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Sample records for bivalvia ostreidae mantenidos

  1. The complete mitochondrial genome of Crassostrea gasar (Bivalvia: Ostreidae).

    Science.gov (United States)

    Cavaleiro, Nathalia P; Solé-Cava, Antonio M; Melo, Cláudio M R; de Almeida, Luiz G; Lazoski, Cristiano; Vasconcelos, Ana Tereza R

    2016-07-01

    The complete mitochondrial genome of Crassostrea gasar was sequenced using the Ion Proton technology in combination with 454 Roche GS-FLX plataform data. We assembled a 17,686 bp complete circular mitochondrial genome, containing 13 protein-coding genes, a major non-coding region (MNR), two ribosomal RNA genes and 24 transfer RNA genes. Phylogenetic analysis of concatenated amino acid sequences from mitochondria showed monophyletic clades formed with high bootstrap values. This is the first complete mitochondrial sequence of an oyster from South America. Mitogenome sequence was deposited in GenBank under the accession number KR856227. PMID:27158791

  2. [Reproductive cycle of the mangrove oyster Crassostrea rhizophorae (Bivalvia: Ostreidae) in Camamu Bay, Bahia, Brasil].

    Science.gov (United States)

    Lenz, Tiago; Boehs, Guisla

    2011-03-01

    The mangrove oyster Crassostrea rhizophorae is important fishery resource along the entire Brasilian coast with excellent potential for marine culture. The purpose of this paper was to examine the reproductive characteristics of the oyster of the Maraú river estuary in Camamu Bay, Bahia, Brasil. The samples were collected monthly, from September 2006 to August 2007, at two points (I and II) in Camamu Bay. At each site 20 oysters were collected for histological analysis, fixed in Davidson's solution, embedded in paraffin, dehydrated in an ethanol series, sectioned (7 microm thick) and stained with Harris hematoxylin and Eosin (HE). Additionally, 30 oysters were sampled, at each point, for a condition index analysis. The water temperature ranged from 23.5 degrees C to 30 degrees C and the salinity from 15 to 25 ups at Point I (Maraú) and from 25 to 35 at Point II (Tanque Island). The oyster's height ranged from 30 to 92 mm at Point I and from 27 to 102 mm at Point II, with an average of 49.0 mm +/- 9.1 (n = 230) and 49.9 mm +/- 9.9 (n = 237), respectively. Among the sampled oysters at Point I, 59.1% were females, 31.3% males, 1.3% hermaphrodites and 8.2% of the oysters of undetermined sex. At Point II, 66.2% were females, 30.4% males, 0.8% hermaphrodites and 2.5% (n = 237) of undetermined sex. The gonadic stage analysis indicated that the reproduction period of the C. rhizophorae in the Maraú Peninsula was continuous all year, without any regressive phase. The condition index (R) ranged from 8.0% to 17.7%. The peak periods of R coincided with the expressive oyster's percentage in the maturation and liberation gametic stages. The results of these findings will contribute information for the oyster spat collection and to the process installation of the oyster culture in Camamu Bay. PMID:21516642

  3. Combined effects of temperature acclimation and cadmium exposure on mitochondrial function in eastern oysters Crassostrea virginica gmelin (Bivalvia: Ostreidae).

    Science.gov (United States)

    Cherkasov, Anton S; Ringwood, Amy H; Sokolova, Inna M

    2006-09-01

    Cadmium and temperature have strong impacts on the metabolic physiology of aquatic organisms. To analyze the combined impact of these two stressors on aerobic capacity, effects of Cd exposure (50 microg/L) on mitochondrial function were studied in oysters (Crassostrea virginica) acclimated to 12 and 20 degrees C in winter and to 20 and 28 degrees C in fall. Cadmium exposure had different effects on mitochondrial bioenergetics of oysters depending on the acclimation temperature. In oysters acclimated to 12 degrees C, Cd exposure resulted in elevated intrinsic rates of mitochondrial oxidation, whereas at 28 degrees C, a rapid and pronounced decrease of mitochondrial oxidative capacity was found in Cd-exposed oysters. At the intermediate acclimation temperature (20 degrees C), effects of Cd exposure on intrinsic rates of mitochondrial oxidation were negligible. Degree of coupling significantly decreased in mitochondria from 28 degrees C-acclimated oysters but not in that from 12 degrees C- or 20 degrees C-acclimated oysters. Acclimation at elevated temperatures also increased sensitivity of oyster mitochondria to extramitochondrial Cd. Variation in mitochondrial membrane potential explained 41% of the observed variation in mitochondrial adenosine triphosphate synthesis and proton leak between different acclimation groups of oysters. Temperature-dependent sensitivity of metabolic physiology to Cd has significant implications for toxicity testing and for extrapolation of laboratory studies to field populations of aquatic poikilotherms, indicating the importance of taking into account the thermal regime of the environment. PMID:16986802

  4. Tissue-specific accumulation of cadmium in subcellular compartments of eastern oysters Crassostrea virginica Gmelin (Bivalvia: Ostreidae)

    International Nuclear Information System (INIS)

    Cadmium distribution was studied in different subcellular fractions of gill and hepatopancreas tissues of eastern oysters Crassostrea virginica. Oysters were exposed for up to 21 days to low sublethal Cd concentrations (25 μg L-1). Gill and hepatopancreas tissues were sampled and divided into organelle fractions and cytosol by differential centrifugation. Organelle content of different fractions was verified by activities of marker enzymes, citrate synthase and acid phosphatase for mitochondria and lysosomes, respectively. In both tissue types, there was a significant accumulation of cadmium in cytosol reaching 230-350 ng mg-1 protein. Among organelles, mitochondria were the main target for Cd bioaccumulation in gills (250-300 ng mg-1 protein), whereas in hepatopancreas tissues, the highest cadmium accumulation occurred in lysosomes (90-94 ng mg-1 protein). Although 75-83% of total cadmium burden was associated with the cytosol reflecting high volume fraction of this compartment, Cd concentrations in organelle fractions reached levels that could cause dysfunction of mitochondria and lysosomes. Organ- and organelle-specific patterns of cadmium bioaccumulation support our previous in vivo studies, which showed adverse effects of cadmium exposures on mitochondrial oxidation in gills and on the lysosomal system of hepatopancreas. This may have important implications for the development of biomarkers of effect for heavy metals and for understanding the mechanisms of toxic effects of metals

  5. Phylogenetic analysis of Thai oyster (Ostreidae) based on partial sequences of the mitochondrial 16S rDNA gene

    DEFF Research Database (Denmark)

    Bussarawit, Somchai; Gravlund, Peter; Glenner, Henrik;

    2006-01-01

    Ten oyster species of the family Ostreidae (Subfamilies Crassostreinae and Lophinae) from Thailand were studied using morphological data and mitochondrial 16S rDNA gene sequences. Additional sequence data from five specimens of Ostreidae and one specimen of Tridacna gigas were downloaded from Gen......Bank (T. gigas was used as outgroup). Some specimens were found to be genetically identical despite obvious morphological differences (e.g. four specimens of Crassostrea iredalei from east and west sides of the Malaysian peninsula and Saccostrea forskali and S. cf. malabonensis, both from Thai waters...

  6. Ciclo reproductivo del ostión de manglar Crassostrea rhizophorae (Bivalvia: Ostreidae) en la Bahía de Camamu, Bahia, Brasil

    OpenAIRE

    Tiago Lenz; Guisla Boehs

    2011-01-01

    El ostión de manglar es un importante recurso pesquero que se distribuye por toda la costa brasileña y una de las especies nativas con mayor potencial para maricultura. Este estudio tuvo como objetivo conocer las características reproductivas del ostión de manglar Crassostrea rhizophorae en el estero del Río Maraú, Bahía de Camamu, Bahia, Brasil. Las muestras fueran recolectadas mensualmente, entre agosto de 2006 y septiembre de 2007, en dos sitios. Las metodologías utilizadas fueron el análi...

  7. Reproductive traits of the symbiotic pea crab Austinotheres angelicus (Crustacea, Pinnotheridae) living in Saccostrea palmula (Bivalvia, Ostreidae), Pacific coast of Costa Rica

    Science.gov (United States)

    Salas-Moya, Carolina; Mena, Sebastián; Wehrtmann, Ingo S.

    2014-01-01

    Abstract Pea crabs of the family Pinnotheridae exhibit a symbiotic life style and live associated with a variety of different marine organisms, especially bivalves. Despite the fact that pea crabs can cause serious problems in bivalve aquaculture, the available information about the ecology of these crabs from Central America is extremely limited. Therefore, the present study aimed to describe different reproductive features of the pinnotherid crab Austinotheres angelicus associated with the oyster Saccostrea palmula in the Golfo de Nicoya, Pacific coast of Costa Rica. Monthly sampling was conducted from April to December 2012. Average carapace width (CW) of the 47 analyzed ovigerous females was 7.62 mm. The species produced on average 2677 ± 1754 recently -extruded embryos with an average volume of 0.020 ± 0.003 mm3; embryo volume increased during embryogenesis by 21%, but did not vary significantly between developmental stages. Brood mass volume varied greatly (between 11.7 and 236.7 mm3), and increased significantly with female CW. Females invested on average 76.7% (minimum: 21.7%; maximum: 162.8%) of their body weight in brood production, which confirms a substantially higher energy allocation for embryo production in pinnotherid crabs compared to free-living decapods. PMID:25561840

  8. Reproductive traits of the symbiotic pea crab Austinotheres angelicus (Crustacea, Pinnotheridae living in Saccostrea palmula (Bivalvia, Ostreidae, Pacific coast of Costa Rica

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    Carolina Salas-Moya

    2014-11-01

    Full Text Available Pea crabs of the family Pinnotheridae exhibit a symbiotic life style and live associated with a variety of different marine organisms, especially bivalves. Despite the fact that pea crabs can cause serious problems in bivalve aquaculture, the available information about the ecology of these crabs from Central America is extremely limited. Therefore, the present study aimed to describe different reproductive features of the pinnotherid crab Austinotheres angelicus associated with the oyster Saccostrea palmula in the Golfo de Nicoya, Pacific coast of Costa Rica. Monthly sampling was conducted from April to December 2012. Average carapace width (CW of the 47 analyzed ovigerous females was 7.62 mm. The species produced on average 2677 ± 1754 recently -extruded embryos with an average volume of 0.020 ± 0.003 mm3; embryo volume increased during embryogenesis by 21%, but did not vary significantly between developmental stages. Brood mass volume varied greatly (between 11.7 and 236.7 mm3, and increased significantly with female CW. Females invested on average 76.7% (minimum: 21.7%; maximum: 162.8% of their body weight in brood production, which confirms a substantially higher energy allocation for embryo production in pinnotherid crabs compared to free-living decapods.

  9. Preferencias de consumo de cuatro forrajes por venado cola blanca (Odocoileus virginianus mantenidos en cautiverio en Yucatan

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    Israel Fernando Castillo-López

    2011-02-01

    Full Text Available El  venado cola blanca  (Odocoileus  virginianus.Zimmermann es uno de los recursos silvestres y cinegéticos más  importantes  en México.  Sin embargo,  los estudios que existen sobre  su crianza en cautiverio son insuficientes para optimizar su producción. El objetivo planteado en este trabajo fue  evaluar  la  preferencia  relativa  de  cuatro forrajes,  comparar  el  consumo  ad  libitum  del forraje nativo preferido contra un pasto de corte, en venados cola blanca mantenidos en cautiverio, y medir  la relación entre el contenido de sustancias antinutricionales de  los alimentos con el consumo.Se utilizaron cuatro venados cola blanca machos adultos  con  peso  promedio  de  45  Kg,  y  tres especies de árboles  forrajeros nativos: Leucaena leucocephala, Guazuma ulmifolia,  Brosimum alicastrum  y  el  pasto  de  corte  Pennisetum purpureum.  Para  medir  la  preferencia  se realizaron dos experimentos, mediante el diseño

  10. Corbicula fluminea (Mollusca, Bivalvia) - the new freshwater clam for Slovakia

    International Nuclear Information System (INIS)

    Specimens of the expansive Asian freshwater clam Corbicula fluminea O. F. Mueller, 1774 (Mollusca: Bivalvia, Corbiculidae) were found on the following three localities of Danube river of Slovakia: Radvan nad Dunajom env. (DFS - 8276a), Komarno env. (DFS - 8274b), Gabcikovo env. (DFS - 8171a). The basic information about this species, key for determination and a photo of an adult individual are presented on the poster. (authors)

  11. Silurian Bivalvia from Chichagof Island, Southeast Alaska (Alexander terrane

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    Kříž J

    2011-06-01

    Full Text Available The new Silurian Bivalvia Goniophora thula-Mytilarca boucoti Community from a new locality east of the Hoonah Airport on Chichagof Island, Southeast Alaska, U.S.A. is composed of 9 species [?Colpomya aff. hugini Liljedahl, 1994 and ?Colpomya aff. audae Liljedahl, 1994 (Colpomyidae; Modiolopsis aff. modiolaris Conrad, 1838 (Modiolopsidae; Mytilarca boucoti sp. nov. (Ambonychiidae; ?Schizodus sp. A and ?Schizodus sp. B (Schizodidae; Sanguinolites sp. (Sanguinolitidae; ?Modiomorpha sp. and Goniophora thula sp. nov. (Modiomorphinae]. In this paper two new species are described. The Goniophora thula-Mytilarca boucoti Community most probably occupied a gently inclined upper slope environment lying seaward of a cyanobacterial reef front which marked the outer edge of a late Silurian carbonate platform (represented by the Kennel Creek Limestone. The fauna of this locality consists of a rich benthos, especially rich in brachiopods, but secondarily dominated by bivalves and gastropods. Cephalopods are rare, favositid tabulate corals are also present, but form only a very minor component. The new community is most closely related to the homologous and analogous late Wenlock Bivalvia community described from Gotland, Sweden, Baltica. Similar biotic ties are with the shallow water early Ludlow Janicula potens Community from the Prague Basin, Bohemia, Perunica. Cosmopolitanism is characteristic for the Silurian Bivalvia genera, which were dispersed in most regions of the world due to their relatively long pelagic larval life and relatively small distances between the basins, islands and continents in the Silurian. For the distribution of Bivalvia during the Silurian were more limiting physical factors like temperature, salinity, substrate, food, oxygen content, light, and depth. The fauna described here is from the Alexander terrane, an accreted terrane

  12. Comparative genomics of vesicomyid clam (Bivalvia: Mollusca chemosynthetic symbionts

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    Girguis Peter R

    2008-12-01

    Full Text Available Abstract Background The Vesicomyidae (Bivalvia: Mollusca are a family of clams that form symbioses with chemosynthetic gamma-proteobacteria. They exist in environments such as hydrothermal vents and cold seeps and have a reduced gut and feeding groove, indicating a large dependence on their endosymbionts for nutrition. Recently, two vesicomyid symbiont genomes were sequenced, illuminating the possible nutritional contributions of the symbiont to the host and making genome-wide evolutionary analyses possible. Results To examine the genomic evolution of the vesicomyid symbionts, a comparative genomics framework, including the existing genomic data combined with heterologous microarray hybridization results, was used to analyze conserved gene content in four vesicomyid symbiont genomes. These four symbionts were chosen to include a broad phylogenetic sampling of the vesicomyid symbionts and represent distinct chemosynthetic environments: cold seeps and hydrothermal vents. Conclusion The results of this comparative genomics analysis emphasize the importance of the symbionts' chemoautotrophic metabolism within their hosts. The fact that these symbionts appear to be metabolically capable autotrophs underscores the extent to which the host depends on them for nutrition and reveals the key to invertebrate colonization of these challenging environments.

  13. Scanning electron microscopic structure of the prismatic layer in the Bivalvia

    Institute of Scientific and Technical Information of China (English)

    Iwao KOBAYASHI

    2008-01-01

    The shell structure of the Bivalvia has been observed with the use of optical and electron microscopes since the early 1900's. The prismatic structure is one of the more attractive shell structures in bivalved mollusks. This structure is composed of the aggregation of polygonal prisms arranged densely. Each prism is made of small calcite crystallites arranged perpendicular to a growth shell surface. Organic materials, named organic sheaths, accumulate around prisms and stain well with heamatox-ylin-eosin.The Bivalvia, which make prismatic structures, are divided into two groups. One group has the inner shell layer made up of a nacreous structure, and the other has the inner shell layer made up of a foliated structure. The aragonite prismatic layer and the prismatic layer are clo-sely related to each other, as is the aragonite prismatic layer to the composite prismatic one.

  14. DIVERSITAS DAN KERAPATAN MANGROVE, GASTROPODA DAN BIVALVIA DI ESTUARI PERANCAK, BALI

    OpenAIRE

    Susiana; Ali, Syamsu Alam; Rukminasari, Nita

    2011-01-01

    Penelitian ini bertujuan membandingkan diversitas dan kerapatan mangrove dengan kepadatan gastropoda dan bivalvia di mangrove alami dan rehabilitasi. Pengukuran ekosistem mangrove menggunakan transek kuadrat 10 m x 10 m. Kelimpahan dan kepadatan gastropoda dan bialvia menggunakan transek kuadrat berukuran 1 m x 1 m. Analisis nMDS, cluster untuk melihat hubungan karekteristik mangrove alami dan rehabilitasi dianalisis secara deskriptif dan analisis regresi untuk mendetermi...

  15. Molecular phylogeny and shell microstructure of Fungiacava eilatensis Goreau et al. 1968, boring into mushroom corals (Scleractinia: Fungiidae), in relation to other mussels (Bivalvia: Mytilidae)

    NARCIS (Netherlands)

    Owada, M.; Hoeksema, B.W.

    2011-01-01

    Research on the evolution of the symbiosis between the boring mussel Fungiacava eilatensis (Bivalvia: Mytilidae) and its mushroom coral hosts (Scleractinia: Fungiidae), which requires phylogenetic reconstructions of both the Mytilidae and the Fungiidae, contributes to the understanding of the comple

  16. Aspectos bioecológicos do mexilhao dourado Limnoperna Fortunei (bivalvia,mytilidae)(DUNKER, 1857)

    OpenAIRE

    Silva, Debora Pestana da

    2013-01-01

    Experimentos laboratoriais e análises em campo foram feitos para elucidar alguns aspectos da biologia de Limnoperna fortunei (BIVALVIA:MYTILIDAE), um molusco invasor originário do sudoeste asiático que vem colonizando a América do Sul desde 1991. Em relação ao seu hábito filtrador, comparando-se dois tipos de alimento, foi verificado que a temperatura teve menos influência na taxa de filtração do que o tamanho da partícula filtrada. A temperatura só influenciou sobre os valores de filtração n...

