (Brachyura: Sesarmidae) and the phylogenetic relationship to its presumed sister species N. fourmanoiri in the IWP in order to compare intraspecific with interspecific diversity. Portions of the mitochondrial genes 16S and CoxI were sequenced for 23 specimens of N. meinerti and 5 N. fourmanoiri, while a fragment of the 28S was obtained for a subset of specimens. Genetic data are supplemented by morphometric and based on 37 adult males of N. meinerti and 9 males of N. fourmanoiri. The conserved nuclear 28S reveals the existence of a genetic break between the Indian and Pacific oceans. Otherwise, mitochondrial genes as well as morphometry clearly support the presence of a species complex within N. meinerti composed by four well structured and geographically defined lineages: East African coast; western Indian Ocean islands; South East Asia; and Australia. PMID:19394431

  12. Lilliput effect in a retroplumid crab (Crustacea: Decapoda) across the K/Pg boundary

    NASA Astrophysics Data System (ADS)

    Martínez-Díaz, José Luis; Phillips, George E.; Nyborg, Torrey; Espinosa, Belinda; Távora, Vladimir de Araújo; Centeno-García, Elena; Vega, Francisco J.

    2016-08-01

    The genus Costacopluma (Brachyura: Decapoda: Retroplumidae) had a wide distribution during the early Paleogene and is currently represented by 14 species across the Late Cretaceous and early Paleogene. Described early Paleogene species have a smaller mean body size compared to Campanian-Maastrichtian populations of Africa, northeastern Mexico, and southeastern United States. Originally described from the Paleocene and Eocene of Alabama, Costacopluma grayi Feldmann and Portell, 2007, is now documented from the uppermost Maastrichtian (66.2 Ma) of northeastern Mexico and Mississippi and Lower Paleocene of Arkansas, all representing medium size specimens. The morphological features of latest Maastrichtian (66.2 Ma) individuals are identical to those observed among populations of C. grayi from the Paleogene of Alabama and Arkansas, which have a smaller mean size. This size reduction, or dwarfism, in C. grayi across the K-Pg boundary is an example of the Lilliput effect. Dwarfism has been documented in several invertebrate groups as a response to environmental stress, but this is the first record of the Lilliput effect in brachyuran crustaceans. The stratigraphic and geographic range for Costacopluma mexicana Vega and Perrilliat, 1989, is extended to the upper Campanian in northeastern Mexico and lower Maastrichtian in Mississippi and is suggested as a possible ancestor of C. grayi. Different preservational modes for this species in northeastern Mexico are discussed.

  13. Antarctic Crabs: Invasion or Endurance?

    PubMed Central

    Griffiths, Huw J.; Whittle, Rowan J.; Roberts, Stephen J.; Belchier, Mark; Linse, Katrin

    2013-01-01

    Recent scientific interest following the “discovery” of lithodid crabs around Antarctica has centred on a hypothesis that these crabs might be poised to invade the Antarctic shelf if the recent warming trend continues, potentially decimating its native fauna. This “invasion hypothesis” suggests that decapod crabs were driven out of Antarctica 40–15 million years ago and are only now returning as “warm” enough habitats become available. The hypothesis is based on a geographically and spatially poor fossil record of a different group of crabs (Brachyura), and examination of relatively few Recent lithodid samples from the Antarctic slope. In this paper, we examine the existing lithodid fossil record and present the distribution and biogeographic patterns derived from over 16,000 records of Recent Southern Hemisphere crabs and lobsters. Globally, the lithodid fossil record consists of only two known specimens, neither of which comes from the Antarctic. Recent records show that 22 species of crabs and lobsters have been reported from the Southern Ocean, with 12 species found south of 60°S. All are restricted to waters warmer than 0°C, with their Antarctic distribution limited to the areas of seafloor dominated by Circumpolar Deep Water (CDW). Currently, CDW extends further and shallower onto the West Antarctic shelf than the known distribution ranges of most lithodid species examined. Geological evidence suggests that West Antarctic shelf could have been available for colonisation during the last 9,000 years. Distribution patterns, species richness, and levels of endemism all suggest that, rather than becoming extinct and recently re-invading from outside Antarctica, the lithodid crabs have likely persisted, and even radiated, on or near to Antarctic slope. We conclude there is no evidence for a modern-day “crab invasion”. We recommend a repeated targeted lithodid sampling program along the West Antarctic shelf to fully test the validity of the

  14. Comparing quality of estuarine and nearshore intertidal habitats for Carcinus maenas

    NASA Astrophysics Data System (ADS)

    Amaral, Valter; Cabral, Henrique N.; Jenkins, Stuart; Hawkins, Stephen; Paula, José

