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Sample records for scaphopod graptacme eborea

  1. Complete sequences of the highly rearranged molluscan mitochondrial genomes of the scaphopod graptacme eborea and the bivalve mytilus edulis

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    Boore, Jeffrey L.; Medina, Monica; Rosenberg, Lewis A.

    2004-01-31

    We have determined the complete sequence of the mitochondrial genome of the scaphopod mollusk Graptacme eborea (Conrad, 1846) (14,492 nts) and completed the sequence of the mitochondrial genome of the bivalve mollusk Mytilus edulis Linnaeus, 1758 (16,740 nts). (The name Graptacme eborea is a revision of the species formerly known as Dentalium eboreum.) G. eborea mtDNA contains the 37 genes that are typically found and has the genes divided about evenly between the two strands, but M. edulis contains an extra trnM and is missing atp8, and has all genes on the same strand. Each has a highly rearranged gene order relative to each other and to all other studied mtDNAs. G. eborea mtDNA has almost no strand skew, but the coding strand of M. edulis mtDNA is very rich in G and T. This is reflected in differential codon usage patterns and even in amino acid compositions. G. eborea mtDNA has fewer non-coding nucleotides than any other mtDNA studied to date, with the largest non-coding region being only 24 nt long. Phylogenetic analysis using 2,420 aligned amino acid positions of concatenated proteins weakly supports an association of the scaphopod with gastropods to the exclusion of Bivalvia, Cephalopoda, and Polyplacophora, but is generally unable to convincingly resolve the relationships among major groups of the Lophotrochozoa, in contrast to the good resolution seen for several other major metazoan groups.

  2. Living scaphopods from the Valencian coast (E Spain and description of Antalis caprottii n. sp. (Dentaliidae

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    Martínez–Ortí, A.

    2012-01-01

    Full Text Available This paper reports on eight scaphopod species found at 128 sampling stations near the coast of Valencia (Spain during the campaigns of the Water Framework Directive (2000/60/CE 2005, 2006 and 2008. Samples deposited in several Valencian institutions and private collections are also described. The identified species belong to four families: Dentaliidae (Antalis dentalis, A. inaequicostata, A. novemcostata, A. vulgaris, and A. caprottii n. sp., a new species described from material found on the coasts of the province of Castellón, Fustiariidae (Fustiaria rubescens, Entalinidae (Entalina tetragona and Gadilidae (Dischides politus. We describe the characteristics and conchiological variations for each species and give geographic distribution maps on the Valencian coast for each species

  3. The ParaHox gene Gsx patterns the apical organ and central nervous system but not the foregut in scaphopod and cephalopod mollusks.

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    Wollesen, Tim; Rodríguez Monje, Sonia Victoria; McDougall, Carmel; Degnan, Bernard M; Wanninger, Andreas

    2015-01-01

    It has been hypothesized that the ParaHox gene Gsx patterned the foregut of the last common bilaterian ancestor. This notion was corroborated by Gsx expression in three out of four lophotrochozoan species, several ecdysozoans, and some deuterostomes. Remarkably, Gsx is also expressed in the bilaterian anterior-most central nervous system (CNS) and the gastropod and annelid apical organ. To infer whether these findings are consistent with other mollusks or even lophotrochozoans, we investigated Gsx expression in developmental stages of representatives of two other molluscan classes, the scaphopod Antalis entalis and the cephalopod Idiosepius notoides. Gsx is not expressed in the developing digestive tract of Antalis entalis and Idiosepius notoides. Instead, it is expressed in cells of the apical organ in the scaphopod trochophore and in two cells adjacent to this organ. Late-stage trochophores express Aen-Gsx in cells of the developing cerebral and pedal ganglia and in cells close to the pavilion, mantle, and foot. In postmetamorphic specimens, Aen-Gsx is expressed in the cerebral and pedal ganglia, the foot, and the nascent captacula. In early squid embryos, Ino-Gsx is expressed in the cerebral, palliovisceral, and optic ganglia. In late-stage embryos, Ino-Gsx is additionally expressed close to the eyes and in the supraesophageal and posterior subesophageal masses and optic lobes. Developmental stages close to hatching express Ino-Gsx only close to the eyes. Our results suggest that Gsx expression in the foregut might not be a plesiomorphic trait of the Lophotrochozoa as insinuated previously. Since neither ecdysozoans nor deuterostomes express Gsx in their gut, a role in gut formation in the last common bilaterian ancestor appears unlikely. Gsx is consistently expressed in the bilaterian anterior-most CNS and the apical organ of lophotrochozoan larvae, suggesting a recruitment of Gsx into the formation of this organ in the Lophotrochozoa. The cephalopod posterior