  17. Karakteristik Fisika-Kimia Perairan Dan Struktur Komunitas Moluska (Bivalvia Dan Gastropoda) Di Pantai Cermin Sumatera Utara

    OpenAIRE

    Siregar, Raissha Amanda

    2014-01-01

    RAISSHA AMANDA SIREGAR, Physical and Chemical Characteristics of Aquatic and Community structures Many activities around Cermin Beach feared of mollusca (bivalvia and gastropoda) in Cermin Beach, North Sumatera. Under guided YUNASFI and ANI SURYANTI. can alter the water quality of Cermin Beach. Information and understanding of environmental change is indispensable in ecosystem monitoring efforts. This research aims to determine the status of the water quality seen on characteristics of chemic...

  18. Spermatozoa and spermatogenesis in the northern quahaug Mercenaria mercenaria (Mollusca, Bivalvia)

    Science.gov (United States)

    Ying, Xue-Ping; Yang, Wan-Xi; Dahms, Hans-U.; Lin, Zhihua; Chai, Xueliang

    2008-12-01

    We studied the ultrastructure of spermatogenesis and spermatozoa in the northern quahaug, the clam Mercenaria mercenaria. Spermatogenetic cells gradually elongate. Mitochondria gradually fuse and increase in size and electron density. During spermatid differentiation, proacrosomal vesicles migrate towards the presumptive anterior pole of the nucleus and eventually form the acrosome. The spermatozoon of M. mercenaria is of a primitive type. It is composed of head, mid-piece, and tail. The acrosome shows a subacrosomal space with a short conical contour. The slightly curved nucleus of the spermatozoon contains fine-grained dense chromatin. The middle piece consists of a centriolar complex which is surrounded by four mitochondria. The flagellum has a standard “9 + 2” microtubular structure. The ultrastructure of spermatozoa and spermatogenesis of M. mercenaria shares a number of features with other species of the family Veneridae. M. mercenaria may be a suitable model species for further investigations into the mechanisms of spermatogenesis in the Bivalvia.

  19. Biocenosis de Bivalvia y Polyplacophora del intermareal rocoso en playa Tlacopanocha, Acapulco, Guerrero, México Polyplacophora and Bivalvia biocenosis at rocky intertidal Tlacopanocha beach, Acapulco, Guerrero, Mexico

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    Lizeth Galeana-Rebolledo

    2012-11-01

    Full Text Available El Estado de Guerrero, México, tiene regiones marinas prioritarias para la conservación de su biodiversidad y la información acerca de la diversidad de moluscos es escasa, por lo que es necesario realizar inventarios de especies, estudios de ecología de poblaciones y comunidades. Este estudio se efectuó en el intermareal rocoso de la playa Tlacopanocha. Los objetivos fueron: determinar la riqueza, densidad y diversidad de especies; analizar la composición de especies y estructura de tallas. El área de muestreo fue de 10 m² y la unidad de muestreó fue de 1 m². Se identificaron 35 especies, de las cuales tres son nuevos registros para el intermareal rocoso de Guerrero: las familias mejor representadas en riqueza de especies fueron Ischnochitonidae y Arcidae, y en abundancia Chitonidae y Chamidae; la densidad fue de 31,60 ind m-2. Polyplacophora presentó 42,9% de especies dominantes y Bivalvia 19,0%. Chama corallina presentó la mayor talla en longitud y Chama sordida en ancho. La riqueza de especies de moluscos registrada se considera alta y corresponde a lo esperado para un sustrato rocoso en zona tropical. Polyplacophora presentó alta composición de especies, que podría ser resultado de la adaptación de los organismos a las condiciones dinámicas del intermareal rocoso. Los nuevos registros indican la importancia de los inventarios de especies y también del conocimiento de las poblaciones y comunidades de la fauna marina de Guerrero.The State of Guerrero, Mexico, has priority marine areas for conservation of its biodiversity, but information concerning diversity of mollusks is limited, so it is convenient to carry out species inventories, studies of populations and community ecology. This study was conducted in the intertidal rocky beach Tlacopanocha. The objectives were to determine richness, density and species diversity, analyze the species composition and size structure. The sampling area was 10 m² and the sampling unit was

  20. The Histopathology of the Infection of Tilapia rendalli and Hypostomus regani (Osteichthyes by Lasidium Larvae of Anodontites trapesialis (Mollusca, Bivalvia

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    Silva-Souza Ângela Teresa

    2002-01-01

    Full Text Available It is described the histopathology of the infection of Tilapia rendalli (Osteichthyes, Perciformes, Cichlidae and Hypostomus regani (Osteichthyes, Siluriformes, Loricariidae by lasidium larvae of Anodontites trapesialis (Mollusca, Bivalvia, Mycetopodidae. The larvae were encysted within the epidermis of the host, being surrounded by a thin hyaline membrane, 3-6 µm thick, of parasite origin. A proliferative host cell reaction did not occur. The histopathology of the infection shows that the lesions induced by the parasites are minimal. However, the numerous small lesions produced by the release of the larvae may provide optimal conditions for the infection by opportunistic pathogens, namely fungus, which may eventually cause the death of the host.

  1. The histopathology of the infection of Tilapia rendalli and Hypostomus regani (Osteichthyes) by lasidium larvae of Anodontites trapesialis (Mollusca, Bivalvia).

    Science.gov (United States)

    Silva-Souza, Angela Teresa; Eiras, Jorge C

    2002-04-01

    It is described the histopathology of the infection of Tilapia rendalli (Osteichthyes, Perciformes, Cichlidae) and Hypostomus regani (Osteichthyes, Siluriformes, Loricariidae) by lasidium larvae of Anodontites trapesialis (Mollusca, Bivalvia, Mycetopodidae). The larvae were encysted within the epidermis of the host, being surrounded by a thin hyaline membrane, 3-6 microm thick, of parasite origin. A proliferative host cell reaction did not occur. The histopathology of the infection shows that the lesions induced by the parasites are minimal. However, the numerous small lesions produced by the release of the larvae may provide optimal conditions for the infection by opportunistic pathogens, namely fungus, which may eventually cause the death of the host. PMID:12048579

  2. LISTA DE LOS MOLUSCOS (GASTROPODA-BIVALVIA) DULCEACUÍCOLAS Y ESTUARINOS DE LA CUENCA DEL ORINOCO (VENEZUELA)

    OpenAIRE

    Lasso, Carlos A.; Martínez-Escarbassiere, Rafael; Capelo, Juan Carlos; Morales-Betancourt, Mónica A.; Sánchez-Maya, Alejandro

    2009-01-01

    Se realizó una revisión bibliográfica y de colecciones en museos, así como de datos originales de los autores, para reconocer las especies dulceacuícolas y estuarinas de moluscos gastrópodos y bivalvos presentes en la cuenca del Orinoco (Venezuela). Se consolida un listado preliminar para la cuenca de 104 especies distribuidas entre la clase Gastropoda (14 familias y 58 especies) y la clase Bivalvia (13 familias y 45 especies). Entre los gastrópodos la familia Ampullaridae fue la más diversa ...

  3. Phylogenetic analysis of Pectinidae (Bivalvia) based on the ribosomal DNA internal transcribed spacer region

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The ribosomal DNA internal transcribed spacer (ITS) region is a useful genomic region for understanding evolutionary and genetic relationships. In the current study, the molecular phylogenetic analysis of Pectinidae (Mollusca: Bivalvia) was performed using the nucleotide sequences of the nuclear ITS region in nine species of this family. The sequences were obtained from the scallop species Argopecten irradians, Mizuhopecten yessoensis, Amusium pleuronectes and Mimachlamys nobilis, and compared with the published sequences of Aequipecten opercularis, Chlamys farreri, C. distorta, M. varia, Pecten maximus, and an outgroup species Perna viridis. The molecular phylogenetic tree was constructed by the neighbor-joining and maximum parsimony methods. Phylogenetic analysis based on ITS1, ITS2, or their combination always yielded trees of similar topology. The results support the morphological classifications of bivalve and are nearly consistent with classification of two subfamilies (Chlamydinae and Pectininae) formulated by Waller. However, A. irradians, together with A. opercularis made up of genera Amusium, evidences that they may belong to the subfamily Pectinidae. The data are incompatible with the conclusion of Waller who placed them in Chlamydinae by morphological characteristics. These results provide new insights into the evolutionary relationships among scallop species and contribute to the improvement of existing classification systems.

  4. 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

    Full Text Available This study deals with detailed morphology and anatomy of 4 species of Scaphopoda and 5 species of protobranch Bivalvia. Both classes are traditionally grouped in the taxon Diasoma, which has been questioned by different methodologies, such as molecular and developmental. This study is developed under a phylogenetic methodology with the main concern in performing it in an intelligible and testable methodology. The analyzed Scaphopoda species came from the Brazilian coast and belong to the family Dentaliidae [(1 Coccodentalium carduus; (2 Paradentalium disparile] and Gadiliidae; [(3 Polyschides noronhensis, n. sp. from Fernando de Noronha Archipelago; (4 Gadila braziliensis]. These species represent the main branches of the class Scaphopoda. From protobranch bivalves, representatives of the families Solemyidae [(5 Solemya occidentalis, from Florida; S. notialis, n. sp. from S.E. Brazil], Nuculanidae [(6 Propeleda carpentieri from Florida], and Nuculidae [(7 Ennucula puelcha, from south Brazil] are included. These species represent the main branches of the basal Bivalvia. The descriptions on the anatomy of S. occidentalis and of P. carpentieri are published elsewhere. The remaining are included here, for which a complete taxonomical treatment is performed. Beyond these species, representatives of other taxa are operationally included as part of the ingroup (indices are then shared with them, as a procedure to test the morphological monophyly of Diasoma. These taxa are: two lamellibranch bivalves [(8 Barbatia - Arcidae; (9 Serratina - Tellinidae; both published elsewhere;, and Propilidium (10 Patellogastropoda, and (11 Nautilus, basal Cephalopoda, based on basal taxa. The effective outgroups are (12 Neopilina (Monoplacophora and (13 Hanleya (Polyplacophora. The phylogenetic analysis based on morphology revealed that the taxon Diasoma is supported by 14 synapomorphies, and is separated from Cyrtosoma (Gastropoda + Cephalopoda. Although they are not

  5. Systematics and distribution of Cristaria plicata (Bivalvia, Unionidae) from the Russian Far East.

    Science.gov (United States)

    Klishko, Olga K; Lopes-Lima, Manuel; Froufe, Elsa; Bogan, Arthur E; Abakumova, Vera Y

    2016-01-01

    The number of anodontine bivalve species placed in the genus Cristaria (Bivalvia, Unionidae) from the Russian Far East is still not stable among authors. Some recognize only one valid species Cristaria plicata (Leach, 1815) while others accept two additional species, Cristaria tuberculata Schumacher, 1817 and Cristaria herculea (Middendorff, 1847). In the present study, these taxonomic doubts are addressed using analyses of mitochondrial DNA sequences and shell morphometry. No significant differences have been revealed by the COI DNA sequences or the main statistical morphometric indices from the three Cristaria forms. In the specimens analysed, changes in shell morphometry with age suggest that original descriptions of the different forms may be attributed solely to differences in age and sex. We consider that Cristaria plicata, Cristaria tuberculata and Cristaria herculea from the Russian Far East should be considered as a single species, namely Cristaria plicata (Leach, 1815), with Cristaria tuberculata and Cristaria herculea as junior synonyms. The geographic range of Cristaria plicata and its conservation status are also presented here. PMID:27110206

  6. The mitogenome of Paphia euglypta (Bivalvia: Veneridae) and comparative mitogenomic analyses of three venerids.

    Science.gov (United States)

    Xu, Xiaodong; Wu, Xiangyun; Yu, Ziniu

    2010-12-01

    Extraordinary variation has been found in mitochondrial (mt) genome inheritance, gene content and arrangement among bivalves. However, only few bivalve mt genomes have been comparatively analyzed to infer their evolutionary scenarios. In this study, the complete mt genome of the venerid Paphia euglypta (Bivalvia: Veneridae) was firstly studied and, secondly, it was comparatively analyzed with other venerids (e.g., Venerupis philippinarum and Meretrix petechialis) to better understand the mt genome evolution within a family. Though several common features such as the AT content, codon usage of protein-coding genes, and AT/GC skew are shared by the three venerids, a high level of variability is observed in genome size, gene content, gene order, arrangements and primary sequence of nucleotides or amino acids. Most of the gene rearrangement can be explained by the "tandem duplication and random loss" model. From the observed rearrangement patterns, we speculate that block interchange between adjacent genes may be common in the evolution of mt genomes in venerids. Furthermore, this study presents several new findings in mt genome annotation of V. philippinarum and M. petechialis, and hence we have reannotated the genome of these two species as: (1) the ORF of the formerly annotated cox2 gene in V. philippinarum is deduced by using a truncated "T" codon and a second cox2 gene is identified; (2) the trnS-AGN gene is identified and marked in the mt genome of both venerids. Thus, this study demonstrated a high variability of mt genomes in the Veneridae, and showed the importance of comparative mt genome analysis to interpret the evolution of the bivalve mt genome. PMID:21164537

  7. Vesicomyinae (Bivalvia: Vesicomyidae) of the Kuril-Kamchatka Trench and adjacent abyssal regions

    Science.gov (United States)

    Krylova, Elena M.; Kamenev, Gennady M.; Vladychenskaya, Irina P.; Petrov, Nikolai B.

    2015-01-01

    Representatives of the subfamily Vesicomyinae (Bivalvia, Vesicomyidae) are tiny deep-sea molluscs distributed worldwide and reaching huge abundances of hundreds and thousands of specimens in trawl catches. During the German-Russian deep-sea expedition KuramBio (R/V Sonne, 2012) for the first time two vesicomyin species were collected from the abyssal plain adjacent to the Kuril-Kamchatka Trench from the depths of 4861-5787 m, Vesicomya pacifica (Smith, 1885) and "Vesicomya" filatovae sp.n. Two species of vesicomyins, V. sergeeviFilatova, 1971 and V. profundiFilatova, 1971, which were previously reported from the hadal of the Kuril-Kamchatka Trench, were not collected at the abyssal depth despite of the close geographical proximity of the sampling area to their distribution ranges. Altogether nine species of vesicomyins are recorded now from the West and Indo-West Pacific; data on distribution and morpho-anatomical characters of these species are provided. Taxonomic description of V. pacifica is revised including information on its soft part anatomy, new localities and COI sequences. For the first time for a vesicomyin bivalve molecular data is given for a species with an explicit morphological description and unambiguous taxonomic affiliation. Molecular analysis of 160 published COI sequences of vesicomyids and newly obtained molecular data on V. pacifica showed that V. pacifica and two undescribed vesicomyin species forming a monophyletic clade which exhibits sister relationships with the Pliocardiinae, the group of chemosymbiotic vesicomyids. "Vesicomya" filatovae sp.n. is provisionally assigned to the genus Vesicomya (s.l.) until additional morphological and molecular data are obtained. It differs from Vesicomya s.s. by a broader hinge margin with more radiating teeth and the presence of only one pair of demibranchs.

  8. Factors driving changes in freshwater mussel (Bivalvia, Unionida) diversity and distribution in Peninsular Malaysia.

    Science.gov (United States)

    Zieritz, Alexandra; Lopes-Lima, Manuel; Bogan, Arthur E; Sousa, Ronaldo; Walton, Samuel; Rahim, Khairul Adha A; Wilson, John-James; Ng, Pei-Yin; Froufe, Elsa; McGowan, Suzanne

    2016-11-15

    Freshwater mussels (Bivalvia, Unionida) fulfil important ecosystem functions and are one of the most threatened freshwater taxa globally. Knowledge of freshwater mussel diversity, distribution and ecology in Peninsular Malaysia is extremely poor, and the conservation status of half of the species presumed to occur in the region has yet to be assessed. We conducted the first comprehensive assessment of Peninsular Malaysia's freshwater mussels based on species presence/absence and environmental data collected from 155 sites spanning all major river catchments and diverse habitat types. Through an integrative morphological-molecular approach we recognised nine native and one widespread non-native species, i.e. Sinanodonta woodiana. Two species, i.e. Pilsbryoconcha compressa and Pseudodon cambodjensis, had not been previously recorded from Malaysia, which is likely a result of morphological misidentifications of historical records. Due to their restriction to single river catchments and declining distributions, Hyriopsis bialata, possibly endemic to Peninsular Malaysia, Ensidens ingallsianus, possibly already extinct in the peninsula, and Rectidens sumatrensis, particularly require conservation attention. Equally, the Pahang, the Perak and the north-western river catchments are of particular conservation value due to the presence of a globally unique freshwater mussel fauna. Statistical relationships of 15 water quality parameters and mussel presence/absence identified acidification and nutrient pollution (eutrophication) as the most important anthropogenic factors threatening freshwater mussel diversity in Peninsular Malaysia. These factors can be linked to atmospheric pollution, deforestation, oil-palm plantations and a lack of functioning waste water treatment, and could be mitigated by establishing riparian buffers and improving waste water treatment for rivers running through agricultural and residential land. PMID:27473771

  9. Unionid bivalves (Mollusca: Bivalvia: Unionidae) of Presque Isle Bay, Erie, Pennsylvania

    Science.gov (United States)

    Masteller, E.C.; Maleski, K.R.; Schloesser, D.W.

    1993-01-01

    The purpose of this study was to determine species composition and relative abundance of unionid bivalves (Mollusca: Bivalvia: Unionidae) in Presque Isle Bay, Erie, Pennsylvania 1990-1992. This information was compared with data from the only other extensive survey of unionids in the bay conducted in 1909-1911 (Ortmann 1919) to assess changes over the 80 years preceding the present study. A total of 1,540 individuals representing 18 species were collected in 1990-1992. Five relatively common species (between 7 and 42% of total individuals), six uncommon species (2 and 6%), and seven rare species (<1%) were found. The rare species were Anodontoides ferussacianus, Lasmigona costata, Ligumia recta, Ptychobranchus fasciolaris, Quadrula pustulosa pustulosa, Strophitus undaulatus, and Truncilla donaciformis. Five of the species found in Presque Isle Bay (Leptodea fragilis, Ligumia nasuta, Potamilus alatus, Quadrula quadrula, and Truncilla donaciformis) are listed as critically imperiled and one species (Truncilla truncata) as extirpated in the State of Pennsylvania by the Western Pennsylvania Conservancy. Comparisons between unionid populations in 1909-1911 and 1990-1992 indicate few substantial changes occurred during the past 80 years. A total of 22 species were found; 21 in 1909-1911 and 18 in 1990-1992. Seventeen species were found in both studies, an additional four in 1909-1911 and one in 1990-1992. The relative abundance of 11 of the 17 species found in both studies remained stable (i.e., common or uncommon) over the past 80 years. Only four species listed as uncommon in 1909-1911 were listed as rare in 1990-1992. However, the invasion of the zebra mussel (Dreissena polymorpha) is considered a threat to the continued existence of the entire Unionidae fauna in Presque Isle Bay, a unique habitat of the Great Lakes.