    2009-06-01

    Estuarine and nearshore marine areas are vital habitats for several fish and benthic invertebrates. The shore crab Carcinus maenas (Crustacea: Brachyura: Portunidae) inhabits a variety of coastal, estuarine and lagoon habitats. At low tide, habitat structural complexity may be most important for crabs in the intertidal, providing refuge from predation and desiccation. The quality of different vegetated and nonvegetated estuarine and rocky shore habitats in SW Portugal and SW England was evaluated for intertidal C. maenas populations. We estimated population density, size-structure, and potential growth (RNA/DNA ratios) to investigate habitat quality. Vegetated estuarine habitats supported higher crab densities, than nonvegetated estuarine and rocky shore habitats. Investigation of population size-structure revealed that all habitats seem important recruitment and nursery areas although estuarine habitats in SW Portugal appeared to support higher densities of new recruits than equivalent habitats in SW England. Significant variation was found in RNA/DNA ratios among habitats. Ratios were highest in the rocky shore suggesting a high quality habitat where growth potential is high. We speculate that competition from other top-predators ( Pachygrapsus spp.) rather than low habitat quality may limit the occurrence of C. maenas in intertidal rocky shore habitats in SW Portugal. In estuarine environments RNA/DNA ratios were significantly higher in the vegetated than in the nonvegetated estuarine habitats in SW Portugal but not in SW England, suggesting geographic differences in the extent to which highly structure habitats represent high quality. Our results challenge the current paradigm that structured habitats are necessarily those of higher quality for C. maenas.

  15. Antarctic crabs: invasion or endurance?

    PubMed

    Griffiths, Huw J; Whittle, Rowan J; Roberts, Stephen J; Belchier, Mark; Linse, Katrin

    2013-01-01

    Recent scientific interest following the "discovery" of lithodid crabs around Antarctica has centred on a hypothesis that these crabs might be poised to invade the Antarctic shelf if the recent warming trend continues, potentially decimating its native fauna. This "invasion hypothesis" suggests that decapod crabs were driven out of Antarctica 40-15 million years ago and are only now returning as "warm" enough habitats become available. The hypothesis is based on a geographically and spatially poor fossil record of a different group of crabs (Brachyura), and examination of relatively few Recent lithodid samples from the Antarctic slope. In this paper, we examine the existing lithodid fossil record and present the distribution and biogeographic patterns derived from over 16,000 records of Recent Southern Hemisphere crabs and lobsters. Globally, the lithodid fossil record consists of only two known specimens, neither of which comes from the Antarctic. Recent records show that 22 species of crabs and lobsters have been reported from the Southern Ocean, with 12 species found south of 60 °S. All are restricted to waters warmer than 0 °C, with their Antarctic distribution limited to the areas of seafloor dominated by Circumpolar Deep Water (CDW). Currently, CDW extends further and shallower onto the West Antarctic shelf than the known distribution ranges of most lithodid species examined. Geological evidence suggests that West Antarctic shelf could have been available for colonisation during the last 9,000 years. Distribution patterns, species richness, and levels of endemism all suggest that, rather than becoming extinct and recently re-invading from outside Antarctica, the lithodid crabs have likely persisted, and even radiated, on or near to Antarctic slope. We conclude there is no evidence for a modern-day "crab invasion". We recommend a repeated targeted lithodid sampling program along the West Antarctic shelf to fully test the validity of the "invasion hypothesis

  16. Mitogenomic analysis of decapod crustacean phylogeny corroborates traditional views on their relationships.

    PubMed

    Shen, Hong; Braband, Anke; Scholtz, Gerhard

    2013-03-01

    Phylogenetic relationships within decapod crustaceans are highly controversial. Even recent analyses based on molecular datasets have shown largely contradictory results. Previous studies using mitochondrial genomes are promising but suffer from a poor and unbalanced taxon sampling. To fill these gaps we sequenced the (nearly) complete mitochondrial genomes of 13 decapod species: Stenopus hispidus, Polycheles typhlops, Panulirus versicolor, Scyllarides latus, Enoplometopus occidentalis, Homarus gammarus, Procambarus fallax f. virginalis, Upogebia major, Neaxius acanthus, Calocaris macandreae, Corallianassa coutierei, Cryptolithodes sitchensis, Neopetrolisthes maculatus, and add that of Dromia personata. Our new data allow for comprehensive analyses of decapod phylogeny using the mitochondrial genomes of 50 species covering all major taxa of the Decapoda. Five species of Stomatopoda and one species of Euphausiacea serve as outgroups. Most of our analyses using Maximum Likelihood (ML) and Bayesian inference (BI) of nucleotide and amino acid datasets revealed congruent topologies for higher level decapod relationships: (((((((Anomala, Brachyura), Thalassinida: Gebiidea), Thalassinida: Axiidea), (Astacidea, Polychelida), Achelata), Stenopodidea), Caridea), Dendrobranchiata). This result corroborates several traditional morphological views and adds new perspectives. In particular, the position of Polychelida is surprising. Nevertheless, some problems can be identified. In a minority of analyses the basal branching of Reptantia is not fully resolved, Thalassinida are monophyletic; Polychelida are the sister group to Achelata, and Stenopodidea are resolved as sister group to Caridea. Despite this and although some nodal supports are low in our phylogenetic trees, we think that the largely stable topology of the trees regardless of different types of analyses suggests that mitochondrial genomes show good potential to resolve the relationship within Decapoda. PMID:23202543

  17. Molecular and mass spectral identification of the broadly conserved decapod crustacean neuropeptide pQIRYHQCYFNPISCF: the first PISCF-allatostatin (Manduca sexta- or C-type allatostatin) from a non-insect

    PubMed Central

    Stemmler, Elizabeth A.; Bruns, Emily A.; Cashman, Christopher R.; Dickinson, Patsy S.; Christie, Andrew E.