  4. A neurophylogenetic approach provides new insight to the evolution of Scaphopoda.

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    Sumner-Rooney, Lauren H; Schrödl, Michael; Lodde-Bensch, Eva; Lindberg, David R; Heß, Martin; Brennan, Gerard P; Sigwart, Julia D

    2015-01-01

    The position of scaphopods in molluscan phylogeny remains singularly contentious, with several sister relationships supported by morphological and phylogenomic data: Scaphopoda + Bivalvia (Diasoma), Scaphopoda + Cephalopoda (Variopoda), and Scaphopoda + Gastropoda. Nervous system architecture has contributed significant insights to reconstructing phylogeny in the Mollusca and other invertebrate groups, but a modern neurophylogenetic approach has not been applied to molluscs, hampered by a lack of clearly defined homologous characters that can be unequivocally compared across the radical body plan disparity among the living clades. We present the first three-dimensional reconstruction of the anterior nervous system of a scaphopod, Rhabdus rectius, using histological tomography. We also describe a new putative sensory organ, a paired and pigmented sensory mantle slit. This structure is restricted to our study species and not a general feature of scaphopods, but it forms an integral part of the description of the nervous system in R. rectius. It also highlights the potential utility of neuro-anatomical characters for multiple levels of phylogenetic inference beyond this study. This potential has not previously been exploited for the thorny problem of molluscan phylogeny. The neuroanatomy of scaphopods demonstrates a highly derived architecture that shares a number of key characters with the cephalopod nervous system, and supports a Scaphopoda + Cephalopoda grouping. © 2015 Wiley Periodicals, Inc.

  5. Marine shell hoard from the Late Neolithic site of Čepin-Ovčara (Slavonia, Croatia

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    Boban Tripković

    2016-12-01

    Full Text Available The focus of this paper is the ornament hoard from the Sopot culture site of Čepin-Ovčara in eastern Slavonia (the Republic of Croatia. The hoard contained pendants and beads made of shells of marine clam Spondylus gaederopus and scaphopod Antalis vulgaris. The paper analyses the context and use wear of the objects in the hoard. The results form a basis for: the reconstruction of the role of some of the items and the ways in which they were worn; the premise that the dynamics and mechanisms of acquisition of ornaments made of the two Mediterranean mollusc species could have differed; and the identification of a cross-cultural pattern of deposition of ornament hoards.

  6. The Continuing Debate on Deep Molluscan Phylogeny: Evidence for Serialia (Mollusca, Monoplacophora + Polyplacophora

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    I. Stöger

    2013-01-01

    Full Text Available Molluscs are a diverse animal phylum with a formidable fossil record. Although there is little doubt about the monophyly of the eight extant classes, relationships between these groups are controversial. We analysed a comprehensive multilocus molecular data set for molluscs, the first to include multiple species from all classes, including five monoplacophorans in both extant families. Our analyses of five markers resolve two major clades: the first includes gastropods and bivalves sister to Serialia (monoplacophorans and chitons, and the second comprises scaphopods sister to aplacophorans and cephalopods. Traditional groupings such as Testaria, Aculifera, and Conchifera are rejected by our data with significant Approximately Unbiased (AU test values. A new molecular clock indicates that molluscs had a terminal Precambrian origin with rapid divergence of all eight extant classes in the Cambrian. The recovery of Serialia as a derived, Late Cambrian clade is potentially in line with the stratigraphic chronology of morphologically heterogeneous early mollusc fossils. Serialia is in conflict with traditional molluscan classifications and recent phylogenomic data. Yet our hypothesis, as others from molecular data, implies frequent molluscan shell and body transformations by heterochronic shifts in development and multiple convergent adaptations, leading to the variable shells and body plans in extant lineages.