  10. Molecular phylogeny of pearl oysters and their relatives (Mollusca, Bivalvia, Pterioidea

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    Tëmkin Ilya

    2010-11-01

    Full Text Available Abstract Background The superfamily Pterioidea is a morphologically and ecologically diverse lineage of epifaunal marine bivalves distributed throughout the tropical and subtropical continental shelf regions. This group includes commercially important pearl culture species and model organisms used for medical studies of biomineralization. Recent morphological treatment of selected pterioideans and molecular phylogenetic analyses of higher-level relationships in Bivalvia have challenged the traditional view that pterioidean families are monophyletic. This issue is examined here in light of molecular data sets composed of DNA sequences for nuclear and mitochondrial loci, and a published character data set of anatomical and shell morphological characters. Results The present study is the first comprehensive species-level analysis of the Pterioidea to produce a well-resolved, robust phylogenetic hypothesis for nearly all extant taxa. The data were analyzed for potential biases due to taxon and character sampling, and idiosyncracies of different molecular evolutionary processes. The congruence and contribution of different partitions were quantified, and the sensitivity of clade stability to alignment parameters was explored. Conclusions Four primary conclusions were reached: (1 the results strongly supported the monophyly of the Pterioidea; (2 none of the previously defined families (except for the monotypic Pulvinitidae were monophyletic; (3 the arrangement of the genera was novel and unanticipated, however strongly supported and robust to changes in alignment parameters; and (4 optimizing key morphological characters onto topologies derived from the analysis of molecular data revealed many instances of homoplasy and uncovered synapomorphies for major nodes. Additionally, a complete species-level sampling of the genus Pinctada provided further insights into the on-going controversy regarding the taxonomic identity of major pearl culture species.

  11. Determination of protein-carbonyls and ubiquitin-mediated proteolysis as biomarkers of oxidative-stress in bivalvia and anthozoa

    International Nuclear Information System (INIS)

    This study describes the investigation of biomarkers of oxidative-stress in the bivalves Mytilus edulis and Dosinia lupinus, together with host and symbiont tissues of the scleractinian Anthozoa Agaricia agaricites. The biomarkers used were assay of total (via spectrophotometry) and individual (via Western blotting; Oxyblot kit) protein-carbonyls (PC=Os) and content of ubiquitin protein conjugates (UPC) via Western blotting (Bivalvia and Anthozoa) and immunohistochemistry (Anthozoa only). Additional assays for Bivalvia were Trolox equivalent antioxidant capacity (TEAC); and post γ-irradiation survival rates. Experimental stressors for Bivalvia were increased seawater temperature, H2O2 and 60Co γ-radiation (latter two were used in vivo and in vitro). Comparisons of clean and polluted marine sites are included. Stressors used for Anthozoa were increased solar irradiation concomitant with elevated seawater temperature. Results and conclusions were as follows: individual samples showed considerable variation, pooling of samples improved consistency. Controls for both biomarkers had detectable background levels in each phylum, against which relatively small differences were assessed. In M. edulis, no measurable differences in PC=Os could be determined when elevated seawater temperature or dilute H2O2 (2O2 (30% v/v) produced a small difference. 60Co γ-radiation produced clearer differences via Oxyblot and spectrophotometric assays. Comparison of four different tissues from the two bivalves found considerable species-specific and tissue-specific differences. Post-irradiation mortality between species was significantly different (<0.001), D. lupinus was more susceptible than M. edulis. TEAC values generally showed a decrease following irradiation (except for digestive gland). UPCs were clearly different between tissues and between species. PC=Os can be detected by DNPH-reactivity/Western blotting assay in host A. agaricites. UPCs can be assayed via Western blotting and

  12. Systematics, biology and conservation of Unio tumidiformis Castro, 1885 (Unionidae: Bivalvia) in the South-West of the Iberian Peninsula

    OpenAIRE

    Reis, Joaquim Manuel Cardoso, 1976-

    2010-01-01

    Os mexilhões-de-rio ou náiades (Bivalvia: ordem Unionoida) estão entre os grupos faunísticos mais ameaçados do mundo. Nos Estados Unidos são mesmo considerados o grupo mais ameaçado, com inúmeras espécies já extintas e uma proporção muito significativa de espécies ameaçadas e protegidas a nível federal ou estatal. No entanto, os esforços para a conservação destas espécies não têm sido adequados em várias regiões do mundo, nomeadamente na Europa, devido a um conhecimento deficiente da diversid...

  13. Occurrence and settlement of the common shipworm Teredo navalis (Bivalvia: Teredinidae) in Bremerhaven harbours, northern Germany

    Science.gov (United States)

    Tuente, Uda; Piepenburg, Dieter; Spindler, Michael

    2002-06-01

    The shipworm Teredo navalis L. is a xylophagous bivalve mollusc (Bivalvia: Teredinidae) with a long record of being very destructive to wooden ships and harbour buildings. It has been reported from numerous sites at the coasts of both the North and Baltic Seas since the eighteenth century. Here, we document for the first time the occurrence of live adult T. navalis in the harbours of Bremerhaven (Weser estuary, northern Germany). From August to December 1998, various wooden structures (fir floating fenders and pier posts, oak piles) from seven stations in different docks of two harbours (Überseehafen, Fischereihafen) were investigated for the presence and density of live specimens and burrows of T. navalis. The settlement of larval shipworms was studied by exposing experimental fir panels 0.06 m2 in size at 20 stations at water depths between 1 and 2 m for periods of 4 months between July and November. In addition, hydrographic profiles (0-8 m water depth) were obtained at 17 stations in five docks once every month from August to December. Live adult shipworms were found in both fir floating fenders and oak piles at four stations. The largest specimen found was 250 mm long. Shipworm burrows were detected at five stations in almost every wooden structure investigated but their abundances differed significantly: Maximum values were >10,000 m-2 in fir floating fenders, 4,600 m-2 in oak piles and 200 m-2 in fir pier posts. Actual shipworm infestation was detected at three of 16 stations in the exposed fir panels (1-3 burrow holes per panel). Water temperatures and salinities varied considerably during the 4-month investigation period. Temperatures decreased from 19.9°C in August to 0.7°C in December. Salinities ranged from 17.6 in August to 1.1 in November, but only at two lock stations during November and December did value drop below 5, which is regarded as the lethal limit for the larvae of this euryhaline teredinid species. We conclude that T. navalis encounters

  14. Simbiontes associados com Anomalocardia brasiliana (Gmelin (Mollusca, Bivalvia, Veneridae na Ilha de Santa Catarina e região continental adjacente, Santa Catarina, Brasil Symbionts associated with Anomalocardia brasiliana (Gmelin (Mollusca, Bivalvia, Veneridae on Santa Catarina Island and adjacent continental region, Santa Catarina, Brazil

    Directory of Open Access Journals (Sweden)

    Guisla Boehs

    2004-12-01

    Full Text Available Berbigões, Anomalocardia brasiliana (Gmelin, 1791, de bancos naturais da Ilha de Santa Catarina e região continental adjacente (SC, Brasil, foram examinados quanto a presença de simbiontes. Holothuriophilus tomentosus (Ortmann, 1894 (Brachyura, Sphenia antillensis Dall & Simpson, 1901 (Bivalvia e poliquetos espionídeos (Polychaeta foram observados macroscopicamente. A análise das secções histológicas evidenciou esporocistos de trematódeos (Digenea, um metacestóide (Cestoda e dois ciliados (Ciliophora.Pointed venus, Anomalocardia brasiliana (Gmelin, 1791, from natural beds of Santa Catarina Island and adjacent continental region (SE Brazil were examined in respect of symbiotic associations. Holothuriophilus tomentosus (Ortmann, 1894 (Brachyura, Sphenia antillensis Dall & Simpson, 1901 (Bivalvia, and polychaete worms (Polychaeta were found by macroscopic diagnosis. By analysis of histological sections, it was noted trematode sporocysts (Digenea, a metacestode (Cestoda and two ciliates (Ciliophora.

  15. Crustaceans associated with Cnidaria, Bivalvia, Echinoidea and Pisces at São Tomé and Príncipe islands.

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    Wirtz, P.

    2008-01-01

    Full Text Available Symbiotic crustaceans were searched for at sea anemones (Actiniaria, encrusting anemones (Zoantharia, horny coral (Gorgonaria, black coral (Antipatharia, bivalves (Bivalvia, and sea urchins (Echinoidea at São Tomé and Príncipe Islands (Gulf of Guinea, eastern central Atlantic. Sixteen species of crustaceans were found in association with these invertebrate hosts; eleven of them were new records for the area and two species, belonging to the genera Hippolyte and Heteromysis, were new for science. The thalassinid Axiopsis serratifrons was occasionally associated with an undescribed species of gobiid fish.

  16. The influence of fish cage culture on δ13C and δ15N of filter-feeding Bivalvia (Mollusca)

    International Nuclear Information System (INIS)

    The objective of this study was to evaluate the effect of Oreochromis niloticus cage culture promoted variations in the δ13C and δ15N in Corbicula fluminea (Mollusca; Bivalvia) and in the sediment of an aquatic food web. Samples were taken before and after net cage installation in the Rosana Reservoir (Paranapanema River, PR-SP). Samples of specimens of the bivalve filter C. fluminea and samples of sediment were collected using a modified Petersen grab. All samples were dried in an oven (60 °C) for 72 hours, macerated to obtain homogenous fine powders and sent for carbon (δ13C) and nitrogen (δ15N) isotopic value analysis in a mass spectrometer. There were significant differences in the δ13C and δ15N values of the invertebrate C. fluminea between the beginning and the end of the experiment. There were no differences between the δ13C and δ15N values of sediment. These results indicate that the installation of fish cage culture promoted impacts in the isotopic composition of the aquatic food web organisms, which could exert influence over the native species and the ecosystem. (author)

  17. Comparative studies on the morphometry and physiology of European populations of the lagoon specialist Cerastoderma glaucum (Bivalvia

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    Katarzyna Tarnowska

    2009-09-01

    Full Text Available Seasonal changes in the morphometric and physiological parameters of the cockle Cerastoderma glaucum (Bivalvia from the Baltic Sea (GD, the North Sea (LV, and the Mediterranean Sea (BL were investigated. The cockles from GD were much smaller than those from other populations due to osmotic stress. The female to male ratios did not differ significantly from 1:1. The northern populations (GD, LV had a monocyclic reproductive pattern, whereas the southern population (BL seemed to reproduce throughout the year. Seasonal changes in the contents of biochemical components appeared to be correlated with changes in trophic conditions and the reproductive cycle. Protein content was the highest in spring for all the populations. The highest lipid contents and lowest carbohydrate contents were noted in GD and BL in spring, while no marked differences were noted among seasons in LV (probably because the data from both sexes were pooled. Respiration rates in GD were the highest among the populations, which could have been due to osmotic stress. High metabolic rates expressed by high respiration rates in GD and LV in spring and autumn could have resulted from gamete development (in spring and phytoplankton blooms (in spring and autumn.

  18. Thermal dependency of shell growth, microstructure, and stable isotopes in laboratory-reared Scapharca broughtonii (Mollusca: Bivalvia)

    Science.gov (United States)

    Nishida, Kozue; Suzuki, Atsushi; Isono, Ryosuke; Hayashi, Masahiro; Watanabe, Yusuke; Yamamoto, Yuzo; Irie, Takahiro; Nojiri, Yukihiro; Mori, Chiharu; Sato, Mizuho; Sato, Kei; Sasaki, Takenori

    2015-07-01

    We experimentally examined the growth, microstructure, and chemistry of shells of the bloody clam, Scapharca broughtonii (Mollusca: Bivalvia), reared at five temperatures (13, 17, 21, 25, and 29°C) with a constant pCO2 condition (˜450 μatm). In this species, the exterior side of the shell is characterized by a composite prismatic structure; on the interior side, it has a crossed lamellar structure on the interior surface. We previously found a negative correlation between temperature and the relative thickness of the composite prismatic structure in field-collected specimens. In the reared specimens, the relationship curve between temperature and the growth increment of the composite prismatic structure was humped shaped, with a maximum at 17°C, which was compatible with the results obtained in the field-collected specimens. In contrast, the thickness of the crossed lamellar structure was constant over the temperature range tested. These results suggest that the composite prismatic structure principally accounts for the thermal dependency of shell growth, and this inference was supported by the finding that shell growth rates were significantly correlated with the thickness of the composite prismatic structure. We also found a negative relationship between the rearing temperature and δ18O of the shell margin, in close quantitative agreement with previous reports. The findings presented here will contribute to the improved age determination of fossil and recent clams based on seasonal microstructural records.

  19. Conchological Variability of Anadara Inaequivalvis (Bivalvia, Arcidae In the Black–Azov Sea Basin

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    Anistratenko V. V.

    2014-10-01

    Full Text Available Конхологическая изменчивость Anadara inaequivalvis (Bivalvia, Arcidae в Азово-Черноморском бассейне. Анистратенко В. В., Анистратенко О. Ю., Халиман И. А. - Показан широкий диа- пазон изменчивости раковины Anadara inaequivalvis (Bruguiere, 1789 - вида-вселенца в Азово- Черноморском бассейне. В изученном материале (более 900 створок выделены 6 основных форм комиссурального просвета раковины, которые, однако, не являются дискретными состояниями. Наличие промежуточных вариантов свидетельствует о плавной (непрерывной изменчивости и принадлежности всех изученных популяций к одному виду. Обсуждается варьирование некото- рых других признаков раковины Anadara: количество и скульптированность рёбер на поверхно- сти створок, количество шевронов на лигаментной площадке, форма замочного края и количество зубов замка. Сопоставление морфологических характеристик раковины Anadara из Чёрного и Азовского морей и A. inaequivalvis из юго-восточной Индии подтверждает, что границы и харак- тер изменчивости моллюсков рода Anadara, обитающих в азово-черноморском бассейне, вполне соответствуют изменчивости A. inaequivalvis из типовой

  20. Population dynamics of freshwater oyster Etheria elliptica (Bivalvia: Etheriidae in the Pendjari River (Benin-Western Africa

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    Akélé G.D.

    2015-01-01

    Full Text Available Etheria elliptica (Bivalvia: Etheriidae is the only freshwater oyster occurring in Africa. The current study provides the first data on the population structure, growth, age, mortality and exploitation status of this species in the Pendjari River. E. elliptica length-frequency data were collected monthly from January to December 2009 and analyzed with FiSAT software. Population parameters including the asymptotic length (L∞ and growth coefficient (K were assessed to evaluate the stock status. The recruitment pattern was modeled with a FiSAT routine. The asymptotic length (L∞ was 14.75 cm, while the growth coefficient (K was 0.38 year-1. The growth performance index (ø′ reached 1.92. Specimens of Etheria elliptica reached a mean size of 4.66 cm and 6.41 cm at the end of one year and 1.5 years, respectively. We estimated total mortality (Z, natural mortality (M and fishing mortality (F to be 2.90 year-1, 1.16 year-1 and 1.74 year-1, respectively. The recruitment pattern was continuous over the year with one major peak event during the rainy season (July. The exploitation rate (E = 0.60 revealed that the freshwater oyster was probably facing overexploitation due to lack of a minimum limit size and also due to an increase in the harvesting effort. Therefore, efficient management methods were urgently required to conserve the species. The return of empty shells into the water to increase the recruitment surface, rotation planning among harvesting sites and the imposition of a minimum limit size were recommendations made in order to ensure the sustainable exploitation of wild stocks.

  1. De novo assembly and characterization of two transcriptomes reveal multiple light-mediated functions in the scallop eye (Bivalvia: Pectinidae.

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    Autum N Pairett

    Full Text Available BACKGROUND: The eye has evolved across 13 separate lineages of molluscs. Yet, there have been very few studies examining the molecular machinary underlying eye function of this group, which is due, in part, to a lack of genomic resources. The scallop (Bivalvia: Pectinidae represents a compeling molluscan model to study photoreception due to its morphologically novel and separately evolved mirror-type eye. We sequenced the adult eye transcriptome of two scallop species to: 1 identify the phototransduction pathway components; 2 identify any additional light detection functions; and 3 test the hypothesis that molluscs possess genes not found in other animal lineages. RESULTS: A total of 3,039 contigs from the bay scallop, Argopecten irradians and 26,395 contigs from the sea scallop, Placopecten magellanicus were produced by 454 sequencing. Targeted BLAST searches and functional annotation using Gene Ontology (GO terms and KEGG pathways identified transcripts from three light detection systems: two phototransduction pathways and the circadian clock, a previously unrecognized function of the scallop eye. By comparing the scallop transcriptomes to molluscan and non-molluscan genomes, we discovered that a large proportion of the transcripts (7,776 sequences may be specific to the scallop lineage. Nearly one-third of these contain transmembrane protein domains, suggesting these unannotated transcripts may be sensory receptors. CONCLUSIONS: Our data provide the most comprehensive transcriptomic resource currently available from a single molluscan eye type. Candidate genes potentially involved in sensory reception were identified, and are worthy of further investigation. This resource, combined with recent phylogenetic and genomic data, provides a strong foundation for future investigations of the function and evolution of molluscan photosensory systems in this morphologically and taxonomically diverse phylum.