    2009-01-01

    The PISCF-allatostatins (Manduca sexta- or C-type allatostatins) are a family of pentadecapeptides characterized by a pyroglutamine blocked N-terminus, an unamidated –PISCF C-terminus, and a disulfide bridge between two internal Cys residues. Several isoforms of PISCF-AST are known, all from holometabolous insects. Using a combination of transcriptomics and mass spectrometry, we have identified the first PISCF-type peptides from a non-insect species. In silico analysis of crustacean ESTs identified several Litopenaeus vannamei (infraorder Penaeidea) transcripts encoding putative PISCF-AST precursors. Translation of these ESTs, with subsequent prediction of their putative post-translational processing, revealed the existence of as many as three PISCF-type peptides, including pQIRYHQCYFNPISCF (disulfide bridging between Cys7 and Cys14). Although none of the predicted isoforms was detected by mass spectrometry in L. vannamei, MALDI-FTMS mass profiling identified an m/z signal corresponding to pQIRYHQCYFNPISCF (disulfide bridge present) in neural tissue from 28 other decapods, which included members of six infraorders (Stenopodidea, Astacidea, Thalassinidea, Achelata, Anomura and Brachyura). Further characterization of the peptide using SORI-CID and chemical derivatization/enzymatic digestion supported the theorized structure. In both the crab Cancer borealis and the lobster Homarus americanus, MALDI-based tissue surveys suggest that pQIRYHQCYFNPISCF is broadly distributed in the nervous system; it was also detected in the posterior midgut caecum. Collectively, our data show that members of the PISCF-AST family are not restricted to the holometabolous insects, but instead may be broadly conserved within the Pancrustacea. Moreover, our data suggest that one highly conserved PISCF-type peptide, pQIRYHQCYFNPISCF, is present in decapod crustaceans, functioning as a brain-gut paracrine/hormone. PMID:19467234

  18. Identification of potential essential fish habitats for skates based on fishers' knowledge.

    PubMed

    Serra-Pereira, Bárbara; Erzini, Karim; Maia, Catarina; Figueiredo, Ivone

    2014-05-01

    Understanding of spatio-temporal patterns of sensitive fish species such as skates (Rajidae) is essential for implementation of conservation measures. With insufficient survey data available for these species in Portuguese Continental waters, this study shows that fishery-dependent data associated with fishers' knowledge can be used to identify potential Essential Fish Habitats (EFH) for seven skate species. Sites with similar geomorphology were associated with the occurrence of juveniles and/or adults of the same group of species. For example, sites deeper than 100 m with soft sediment include predominantly adults of Raja clavata, and are the habitat for egg deposition of this species. Raja undulata and R. microocellata are the more coastal species, preferring sand or gravel habitats, while coastal areas with rocks and sand seabed are potential nursery areas for R. brachyura, R. montagui and R. clavata. The main output of this study is the identification of preferential fishing sites enclosing potential EFH for some species, associated with egg-laying and nursery grounds. The location of these areas will be considered for future seasonal closures, and studies will be conducted to evaluate the biological and socio-economic impacts of such measures. As in the past, fishermen will collaborate in the process of evaluating those impacts, since they have practical and applied knowledge that is extremely valuable for evaluating the advantages and disadvantages of such closures. In conclusion, this study is a first contribution to the understanding and identification of EFH for skate species, associated with nursery and egg deposition sites, with direct application to management. PMID:24573167

  19. Antarctic crabs: invasion or endurance?

    PubMed

    Griffiths, Huw J; Whittle, Rowan J; Roberts, Stephen J; Belchier, Mark; Linse, Katrin

    2013-01-01

    Recent scientific interest following the "discovery" of lithodid crabs around Antarctica has centred on a hypothesis that these crabs might be poised to invade the Antarctic shelf if the recent warming trend continues, potentially decimating its native fauna. This "invasion hypothesis" suggests that decapod crabs were driven out of Antarctica 40-15 million years ago and are only now returning as "warm" enough habitats become available. The hypothesis is based on a geographically and spatially poor fossil record of a different group of crabs (Brachyura), and examination of relatively few Recent lithodid samples from the Antarctic slope. In this paper, we examine the existing lithodid fossil record and present the distribution and biogeographic patterns derived from over 16,000 records of Recent Southern Hemisphere crabs and lobsters. Globally, the lithodid fossil record consists of only two known specimens, neither of which comes from the Antarctic. Recent records show that 22 species of crabs and lobsters have been reported from the Southern Ocean, with 12 species found south of 60 °S. All are restricted to waters warmer than 0 °C, with their Antarctic distribution limited to the areas of seafloor dominated by Circumpolar Deep Water (CDW). Currently, CDW extends further and shallower onto the West Antarctic shelf than the known distribution ranges of most lithodid species examined. Geological evidence suggests that West Antarctic shelf could have been available for colonisation during the last 9,000 years. Distribution patterns, species richness, and levels of endemism all suggest that, rather than becoming extinct and recently re-invading from outside Antarctica, the lithodid crabs have likely persisted, and even radiated, on or near to Antarctic slope. We conclude there is no evidence for a modern-day "crab invasion". We recommend a repeated targeted lithodid sampling program along the West Antarctic shelf to fully test the validity of the "invasion hypothesis".