  7. The continuing debate on deep molluscan phylogeny: evidence for Serialia (Mollusca, Monoplacophora + Polyplacophora).

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    Stöger, I; Sigwart, J D; Kano, Y; Knebelsberger, T; Marshall, B A; Schwabe, E; Schrödl, M

    2013-01-01

    Molluscs are a diverse animal phylum with a formidable fossil record. Although there is little doubt about the monophyly of the eight extant classes, relationships between these groups are controversial. We analysed a comprehensive multilocus molecular data set for molluscs, the first to include multiple species from all classes, including five monoplacophorans in both extant families. Our analyses of five markers resolve two major clades: the first includes gastropods and bivalves sister to Serialia (monoplacophorans and chitons), and the second comprises scaphopods sister to aplacophorans and cephalopods. Traditional groupings such as Testaria, Aculifera, and Conchifera are rejected by our data with significant Approximately Unbiased (AU) test values. A new molecular clock indicates that molluscs had a terminal Precambrian origin with rapid divergence of all eight extant classes in the Cambrian. The recovery of Serialia as a derived, Late Cambrian clade is potentially in line with the stratigraphic chronology of morphologically heterogeneous early mollusc fossils. Serialia is in conflict with traditional molluscan classifications and recent phylogenomic data. Yet our hypothesis, as others from molecular data, implies frequent molluscan shell and body transformations by heterochronic shifts in development and multiple convergent adaptations, leading to the variable shells and body plans in extant lineages.

  8. The Continuing Debate on Deep Molluscan Phylogeny: Evidence for Serialia (Mollusca, Monoplacophora + Polyplacophora)

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    Stöger, I.; Sigwart, J. D.; Kano, Y.; Knebelsberger, T.; Marshall, B. A.; Schwabe, E.; Schrödl, M.

    2013-01-01

    Molluscs are a diverse animal phylum with a formidable fossil record. Although there is little doubt about the monophyly of the eight extant classes, relationships between these groups are controversial. We analysed a comprehensive multilocus molecular data set for molluscs, the first to include multiple species from all classes, including five monoplacophorans in both extant families. Our analyses of five markers resolve two major clades: the first includes gastropods and bivalves sister to Serialia (monoplacophorans and chitons), and the second comprises scaphopods sister to aplacophorans and cephalopods. Traditional groupings such as Testaria, Aculifera, and Conchifera are rejected by our data with significant Approximately Unbiased (AU) test values. A new molecular clock indicates that molluscs had a terminal Precambrian origin with rapid divergence of all eight extant classes in the Cambrian. The recovery of Serialia as a derived, Late Cambrian clade is potentially in line with the stratigraphic chronology of morphologically heterogeneous early mollusc fossils. Serialia is in conflict with traditional molluscan classifications and recent phylogenomic data. Yet our hypothesis, as others from molecular data, implies frequent molluscan shell and body transformations by heterochronic shifts in development and multiple convergent adaptations, leading to the variable shells and body plans in extant lineages. PMID:24350268

  9. Shell occupation and microhabitat use by hermit crabs (Decapoda: Anomura on Fortaleza beach, Ubatuba, São Paulo

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    Giuliano Buzá Jacobucci

    2009-06-01

    Full Text Available Most species of hermit crabs use the empty shells of gastropods as mobile shelters. The variation of shell availability in different microhabitats can reduce competitive interactions between sympatric species, favoring their coexistence. This work aimed to characterize the occupation of gastropod shells by three species of hermit crabs, and assessing the availability of shells and evaluating the use of microhabitats crabs and gastropods in an infralitoral area on the north coast of São Paulo state. For this purpose, transect lines were established and all hermit crabs, gastropods and empty shells found were collected, recording the type of microhabitat used. In a sub-sample, the hermit crabs were identified and classified into reproductive categories. The shells used by the crabs were identified and evaluated according to physical damage and incrustation. Three species of hermit crabs (Paguristes tortugae, Pagurus brevidactylus and Pagurus criniticornis were recorded, using 15 species of gastropod shells and one of scaphopod (Dentalium sp.. Physical damage and incrustation of shells were significantly different among the hermit crab species. Considering microhabitat use, P. tortugae and P. brevidactylus were mainly found in calcareous algae, while P. criniticornis mainly occurred in sand substrate. Despite the differences in shell and microhabitat use, the high resource overlap, especially by the pagurids, indicates that competitive interactions are important regulatory factors for these populations.