  2. The influence of fish cage culture on δ{sup 13}C and δ{sup 15}N of filter-feeding Bivalvia (Mollusca)

    Energy Technology Data Exchange (ETDEWEB)

    Benedito, E.; Takeda, A.M., E-mail: eva@nupelia.uem.br [Universidade Estadual de Maringa (UEM), PR (Brazil). Nucleo de Pesquisas em Limnologia, Ictiologia e Aquicultura; Figueroa, L. [Universidade Estadual de Maringa (UEM), PR (Brazil). Pos-Graduacao em Ecologia de Ambientes Aquaticos Continentais; Manetta, GI. [Universidade Estadual de Maringa (UEM), PR (Brazil). Pos-Graduacao em Biologia Comparada

    2013-11-15

    The objective of this study was to evaluate the effect of Oreochromis niloticus cage culture promoted variations in the δ{sup 13}C and δ{sup 15}N in Corbicula fluminea (Mollusca; Bivalvia) and in the sediment of an aquatic food web. Samples were taken before and after net cage installation in the Rosana Reservoir (Paranapanema River, PR-SP). Samples of specimens of the bivalve filter C. fluminea and samples of sediment were collected using a modified Petersen grab. All samples were dried in an oven (60 °C) for 72 hours, macerated to obtain homogenous fine powders and sent for carbon (δ{sup 13}C) and nitrogen (δ{sup 15}N) isotopic value analysis in a mass spectrometer. There were significant differences in the δ{sup 13}C and δ{sup 15}N values of the invertebrate C. fluminea between the beginning and the end of the experiment. There were no differences between the δ{sup 13}C and δ{sup 15}N values of sediment. These results indicate that the installation of fish cage culture promoted impacts in the isotopic composition of the aquatic food web organisms, which could exert influence over the native species and the ecosystem. (author)

  3. Verspreiding en habitats van Unio caffer Krauss, 1848 (Bivalvia: Unionoida: Unionidae in Suid-Afrika gebaseer op die rekords in die databasis van die Nasionale Varswaterslakversameling

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    K. N. de Kock

    2010-01-01

    Full Text Available Die kosmopolities-verspreide Unionoida bereik hul grootste diversiteit in Noord-Amerika. In Suid-Afrika word twee genera van die familie Unionidae, naamlik Unio en Coelatura wat vier spesies insluit, aangetref. Hierdie artikel handel oor die verspreiding en habitats van Unio caffer Krauss, 1848 gebaseer op die rekords in die Nasionale Varswaterslakversameling (NVWSV van Suid-Afrika. Alhoewel dit elders in Suid-Afrika sporadies aangetref is, is die Wes-Kaap die enigste provinsie waarvan geen monster op rekord in die databasis van die NVWSV is nie. Van die 58 monsters wat op rekord is, is die meerderheid in riviere (32.8% en damme (20.7% versamel en in watertoestande wat as standhoudend, staande, helder en vars beskryf is. ’n Temperatuur-indeks wat vir hierdie spesie bereken is, het dit vyfde in rangorde geplaas van die 12 Bivalvia-spesies wat in die databasis verteenwoordig word op grond van ’n assosiasie met lae omgewingstemperature. ’n Besluitnemingsboom-analise het aangedui dat temperatuur, substratum en waterbronne die mees betekenisvolle bydrae gelewer het tot die daarstelling van die gedokumenteerde geografiese verspreiding van U. caffer. Omdat omvattende opnames van varswater Mollusca deur staatsinstansies reeds in die tagtigerjare van die vorige eeu uitgefaseer is en die meerderheid versamelpunte sedertdien nie weer gemonster is nie, is kennis oor hul huidige stand van bewaring en spesiediversiteit gebrekkig. Negatiewe resultate by drie voormalige lokaliteite van U. caffer wat wel intussen deur die outeurs besoek is, dui egter daarop dat die voortbestaan daarvan, soos van sommige verwante spesies elders in die wêreld, bedreig word. Dit word bepleit dat opnames van varswater Mollusca met die gedokumenteerde verspreiding in die databasis van die NVWSV as riglyn, beplan en uitgevoer behoort te word. Die resultate van sulke opnames behoort ’n groot bydrae te lewer om die huidige stand van die verspreiding en spesiediversiteit van

  4. The linked units of 5S rDNA and U1 snDNA of razor shells (Mollusca: Bivalvia: Pharidae).

    Science.gov (United States)

    Vierna, J; Jensen, K T; Martínez-Lage, A; González-Tizón, A M

    2011-08-01

    The linkage between 5S ribosomal DNA and other multigene families has been detected in many eukaryote lineages, but whether it provides any selective advantage remains unclear. In this work, we report the occurrence of linked units of 5S ribosomal DNA (5S rDNA) and U1 small nuclear DNA (U1 snDNA) in 10 razor shell species (Mollusca: Bivalvia: Pharidae) from four different genera. We obtained several clones containing partial or complete repeats of both multigene families in which both types of genes displayed the same orientation. We provide a comprehensive collection of razor shell 5S rDNA clones, both with linked and nonlinked organisation, and the first bivalve U1 snDNA sequences. We predicted the secondary structures and characterised the upstream and downstream conserved elements, including a region at -25 nucleotides from both 5S rDNA and U1 snDNA transcription start sites. The analysis of 5S rDNA showed that some nontranscribed spacers (NTSs) are more closely related to NTSs from other species (and genera) than to NTSs from the species they were retrieved from, suggesting birth-and-death evolution and ancestral polymorphism. Nucleotide conservation within the functional regions suggests the involvement of purifying selection, unequal crossing-overs and gene conversions. Taking into account this and other studies, we discuss the possible mechanisms by which both multigene families could have become linked in the Pharidae lineage. The reason why 5S rDNA is often found linked to other multigene families seems to be the result of stochastic processes within genomes in which its high copy number is determinant. PMID:21364693

  5. Evaluation of the levels of Br, Cl, K, Mg, Mn and V in Perna perna mussels (Linnaeus, 1758: Mollusca Bivalvia) collected in the coast of Sao Paulo state, Brazil; Avaliacao dos teores de Br, Cl, K, Mg, Mn e V em mexilhoes Perna perna (Linnaeus, 1758: Mollusca Bivalvia) coletados no litoral do estado de Sao Paulo, Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Daniele

    2012-07-01

    The coastal environment has been heavily altered by multiple environmental impacts of human activities, such as disposal of sewage from urban areas, the release of numerous chemical industries, agriculture and the flow of vessels, which can lead to accidental spills of oil and oil products, fuels and other products transported by sea. In this context, a means of determining concentrations of these potentially toxic substances in the sea water is the biomonitoring by means of different types of bivalves, which have been used by various researchers, in Brazil and other countries. With regard to bivalve mollusks, particularly mussels, their use in monitoring the marine contamination is mainly due to their wide geographic distribution, sessile habit and ability to concentrate toxic metals to 102-105 times in relation to the concentrations detected in water. In the present study, we employed the passive biomonitoring using the Perna perna bivalve mollusk with respect to the elements Br, Cl, K, Mg, Mn and V. These elements were chosen since they can be determined by INAA method (Instrumental Neutron Activation Analysis), by means of short irradiation which provides faster analyzes and also due to their importance from the standpoint of environmental or nutritional studies. The aim of this study was to evaluate the content of Br, Cl, K, Mg, Mn and V in samples of Perna perna mussels (Linnaeus, 1758: Mollusca, Bivalvia) collected in coastal regions of Sao Paulo subject to anthropogenic contamination (Ponta de Itaipu and Palmas Island, in Santos), comparing the values obtained in sites potentially impacted with the values of the control site in Praia da Cocanha, in Caraguatatuba. The collection points located in Sao Paulo coast are located in the geographical areas 23 Masculine-Ordinal-Indicator 37'S - 45 Degree-Sign 24' W (Caraguatatuba) and 23 Masculine-Ordinal-Indicator 57'S - 46 Masculine-Ordinal-Indicator 20' W (Santos). The collection of organisms

  6. Karyotype details of Crassostrea gryphoides (Rivalvia: Ostreidae) from central west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Goswami, U.

    stream_size 4 stream_content_type text/plain stream_name Chromosome_Inf_Ser_50_7.pdf.txt stream_source_info Chromosome_Inf_Ser_50_7.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset=ISO-8859-1 ...

  7. An Efficient Method for Genomic DNA Extraction from Different Molluscs Species

    Directory of Open Access Journals (Sweden)

    Henrique Guedes-Pinto

    2011-11-01

    Full Text Available The selection of a DNA extraction method is a critical step when subsequent analysis depends on the DNA quality and quantity. Unlike mammals, for which several capable DNA extraction methods have been developed, for molluscs the availability of optimized genomic DNA extraction protocols is clearly insufficient. Several aspects such as animal physiology, the type (e.g., adductor muscle or gills or quantity of tissue, can explain the lack of efficiency (quality and yield in molluscs genomic DNA extraction procedure. In an attempt to overcome these aspects, this work describes an efficient method for molluscs genomic DNA extraction that was tested in several species from different orders: Veneridae, Ostreidae, Anomiidae, Cardiidae (Bivalvia and Muricidae (Gastropoda, with different weight sample tissues. The isolated DNA was of high molecular weight with high yield and purity, even with reduced quantities of tissue. Moreover, the genomic DNA isolated, demonstrated to be suitable for several downstream molecular techniques, such as PCR sequencing among others.

  8. Evaluation of the levels of Br, Cl, K, Mg, Mn and V in Perna perna mussels (Linnaeus, 1758: Mollusca Bivalvia) collected in the coast of Sao Paulo state, Brazil

    International Nuclear Information System (INIS)

    The coastal environment has been heavily altered by multiple environmental impacts of human activities, such as disposal of sewage from urban areas, the release of numerous chemical industries, agriculture and the flow of vessels, which can lead to accidental spills of oil and oil products, fuels and other products transported by sea. In this context, a means of determining concentrations of these potentially toxic substances in the sea water is the biomonitoring by means of different types of bivalves, which have been used by various researchers, in Brazil and other countries. With regard to bivalve mollusks, particularly mussels, their use in monitoring the marine contamination is mainly due to their wide geographic distribution, sessile habit and ability to concentrate toxic metals to 102-105 times in relation to the concentrations detected in water. In the present study, we employed the passive biomonitoring using the Perna perna bivalve mollusk with respect to the elements Br, Cl, K, Mg, Mn and V. These elements were chosen since they can be determined by INAA method (Instrumental Neutron Activation Analysis), by means of short irradiation which provides faster analyzes and also due to their importance from the standpoint of environmental or nutritional studies. The aim of this study was to evaluate the content of Br, Cl, K, Mg, Mn and V in samples of Perna perna mussels (Linnaeus, 1758: Mollusca, Bivalvia) collected in coastal regions of São Paulo subject to anthropogenic contamination (Ponta de Itaipu and Palmas Island, in Santos), comparing the values obtained in sites potentially impacted with the values of the control site in Praia da Cocanha, in Caraguatatuba. The collection points located in São Paulo coast are located in the geographical areas 23º 37'S - 45° 24' W (Caraguatatuba) and 23º 57'S - 46º 20' W (Santos). The collection of organisms was performed in all seasons of the year, beginning in spring 2008 and ending in winter 2009. The samples

  9. Vesicomyidae (bivalvia: current taxonomy and distribution.

    Directory of Open Access Journals (Sweden)

    Elena M Krylova

    Full Text Available Vesicomyid bivalves are a consistent component of communities of sulphide-rich reducing environments distributed worldwide from 77 degrees N to 70 degrees S at depths from 100 to 9050 m. Up-to-now the taxonomy of the family has been uncertain. In this paper, the current state of vesicomyid taxonomy and distribution at the generic rank are considered. This survey is founded on a database including information both from literature sources and also unpublished data of the authors on all recent species of vesicomyids. We suggest that the Vesicomyidae is not a synonym of Kelliellidae, and is therefore a valid family name. We propose to divide the family Vesicomyidae into two subfamilies: Vesicomyinae and Pliocardiinae. The Vesicomyinae includes one genus, Vesicomya, which comprises small-sized bivalves characterized by non-reduced gut and the absence of subfilamental tissue in gills. Symbiosis with chemoautotrophic bacteria has, so far, not been proved for Vesicomya and the genus is not restricted to sulphide-rich reducing habitats. The subfamily Pliocardiinae currently contains about 15 genera with mostly medium or large body size, characterized by the presence of subfilamental tissue in the gills. The Pliocardiinae are highly specialized for sulphide-rich reducing environments, harbouring chemoautrophic bacteria in their gills. This is the first summary of the generic structure of the family Vesicomyidae that allow us to analyze the distribution of vesicomyids at the generic level. We recognize here five different distribution patterns that are related to the specific environmental demands. The general trends in the distribution patterns of the vesicomyids are an occurrence of the majority of genera in broad geographical ranges and the prevalence of near continental type of distribution.

  10. Ecomorphology of Crassostrea cucullata (Born, 1778) (Ostreidae) in a mangrove creek (Gazi, Kenya)

    OpenAIRE

    Tack, J.F.; Vanden Berghe, E; Polk, F.

    1992-01-01

    Variations of shell form and shell-length were studied for oysters growing in the mangroves of Gazi Creek, Kenya, and related to different environmental factors. For the study of the form, Fourier analysis was performed on the circumference of 85 oysters. The resulting coefficients were compared among specimens using cluster analysis. The correspondence between this classification and substrate diameter is virtually perfect ( only one misclassification out of 85 oysters). For the clusters bas...

  11. Comparación histomorfométrica in vitro del ligamento periodontal de premolares extraídos mantenidos en cuatro medios de conservación

    OpenAIRE

    I. Prokopowitsch; R Cabrales Salgado; A. Díaz Caballero; M. Simancas Pallares

    2013-01-01

    Objetivo: El propósito de este estudio fue evaluar histológica y morfométricamente los resultados de diferentes tipos de medios de almacenamiento para los dientes avulsionados en el mantenimiento de la preservación de la integridad del ligamento periodontal. Material y métodos: Estudio de tipo experimental de laboratorio, se utilizaron veintitrés premolares extraídos por motivos ortodóncicos. Los medios de conservación evaluados fueron: leche tipo "B" y tipo "C", solución salina y medio seco....

  12. Crecimiento y desempeño general de juveniles silvestres de mero guasa Epinephelus itajara (Lichtenstein) Mantenidos en jaulas flotantes bajo diferentes condiciones de cultivo

    OpenAIRE

    Botero, J.; Ospina, J.F.

    2003-01-01

    An experimental culture trial of wild juveniles of jewfish Epinephelus itajara was conducted in two different places in the north coast of Colombia in order to evaluate the growth rate of the species and its tolerance to captivity conditions. Two different groups of fish were evaluated in each place, one fed on an artificial diet and the other on trash fish. All fish were held in floating cages for periods ranging from 63 to 89 days. Results showed excellent individual daily weight increase (...

  13. Reproduction and sperm structure in Galeommatidae (Bivalvia, Galeommatoidea)

    DEFF Research Database (Denmark)

    Jespersen, Åse; Lützen, Jørgen

    2006-01-01

    brood chamber as masses of agglutinated and non-encapsulated spermatozoa. The smallest specimens are males, but change into the female sex and there is a strong indication that some of the species are alternate hermaphrodites. Dwarf males occur in one species (Galeomma layardi). The sperm of all 18...

  14. Carbonate-associated sulfate in lucinid (Bivalvia) shells

    Science.gov (United States)

    Peng, Y.; Bao, H.; Anderson, L.; Engel, A. S.

    2007-12-01

    Symbiosis is a fundamental driver of evolution, with examples ranging from mitochondria in eukaryotic cells to barnacle-whale commensalism. The association between sulfur-oxidizing (thiotrophic) bacteria and the lucinid bivalve clade is particularly intriguing because the inferred antiquity of the relationship (>400 m.y.) seems at odds with the relatively loose ecologic linkage of living members. Because only half of genus-level lucinid taxa are extant, and the δ13C of shell carbonate exhibits no systematic difference between symbiotic and non- symbiotic bivalves, a new morphologically-independent proxy to determine whether fossil taxa possessed thiotrophic endosymbionts is needed. The δ34S of carbonate-associated sulfate (CAS) in bivalve shells may hold promise because biogenic carbonate incorporates sulfate into its crystal structure during biomineralization. Incorporation of bacterially derived SO42- (with a more negative δ34S value due to its reduced sulfur origin) into the lucinid-shell crystal lattice would, therefore, impart a distinctly lower δ34SCAS value than that from seawater SO42-, and would be distinguishable from CAS values of co- occurring heterotrophic bivalves. We measured CAS contents, δ34SCAS and δ18OCAS values of 15 sets of lucinid and co-occurring infaunal and epifaunal heterotrophic bivalve shells collected from modern and Cenozoic shallow marine sites. The modern bivalve shells had variable CAS content, from 100 to 2600 ppm. Epifauna often had the highest concentrations relative to the other ecological groups. The δ34SCAS and δ18OCAS clustered at values corresponding to modern seawater sulfate, but with significant scatter. There was no systematic isotope- compositional difference among all bivalves in the same habitat, or among the same lucinid, infaunal, or epifaunal groups across different sites. The fossil bivalve shells tended to preserve lower CAS concentrations and the isotope compositions further deviated from seawater values. These data suggest that 1) pore-water sulfate in shallow sediments is highly heterogeneous in its concentration and isotope composition, probably due to active microbial sulfate reduction, bioturbation, and water-pumping by bivalves and other infaunal filter feeders; 2) CAS is derived from ambient porewater or pumped-in seawater for infauna or epifauna, as well as for lucinids; and 3) CAS concentration and isotope compositions are vulnerable to later diagenetic processes.

  15. Sublethal foot-predation on Donacidae (Mollusca: Bivalvia)

    Science.gov (United States)

    Salas, Carmen; Tirado, Cristina; Manjón-Cabeza, Maria Eugenia

    2001-08-01

    The incidence of foot nipping was studied on the Donax spp. of the littoral of Málaga (Southern Spain, 2875 specimens collected from February 1990 to January 1991) and of Ré island (French Atlantic coast, 262 specimens of Donax vittatus (Da Costa, 1778) collected in May 1996). In Málaga, Donax trunculus L., 1758 was the species most regularly nipped (18% of individuals), with peaks in summer (25% in August and 48% in September) and winter (34% in December). In Ré island, 27% of the specimens showed a nipped foot. Logistic regression shows that in D. trunculus length is the variable that most influences the probability of foot nipping, followed by weight and chlorophyll a. However, the difference in length between damaged and undamaged individuals was not significant (U-Mann-Whitney test). The size class frequency and the values of Ivlev's index show that the small size classes were avoided, while for the other size classes predation remained balanced throughout the year. Therefore, the avoidance of the small size classes makes length the most influential variable. The logistic regression indicated a coefficient B=-0.03 for weight. This implies a slightly negative influence on the probability of foot nipping. However, without the data of September, there is a positive correlation ( r=0.76, p<0.01) between the monthly percentages of predation and the flesh dry weight of a standard individual (25 mm long). The peak in September could be due to the recruitment peak of bivalves, which may have attracted more predators to the area, and/or to the recruitment of predators such as crabs to the swash zone. Logistic regression and test of comparison of percentages indicate that there was not any influence of the sex of an animal on the probability of foot nipping. Only in February was a significantly higher percentage ( p<0.05) of females nipped (44.44%) than the total of females in the sample (20.20%). The biomass (as flesh dry weight) of D. trunculus lost by foot nipping amounts to more than 20% in most of the size classes. There was an increase from the small sizes to the largest ones, in which it reaches 37%, with a positive correlation ( r=0.84; p<0.005) between size class and loss of biomass. Possible predators responsible for the foot nipping are crabs. Crab species usually found together with the donacids were Portumnus latipes (Pennant, 1777) Liocarcinus vernalis (Risso, 1816) and Atelecyclus undecimdentatus (Herbst, 1783). In aquarium experiments, they demonstrated an ability to nip the foot of clams. Portumnus latipes was the most active foot nipper, but left alive all the damaged clams. Therefore, we conclude that crabs are the most likely foot-nipping predators in the field.