  20. Identification of SYWKQCAFNAVSCFamide: a broadly conserved crustacean C-type allatostatin-like peptide with both neuromodulatory and cardioactive properties

    PubMed Central

    Dickinson, Patsy S.; Wiwatpanit, Teerawat; Gabranski, Emily R.; Ackerman, Rachel J.; Stevens, Jake S.; Cashman, Christopher R.; Stemmler, Elizabeth A.; Christie, Andrew E.

    2009-01-01

    Summary The allatostatins comprise three structurally distinct peptide families that regulate juvenile hormone production by the insect corpora allata. A-type family members contain the C-terminal motif –YXFGLamide and have been found in species from numerous arthropod taxa. Members of the B-type family exhibit a –WX6Wamide C-terminus and, like the A-type peptides, appear to be broadly conserved within the Arthropoda. By contrast, members of the C-type family, typified by the unblocked C-terminus –PISCF, a pyroglutamine blocked N-terminus, and a disulfide bridge between two internal Cys residues, have only been found in holometabolous insects, i.e. lepidopterans and dipterans. Here, using transcriptomics, we have identified SYWKQCAFNAVSCFamide (disulfide bridging predicted between the two Cys residues), a known honeybee and water flea C-type-like peptide, from the American lobster Homarus americanus (infraorder Astacidea). Using matrix assisted laser desorption/ionization Fourier transform mass spectrometry (MALDI-FTMS), a mass corresponding to that of SYWKQCAFNAVSCFamide was detected in the H. americanus brain, supporting the existence of this peptide and its theorized structure. Furthermore, SYWKQCAFNAVSCFamide was detected by MALDI-FTMS in neural tissues from five additional astacideans as well as 19 members of four other decapod infraorders (i.e. Achelata, Anomura, Brachyura and Thalassinidea), suggesting that it is a broadly conserved decapod peptide. In H. americanus, SYWKQCAFNAVSCFamide is capable of modulating the output of both the pyloric circuit of the stomatogastric nervous system and the heart. This is the first demonstration of bioactivity for this peptide in any species. PMID:19423507

  1. Decapod crustaceans from the state of Ceará, northeastern Brazil: an updated checklist of marine and estuarine species, with 23 new records.

    PubMed

    Pachelle, Paulo P G; Anker, Arthur; Mendes, Cecili B; Bezerra, Luis E A

    2016-06-27

    The present study is the first major assessment of the marine decapod fauna of Ceará, northeastern Brazil, since contributions of J. Fausto-Filho in the 1960s-1970s. A fully updated checklist of all decapod crustaceans occurring in marine and estuarine habitats of Ceará is provided, based on literature records, specimens held in two carcinological collections of the Universidade Federal do Ceará (UFC), and material collected mainly by the authors between 2011 and 2014. A total of 337 decapod species are listed, distributed among the following taxa: Achelata (8 species), Anomura (42 species), Astacidea (1 species), Axiidea (11 species), Brachyura (162 species), Caridea (83 species), Dendrobranchiata (20 species), Gebiidea (9 species), and Stenopodidea (1 species). Among them, 23 species represent new records for Ceará, with 14 species, viz. Alpheus peasei (Armstrong, 1940), A. thomasi Hendrix & Gore, 1973, Ambidexter symmetricus Manning & Chace, 1971, Axianassa australis Rodrigues & Shimizu, 1992, Biffarius biformis (Biffar, 1971), B. fragilis (Biffar, 1970), Leptalpheus axianassae Dworschak & Coelho, 1999, L. forceps Williams, 1965, Lysmata bahia Rhyne & Lin, 2006, L. intermedia (Kingsley, 1878), Merhippolyte americana Holthuis, 1961, Neocallichirus maryae Karasawa, 2004, Ogyrides hayi Williams, 1981, and Typton carneus Holthuis, 1951, now having Ceará as the northern-most limit in their distribution range along the Brazilian coastline. One shrimp species, Lysmata lipkei Okuno & Fiedler, 2010, which was also found in the state of Rio Grande do Norte, possibly represents an invasive taxon in Brazil and the western Atlantic, originating from the Indo-West Pacific. Alpheus buckupi Almeida, Terossi, Araújo-Silva & Mantelatto, 2013, previously recorded from Ceará based on a colour photograph, is confirmed from this state, with specimens from several new localities. A few doubtful records from Ceará are briefly discussed. Colour photographs are provided for most

  2. Evolutionary morphology of the organ systems in squat lobsters and porcelain crabs (crustacea: Decapoda: Anomala): an insight into carcinization.