  10. Biology of Incidental Catch Sea Star Stellaster childreni Gray, 1840 (Echinodermata: Asteroidea, from Malaysian Borneo Exclusive Economic Zone

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    Ruhana Hassan

    2017-01-01

    Full Text Available Sea star (class Asteroidea, phylum Echinodermata is one of the most successful marine organisms inhabiting a wide range of habitats. As one of the key stone species, sea stars are responsible for maintaining much of the local diversity of species within certain communities. Malaysian Exclusive Economic Zone (EEZ Resource Survey had been carried out from 16th Aug to 6th Nov 2015 and one of the invertebrate by-catch organisms is sea star Stellaster childreni Gray, 1840. This study documents morphological characters and diet of the sea star, besides providing brief descriptions of the habitats based on particle size analysis and vessel log data sheet. A total of 217 individuals had been examined throughout this study. Fragments of flora and fauna were found in the gut including Mollusca (gastropod, bivalves, and scaphopods, sponge seagrass, and seaweed as well as benthic Foraminifera. Stellaster childreni were found at depth of 45 m to 185 m in the South China Sea off Sarawak Malaysia, with various sea bottom substrata. Approximately 41% of S. childreni were found at a mixture of sandy and muddy substratum, followed by mixture of sandy and coral (19.3%, muddy substratum (17.5%, coral substratum (11.5%, and sandy areas (10.6%. The widely distributed sea star on different types of sea beds suggested healthy deep sea ecosystem; thus Malaysia should explore further potential fisheries resources in the EEZ off Sarawak coast.

  11. Using microwaves to prepare gastropods for DNA barcoding.

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    Galindo, L A; Puillandre, N; Strong, E E; Bouchet, P

    2014-07-01

    Extracting DNA from gastropods presents particular difficulties due to the capacity of the living animal to retract into the shell, resulting in poor penetration of the ethanol into the tissues. Because the shell is essential to establish the link between sequences and traditional taxonomic identity, cracking the shell to facilitate fixation is not ideal. Several methods are currently in routine use to overcome this difficulty, including chemical relaxation, drilling the shell and boiling. Most of these methods are time-consuming, may be safety hazards and constitute a bottleneck in the preparation of large numbers of specimens in the field. We have experimented with a method traditionally used to clean shells that involves placing the living gastropods in a microwave (MW) oven; the electromagnetic radiation very quickly heats both the animal and the water trapped inside the shell, resulting in separation of the muscles that anchor the animal to the shell. Done properly, the body can be removed intact from the shell and the shell voucher is preserved undamaged. To test the method, the bodies of live-collected specimens from two gastropod species were separated from their shell by microwaving and by anesthetizing/drilling. After identical extraction and PCR procedures, the gels showed no difference in DNA quantity or quality, and the resulting sequences are identical within species. The method was then implemented on a large scale during expeditions, resulting in higher percentage of DNA extraction success. The MWs are also effective for quickly and easily removing other molluscs from their shells, that is, bivalves and scaphopods. Workflows implementing the MW technique show a three- to fivefold increase in productivity compared with other methods. © 2014 John Wiley & Sons Ltd.

  12. Abyssal fauna of the UK-1 polymetallic nodule exploration area, Clarion-Clipperton Zone, central Pacific Ocean: Mollusca.

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    Wiklund, Helena; Taylor, John D; Dahlgren, Thomas G; Todt, Christiane; Ikebe, Chiho; Rabone, Muriel; Glover, Adrian G

    2017-01-01

    We present the first DNA taxonomy publication on abyssal Mollusca from the Clarion-Clipperton Zone (CCZ), central Pacific ocean, using material collected as part of the Abyssal Baseline (ABYSSLINE) environmental survey cruise 'AB01' to the UK Seabed Resources Ltd (UKSRL) polymetallic-nodule exploration area 'UK-1' in the eastern CCZ. This is the third paper in a series to provide regional taxonomic data for a region that is undergoing intense deep-sea mineral exploration for high-grade polymetallic nodules. Taxonomic data are presented for 21 species from 42 records identified by a combination of morphological and genetic data, including molecular phylogenetic analyses. These included 3 heterodont bivalves, 5 protobranch bivalves, 4 pteriomorph bivalves, 1 caudofoveate, 1 monoplacophoran, 1 polyplacophoran, 4 scaphopods and 2 solenogastres. Gastropoda were recovered but will be the subject of a future study. Seven taxa matched published morphological descriptions for species with deep Pacific type localities, and our sequences provide the first genetic data for these taxa. One taxon morphologically matched a known cosmopolitan species but with a type locality in a different ocean basin and was assigned the open nomenclature 'cf' as a precautionary approach in taxon assignments to avoid over-estimating species ranges. One taxon is here described as a new species, Ledella knudseni sp. n. For the remaining 12 taxa, we have determined them to be potentially new species, for which we make the raw data, imagery and vouchers available for future taxonomic study. The Clarion-Clipperton Zone is a region undergoing intense exploration for potential deep-sea mineral extraction. We present these data to facilitate future taxonomic and environmental impact study by making both data and voucher materials available through curated and accessible biological collections.