  16. Intraspecific variability and systematics in South American Syrotrigoniinae (Trigoniida, Bivalvia)

    Science.gov (United States)

    Echevarría, Javier; Damborenea, Susana E.; Manceñido, Miguel O.

    2015-04-01

    The systematics of the genus Syrotrigonia is revised in the light of the intraspecific variability of a large sample of Syrotrigonia sigeli from the Valanginian from Neuquén Basin, Argentina. The genus can be recognized by the presence of concentric or subconcentric costae surrounding the umbo, later on developing an inflection and finally resulting in a set of anterior horizontal to commarginal costae and another set of posterior sub-vertical costae. The anterior part of the area bears transverse, usually anteriorly concave, costae which direct towards the umbo on the escutcheon; initially they are continuous with those on the flank, but later on they usually alternate. General shell shape, the presence of an antecarinal sulcus, the junction pattern between both sets of costae and the number of horizontal costae relative to vertical costae are variable among species, while costae width or density and the development of horizontal vs. commarginal costae may vary highly within species. The presence of commarginal rugae developed on the whole surface of the shell is interpreted as a result of environmental perturbations. A brief biogeographical interpretation of the family Buchotrigoniidae is also outlined. Syrotrigonia probably originated in North America in the Tithonian, being widespread in the Pacific coast of South America by Early Cretaceous times; at least six (probably seven) South American species could be recognized. By Aptian times the taxon reached the Tethyan realm, its last record being Aptian or Albian in age. The frequent presence of different species in marginal marine deposits suggests a euryhaline lineage adapted to salinity variations, this may also be the cause of the frequent presence of commarginal rugae. Considering the high variability displayed in the analyzed material, large samples are needed to characterize new species within the group.

  17. Genus Donax in the Peruvian coast (Bivalvia: Telllnoidea

    Directory of Open Access Journals (Sweden)

    Carlos Paredes

    2014-06-01

    Full Text Available In the present paper the species of Donax Linnaeus, 1758 in Peru are reviewed. The presence of 7 out of the 11 species is confirmed: D. asper Hanley. 1845; D. caelatus rothi Coan, 1983; D. obesulus Reeve, 1854; D. carinatus Hanley, 1843; D. transversus Sowerby 1,1825; D. californicus Conrad, 1837 and D. marincovichi Coan, 1983; in addition, one is recorded for the first time (D. punctatostriatus Hanley, 1843 in Peruvian waters. Information on the distribution geographical and some ecological relations is presented.

  18. Anatomia funcional de Perna perna (Linné) (bivalvia, Mytilidae) Functional anatomy of Perna perna (Linné) (bivalvia, Mytilidae)

    OpenAIRE

    Walter Narchi; Mario Sérgio Galvão-Bueno

    1997-01-01

    Perna perna (Linné, 1758) occurs on the Atlantic littoral from Venezuela to Uruguay. The main organ systems were studied in the living animais, particular attention being paid to the ciliary feeding and cleansing mechanisms in the mantle cavity. The anatomy, functioning of the stomach and the ciliary sorting mechanisms are described. The siphons belong to type A (Yongf. 1948b), the ctenidia to type B( 1) (Atkins 1936c) and the stomach is of type III (Purchon 1957) or Section I (Dinamani 1967)...

  19. Evidence of sexual transition in Leopard Grouper (Mycteroperca rosacea individuals held in captivity Evidencia de transición sexual en individuos de cabrilla sardinera (Mycteroperca rosacea mantenidos en cautiverio

    Directory of Open Access Journals (Sweden)

    Margarita Kiewek-Martínez

    2010-01-01

    Full Text Available This study describes histological observations of the gonads of 12 captive leopard grouper, M. rosacea maintained in captivity. Monthly gonad samples during February to April 2003, were obtained by catheterization and analyzed to determine sex and degree of ovarian development. Oocytes were classified into 5 stages of development and the frequencies were obtained to describe the oocyte distribution in the ovary. Two fish that were females in February were in a bisexual stage in March and functional males in April. The transitional stage was observed during the reproductive season and included degeneration of primary oocytes and proliferation of spermatogonia.Este estudio describe las observaciones histológicas del desarrollo gonadal de 12 individuos de la cabrilla sardinera, en condiciones de cautiverio. De febrero a abril del 2003 se obtuvieron muestras mensuales de la gónada mediante un catéter flexible, las cuales fueron analizadas para determinar el sexo del organismo y el estadio de desarrollo gonadal. Los ovocitos fueron clasificados en 5 etapas de desarrollo y se calcularon las frecuencias para determinar su distribución dentro del ovario. Dos individuos que fueron identificados como hembras en febrero, se encontraron en estadio bisexual en marzo y fueron machos funcionales en abril. Este estadio de transición se observó durante el periodo reproductor y se caracterizó por la degeneración de ovocitos primarios y la proliferación de espermatogonias.

  20. Efecto de la dieta artificial MP sobre la emergencia y relacion de sexos de Phymastichus coffea (Hymenoptera:Eulophidae) mantenido sobre su hueped, Hypothenemus hampei (Coleoptera: Scloytidae)a traves de generaciones contin

    Science.gov (United States)

    Phymastichus coffea La Salle (Hymenoptera: Eulophidae) is an endoparasitoid that attacks the adult coffee berry borer, Hypothenemus hampei Ferrari (Coleoptera: Scolytidae). The MP diet developed by Portilla and Streett is the only reported diet that allows cultures of P. coffea to develop and repr...

  1. Reestablecimiento de Choromytilus chorus (Molina, 1782 (Bivalvia: Mytilidae en el norte de Chile Reestablishment of Choromytilus chorus (Molina, 1782 (Bivalvia: Mytilidae in northern Chile

    Directory of Open Access Journals (Sweden)

    Miguel Avendaño

    2011-07-01

    Full Text Available Hasta fines del siglo pasado no existían registros de la presencia de Choromytilus chorus al norte de los 23°S, pese a antecedentes que señalaban su existencia en épocas pasadas. Ciertos cambios relacionados con las masas de agua costeras de esta zona, habrían generado la ausencia o escasez que presentaba el entorno costero actual. Sin embargo, hace una década atrás, su presencia en el norte de Chile, comienza a tener connotación pesquera. En el presente trabajo se confirma su reestablecimiento en las regiones de Antofagasta y Tarapacá, mediante prospecciones realizadas en seis lugares donde se registró su presencia, así como mediante la captación de semilla en colectores suspendidos. Se indica interacción con Aulacomya ater, a la cual ha desplazado a estratos más profundos, mientras que su reestablecimiento, iniciado en las regiones de Atacama y Antofagasta, y que se amplió posteriormente a la región de Tarapacá; permite postular la hipótesis que la dinámica de estos bancos, respondería a una estructura de metapoblación, dado el sistema de corrientes y vientos que predominan en la zona norte, permitiendo la advección larval de poblaciones existentes en la región de Coquimbo.Despite indications of its presence in past ages, until the end of the last century, no records showed Choromytilus chorus north of 23°S. Certain changes related to coastal water masses in the zone could be responsible for the present lack or scarcity of this species in the coastal area. However, a decade ago, this species appeared in northern Chile in the context of fisheries. This study confirms the re-establishment of C. chorus in the Antofagasta and Tarapaca regions through surveys at six sites where the species had been registered and spat collection using suspended collectors. This species has interacted with Aulacomya ater, displacing it towards deeper habitats. The re-establishment of C. chorus began in the Atacama and Antofagasta regions and later extended to the Tarapaca region. Thus, we hypothesize that the dynamics of these shoals correspond to a metapopulation structure that has allowed larval advection, given the current system and predominant winds in the northern zone, from populations existing in the Coquimbo region.

  2. Reestablecimiento de Choromytilus chorus (Molina, 1782) (Bivalvia: Mytilidae) en el norte de Chile Reestablishment of Choromytilus chorus (Molina, 1782) (Bivalvia: Mytilidae) in northern Chile

    OpenAIRE

    Miguel Avendaño; Marcela Cantillánez

    2011-01-01

    Hasta fines del siglo pasado no existían registros de la presencia de Choromytilus chorus al norte de los 23°S, pese a antecedentes que señalaban su existencia en épocas pasadas. Ciertos cambios relacionados con las masas de agua costeras de esta zona, habrían generado la ausencia o escasez que presentaba el entorno costero actual. Sin embargo, hace una década atrás, su presencia en el norte de Chile, comienza a tener connotación pesquera. En el presente trabajo se confirma su reestablecimien...

  3. Ocorrência do bivalve exótico Mytilopsis leucophaeta (Conrad (Mollusca, Bivalvia, no Brasil Occurrence of exotic bivalve Mytilopsis leucophaeta (Conrad (Mollusca, Bivalvia, in Brazil

    Directory of Open Access Journals (Sweden)

    José R. B. de Souza

    2005-12-01

    Full Text Available O molusco Mytilopsis leucophaeta (Conrad, 1831, natural da América do Norte, foi localizado no litoral de Pernambuco, Brasil, em 2004, trazido provavelmente por água de lastro de navios. Na região, sua distribuição atualmente abrange zonas estuarinas adjacentes ao Porto do Recife. Os organismos foram encontrados restritos à região entre-marés, formando agregados densos com até 176.800 ind./m².The mussel Mytilopsis leucophaeta (Conrad, 1831 is native to North America. It was found at Pernambuco Coast, northeastern Brazil, in 2004, probably brought by ships' ballast water. The distribution of this species has been now spread to estuarial area near Recife Harbour. They showed a clumped distribution with a maximum of 176,800 ind./m² only in the intertidal zone.

  4. Doubly uniparental inheritance (DUI) of mitochondrial DNA in Donax trunculus (Bivalvia: Donacidae) and the problem of its sporadic detection in Bivalvia.

    Science.gov (United States)

    Theologidis, Ioannis; Fodelianakis, Stilianos; Gaspar, Miguel B; Zouros, Eleftherios

    2008-04-01

    Mitochondrial DNA is transmitted maternally in metazoan species. This rule does not hold in several species of bivalves that have two mtDNA types, one that is transmitted maternally and the other paternally. This system of mitochondrial DNA transmission is known as doubly uniparental inheritance (DUI). Here we present evidence of DUI in the clam Donax trunculus making Donacidae the sixth bivalve family in which the phenomenon has been found. In addition, we present the taxonomic affiliation of all species in which DUI is currently known to occur and construct a phylogeny of the maternal and paternal genomes of these species. We use this information to address the question of a single or multiple origins of DUI and to discuss whether failed attempts to demonstrate the presence of DUI in several bivalve species might be due to problems of detection or to genuine absence of the phenomenon. PMID:18208565

  5. Environ: E00159 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available E00159 Oyster shell (JP16) Crude drug Calcium carbonate [CPD:C08129], Scleroprotein, Calcium... phosphate, Silicate Ostreidae [TAX:6563] Same as: D06790 Osteridae Oyster shell Major component: Calcium carbonate [CPD:C08129] ...

  6. Redescription and anatomy of Diplodonta portesiana (d’Orbigny, 1846 (Bivalvia, Ungulinidae from Brazil

    Directory of Open Access Journals (Sweden)

    Bárbara Romera

    2013-03-01

    Full Text Available The present redescription of Diplodonta portesiana (d’Orbigny, 1846 is the first part of the revision of this genus in the East Atlantic. This species, despite being common in the Atlantic coast, remains poorly known. A detailed shell and anatomical study was conducted based not only on specimens from the type locality’s vicinities but also on samples from other regions. Diagnostic characters for D. portesiana includes: rounded shell with a small ligament; triangular, short and deep nymph; external micro ornamentation composed of small concavities in a concentric pattern; small adductor muscles; reduced pedal gape; pair of long hemipalps with a large area covered by folds; stomach with four ducts leading to digestive diverticula; and long intestine length. Our study suggests at least two new diagnostic characters to the genus: the two pair of muscles that controls the incurrent and excurrent openings and a residual ring-like tissue surrounding the anterior half of the posterior foot retractor muscle.

  7. Faecal bacteria in Perna perna (Linnaeus, 1758 (Mollusca: Bivalvia for biomonitoring coastal waters and seafood quality

    Directory of Open Access Journals (Sweden)

    Diego Igawa Martinez

    2010-06-01

    Full Text Available Urban development in coastal areas is intense and leads to the increase of sewage outfall and other negative impacts as consequences. Thus, stringent regulations establishing limits to the microbiological contamination of water and seafood are needed. The objective of this study is to evaluate the usefulness of Enterococci and Thermotolerant Coliform densities in the flesh of mussels Perna perna as an alternative tool for monitoring the microbiological quality of coastal waters. The study also considers allometric relations applied to clearance rates to understand rates of bacterial concentration. Bacterial loads obtained in mussels' flesh were from 50 to 4,300 times greater than in the water sampled in the vicinity of the mussels and some were considered inappropriate for consumption even when the water presented no restrictions. The mean clearance rate obtained for Enterococci retention was 317.7 ml h-1 and this rate (CR is related to the mussels' size (L by the equation CR = 28.3229L1.6421. The results showed that bacterial densities in the mussels' tissues may reflect chronic contamination of the environment and that clearance rates are important for taking the best decision in situations where, for example, it is desired to introduce mussels for aquaculture and the evaluation of the water concerned is required.O desenvolvimento urbano em áreas costeiras é intenso e o aumento das descargas de esgoto é uma das conseqüências. Assim, leis específicas que regulem limites para a contaminação microbiológica das águas e de alimentos de origem marinha são necessárias. O objetivo deste estudo é avaliar a utilização de Enterococos e coliformes termotolerantes na carne de mexilhões Perna perna como alternativa para o monitoramento da qualidade microbiológica de águas costeiras. O estudo também considera relações alométricas aplicadas às taxas de "clearance" para entender a concentração de bactérias pelo molusco. As densidades bacterianas obtidas no molusco foram de 50 a 4300 vezes maiores do que nas amostras de água coletadas próximas dos moluscos e alguns foram considerados impróprios para consumo, mesmo quando as águas não mostraram restrições. A taxa de "clearance" média obtida para retenção de Enterococos foi 317.7 ml h-1 e essas taxas (CR puderam ser relacionadas com o tamanho dos mexilhões (L pela equação CR = 28.3229L1.6421. Os resultados mostram que as densidades bacterianas nos tecidos dos mexilhões podem refletir a contaminação crônica do ambiente e que as taxas de "clearance" devem ser consideradas para a tomada de decisão em situações onde, por exemplo, se deseja implantar mexilhões para cultivo.

  8. Molecular phylogenetics and historical biogeography amid shifting continents in the cockles and giant clams (Bivalvia: Cardiidae).

    Science.gov (United States)

    Herrera, Nathanael D; Ter Poorten, Jan Johan; Bieler, Rüdiger; Mikkelsen, Paula M; Strong, Ellen E; Jablonski, David; Steppan, Scott J

    2015-12-01

    Reconstructing historical biogeography of the marine realm is complicated by indistinct barriers and, over deeper time scales, a dynamic landscape shaped by plate tectonics. Here we present the most extensive examination of model-based historical biogeography among marine invertebrates to date. We conducted the largest phylogenetic and molecular clock analyses to date for the bivalve family Cardiidae (cockles and giant clams) with three unlinked loci for 110 species representing 37 of the 50 genera. Ancestral ranges were reconstructed using the dispersal-extinction-cladogenesis (DEC) method with a time-stratified paleogeographic model wherein dispersal rates varied with shifting tectonics. Results were compared to previous classifications and the extensive paleontological record. Six of the eight prior subfamily groupings were found to be para- or polyphyletic. Cardiidae originated and subsequently diversified in the tropical Indo-Pacific starting in the Late Triassic. Eastern Atlantic species were mainly derived from the tropical Indo-Mediterranean region via the Tethys Sea. In contrast, the western Atlantic fauna was derived from Indo-Pacific clades. Our phylogenetic results demonstrated greater concordance with geography than did previous phylogenies based on morphology. Time-stratifying the DEC reconstruction improved the fit and was highly consistent with paleo-ocean currents and paleogeography. Lastly, combining molecular phylogenetics with a rich and well-documented fossil record allowed us to test the accuracy and precision of biogeographic range reconstructions. PMID:26234273

  9. Posture of Iridina spekei (Bivalvia: Mutelidae) on the Flat Sandy Bottom of Lake Tanganyika

    OpenAIRE

    KONDO, Takaki

    1986-01-01

    Length, height and angle of the exposed part of mussel, Iridina spekei, above the bottom were examined on the sandy flat of Lake Tanganyika. The larger mussel protruded higher above the bottom, which seemed to be advantageous to scatter sperm or larvae father in order to increase chances of the fertilization or parasitism of larvae on fish. Immature mussels seemed to lie hidden to avoid predation by fish.

  10. Direct evidence for maternal inheritance of bacterial symbionts in small deep-sea clams (Bivalvia: Vesicomyidae)

    Science.gov (United States)

    Szafranski, Kamil M.; Gaudron, Sylvie M.; Duperron, Sébastien

    2014-05-01

    Bacterial symbiont transmission is a key step in the renewal of the symbiotic interaction at each host generation, and different modes of transmission can be distinguished. Vesicomyidae are chemosynthetic bivalves from reducing habitats that rely on symbiosis with sulfur-oxidizing bacteria, in which two studies suggesting vertical transmission of symbionts have been published, both limited by the imaging techniques used. Using fluorescence in situ hybridization and transmission electron microscopy, we demonstrate that bacterial symbionts of Isorropodon bigoti, a gonochoristic Vesicomyidae from the Guiness cold seep site, occur intracellularly within female gametes at all stages of gametogenesis from germ cells to mature oocytes and in early postlarval stage. Symbionts are completely absent from the male gonad and gametes. This study confirms the transovarial transmission of symbionts in Vesicomyidae and extends it to the smaller species for which no data were previously available.