    PubMed

    Keiler, Jonas; Richter, Stefan; Wirkner, Christian S

    2015-01-01

    Porcelain crabs (Porcellanidae) are one of three taxa within anomuran crustaceans (Anomala) which possess a crab-like body form. Curiously, these three lineages evolved this shape independently from true crabs (Brachyura) in the course of the evolutionary process termed carcinization. The entire pleon in porcelain crabs is flexed under the cephalothorax and the carapace is approximately as broad as long. Despite their crab-like habitus, porcelain crabs are phylogenetically nested within squat lobsters (Munidopsidae, Munididae, Galatheidae). With a pleon which is only partly flexed under the cephalothorax and a cephalothorax which is longer than it is broad, squat lobsters represent morphologically intermediate forms between lobster-like and crab-like body shapes. Carcinization has so far mostly been studied with respect to outer morphology; however, it is evident that internal anatomical features are influenced through this change of body shape too. In this paper, the situation in Galatheoidea is elucidated by adding more taxa to existing descriptions of the hemolymph vascular systems and associated structures and organs. Micro-computer tomography and 3D reconstruction provide new insights. Autapomorphic states of various internal anatomical characters are present in nearly all the studied species, also reflecting some degree of anatomical disparity found within Galatheoidea. The ventral vessel system of porcelain crabs differs distinctly from that of squat lobsters. The differences in question are coherent (i.e. structural dependent) with morphological transformations in the integument, such as the shortening of the sternal plastron, which evolved in the course of carcinization. Shifts in the gonads and the pleonal neuromeres are coherent with the loss of the caridoid escape reaction, which in turn is a consequence of carcinization. The arterial transformations, however, are minor compared to other instances of carcinization in anomuran crustaceans since the last

  3. Identification of potential essential fish habitats for skates based on fishers' knowledge.

    PubMed

    Serra-Pereira, Bárbara; Erzini, Karim; Maia, Catarina; Figueiredo, Ivone

    2014-05-01

    Understanding of spatio-temporal patterns of sensitive fish species such as skates (Rajidae) is essential for implementation of conservation measures. With insufficient survey data available for these species in Portuguese Continental waters, this study shows that fishery-dependent data associated with fishers' knowledge can be used to identify potential Essential Fish Habitats (EFH) for seven skate species. Sites with similar geomorphology were associated with the occurrence of juveniles and/or adults of the same group of species. For example, sites deeper than 100 m with soft sediment include predominantly adults of Raja clavata, and are the habitat for egg deposition of this species. Raja undulata and R. microocellata are the more coastal species, preferring sand or gravel habitats, while coastal areas with rocks and sand seabed are potential nursery areas for R. brachyura, R. montagui and R. clavata. The main output of this study is the identification of preferential fishing sites enclosing potential EFH for some species, associated with egg-laying and nursery grounds. The location of these areas will be considered for future seasonal closures, and studies will be conducted to evaluate the biological and socio-economic impacts of such measures. As in the past, fishermen will collaborate in the process of evaluating those impacts, since they have practical and applied knowledge that is extremely valuable for evaluating the advantages and disadvantages of such closures. In conclusion, this study is a first contribution to the understanding and identification of EFH for skate species, associated with nursery and egg deposition sites, with direct application to management.

  4. Evolutionary morphology of the organ systems in squat lobsters and porcelain crabs (crustacea: Decapoda: Anomala): an insight into carcinization.

    PubMed

    Keiler, Jonas; Richter, Stefan; Wirkner, Christian S

    2015-01-01

    Porcelain crabs (Porcellanidae) are one of three taxa within anomuran crustaceans (Anomala) which possess a crab-like body form. Curiously, these three lineages evolved this shape independently from true crabs (Brachyura) in the course of the evolutionary process termed carcinization. The entire pleon in porcelain crabs is flexed under the cephalothorax and the carapace is approximately as broad as long. Despite their crab-like habitus, porcelain crabs are phylogenetically nested within squat lobsters (Munidopsidae, Munididae, Galatheidae). With a pleon which is only partly flexed under the cephalothorax and a cephalothorax which is longer than it is broad, squat lobsters represent morphologically intermediate forms between lobster-like and crab-like body shapes. Carcinization has so far mostly been studied with respect to outer morphology; however, it is evident that internal anatomical features are influenced through this change of body shape too. In this paper, the situation in Galatheoidea is elucidated by adding more taxa to existing descriptions of the hemolymph vascular systems and associated structures and organs. Micro-computer tomography and 3D reconstruction provide new insights. Autapomorphic states of various internal anatomical characters are present in nearly all the studied species, also reflecting some degree of anatomical disparity found within Galatheoidea. The ventral vessel system of porcelain crabs differs distinctly from that of squat lobsters. The differences in question are coherent (i.e. structural dependent) with morphological transformations in the integument, such as the shortening of the sternal plastron, which evolved in the course of carcinization. Shifts in the gonads and the pleonal neuromeres are coherent with the loss of the caridoid escape reaction, which in turn is a consequence of carcinization. The arterial transformations, however, are minor compared to other instances of carcinization in anomuran crustaceans since the last

  5. Neutrino-driven wakefield plasma accelerator

    NASA Astrophysics Data System (ADS)

    Rios, L. A.; Serbeto, A.