  13. Earth-System Scales of Biodiversity Variability in Shallow Continental Margin Seafloor Ecosystems

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    Moffitt, S. E.; White, S. M.; Hill, T. M.; Kennett, J.

    2015-12-01

    High-resolution paleoceanographic sedimentary sequences allow for the description of ecosystem sensitivity to earth-system scales of climate and oceanographic change. Such archives from Santa Barbara Basin, California record the ecological consequences to seafloor ecosystems of climate-forced shifts in the California Current Oxygen Minimum Zone (OMZ). Here we use core MV0508-20JPC dated to 735,000±5,000 years ago (Marine Isotope Stage 18) as a "floating window" of millennial-scale ecological variability. For this investigation, previously published archives of planktonic δ18O (Globigerina bulloides) record stadial and interstadial oscillations in surface ocean temperature. Core MV0508-20JPC is an intermittently laminated archive, strongly influenced by the California Current OMZ, with continuously preserved benthic foraminifera and discontinuously preserved micro-invertebrates, including ophiuroids, echinoderms, ostracods, gastropods, bivalves and scaphopods. Multivariate statistical approaches, such as ordinations and cluster analyses, describe climate-driven changes in both foraminiferal and micro-invertebrate assemblages. Statistical ordinations illustrate that the shallow continental margin seafloor underwent predictable phase-shifts in oxygenation and biodiversity across stadial and interstadial events. A narrow suite of severely hypoxic taxa characterized foraminiferal communities from laminated intervals, including Bolivina tumida, Globobulimina spp., and Nonionella stella. Foraminiferal communities from bioturbated intervals are diverse and >60% similar to each other, and they are associated with echinoderm, ostracod and mollusc fossils. As with climate shifts in the latest Quaternary, there is a sensitive benthic ecosystem response in mid-Pleistocene continental margins to climatically related changes in OMZ strength.

  14. Drilling predation on serpulid polychaetes (Ditrupa arietina from the pliocene of the Cope Basin, Murcia Region, Southeastern Spain.

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    Jordi Martinell

    Full Text Available We report quantitative analyses of drilling predation on the free-living, tube-dwelling serpulid polychaete Ditrupa arietina from the Cope Cabo marine succession (Pliocene, Spain. Tubes of D. arietina are abundant in the sampled units: 9 bulk samples from 5 horizons yielded ~5925 specimens of D. arietina. Except for fragmentation, tubes were well preserved. Complete specimens ranged from 3.1 to 13.4 mm in length and displayed allometric growth patterns, with larger specimens being relatively slimmer. Drilled Ditrupa tubes were observed in all samples. Drillholes, identified as Oichnus paraboloides, were characterized by circular to elliptical outline (drillhole eccentricity increased with its diameter, parabolic vertical profile, outer diameter larger than inner diameter, penetration of one tube wall only, narrow range of drill-hole sizes, and non-random (anterior distribution of drillholes. A total of 233 drilled specimens were identified, with drilling frequencies varying across horizons from 2.7% to 21% (3.9% for pooled data. Many tube fragments were broken across a drillhole suggesting that the reported frequencies are conservative and that biologically-facilitated (drill-hole induced fragmentation hampers fossil preservation of complete serpulid tubes. No failed or repaired holes were observed. Multiple complete drillholes were present (3.9%. Drilled specimens were significantly smaller than undrilled specimens and tube length and drill-hole diameter were weakly correlated. The results suggest that drillholes were produced by a size-selective, site-stereotypic predatory organism of unknown affinity. The qualitative and quantitative patterns reported here are mostly consistent with previous reports on recent and fossil Ditrupa and reveal parallels with drilling patterns documented for scaphopod mollusks, a group that is ecologically and morphologically similar to Ditrupa. Consistent with previous studies, the results suggest that free

  15. Drilling Predation on Serpulid Polychaetes (Ditrupa arietina) from the Pliocene of the Cope Basin, Murcia Region, Southeastern Spain

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    Martinell, Jordi; Kowalewski, Michał; Domènech, Rosa