  11. Early development, survival and growth rates of the giant clam Tridacna crocea (Bivalvia: Tridacnidae)

    OpenAIRE

    Miguel Mies; Felipe Braga; Marcello Santos Scozzafave; Daniel Eduardo Lavanholi de Lemos; Paulo Yukio Gomes Sumida

    2012-01-01

    Tridacnid clams are conspicuous inhabitants of Indo-Pacific coral reefs and are traded and cultivated for the aquarium and food industries. In the present study, daily growth rates of larvae of the giant clam Tridacna crocea were determined in the laboratory during the first week of life. Adults were induced to spawn via intra-gonadal serotonin injection through the byssal orifice. After spawning oocytes were collected, fertilized and kept in 3 L glass beakers and raceways treated with antibi...

  12. [Mollusc diversity in an Arca zebra (Mollusca: Bivalvia) community, Chacopata, Sucre, Venezuela].

    Science.gov (United States)

    Prieto, A S; Ruiz, L J; García, N; Alvarez, M

    2001-06-01

    The diversity of a subtidal epifaunal mollusk community was studied from September, 1990 to September, 1991 in Chacopata, Sucre State, Venezuela. There were 40 species (24 bivalves and 16 gastropods). The diversity indexes (H' = 2.087, J' = 0.392, 1/D = 0.528) were low when compared with other tropical zones. Monthly diversity reached its maximum in September, 1990 (1.63 bits/ind.) and July, 1991 (1.60 bits/ind.); minimum diversity occurred in June, 1991 (0.52 bits/ind.). A Log series model applied to species abundance data showed a straight line with a diversity index alpha of 5.56. Of 40 species identified, the turkeywing Arca zebra was dominant (69% in number of individuals and 72% of biomass) followed by Pinctada imbricata, Modiolus squamosus, Chama macerophyla and Anadara notabilis. The predatory snails Phyllonotus pomum, Chicoreus brevifrons and Murex recurvirostris seemed to have trophic relationships with A. zebra. The total mean biomass in wet weight (469.20 +/- 263 g m-2, shell included) was high which indicates that A. zebra, a species with a rapid growth rate, occupies a central role in the assemblage as an efficient filter feeder that converts planktonic food into available biomass, supporting one of the most important fisheries in Venezuela. PMID:11935909

  13. Transcriptomics provides insight into Mytilus galloprovincialis (Mollusca: Bivalvia) mantle function and its role in biomineralisation.

    Science.gov (United States)

    Bjärnmark, Nadège A; Yarra, T; Churcher, A M; Felix, R C; Clark, M S; Power, D M

    2016-06-01

    The mantle is an organ common to all molluscs and is at the forefront of the biomineralisation process. The present study used the Mediterranean mussel (Mytilus galloprovincialis) as a model species to investigate the structural and functional role of the mantle in shell formation. The transcriptomes of three regions of the mantle edge (umbo to posterior edge) were sequenced using Illumina technology which yielded a total of 61,674,325 reads after adapter trimming and filtering. The raw reads assembled into 179,879 transcripts with an N50 value of 1086bp. A total of 1363 transcripts (321, 223 and 816 in regions 1, 2 and 3, respectively) that differed in abundance in the three mantle regions were identified and putative function was assigned to 54% using BLAST sequence similarity searches (cut-off less than 1e(-10)). Morphological differences detected by histology of the three mantle regions was linked to functional heterogeneity by selecting the top five most abundant Pfam domains in the annotated 1363 differentially abundant transcripts across the three mantle regions. Calcium binding domains dominated region two (middle segment of the mantle edge). Candidate biomineralisation genes were mined and tested by qPCR. This revealed that Flp-like, a penicillin binding protein potentially involved in shell matrix maintenance of the Pacific oyster (Crassostrea gigas), had significantly higher expression in the posterior end of the mantle edge (region one). Our findings are intriguing as they indicate that the mantle edge appears to be a heterogeneous tissue, displaying structural and functional bias. PMID:27037218

  14. The biology and functional morphology of Macoma biota (Bivalvia: Tellinidae: Macominae

    Directory of Open Access Journals (Sweden)

    Pedro Ribeiro Piffer

    2011-06-01

    Full Text Available Macoma biota Arruda & Domaneschi, 2005, is a recently described species known only from the intertidal zone of Praia da Cidade, Caraguatatuba Bay, in the state of São Paulo, southeastern Brazil. The main purpose of the present paper is to describe the biology of M. biota, beginning with a detailed analysis of its anatomy and functional morphology and how these attributes are correlated with its habitat and life history. The morphology of the organs in the pallial cavity and their sorting devices indicate that this species has efficient mechanisms to process large amounts of particles that enter this cavity via the inhalant current. M. biota can rapidly select the material suitable for ingestion and direct the undesired excess to the rejection mantle tracts. These characteristics along with the siphon's behavior and the digestive tract configuration reveal that this species can be classified primarily as a deposit feeder, like other species of the genus; however, it can also behave as a suspension feeder, depending on the environmental conditions.

  15. Complete sequence and polymorphisms of female Ruditapes philippinarum (Mollusca: Bivalvia) mitochondria genome.

    Science.gov (United States)

    Hwang, Jae Yeon; Han, Geon Goo; Park, Jung Youn; Kim, Eun-Mi; An, Cheul Min; Kang, Jung-Ha; Choi, Yun-Jaie; Kim, Eun Bae

    2016-09-01

    Mitogenome of female Ruditapes philippinarum organism was sequenced, and genomic variation and phylogeny were examined in this study. Length of the mitogenome was 22 089 bp showing 94.28% of sequence identity with previously reported sequence. Total 707 single nucleotide polymorphisms, SNPs, were detected and 50 residues were non-synonymous SNPs among the 202 SNPs in protein-coding genes. Deleted genomic fragments with of 265 bp and 322 bp were observed in non-coding regions, ND2 to ND4L and ND4L to tRNA(Ile), respectively. Phylogenic analysis confirmed that used organisms were female R. philippinarum, and the species has closer evolutionary distance with genus Paphia rather than genus Meretrix. Our finding will be help to set an insight for population and evolutionary genomics of Veneroida clams as well as application to marine industry. PMID:26248000

  16. Abnormal features of Macoma balthica (Bivalvia) in the Baltic Sea: alerting symptoms of environmental adversity?

    International Nuclear Information System (INIS)

    Recent studies of the Baltic clam Macoma balthica (L.) from the southern Baltic (the Gulf of Gdansk) have revealed striking morphological, histological and cytogenetic features. Strong deformation of the shell, including elongation of the posterior end and the appearance of an easily visible flexure in this part, has been recorded. The population contribution of the deformed blunt shelled ('irregular') clams ranged from 0% to 65% and tended to increase with depth. The morphologically 'irregular' clams had higher accumulated tissue concentrations of trace metals (As, Ag, Cd, Pb, Cu and Zn), indicating a different metal handling ability. Adverse conditions in deeper water regions of the Gulf (e.g. hypoxia, hydrogen sulphide, elevated bioavailability of contaminants) have been suggested as inducers of the phenotypical changes (morphological deformation) in part of the population and, in parallel, of the specific physiological adaptations that result in higher metal accumulation in the 'irregular' clams. Cytogenetic and histological analyses showed the presence of tumours in gill cells and digestive system of the affected clams, the prevalence of disseminated neoplasia ranging from 0% to 94% depending on the site. The disease was manifested by a modified karyotype (i.e. an abnormal number and morphology of chromosomes), a higher activity of nucleolar organizer regions (AgNORs), and tissue lesions (enlarged cells, actively proliferative with pleomorphic nuclei). Bottom sediments showed acute toxicity and have been proposed as a source of an initialising carcinogenic factor. However, none of the ecotoxicological studies provided was successful in the clear demonstration of a single (or multifactorial) agent that can account for the disseminated neoplasia

  17. Growth and production of Donax striatus (Bivalvia: Donacidae) from Las Balsas beach, Gibara, Cuba.

    Science.gov (United States)

    Ocaña, Frank A

    2015-09-01

    Clams of the genus Donax are worldwide the dominating group of the invertebrate community on sandy beaches. They are primary consumers that provide a significant abundance and biomass to the ecosystem. In the Caribbean, Donax striatus has an important role for nature and human, nonetheless studies on the population dynamics of this beach clam are scarce and no information exists on secondary production of this species. Growth parameters and secondary production of D. striatus were estimated from February 2008 to November 2009 at Las Balsas beach, Northeastern Cuba, in order to provide basic information for management purposes. In each month 45 samples were taken by means of a PVC corer of 0.025 m2 area and sieved with a 1 mm mesh. Animals were measured and weighted with and without shell. A total of 5 471 specimens were collected during the sampling period. Shell length ranged from 2.7-33.3 mm. Growth parameters estimated from length frequency data were L∞ = 36.1 mm, K= 0.8/yr and t0= 0.2/yr. The growth performance resulted in values of Φ'= 3.02. Life span was 2.4 yrs and mortality rate was 3.07 /yr. In 2008, mean abundance of D. striatus ranged between 17.1 - 770.7 ind./m2. In 2009 the lowest mean abundance was 34.4 and the highest was 892.5 ind./m2. During 2009 biomass and production was more than twice higher in comparison with 2008. Individual production showed highest values in the 24 mm shell size (3.74 g/m2.yr) and 25 mm (0.71 g/m2.yr), considering mass with shell and without shell, respectively. During 2009 abundance of individuals with 15 mm shell length or more increased resulting in higher biomass and production, compared to 2008. Using the conversion factor of wet mass to ash free dry mass (AFDM), annual production ranged between 2.87-6.11 g AFDM/m2.yr, resulting in a turnover rate (P/B) between 5.11 and 3.47 in 2008 and 2009, respectively. The rapid growth and high turnover rate of D. striatus suggest a rapid recovery of the population. These results support the idea that this beach clam is an important resource at Las Balsas beach. Thus its exploitation must continue with caution, and only at the level of a recreational fishery. PMID:26666121

  18. Reproductive cycle and gonad development of the Northern Argentinean Mesodesma mactroides (Bivalvia: Mesodesmatidae)

    Science.gov (United States)

    Herrmann, Marko; Alfaya, José E. F.; Lepore, Mauro L.; Penchaszadeh, Pablo E.; Laudien, Jürgen

    2009-09-01

    The reproductive cycle and gonad development of the yellow clam Mesodesma mactroides was studied over a period of 24 months (January 2005-December 2006) at the Argentinean sandy beach Santa Teresita. Histological examination of gonadal tissue revealed that sex ratios did not significantly deviate from the proportion of 1:1 and no case of hermaphroditism was found. The reproductive cycle of M. mactroides followed an annual cyclicality, which was significantly correlated to monthly mean sea surface temperatures (SST). Oocytes showed highest abundance in winter, indicating a process of gonadal development and sexual maturation. The mean oocyte size decreased significantly during spring. Modal oocyte sizes decreased significantly during winter and late spring of each year, suggesting spawning events. The condition index was not useful in describing the annual reproductive cycle of M. mactroides. Ash-free, shell-free dry mass was chosen to detect the condition of the specimens, and this significantly correlated with monthly mean SST and the gametogenic cycle. Annual recruitment patterns during summer-autumn indicated a 3-month-long planktonic phase of M. mactroides. The reproduction cycle and gonad development of M. mactroides showed only weak differences between data from the present study and those collected 40 years ago.

  19. Sperm structure and sperm transfer in Pseudopythina subsinuata (Bivalvia, Galeommatoidea)

    DEFF Research Database (Denmark)

    Jespersen, Åse

    2009-01-01

    -thick paraspermatozoa have a terminally placed irregularly cork-screw-shaped acrosome and a bundle of ca. 16 flagella emerging from behind the nucleus. The role of the paraspermatozoa is obscure. Euspermatozoa are transferred to the seminal receptacles of the females and attach with the tip of the acrosome to the...... elongate cells. Most females contain one to three "sperm trees", structures consisting of a short stem and numerous branches. They are firmly implanted in the abfrontal part of the gill filament and protrude into the posterior part of the suprabranchial (brooding) chamber. Implantation of the trees causes...

  20. On the identity of broad-shelled mussels (Mollusca, Bivalvia, Mytilus) from the Dutch delta region

    OpenAIRE

    Groenenberg, D.S.J.; Wesselingh, F.P.; Rajagopal, S.; Jansen, J.M.; Bos, M.M.

    2011-01-01

    Late Quaternary (Eemian) deposits of the Netherlands contain shells that resemble those of living Mytilus galloprovincialis. Similar broad-shelled mytilids also occur in estuaries of the southwestern Netherlands together with slender individuals typical of M. edulis. We sampled living mussels along a depth gradient in the Oosterschelde to a) investigate whether a relation exists between shell shape and depth, b) test if the broad-shelled specimens might represent M. galloprovincialis (or a hy...

  1. On the identity of broad-shelled mussels (mollusca, bivalvia, mytilus) from the Dutch delta region

    OpenAIRE

    Groenenberg, D.S.J.; Wesselingh, F.P.; Rajagopal, S.; Jansen, J.M.; Bos, M.M.; Van De Velde, G; Gittenberger, E; Hoeksema, B.W.; Raad, H.; Hummel, H

    2011-01-01

    Late Quaternary (Eemian) deposits of the Netherlands contain shells that resemble those of living Mytilus galloprovincialis. Similar broad-shelled mytilids also occur in estuaries of the southwestern Netherlands together with slender individuals typical of M. edulis. We sampled living mussels along a depth gradient in the Oosterschelde to a) investigate whether a relation exists between shell shape and depth, b) test if the broadshelled specimens might represent M. galloprovincialis (or a hyb...

  2. Winter distribution, density and size of Mesodesma mactroides (Bivalvia, Mactracea in Monte Hermoso beach (Argentina

    Directory of Open Access Journals (Sweden)

    Sandra Marcela Fiori

    2004-03-01

    Full Text Available The yellow clam Mesodesma mactroides (Deshayes, 1854 is a seasonal migrant that moves in spring to the sandy upper intertidal level. In this paper we analyze the spatial distribution of density and mean shell size of the yellow clam population in Monte Hermoso beach (Argentina in winter 1995, i.e., three months before the mass mortality occurred in November 1995. Sampling covered 32 km of beach, with a regular design of 22 transects. The major environmental gradient in the beach was determined using principal component analysis (PCA on the correlation matrix of the environmental data (beach morphology, slope, and sand granulometry. Correlation analysis was used to assess the relationship between the score of a site (transect on the first and second principal component, and clam mean density and mean shell size. Most of the beach seems to be habitable for clams, their spatial heterogeneity not having been explained by the measured variables since, although the first axis of the PCA has demonstrated an E-W physical gradient, clam density was not in correlation with it. Density was maximum near the piers, even though these are points with high tourist activity. It seems that non-extractive touristic activities do not affect population density but rather mean shell size, probably due to reduction of growth rates. The abundance of the winter population, as compared with the assessment done after the mass mortality of November, strongly suggests that a great part of the population was overwintering in the intertidal fringe.O molusco Mesodesma mactroides (Deshayes, 1854 é uma espécie migrante sazonal que na primavera move-se para o nível entremarés superior da praia. Neste estudo, analisamos a distribuição espacial da densidade e o tamanho médio da população do bivalve na praia de Monte Hermoso (Argentina no inverno de 1995, i. é, três meses antes da mortalidade massiva desses moluscos, acontecida em novembro de 1995. A amostragem cobriu 32 km da praia, utilizando-se 22 transectos distribuídos regularmente. O gradiente ambiental principal na praia foi determinado mediante Análise de Componentes Principais (ACP a partir da matriz de correlação dos dados ambientais (morfologia e declividade da praia, e granulometria da areia. A análise da correlação foi utilizada para avaliar a relação entre o escore de um local (transecto no primeiro e segundo componentes principais, a densidade média dos moluscos e tamanho médio da concha. A maior parte da praia parece ser um habitat apropriado para esses moluscos e sua heterogeneidade espacial não foi explicada pelas variáveis medidas, uma vez que, embora o primeiro eixo da PCA tenha demonstrado um gradiente físico no sentido L-O, a densidade dos moluscos não apresentou correlação com o mesmo. A densidade apresentou o máximo valor próximo aos molhes, pontos de grande fluxo turístico, atividade esta que quando não acarreta coleta de moluscos parece não afetar a densidade da população, mas sim o tamanho médio da concha através de uma redução da taxa de crescimento. A abundância da população no inverno, em comparação com a avaliação feita após a mortalidade em massa de novembro, sugere que a maior parte da população passa o inverno na faixa entremarés.

  3. Gill Development and Its Functional and Evolutionary Implications in the Blue Mussel Mytilus edulis (Bivalvia: Mytilidae)

    OpenAIRE

    Cannuel, Rozenn; Beninger, Peter G.; Mccombie, Helen; Boudry, Pierre

    2009-01-01

    Study of gill development in bivalve larvae and postlarvae provides information on the evolution of this organ and feeding mechanisms of early stages. Scanning electron microscopy was used to document the development of the filibranch homorhabdic gill in hatchery-reared larval, postlarval, and juvenile Mytilus edulis. Four key stages were identified during gill development: (1) transfer of the particle collection function from velum to gill at metamorphosis, with subsequent elongation of the ...

  4. Seawater temperature and salinity controls on Li/Ca ratios in Mytilus edulis (bivalvia) shells

    Science.gov (United States)

    Clarke, L. J.; Wanamaker, A. D., Jr.; Kreutz, K. J.; Borns, H. W., Jr.; Introne, D. S.

    2009-04-01

    In this study we have investigated the effects of seawater temperature and salinity on Li/Ca ratios in newly precipitated shell calcite in Mytilus edulis shells, since this potential temperature proxy has not been widely applied beyond brachiopods and inorganic calcite. Juvenile specimens of M. edulis collected from western Greenland were cultured in laboratory aquaria using a four-by-three factorial design that consisted of four circulating temperature baths and three salinities. New shell growth precipitated during the constrained culturing experiment was identified carefully and subsequently dissected from the shells. Following acid dissolution, Li/Ca ratios were measured by ICP-MS, enabling an assessment of temperature and salinity controls on shell Li/Ca ratios. Furthermore, measurement of Li/Ca ratios in the aquaria seawaters has enabled calculation of Li/Ca ratio partition coefficients and direct comparison to Li/Ca ratio to temperature relationships observed for brachiopods and inorganic calcite. The results of this study suggest that bivalve shell Li/Ca ratios can be used as a new temperature proxy.