    2003-08-01

    Processos envolvendo neutrinos são importantes em uma grande variedade de fenômenos astrofísicos, como as explosões de supernovas. Estes objetos, assim como os pulsares e as galáxias starburst, têm sido propostos como aceleradores cósmicos de partículas de altas energias. Neste trabalho, um modelo clássico de fluidos é utilizado para estudar a interação não-linear entre um feixe de neutrinos e um plasma não-colisional relativístico de pósitrons e elétrons na presença de um campo magnético. Durante a interação, uma onda híbrida superior de grande amplitude é excitada. Para parâmetros típicos de supernovas, verificamos que partículas carregadas "capturadas" por essa onda podem ser aceleradas a altas energias. Este resultado pode ser importante no estudo de mecanismos aceleradores de partículas em ambientes astrofísicos.

  6. Capture of Anastrepha species (Diptera: Tephritidae) with multilure traps and biolure attractants in Guatemala

    SciTech Connect

    Martinez, A.J.; Salinas, E.J.; Rendon, P.

    2007-03-15

    . distincta Greene, A. fraterculus Weidemann y Ceratitis capitata Weidemann. Ademas, se capturaron 13 especias adicionales de Anastrepha asi como Toxotrypana curvicauda Gerstaecker con el cebo sintetico. El cebo sintetico fue efectivo por diez semanas sin recebar. Las trampas de plastico capturaron mas moscas del genero Anastrepha que la trampa de cristal McPhail. Las excepciones fueron A. distincta en donde no hubo differencias el la captura con la trampa de plastico con base amarillo y la trampa McPhail de cristal asi como A. fraterculus en donde no hubo differencias comparando la captura de moscas con ambos sistemas. La proporcion sexual de las moscas capturadas con los dos sistemas fue al favor de las hembras. La captura de otros tipos de insectos fue significantemente elevado, sin embargo, las moscas capturadas con los cebos sinteticos no fueron afectados adversamente por estos insectos. El 10% del anticongelante, glicol propilico, fue superior al borax/agua como conservador de las moscas capturardas. (author)

  7. Distribution and bioconcentration of heavy metals in a tropical aquatic food web: A case study of a tropical estuarine lagoon in SE Mexico.

    PubMed

    Mendoza-Carranza, Manuel; Sepúlveda-Lozada, Alejandra; Dias-Ferreira, Celia; Geissen, Violette

    2016-03-01

    Despite the increasing impact of heavy metal pollution in southern Mexico due to urban growth and agricultural and petroleum activities, few studies have focused on the behavior and relationships of these pollutants in the biotic and abiotic components of aquatic environments. Here, we studied the bioaccumulation of heavy metals (Cd, Cr, Ni, Pb, V, Zn) in suspended load, sediment, primary producers, mollusks, crustaceans, and fish, in a deltaic lagoon habitat in the Tabasco coast, with the aim to assess the potential ecological risk in that important wetland. Zn showed the highest concentrations, e.g., in suspended load (mean of 159.58 mg kg(-1)) and aquatic consumers (15.43-171.71 mg kg(-1)), particularly Brachyura larvae and ichthyoplankton (112.22-171.71 mg kg(-1)), followed by omnivore Callinectes sp. crabs (113.81-128.07 mg kg(-1)). The highest bioconcentration factors (BCF) of Zn were observed for planktivore and omnivore crustaceans (3.06-3.08). Zn showed a pattern of distribution in the food web through two pathways: the pelagic (where the higher concentrations were found), and the benthic (marsh plants, sediment, mollusk, fish). The other heavy metals had lower occurrences in the food web. Nevertheless, high concentrations of Ni and Cr were found in phytoplankton and sediment (37.62-119.97 mg kg(-1)), and V in epiphytes (68.64 mg kg(-1)). Ni, Cr, and Cd concentrations in sediments surpassed international and national threshold values, and Cd entailed a "considerable" potential risk. These heavy metals are most likely transferred into the food web up to fishes through the benthic pathway. Most of the collected fishes are residents in this type of habitat and have commercial importance. Our results show that the total potential ecological risk in the area can be considered as "moderate". Nevertheless, heavy metal values were similar or surpassed the values from other highly industrialized tropical coastal regions. PMID:26708770

  8. Inorganic Biominerals in Crustaceans are Structurally Independent of Organic Framework

    NASA Astrophysics Data System (ADS)

    Mergelsberg, S. T.; Michel, F. M.; Mukhopadhyay, B.; Dove, P. M.