    2012-01-01

    We report quantitative analyses of drilling predation on the free-living, tube-dwelling serpulid polychaete Ditrupa arietina from the Cope Cabo marine succession (Pliocene, Spain). Tubes of D. arietina are abundant in the sampled units: 9 bulk samples from 5 horizons yielded ∼5925 specimens of D. arietina. Except for fragmentation, tubes were well preserved. Complete specimens ranged from 3.1 to 13.4 mm in length and displayed allometric growth patterns, with larger specimens being relatively slimmer. Drilled Ditrupa tubes were observed in all samples. Drillholes, identified as Oichnus paraboloides, were characterized by circular to elliptical outline (drillhole eccentricity increased with its diameter), parabolic vertical profile, outer diameter larger than inner diameter, penetration of one tube wall only, narrow range of drill-hole sizes, and non-random (anterior) distribution of drillholes. A total of 233 drilled specimens were identified, with drilling frequencies varying across horizons from 2.7% to 21% (3.9% for pooled data). Many tube fragments were broken across a drillhole suggesting that the reported frequencies are conservative and that biologically-facilitated (drill-hole induced) fragmentation hampers fossil preservation of complete serpulid tubes. No failed or repaired holes were observed. Multiple complete drillholes were present (3.9%). Drilled specimens were significantly smaller than undrilled specimens and tube length and drill-hole diameter were weakly correlated. The results suggest that drillholes were produced by a size-selective, site-stereotypic predatory organism of unknown affinity. The qualitative and quantitative patterns reported here are mostly consistent with previous reports on recent and fossil Ditrupa and reveal parallels with drilling patterns documented for scaphopod mollusks, a group that is ecologically and morphologically similar to Ditrupa. Consistent with previous studies, the results suggest that free-dwelling serpulid

  16. Experimental calibration of Mg isotope fractionation between aragonite and seawater

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    Wang, Zhengrong; Hu, Ping; Gaetani, Glenn; Liu, Chao; Saenger, Casey; Cohen, Anne; Hart, Stanley

    2013-02-01

    The detectable magnesium (Mg) isotope fractionation between biogenic aragonite (including aragonitic corals, bivalves, scaphopod, and sclerosponges) and seawater can potentially be applied to reconstruct sea surface temperature (SST) in the past. To calibrate this thermometer, eight sets of inorganic precipitation experiments ('free-drift') in seawater (Mg/Ca = 5 or 10) have been carried out at 25-55 °C over a range of degassing rate. A cleaning procedure was adopted to remove Mg contamination by sea salt, surface absorbed Mg and silicate dust as nucleation centers. The Mg isotope fractionation between cleaned aragonite and seawater-like aqueous solution varies insignificantly with Mg/Ca ratios and Mg isotope compositions of the initial solution, and the CO2-degassing rate (0-75 cc/min), but decreases noticeably with increasing temperatures having a temperature sensitivity of ˜0.008-0.01‰/°C in the following form: Δ≈1000lnα=1.67(±0.36)-0.82(±0.11)×{1000}/{T} where αaragonite-seawater is the fractionation factor, and T is the absolute temperature in Kelvin. It is consistent with equilibrium fractionation between Mg2+ aquo-complex and magnesite predicted by one theoretical calculation. Qualitative comparison among Mg-bearing carbonates based on Mg-O bond strengths show the relative sequence of 26Mg enrichment is aragonite > dolomite > magnesite > calcite. Thus, the surprising agreement indicates either the calculation overestimated Mg fractionation between magnesite and fluid, or both theoretical calculation and our calibration represent Mg isotope fractionation between MgCO30-H2O cluster and Mg2+ aquo complexes. Comparison of our calibration with the Mg isotope fractionation between biogenic aragonite and seawater suggests Mg and oxygen isotope fractionations of some biogenic aragonites (e.g., Porites sp. corals) agree with our calibration within analytical uncertainty, whereas others deviate significantly, indicating biological and/or kinetic isotope