  5. Growth, mortality, and reproduction of Tagelus plebeius (Bivalvia: Solecurtidae) in Southeast Brazil

    Science.gov (United States)

    da Silva, Camila Fernanda; Corte, Guilherme Nascimento; Yokoyama, Leonardo Querobim; Abrahão, Jolnnye Rodrigues; Amaral, Antônia Cecília Zacagnini

    2015-03-01

    Tagelus plebeius (Lightfoot, 1786) is a stout razor clam that is economically exploited in several countries, including several local fisheries along the Brazilian coast. Despite its wide distribution and economic importance, there are few studies that have examined the population biology of this species. This study aimed to improve the current knowledge about the biology of T. plebeius by investigating its growth and mortality on a subtropical sandy beach in Southeast Brazil over a 1-year period. In addition, the reproduction of T. plebeius was analyzed through qualitative and quantitative histological analyses during the last 7 months of the study. The parameters of the von Bertalanffy growth function were estimated to be L ∞ = 74.14 mm, K = 0.52 year-1, C = 0.47, and WP = 0.94. The instantaneous mortality rate ( Z) was 2.16 year-1, and the life span was 2.58 years. We confirmed variations ( H = 651.35; P < 0.05) in the shell length over the months of the study, and the recruitment was higher—but still low—in summer. Four cohorts were observed in the distribution of shell length frequencies. The sex ratio of the population was 1:1 during the study period, and a synchronism in gonadal development and spawning was found between males and females. The high mortality ( Z) and low recruitment rates can be interpreted as reflecting that the population of T. plebeius is under a low restoration process and could be an indication that this species has an endangered status in the study area.

  6. Reproductive Features of Indigenous and the Invasive Chinese Freshwater Mussels (Mollusca, Bivalvia, Anodontinae in Ukraine

    Directory of Open Access Journals (Sweden)

    Yanovych L. M.

    2015-10-01

    Full Text Available Процессы размножения аборигенных видов беззубок из водоемов и водотоков Украины протекают неполноценно. Среди Anodonta anatinа (Linnaeus, 1758 примерно только в 60 % пунктов сбора размножаются 100 % самок, в остальных пунктах «беременными» оказываются лишь 17-90 % самок, у A. cygnea (Linnaeus, 1758 - 50 % самок. Примерно в 70 % пунктов сбора самки A. cygnea и Pseudanodonta complanata Rossmassler, 1835 имеют не полностью (от . до . заполненные половыми продуктами марсупии. Зато вид-вселенец китайская беззубка, Sinanodonta woodiana (Lea, 1834, имеет многократные кладки в течение всего года. Полужабры половыми продуктами заполнены полностью.

  7. Toxicological aspects associated with the ecology of Donax trunculus (Bivalvia, Mollusca) in a polluted environment

    International Nuclear Information System (INIS)

    This study provides data on the ecology and toxicology observed in the population of Donax trunculus, a sand dwelling mussel, in the shallow subtidal of Haifa Bay (Mediterranean Sea, Israel). The studied population of the mussel forms a dominant fraction in a community of sand-dwelling molluscs in a zone located 5-25 m from the shoreline, and at depths of 20-120 cm, numbering up to 2000 per m2. Samples of the mussel were collected from three sites, located within 9 km of shore in Haifa Bay. These included a clean site (Akko), a site polluted by a chemical PVC-polymer industry (Frutarom), and a site polluted with oil and waste from the petrochemical industry (Qiryat Yam). Metal analysis indicated site-dependent variations in levels of cadmium, lead, copper and mercury in the mussel soft tissues. Copper levels were similar in the bivalves collected from all the sites. Levels of mercury were significantly higher in specimens from the PVC-polluted site (Frutarom) while levels of cadmium were higher in Akko and Qiryat Yam compared to Frutarom. Lead residues were found only in Donax from Akko. The residual contents of mercury, copper and cadmium were relatively high in the young and noticeably low in Donax of medium body size. The main site of deposition of metals was in the soft tissues of the bivalve, but bioaccumulation of metals was also found in the shells. A marked increase in permeability of gills and mantle to the fluorescent anionic dye-fluorescein (FLU) was detected in Donax from Qiryat Yam and especially Frutarom, compared to the bivalves sampled from Akko. Multiple foci of enhanced permeability (multiple fluorescent spots) were detected in all the individuals sampled from Frutarom but none in the bivalve samples from Akko. Lysosomal accumulation of the metachromatic fluorescent cationic probe, acridine orange - (AO), was significantly decreased in the tissues of D. trunculus from polluted sites, especially polluted by the PVC factory. This decrease correlated with lysosomal enlargement and the formation of secondary lysosomes. D. trunculus appears to possess the most effective biochemical and physiological defense mechanisms enabling it to survive in habitats of polluted shallow waters, where other sand dwelling mollusc species were absent or found only in waters deeper then 2.5 m. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  8. Systematic reviews on the Mesodesmatidae (Mollusca, Bivalvia) I. The Genus Monterosatus Beu, 1971

    NARCIS (Netherlands)

    Rooij-Schuiling, de L.A.

    1977-01-01

    In trying to identify a small Mesodesma from West Irian, New Guinea, much material in the collections of several museums was studied. As a guide for the identification I at first used the revision of the Mesodesmatidae by Lamy (1914), which is based exclusively on the collections of the Parisian mus

  9. Die verspreiding en habitat van Chambardia wahlbergi en Chambardia petersi (Bivalvia: Iridinidae in Suid-Afrika

    Directory of Open Access Journals (Sweden)

    Kenné N. de Kock

    2012-03-01

    Full Text Available Die verspreiding en habitat van Chambardia wahlbergi en C. petersi, soos weerspieël deur data in die databasis van die Nasionale Varswaterslakversameling (NVWSV word weergegee en bespreek. Alhoewel die verspreiding van hierdie twee spesies grootliks in die Limpopo- en Mpumalangaprovinsie oorvleuel, kom C. wahlbergi, anders as wat in die literatuur gerapporteer is, ook in die Noordwes- en Vrystaatprovinsie in die wesvloeiende Vaalrivier en in verskeie lokaliteite in die Gautengprovinsie voor. Die meerderheid monsters van beide spesies is in riviere en damme en in watertoestande wat as standhoudend, staande, helder en vars beskryf is, versamel. Multivariansie-analises het temperatuur, hoogte bo seevlak en waterliggame as faktore uitgewys wat betekenisvol tot hul geografiese verspreiding bygedra het. Min is oor die bewaringstatus van hierdie twee spesies bekend, maar die opgedateerde IUCN Rooidata-lys (Seddon et al. 2011 dui albei as nie-bedreig aan. Die meerderheid rekords van beide spesies in die databasis van die NVWSV spruit uit werk tydens die vorige eeu in die Nasionale Krugerwildtuin (NKW. Meer onlangse versamelings deur die outeurs in die NKW dui egter op ‘n afname in die aantal plekke van voorkoms, asook die getalle per versamelpunt wat aan die hand doen dat daar tog rede tot kommer oor hul voortbestaan mag wees. Die feit dat besonder groot eksemplare van C. wahlbergi tot so onlangs soos 2007 meestal toevallig in die Vaalrivier aangetref is, beklemtoon die behoefte om weer omvattende opnames van varswater Mollusca, soortgelyk aan dié van die vorige eeu, van stapel te stuur om die gedokumenteerde verspreiding op te dateer en ook die vordering van eksotiese indringerspesies te moniteer.

  10. Phylogenetic characterization of three morphs of mussels (Bivalvia, Mytilidae) inhabiting isolated marine environments in Palau Islands.

    Science.gov (United States)

    Goto, Tadasuke V; Tamate, Hidetoshi B; Hanzawa, Naoto

    2011-08-01

    Marine lakes in the Palau Islands are known to harbor unique marine fauna that have remained isolated since the formation of the lakes after the Last Glacial Maximum. We analyzed mussels from marine lakes located on different islands and conducted morphological, phylogenetic and population genetic characterization to clarify their evolutionary history. The mussels were morphologically classified into three differentiated morphs: NS, ON, and MC. Their common characteristics were consistent with the Brachidontes-Hormomya complex of the Mytilidae family. Phylogenetic analysis based on the nuclear 18S ribosomal RNA gene supported the taxonomic position of the mussels among the Mytilidae. In the mitochondrial cytochrome c oxidase subunit I (COI) gene lineage, NS-and MC-morphs were highly diverged from each other; their estimated time of divergence dates back to the mid-Pleistocene. ON-morph was more closely related to MC-morph, although the shell morphologies of ON- and MC-morphs were easily distinguishable. Population genetic analysis revealed the coexistence of highly diverged haplotypes within a population of ON-morph, indicating introgression of mtDNA among the morphs. Our data suggest that morphological differentiation of marine lake mussels can occur in a relatively short period under different environmental conditions. Thus, the marine lakes provide a unique site for the study of diversification in mussels. PMID:21800997

  11. Habitat Preferences and Growth of Ruditapes bruguieri (Bivalvia: Veneridae at the Northern Boundary of Its Range

    Directory of Open Access Journals (Sweden)

    Alla V. Silina

    2014-01-01

    Full Text Available This work is the first attempt to study growth and some morphological parameters of the clam Ruditapes bruguieri, as well as its habitat preferences. It is found that R. bruguieri lives on bottom sediments including pebble and coarse- and medium-grained sand with a slight admixture of silt. At the study area, this bivalve inhabits sea waters with good aeration, stable oceanic water salinity, and a high oxygen concentration. The annual fluctuations of the water temperature from 13-14°C (in winter to 22–29°C (in summer are close to the threshold temperature values, within which the species can exist. Near the boundary of the species range, along the Jeju Island coasts, south of Republic of Korea, 83.8% of all clams die during the coldest period of the year. Here, annual rings are formed on R. bruguieri shells during winter. The maximum age of R. bruguieri, determined during the study, is 6.5 years, but the clam samples contain mainly individuals at 3.0–3.5 years of age (34%. The largest clam dimensions are 36.0 × 26.5 mm (length × height of shell. At the study area, a usual shell length is 20.0–32.0 mm (75% of all the collected individuals.

  12. Characteristics of a refuge for native freshwater mussels (Bivalvia: Unionidae) in Lake St. Clair

    Science.gov (United States)

    McGoldrick, D.J.; Metcalfe-Smith, J. L.; Arts, M.T.; Schloesser, D.W.; Newton, T.J.; Mackie, G.L.; Monroe, E.M.; Biberhofer, J.; Johnson, K.

    2009-01-01

    The Lake St. Clair delta (??? 100??km2) provides an important refuge for native freshwater mussels (Unionidae) wherein 22 of the ??? 35 historical species co-occur with invasive dreissenids. A total of 1875 live unionids representing 22 species were found during snorkeling surveys of 32 shallow (??? 1??m) sites throughout the delta. Richness and density of unionids and zebra mussel infestation rates varied among sites from 3 to 13 unionid species, 0.02 to 0.12 unionids/m2, and refuge for the conservation of native unionids. Crown Copyright ?? 2009.

  13. Temporal dynamics of amino and fatty acid composition in the razor clam Ensis siliqua (Mollusca: Bivalvia)

    Science.gov (United States)

    Baptista, Miguel; Repolho, Tiago; Maulvault, Ana Luísa; Lopes, Vanessa M.; Narciso, Luis; Marques, António; Bandarra, Narcisa; Rosa, Rui

    2014-12-01

    Few studies have been conducted on the temporal dynamics of both amino acid (AA) and fatty acid (FA) profiles in marine bivalves. We investigated the seasonal variation of these compounds in the pod razor clam Ensis siliqua in relation to food availability, salinity, water temperature and reproductive cycle. AA content varied between 46.94 and 54.67 % dry weight (DW), and the AAs found in greater quantity were glutamic acid, glycine and aspartic acid. FA content varied between 34.02 and 87.94 mg g-1 DW and the FAs found in greater quantity were 16:0 and 22:6 n-3. Seasonal trends were observed for AAs and FAs. FAs increased with gametogenesis and decreased with spawning while AA content increased throughout spawning. The effect of increasing temperature and high food availability during the spawning season masked the loss of AAs resulting from gamete release. Still, a comparatively greater increase in the contents of glutamic acid and leucine with spawning indicate their possible involvement in a post-spawning gonad recovery mechanism. A post-spawning decrease in 14:0, 16:0, 16:1 n-7, 18:1 n-7 and 18:1 n-9 is indicative of the importance of these FAs in bivalve eggs. An increase in 18:3 n-3, 18:4 n-3, 20:1 n-9 and 20:2 n-6 during gametogenesis suggests their involvement in oocyte maturation. The FA 22:4 n-6, while increasing with spawning, appears to play a role in post-spawning gonad recovery. Salinity did not have an effect on the AA composition. None of the environmental parameters measured had an effect on FA composition.

  14. Multi-species generalist predation on the stochastic harvested clam Tivela mactroides (Mollusca, Bivalvia)

    Science.gov (United States)

    Turra, Alexander; Fernandez, Wellington S.; Bessa, Eduardo; Santos, Flavia B.; Denadai, Márcia R.

    2015-12-01

    Top-down control is an important force modulating the abundance of prey and structuring marine communities. The harvested trigonal clam Tivela mactroides is hypothesized to be part of the diet of a variety of marine organisms, with its stock influencing predator abundance and being influenced by them. Here we analyzed the diet of potential predators of T. mactroides in Caraguatatuba Bay, northern coast of São Paulo State, Brazil, to identify the main consumers of this marine resource, and also to address the importance of this clam in the diet of each predator. Samples were taken year-round by trawls; all specimens collected were identified and measured and the food items identified and quantified. Twenty-one species consumed T. mactroides, whose importance in the diet varied greatly in both the volume ingested and the frequency of occurrence (pompano Trachinotus carolinus > blue crab Callinectes danae > starfish Astropecten marginatus). Top-down influence on T. mactroides was also dependent on the abundance of consumers (yellow catfish Cathorops spixii > rake stardrum Stellifer rastrifer > barred grunt Conodon nobilis > A. marginatus). Considering the mean volume ingested, the frequency of occurrence of T. mactroides in the diet, and the relative abundance of consumers, the predators that most influenced T. mactroides were T. carolinus, A. marginatus, and C. danae, in decreasing order. Large numbers of small-sized individuals of T. mactroides (<10 mm) were generally preyed upon by A. marginatus, which may have a stronger effect on clam abundance in comparison to C. danae and T. carolinus, which preyed upon larger clams. In conclusion, the results of this study indicate that predators' consumption of T. mactroides in Caraguatatuba Bay can influence its stocks, mainly due to the type and/or abundance of predator species, the volume and number of individuals of T. mactroides preyed upon, and the temporal variations in the abundance of predators.

  15. Phylogeny and evolution of ontogeny of the family Oxytomidae Ichikawa, 1958 (Mollusca: Bivalvia)

    Science.gov (United States)

    Lutikov, O. A.; Temkin, I. E.; Shurygin, B. N.

    2010-08-01

    We described ontogenies and reconstructed morphogeneses of hinges in some supraspecific taxa of the bivalve family Oxytomidae Ichikawa, 1958 from the Mesozoic of Russia. The phylogeny of the family is reconstructed using evolutionary and cladistic methods. The appearance of the endemic genus Arctotis Bodylevsky, 1960 in the epicontinental seas of Siberia can be explained in terms of gradual transformations of the ligament and byssal apparatus in the Northern Siberian members of Praemeleagrinella Lutikov et Shurygin, 2009 and Praearctotis Lutikov et Shurygin, 2009.

  16. Members of the genus Pisidium C. Pfeiffer (Mollusca: Bivalvia) of the Czech Republic

    International Nuclear Information System (INIS)

    Currently, thirteen species assigned to the genus Pisidium are known from the territory of the Czech Republic. This paper contains a new key to them with original figures of definitive characteristics. The key is supplemented with species descriptions and notes on their ecology and distribution in the Czech Republic. Differences between conchologically similar species and possibilities of misidentification with juvenile specimens of the genera Sphaerium and Musculium are commented on as well. (authors)

  17. Spawning, fertilization, and larval development of Potamocorbula amurensis (Mollusca: Bivalvia) from San Francisco Bay, California

    Science.gov (United States)

    Nicolini, M.H.; Penry, D.L.

    2000-01-01

    In Potamocorbula amurensis time for development to the straight-hinge larval stage is 48 hr at 15??C. Potamocorbula amurensis settles at a shell length of approximately 135 ??m 17 to 19 days after fertilization. Our observations of timing of larval devdlopment in P. amurensis support the hypothesis of earlier workers that its route of initial introduction to San Francisco Bay was as veliger larvae transported in ballast water by trans-Pacific cargo ships. The length of the larval period of P. amurensis relative to water mass residence times in San Francisco Bay suggests that it is sufficient to allow substantial dispersal from North Bay to South Bay populations in concordance with previous observations that genetic differentiation among populations of P. amurensis in San Francisco Bay is low. Potamocorbula amurensis is markedly euryhaline at all stages of development. Spawning and fertilization can occur at salinities from 5 to 25 psu, and eggs and sperms can each tolerance at least a 10-psu step increase or decrease in salinity. Embryos that are 2 hr old can tolerate the same range of salinities from (10 to 30 psu), and by the time they are 24 hr old they can tolerate the same range of salinities (2 to 30 psu) that adult clams can. The ability of P. amurensis larvae to tolerate substantial step changes in salinity suggests a strong potential to survive incomplete oceanic exchanges of ballast water and subsequent discharge into receiving waters across a broad range of salinities.

  18. Taxonomic implications of molecular studies on Northern Brazilian Teredinidae (Mollusca: Bivalvia specimens

    Directory of Open Access Journals (Sweden)

    Sonia Maria Lima Santos

    2005-03-01

    Full Text Available The current taxonomy of the Teredinidae (shipworms is wholly based on morphology and up to now no molecular studies of the phylogeny of this group have been published. In the present study the relationships between four genera of the subfamilies Teredininae and Bankiinae were established and the efficiency of the 16S rRNA gene in characterizing four Teredinidae species was tested. Phylogenetic trees support the grouping of Bankia fimbriatula with Nausitora fusticula and of Neoteredo reynei with Psiloteredo healdi, but the genetic distances do not justify the classification of these species into two distinct subfamilies. The results show that B. fimbriatula, N. reynei and P. healdi specimens from the coast of the Brazilian state of Pará have five distinct 16S rRNA haplotypes, with one N. reynei haplotype differing from the other haplotypes in respect to at least seven sequences sites, indicating the existence of two very distinct sympatric lineages.