    2015-12-01

    Biomineralization of calcium carbonate (CaCO3) as crystalline calcite or amorphous CaCO3 (ACC) occurs in the exoskeletons of all crustaceans. These cuticles are complex composites of inorganic mineral and organic macromolecules with highly divergent morphologies that are adapted to the extreme variations in environmental pressures within their diverse ecological niches. The remarkable variations and adaptations that form, infer a highly efficient and regulated mechanism for biomineralization that is most likely orchestrated by a myriad of biomacromolecules (Ziegler A 2012). The roles of these peptides and organic metabolites during CaCO3 biomineralization are not well understood. In part, this is due to a lack of knowledge of crustacean homeostasis. In a step toward understanding cuticle mineralization in crustaceans, this study asks: Which molecules affect biomineralization? Do the biomineral-active molecules vary greatly between species and body parts? Recent studies of polysaccharide controls on mineralization also raise the question of whether small heterogeneities in chitin, the most abundant biopolymer of the composite, could be primarily responsible for differences in CaCO3 crystallinity. This study used a novel spectroscopic approach to characterize the mineral and organic components of exoskeletons from three Malacostraca organisms — American Lobster (Homarus americanus), Dungeness Crab (Metacarcinus magister), and Red Rock Crab (Cancer productus). Using high-energy x-ray diffraction and Raman spectroscopy, the cuticles of three major body parts from these organisms were analyzed for the structure and bulk chemistry of its chitin and CaCO3 components. The findings indicate that Raman spectroscopy provides adequate resolution to show that crystallinity of chitin and the CaCO3 mineral component are chemically independent of each other, although their crystallinities co-vary for Brachyura species (Dungeness and Red Rock Crabs). Insights from this study

  9. DNA barcoding unveils skate (Chondrichthyes: Rajidae) species diversity in ‘ray’ products sold across Ireland and the UK

    PubMed Central

    Egan, Aaron; Fox, Jennifer; Greenfield, Adam; Mariani, Stefano

    2013-01-01

    Skates are widely consumed across the globe, but many large species are subject to considerable concern regarding their conservation and management. Within Europe such issues have recently driven policy changes so that, for the first time, reports of skate landings now have to be made under species-specific names. Total allowable catches have also been established for many groups, which have been set to zero for a number of the most vulnerable species (e.g., Dipturus batis, Raja undulata and Rostoraja alba). Whilst accurate species identification has become an important issue for landings, the sale of skates is still usually made under a blanket term of “skate” or “ray”. The matter of identifying species of skate is further complicated by their morphologically conservative nature and the fact that they are commercially valued for their wings. Thus, before sale their bodies are usually discarded (i.e., “winged”) and often skinned, making morphological identification impossible. For the first time, DNA barcoding (of the mitochondrial COI gene) was applied to samples of skate wings from retail outlets across the British Isles, providing insight into which species are sold for consumption. A total of 98 wing samples were analysed, revealing that six species were sold; blonde ray (Raja brachyura), spotted ray (Raja montagui), thornback ray (Raja clavata), cuckoo ray (Leucoraja naevus) small-eyed ray (Raja microocellata) and shagreen ray (Leucoraja fullonica). Statistical testing demonstrated that there were significant differences in the species sold in the distinct retail groups which suggests complex drivers behind the patterns of sale in skates. The results also indicate that endangered species are not commonly being passed on to consumers. In addition, the practice of selling skate wings under ambiguous labels is highlighted as it makes it extremely difficult for consumers to exercise a right to avoid species of conservation concern. Interestingly, a

  10. Portunoid crabs as indicators of the Red Sea fauna history and endemism

    NASA Astrophysics Data System (ADS)

    Spiridonov, Vassily; Türkay, Michael; Brösing, Andreas; Al-Aidaroos, Ali

    2013-04-01

    Peculiar environmental conditions and "turbulent" geological history make the Red Sea a laboratory of evolution and a significant area for understanding adaptation processes. To interpret the results of this basin-scale evolutionary experiment revised inventories of taxonomic diversity of particular groups of marine biota are essential. As one of the first results of the Red Sea Biodiversity Survey (RSBS) in the years 2011 - 2012 along the coast of Saudi Arabia (http://www.redseabiodiversity.org/) and examination of earlier collections and literature a revised species list is provided for the portunoid (swimming) crabs (Crustacea Decapoda Portunoidea). This superfamily is one of the most species rich and has one of the broadest habitat scopes among Brachyura in the global scale. The present assessment results in 54 shallow water species (including 2 recorded for the first time in the Red Sea during RSBS), 2 deep water species and 1 semipelagic species Charybdis smithii. Doubtful literature records of another 7 shallow water species remain unconfirmed. Among reliably recorded shallow water species 58 % belong to widespread Indo-West-Pacific (IWP) species, 13% are the species restricted to the western Indian Ocean, 11 % are endemics of the Arabian region (occurring also either in the western Gulf of Aden or along the eastern coast of the Arabian Peninsula, or in both areas) which are usually vicariant to the widespread IWP species, 11% are taxa that are similar to the species occurring elsewhere in the IWP but have morphological peculiarities and probably deserve a specific or subspecific status. Finally 4% of species (Thalamita murinae and Liocarcinus subcorrugatus) appear to be endemic for the Red Sea and show remarkable disjunctions from most closely related species. Carcinus sp. (probably C. aestuarii) is an introduced (but not established) species in the northern Red Sea. The deep water fauna of the Red Sea is unique because it lives in the warm (20.5-21.5 ° C

  11. Brain architecture of the largest living land arthropod, the Giant Robber Crab Birgus latro (Crustacea, Anomura, Coenobitidae): evidence for a prominent central olfactory pathway?