  17. A national checklist of marine Mollusca in Spanish waters

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    Serge Gofas

    2017-06-01

    Full Text Available A checklist of marine Mollusca recorded in Spanish jurisdictional waters is presented, based on a thorough literature search and a limited input of recent field work. The list is detailed according to the five demarcations of the Marine Strategy Framework Directive (NOR, Spanish north coast; SUR, Spanish coast of the Gulf of Cádiz; ESAL, Strait of Gibraltar and Alboran Sea; LEBA, East coast of Spain and Balearic Islands; CAN, the Canary Islands. The list differentiates coastal species living from the supralittoral zone to the shelf break, deep-sea benthic or demersal species, and holoplanktonic species, and also distinguishes between non-indigenous species and species endemic to a particular demarcation. A total of 2466 marine Mollusca species have been reported from Spanish waters, of which 1126 are recorded only from waters surrounding the Iberian Peninsula, 498 are recorded from the Canaries only, and 842 are shared. That total number represents around 5.5% of the global marine molluscan richness. Shore and shelf species are the most numerous (1837, followed by deep-sea benthic species (490 and pelagic species (139, but the contribution of the deep-sea species is most noteworthy in NOR. All eight molluscan classes were represented, but solenogastres and scaphopods were notably more represented than usual in NOR. Species richness in SUR and ESAL was higher than would be expected from their areas, supporting the claim that Andalusian waters have an exceptionally diverse molluscan fauna. Thirteen species collected from INDEMARES cruises are here reported for the first time in Spanish waters. The species recorded in Spanish seas represent more than half of the 4340 species of Mollusca recorded within the scope of the European Register of Marine Species, making this the highest species count in European seas. The Canary Islands demarcation holds by far the largest number of endemic species (127, but special mention is needed regarding the ca. 20

  18. Malacofauna marinha da região costeira do Canal de São Sebastião, SP, Brasil: Gastropoda, Bivalvia, Polyplacophora e Scaphopoda A faunal survey of the marine molluscs of the Channel of São Sebastião, SP, Brazil: Gastropoda, Bivalvia, Polyplacophora and Scaphopoda

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    Alvaro Esteves Migotto

    1993-01-01

    Full Text Available Um levantamento faunístico dos moluscos marinhos do Canal de São Sebastião foi realizado entre junho de 1982 e fevereiro de 1983. Um total de 195 espécies foram encontradas: 103 gastrópodes, 87 bivalves, 4 quitons e 1 escafópodo. 140 espécies pertecem a fauna caribeana, 22 são cosmopolitas ou circuntropicais, 13 são endêmicas da costa brasileira e 10 pertecem à fauna patagônica. A maioria das espécies foi encontrada na região entremarés. São também listadas outras 142 espécies de moluscos registradas por outros autores para a região e não reencontradas. Foi notada uma redução no número de espécies ao se comparar os dados do presente trabalho com dados mais recentes, obtidos por outros autores. Levanta-se a hipótese de que esta situação é devida a poluição crônica e outros impactos ambientais.Between June 1982 and February 1983 a survey of the marine molluscs of the Channel of São Sebastião, State of São Paulo, was carried out A total of 195 species were found: 103 gastropods, 87 bivalves, 4 chitons, and 1 scaphopod. 140 species belong to the Caribbean fauna, 22 are circumtropical or worldwide in distribution, 13 are endemic to the Brazilian coast, and 10 belong to the Patagonian fauna. Most species (77,6 % were found in the intertidal zone. 142 species, recorded for the region by other authors and not found in the present survey, are also listed. A reduction in the number of species was also observed comparing the present data (1982-1983 with more recent data from other authors (1987-1989. This situation is probably due to chronic pollution and other environmental impacts.

  19. "Recent" macrofossil remains from the Lomonosov Ridge, central Arctic Ocean

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    Le Duc, Cynthia; de Vernal, Anne; Archambault, Philippe; Brice, Camille; Roberge, Philippe

    2016-04-01

    The examination of surface sediment samples collected from 17 sites along the Lomonosov Ridge at water depths ranging from 737 to 3339 meters during Polarstern Expedition PS87 in 2014 (Stein, 2015), indicates a rich biogenic content almost exclusively dominated by calcareous remains. Amongst biogenic remains, microfossils (planktic and benthic foraminifers, pteropods, ostracods, etc.) dominate but millimetric to centrimetric macrofossils occurred frequently at the surface of the sediment. The macrofossil remains consist of a large variety of taxa, including gastropods, bivalvia, polychaete tubes, scaphopods, echinoderm plates and spines, and fish otoliths. Among the Bivalvia, the most abundant taxa are Portlandia arctica, Hyalopecten frigidus, Cuspidaria glacilis, Policordia densicostata, Bathyarca spp., and Yoldiella spp. Whereas a few specimens are well preserved and apparently pristine, most mollusk shells displayed extensive alteration features. Moreover, most shells were covered by millimeter scale tubes of the serpulid polychaete Spirorbis sp. suggesting transport from low intertidal or subtidal zone. Both the ecological affinity and known geographic distribution of identified bivalvia as named above support the hypothesis of transportation rather than local development. In addition to mollusk shells, more than a hundred fish otoliths were recovered in surface sediments. The otoliths mostly belong to the Gadidae family. Most of them are well preserved and without serpulid tubes attached to their surface, suggesting a local/regional origin, unlike the shell remains. Although recovered at the surface, the macrofaunal assemblages of the Lomonosov Ridge do not necessarily represent the "modern" environments as they may result from reworking and because their occurrence at the surface of the sediment may also be due to winnowing of finer particles. Although the shells were not dated, we suspect that their actual ages may range from modern to several thousands of

  20. Dentalium beads - shells of fosillised sea molluscs at the Vinča-Belo brdo site

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    Dimitrijević Vesna

    2010-01-01

    Full Text Available During excavation of the Vinča-Belo Brdo site a significant number of decorated items made from clay, stone, bone, and seashells or snail shells have been collected over the years. Amongst the decorated objects which could be classified as jewellery the majority are bracelets, pendants, and beads made from Spondylus and Glycymeris shells, as well as beads made from Dentalium shells. The appearance of these beads and the question of their origin have not yet been specifically considered within studies of prehistoric cultures in the central Balkans. Furthermore, they have rarely been illustrated and mentioned in archaeological site inventories, which we presume has not been because of their poor representation, but rather because of their being unfamiliar. The aim of this work is therefore to: a systematize data about Dentalium beads from all phases of excavation of the Belo Brdo site in Vinča; b to show the importance of this kind of jewellery in the study of resources around the Vinča settlement; and c to indicate the wider chronological perspective and the significance of studying Dentalium beads within the prehistory of the central Balkans. Dentalium is a carnivorous Scaphopoda sea mollusc, uncommon and insufficiently studied. Representatives of this class of Scaphopoda have been found on Serbian territory in the Badenian sediments, deposited fifteen million years ago. Badenian sediments were discovered around Loznica, Belgrade, Aranđelovac, Golubac, Zaječar, and Negotin. The region of Belgrade and the surrounding area had been covered by a warm, shallow sea of normal salination. On the territory of Belgrade, offsprings of the Badenian sediments, rich in fossils, have been discovered in the city centre (Tašmajdan, Kalemegdan, as well as in many surrounding places (Rakovica, Kaluđerica, Leštani, and Jajinci (fig. 2. Scaphopod shells found at the Vinča-Belo Brdo archaeological site are usually transversally broken. Judging by the basic

  1. Comparative morphology among representatives of main taxa of Scaphopoda and basal protobranch Bivalvia (Mollusca

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    Luiz Ricardo L. Simone

    2009-01-01

    the main goal of this paper, the taxa Scaphopoda and Bivalvia are supported by 8 and by 7 synapomorphies respectively. The taxon Protobranchia resulted paraphyletic. Both scaphopod orders resulted monophyletic. The obtained cladogram is: ((((Coccodentalium carduus - Paradentalium disparile (Polyschides noronhensis - Gadila brasiliensis ((Solemya occidentalis - S. notialis (Propeleda carpenteri (Ennucula puelcha (Barbatia cancellaria - Serratina capsoides (Propilidium curumim - Nautilus pompilius - Lolliguncula brevis.Este estudo analisa a morfologia e anatomia detalhadas de 4 espécies de Scaphopoda e 5 espécies de bivalves protobrânquios. Ambas as classes são tradicionalmente agrupadas no táxon Diasoma, o qual vem sendo questionado por diferentes metodologias, tais como molecular e de desenvolvimento. Este estudo é desenvolvido sob uma metodologia filogenética, a qual a maior preocupação é fornecer um procedimento inteligível e testável. As espécies de Scaphopoda analisadas provieram da costa brasileira e pertencem à família Dentaliidae [(1 Coccodentalium carduus; (2 Paradentalium disparile] e Gadilidae [(3 Polyschides noronhensis, n. sp. do Arquipélago de Fernando de Noronha; (4 Gadila braziliensis]. Estas espécies representam os ramos principais da classe Scaphopoda. Dos bivalves protobrânquios, representantes das famílias Solemyidae [(5 Solemya occidentalis, da Flórida; S. notialis, n. sp. do S.E. Brasil], Nuculanidae [(6 Propeleda carpentieri, da Flórida] e Nuculidae [(7 Ennucula puelcha, do sul do Brasil] são incluídos. Estas espécies representam os principais ramos dos bivalves basais. As descrições anatômicas de S. occidentalis e de P. carpentieri estão sendo publicadas em outro artigo, as das demais espécies estão incluídas neste, o qual também inclui um completo tratamento taxonômico. Além dessas espécies, representantes de outros táxons são operacionalmente incluídos como parte do ingroup (então os índices s