    PubMed Central

    2010-01-01

    visual and mechanosensory skills that are comparable to those of marine Crustacea. Conclusions In parallel to previous behavioral findings that B. latro has aerial olfaction, our results indicate that their central olfactory pathway is indeed most prominent. Similar findings from the closely related terrestrial hermit crab Coenobita clypeatus suggest that in Coenobitidae, olfaction is a major sensory modality processed by the brain, and that for these animals, exploring the olfactory landscape is vital for survival in their terrestrial habitat. Future studies on terrestrial members of other crustacean taxa such as Isopoda, Amphipoda, Astacida, and Brachyura will shed light on how frequently the establishment of an aerial sense of olfaction evolved in Crustacea during the transition from sea to land. Amounting to ca. 1,000,000, the numbers of interneurons that analyse the olfactory input in B. latro brains surpasses that in other terrestrial arthropods, as e.g. the honeybee Apis mellifera or the moth Manduca sexta, by two orders of magnitude suggesting that B. latro in fact is a land-living arthropod that has devoted a substantial amount of nervous tissue to the sense of smell. PMID:20831795

  12. Dispersal and longevity of wild and mass-reared Anastrepha Ludens and Anastrepha Obliqua (Diptera: Tephritidae)

    SciTech Connect

    Hernandez, E.; Orozco, D.; Flores Breceda, S.; Dominguez, J.

    2007-03-15

    capturadas con mayor frecuencia que los machos. La recaptura de moscas silvestres de A. ludens fue de 0.6 a 24.8%, para A. obliqua fue del 1.3 al 16.2%, para moscas de laboratorio fue de 0.5 a 7.1 y 0.5 a 3%, respectivamente. La esperanza de vida correspondio a 4.7 y 4.3 dias para machos silvestres y de laboratorio de A. obliqua respectivamente; mientras que 3 y 2 dias fueron para los machos silvestres y de laboratorio de A. ludens . La dispersion para A. ludens y A. obliqua fue de 100 a 250 m tanto para individuos silvestres como de laboratorio. Los adultos de A. ludens silvestre se desplazaron del punto central de liberacion al noroeste, los individuos de laboratorio se movieron hacia el oeste del plano Cartesiano. A su vez los adultos de A. obliqua silvestre se movieron hacia el oeste y las de laboratorio hacia el suroeste. Discutimos las implicaciones de nuestros resultados con relacion al espaciamiento y frecuencia de las liberaciones de moscas esteriles para la supresion de poblaciones silvestres. (author)

  13. Disappearance of the last lions and hyenas of Europe in the Late Quaternary - a chain reaction of large mammal prey migration, extinction and human antagonism

    NASA Astrophysics Data System (ADS)

    Diedrich, Cajus G.

    2010-05-01

    recorded anymore in northern and central Germany, such as cave bears. References Begouen R. and Clottes J. 1987. Les Trois Frères after Breuil. Antiquity, 61: 180-187. Bosinski, G. 1987. Die große Zeit der Eiszeitjäger. Europa zwischen 40.000 und 10.000 v.Chr. Jahrbuch des Römisch-Germanischen Zentralmuseums, 34: 13-139. Breuil, H. 1952. Four Hundred Centuries of Cave Art. Montignac, Dordogne, 414 pp. Chauvet, J.-M., Deschamps B.E, and Hillaire C. 1995. Grotte Chauvet. Altsteinzeitliche Höhlenkunst im Tal der Ardèche. Thorbecke Speläo 1, Sigmaringen, 120 pp. Diedrich, C. 2005. Eine oberpleistozäne Population von Crocuta crocuta spelaea (GOLDFUSS 1823) aus dem eiszeitlichen Fleckenhyänenhorst Perick-Höhlen von Hemer (Sauerland, NW Deutschland) und ihr Kannibalismus. Philippia, 12 (2): 93-115, Kassel. Diedrich, C. 2006. The Crocuta crocuta spelaea (Goldfuss 1823) population from the early Upper Pleistocene hyena open air prey deposit site Biedensteg near Bad Wildungen (Hess, NW Germany) and the contribution to their phylogenetic position, coprolites and prey. Cranium, 23 (2): 39-53, Amsterdam. Diedrich, C. 2007a. Upper Pleistocene Panthera leo spelaea (Goldfuss 1810) skeleton remains from Praha-Podbaba and the contribution to other lion finds from loess and river terrace sites in Central Bohemia (Czech Republic). Bulletin of Geosciences, 82 (2), 99-117, Prague. Diedrich, C. 2007b. Crocuta crocuta spelaea (GOLDFUSS 1823) remains from the Upper Pleistocene hyaena Teufelskammer Cave den site near Hochdahl in the Neander valley (NRW, NW Germany). Cranium, 24 (2): 39-44, Amsterdam. Diedrich, C. 2007c. The Upper Pleistocene Crocuta crocuta spelaea (GOLDFUSS 1823) population and its prey from the gypsum karst den site Westeregeln near Magdeburg (Middle Germany). Abhandlungen und Berichte für Naturkunde, 30: 57-83, Magdeburg. Diedrich, C. 2008a. Late Pleistocene Hystrix (Acanthion) brachyura LINNAEUS 1758 from the Fuchsluken cave at the Rote Berg near Saalfeld (Thuringia