  19. Size-differential feeding in Pinna nobilis L. (Mollusca: Bivalvia): Exploitation of detritus, phytoplankton and zooplankton

    Science.gov (United States)

    Davenport, John; Ezgeta-Balić, Daria; Peharda, Melita; Skejić, Sanda; Ninčević-Gladan, Živana; Matijević, Slavica

    2011-04-01

    The endangered fan shell Pinna nobilis is a large bivalve mollusc (<120 cm shell length) endemic to the Mediterranean that lives one-third buried in soft substrata, generally in shallow coastal waters. We hypothesised that P. nobilis of different sizes would ingest different food sources, because small fan shells will inhale material from closer to the substratum than do large fan shells. We studied stomach contents and faeces of 18 fan shells, 6 small (mean 23.0 cm length), 6 medium-sized (mean 41.5 cm length) and 6 large (mean 62.7 cm length) living in a small area of a low-energy coastal detritic bottom characterised by mud, sand and macroalgae at Mali Ston Bay, Croatia. We found that all P. nobilis ingested copious quantities of undetermined detritus (probably at least 95% of ingested material), phytoplankton, micro and mesozooplankton and pollen grains. Large P. nobilis stomach contents showed a preponderance of water column calanoid copepods, while small fan shells had higher numbers of bivalve larvae. All fan shells took in high numbers of harpacticoid copepods that are benthonic, feeding on microbial communities of detritus and benthic vegetation. There was also a significant selection of phytoplankton species, some apparently occurring between inhalation and ingestion. The stomach contents of small P. nobilis had a higher organic matter content than either medium-sized or large fan shells; this indicated that small fan shells ingested detritus of higher organic content than did larger P. nobilis. As the faeces of all P. nobilis had similar organic matter content, this also indicates higher assimilation efficiencies in small fan shells. The demonstration of differential dietary selectivity by different sized animals has implications for future trophic studies of this endangered species. This study also provides the first demonstration of predation on zooplankton by P. nobilis.

  20. Submarine canyons as the preferred habitat for wood-boring species of Xylophaga (Mollusca, Bivalvia)

    Science.gov (United States)

    Romano, C.; Voight, J. R.; Company, J. B.; Plyuscheva, M.; Martin, D.

    2013-11-01

    Submarine canyons are often viewed as natural “debris concentrators” on the seafloor. Organic substrates may be more abundant inside than outside canyon walls. To determine the effects of the presence these substrates in the Blanes submarine canyon (NW Mediterranean) and its adjacent western open slope, we deployed wood to study colonizing organisms. Three replicate pine and oak cubes (i.e. most common trees inland) were moored at 900, 1200, 1500 and 1800 m depth and collected after 3, 9 and 12 months. Wood from inside the canyon was significantly more heavily colonized by the five morphotypes of wood-boring bivalves than was wood on the adjacent open slope. Xylophaga sp. A dominated all wood types and locations, with peak abundance at 900 and 1200 m depth. Its growth rate was highest (0.070 mm d-1) during the first three months and was faster (or it recruits earlier) in pine than in oak. Size distribution showed that several recruitment events may have occurred from summer to winter. Xylophaga sp. B, appeared first after 9 months and clearly preferred pine over oak. As the immersion time was the same, this strongly supported a specific association between recruiters and type of substrate. Three morphotypes, pooled as Xylophaga spp. C, were rare and seemed to colonize preferentially oak inside the canyon and pine in the adjacent open slope. Individuals of Xylophaga were more abundant inside the canyon than in nearby off-canyon locations. Blanes Canyon may serve as a long-term concentrator of land-derived vegetal fragments and as a consequence sustain more animals. Are the species richness and abundance of wood-boring bivalves higher inside the canyon than on the adjacent open slope? Do the composition and density of the wood-boring bivalves change with deployment time and depth, as well as on the type of the sunken wood? What is the growth rate of the dominant wood-boring species?

  1. Clarifying phylogenetic relationships and the evolutionary history of the bivalve order Arcida (Mollusca: Bivalvia: Pteriomorphia).

    Science.gov (United States)

    Combosch, David J; Giribet, Gonzalo

    2016-01-01

    The systematics of the bivalve order Arcida constitutes an unresolved conundrum in bivalve systematics. The current definition of Arcida encompasses two superfamilies: Limopsoidea, which includes the recent families Philobryidae and Limopsidae, and Arcoidea, which encompasses the families Arcidae, Cucullaeidae, Noetiidae, Glycymerididae and Parallelodontidae. This classification, however, is controversial particularly with respect to the position and taxonomic status of Glycymerididae. Previous molecular phylogenies were limited either by the use of only a single molecular marker or by including only a few limopsoid and glycymeridid taxa. The challenging nature of Arcida taxonomy and the controversial results of some of the previous studies, prompted us to use a broad range of taxa (55 species), three nuclear markers (18S rRNA, 28S rRNA and histone H3) and a wide range of algorithmic approaches. This broad but stringent approach led to a number of results that differ significantly from previous studies. We provide the first molecular evidence that supports the separation of Arcoidea from Limopsoidea, although the exact position of Glycymerididae remains unresolved, and the monophyly of Limopsoidea is algorithm-dependent. In addition, we present the first time-calibrated evolutionary tree of Arcida relationships, indicating a significant increase in the diversification of arcidan lineages at the beginning of the Cretaceous, around 140Ma. The monophyly of Arcida, which has been supported previously, was confirmed in all our analyses. Although relationships among families remain somehow unresolved we found support for the monophyly of most arcidan families, at least under some analytical conditions (i.e., Glycymerididae, Noetiidae, Philobryidae, and Limopsidae). However, Arcidae, and particularly Arcinae, remain a major source of inconsistency in the current system of Arcida classification and are in dire need of taxonomic revision. PMID:26427825

  2. Epibiotic relationships on Zygochlamys patagonica (Mollusca, Bivalvia, Pectinidae) increase biodiversity in a submarine canyon in Argentina

    Science.gov (United States)

    Schejter, Laura; López Gappa, Juan; Bremec, Claudia Silvia

    2014-06-01

    The continental slope of the southern SW Atlantic Ocean has many distinguishable deep submarine canyons, varying in depth and extension. The benthic fauna within one of them, detected in April 2005 by means of a multibeam SIMRAD EM1002 sonar, and located at 43°35‧S to 59°33‧W, 325 m depth, was studied to discuss faunal affinities with the neighbouring Patagonian scallop fishing grounds located at upper slope depths. In order to add faunal information to the previous general study, we studied the epibiotic species settled on Patagonian scallops (the dominant species in the area) collected in the reference sampling site using a 2.5-m mouth-opening dredge, 10 mm mesh size. We sampled 103 scallops with shell heights between 22 and 69 mm; epibionts were recorded on both valves. We found 53 epibiotic taxa, which were most conspicuous on the upper valve. Bryozoa was the most diverse group (34 species) while Polychaeta was the most abundant group, recorded on 94% of the scallops. Stylasteridae (2 species) and Clavulariidae (Cnidaria) conform newly recorded epibionts on Z. patagonica and the sponge Tedania (Tedaniopsis) infundibuliformis also represents a new record for the SW Atlantic Ocean.

  3. External morphology of spermatozoa and spermatozeugmata of the freshwater mussel Truncilla truncata (Mollusca: Bivalvia: Unionidae)

    Science.gov (United States)

    Waller, D.L.; Lasee, B.A.

    1997-01-01

    Truncilla truncata males release spherical aggregates of spermatozoa, called spermatozeugmata, at spawning. Sperm aggregates from other bivalve species have been described, but few detailed studies exist of the morphology of unionid spermatozeugmata and spermatozoa. We provide the first description of the external morphology of spermatozeugmata and spermatozoa of T. Truncata. The spermatozeugmata had an inside diameter of 76 mu m and contained 8000-9000 spermatozoa. Heads of spermatozoa were directed toward the center of the sphere into a translucent shell; tails were arranged radially and caused the spermatozeugmata to rotate. Spermatozoa of T. Truncata measured 3.3 mu m in length (excluding tail) and each had a head, a midpiece and a flagellum. We also documented the release of spermatozeugmata in two additional unionid species, Lampsilis cardium and Amblema plicata plicata.

  4. Body condition and gametogenic cycle of Galatea paradoxa (Mollusca: Bivalvia) in the Volta River estuary, Ghana

    Science.gov (United States)

    Adjei-Boateng, D.; Wilson, J. G.

    2013-11-01

    The reproductive cycle of Galatea paradoxa which is the basis for an artisanal fishery in the Volta River estuary, Ghana, was studied using condition indices and histological methods from March 2008 to July 2009. The cycle is annual with a single spawning event between June and October. Gametogenesis starts in November progressing steadily to a peak in June-July when spawning begins until October when the animal is spent. The condition indices (shell-free wet weight/total wet weight, ash-free dry weight/shell weight and gonad wet weight/shell weight) showed a clear relationship with the gametogenic stage rising from a minimum at stage (I) start of gametogenesis, to their highest values at stages (IIIA) ripe and (IIIB) start of spawning before declining significantly to stage (IV) spent.It is suggested that condition index may prove a valuable technique in fishery management to recognise the reproductive stages of G. paradoxa as it is less expensive and time consuming than histological techniques in addition to being easier to teach to non-specialists. The data presented in this study provide information on the timing of spawning events for G. paradoxa, which is necessary for developing sustainable management strategies and selection of broodstock for aquaculture.

  5. Physiological effects of hypercapnia in the deep-sea bivalve Acesta excavata (Fabricius, 1779) (Bivalvia; Limidae)

    DEFF Research Database (Denmark)

    Hammer, Karen M.; Kristiansen, Erlend; Zachariassen, Karl Erik

    2011-01-01

    ) corresponding to conditions reported from natural CO(2) seeps. Effects on acid base status and metabolic rate were related to time of exposure and subsequent recovery. During exposure there was an uncompensated drop in both hemolymph and intracellular pH. Intracellular pH returned to control values, while...

  6. Reproductive Cycle of Hard Clam, Meretrix lyrata Sowerby, 1851 (Bivalvia: Veneridae) from Sarawak, Malaysia

    OpenAIRE

    Hamli, Hadi; Idris, Mohd Hanafi; Rajaee, Amy Halimah; Kamal, Abu Hena Mustafa

    2015-01-01

    A study of the reproductive cycle of the hard clam, Meretrix lyrata, was documented based on histological observation and Gonad Index (GI). Samples were taken from estuarine waters of the Buntal River in Sarawak, Malaysia. The gonad of M. lyrata started to develop in September 2013. Gametogenesis continued to develop until the maturation and spawning stage from February to April 2014. The GI pattern for a one-year cycle showed a significant correlation with chlorophyll a. The corresponding GI...

  7. Growth estimats of the Argentinean surf clam Donax hanleyanus (Bivalvia: Donacidae) derived from fluorescent marking

    OpenAIRE

    Herrmann, Marko; Laudien, Jürgen; Arntz, Wolf; Penchaszadeh, P. E.

    2007-01-01

    RESUMENMicro-growth increments of the Argentinean surf clam Donax hanleyanus were measured at the exposed sandy beach Mar Azul. After marking the shells with the fluorescence marker Calcein, animals were allowed to grow in situ for 36 days. The majority of the marked specimens showed a distinct fluorescent band reflecting the calcein staining time and allowing for growth estimates.Palabras llaves: growth rate, fluorescent marking, Calcein, surf clam, Donax hanleyanusINTRODUCCIÓNGrowth rate is...

  8. Life history and demographics of the endangered birdwing pearlymussel (Lemiox rimosus) (Bivalvia: Unionidae)

    Science.gov (United States)

    Jones, J.W.; Neves, R.J.; Ahlstedt, S.A.; Hubbs, D.; Johnson, M.; Dan, H.; Ostby, B.J.K.

    2010-01-01

    The life history and population demography of the endangered birdwing pearlymussel (Lemiox rimosus) were studied in the Clinch and Duck rivers, Tennessee. Reproducing populations of L. rimosus now occur only in the Clinch, Duck and Powell rivers, as the species is considered extirpated from the remaining portions of its range in the Tennessee River drainage. Females are long-term winter brooders, typically gravid from Oct. to May. Glochidia are contained in the outer gills and are released in association with a mantle-lure that resembles a small freshwater snail. Estimated fecundity, based on 8 gravid females collected from the Clinch and Duck rivers, ranged from 4132 to 58,700 glochidia/mussel. Seven fish species were tested for suitability as hosts for glochidia, and five darter species were confirmed through induced infestations: Etheostoma blennioides, E. camurum, E. rufilineatum, E. simoterum and E. zonale. Ages of L. rimosus shells were determined by thin-sectioning and ranged from 3 to 15 y in both rivers. Shell growth was higher and maximum size greater in males than females in both rivers. Shell growth was greatest in the Duck River. Densities of L. rimosus in the Clinch River were maintained at seemingly stable but low levels ranging from 0.07 to 0.27 m-2 from 20042007, and in the Duck River at similar but higher levels ranging from 0.6 to 1.0 m -2 from 20042006. In the latter river, abundance has increased since 1988, likely due to improved minimum flows and dissolved oxygen levels in water releases from a reservoir upstream. ?? 2010, American Midland Naturalist.

  9. Life history and propagation of the endangered dromedary pearlymussel (Dromus dromas) (Bivalvia:Unionidae)

    Science.gov (United States)

    Jones, J.W.; Neves, R.J.; Ahlstedt, S.A.; Mair, R.A.

    2004-01-01

    The reproduction, demography, and propagation of the endangered dromedary pearlymussel (Dromus dromas) (Lea, 1834) were studied in the Clinch and Powell rivers, Tennessee. Viable populations of the dromedary pearlymussel now occur only in the Clinch and Powell rivers; the species has been extirpated from the remaining portions of its range in the Cumberland and Tennessee river drainages. Females are long-term winter brooders, and they are gravid from October to June. Glochidia are contained in conglutinates that are red to white and resemble freshwater leeches or flatworms. Conglutinates are 20 to 40 mm long and are released through the excurrent aperture. Estimates of fecundity based on 7 gravid females collected from the Clinch River were 55,110 to 253,050 glochidia/mussel. The ages of 66 valves of D. dromas were determined by thin-sectioning and ranged from 3 to 25 y. Annual growth averaged 5 mm/y until age 10 and decreased to ???1.2 mm/ y thereafter. Nineteen fish species were tested for suitability as hosts for glochidia. Ten were confirmed as hosts through induced infestations of glochidia: black sculpin (Cottus baileyi), greenside darter (Etheostoma blennioides), fantail darter (Etheostoma flabellare), snubnose darter (Etheostoma simoterum), tangerine darter (Percina aurantiaca), blotchside logperch (Percina burtoni), logperch (Percina caprodes), channel darter (Percina copelandi), gilt darter (Percina evides), and Roanoke darter (Percina roanoka). Juveniles produced from these hosts were cultured in dishes held in nonrecirculating aquaculture systems containing fine sediment (<105 ??m) and were fed the green alga Nannochloropsis oculata every 2 d. Survival of 2810 newly metamorphosed juveniles was 836 (29.7%) after 1 to 2 wk.

  10. Life history and propagation of the endangered fanshell pearlymussel, Cyprogenia stegaria Rafinesque (Bivalvia: Unionidae)

    Science.gov (United States)

    Jones, J.W.; Neves, R.J.

    2002-01-01

    Aspects of the reproduction, age, growth, fish hosts, and culture of juveniles were determined for the endangered fanshell pearlymussel, Cyprogenia stegaria Rafinesque, 1820, in the Clinch River, Tennessee. Glochidia of C. stegaria are contained in red, worm-like conglutinates that resemble oligochaetes. Conglutinates are 20 to 80 mm long and are released through the excurrent aperture. Estimated fecundity was 22,357 to 63,459 glochidia/mussel. Eighty-four valves of C. stegaria were thin-sectioned for aging; ages ranged from 6 to 26 y. Of 16 fish species tested, 9 hosts were identified through induced infestations of glochidia: mottled sculpin (Cottus bairdi), banded sculpin (Cottus carolinae), greenside darter (Etheostoma blennioides), snubnose darter (Etheostoma simoterurn), banded darter (Etheostoma zonale), tangerine darter (Percina aurantiaca), blotchside logperch (Percina burtoni), logperch (Percina caprodes), and Roanoke darter (Percina roanoka). Newly metamorphosed juveniles were cultured in recirculating and nonrecirculating aquaculture systems within dishes containing sediments of 300 to 500 ??m diameter (sand) or <105 ??m diameter (silt), and fed either the green algae Neochloris oleoabundans or Scenedesrnus quadricauda daily. Growth and survival of juvenile mussels were highest in the nonrecirculating aquaculture system, with a mean survival of 72% after 2 wk and 38% after 4 wk.

  11. The families Carditidae and Condylocardiidae in the Magellan and Perú-Chile provinces (Bivalvia: Carditoidea).

    Science.gov (United States)

    Güller, Marina; Zelaya, Diego G

    2013-01-01

    Based on the study of available types and extant collections, this paper provides a systematic revision of the living species of Carditoidea occurring in the Magellan and Perú-Chile Provinces. Out of the 19 nominal species reported for the area, eight species are recognized as valid: Cyclocardia compressa, C. spurca, C. thouarsii, C. velutina, Carditella naviformis, C. semen, C. tegulata and Carditopsis flabellum. Other eight nominal species are regarded as synonyms: Cardita magellanica of Cyclocardia velutina; Carditella pallida of C. tegulata; Cardita australis and Actinobolus philippi of Carditella naviformis; Cardium pygmaeum of Carditella semen; Cardita paeteliana of Cyclocardia spurca; Carditella pallida duodecimcostata of Carditopsis flabellum; and Cardita congelascens of Cyclocardia thouarsii. Furthermore, Cardita malvinae and Cardium parvulum are nomina dubia, and the occurrence of Carditella exulata in Magellanic waters is doubtful. PMID:25243284

  12. Early development, survival and growth rates of the giant clam Tridacna crocea (Bivalvia: Tridacnidae

    Directory of Open Access Journals (Sweden)

    Miguel Mies

    2012-06-01

    Full Text Available Tridacnid clams are conspicuous inhabitants of Indo-Pacific coral reefs and are traded and cultivated for the aquarium and food industries. In the present study, daily growth rates of larvae of the giant clam Tridacna crocea were determined in the laboratory during the first week of life. Adults were induced to spawn via intra-gonadal serotonin injection through the byssal orifice. After spawning oocytes were collected, fertilized and kept in 3 L glass beakers and raceways treated with antibiotics to avoid culture contamination. Larvae were fed twice with the microalga Isochrysis galbana and zooxanthellae were also offered twice during the veliger stage (days 4 and 6. Larval length was measured using a digitizing tablet coupled to a microcomputer. Larval mortality was exponential during the first 48 hours of life declining significantly afterwards. Mean growth rate was 11.3 μm day-1, increasing after addition of symbionts to 18.0 μm day-1. Survival increased to ca. 75% after the addition of zooxanthellae. The results describe the growth curve for T. crocea larvae and suggest that the acquisition of symbionts by larvae may be useful for larval growth and survival even before larvae have attained metamorphosis.Bivalves tridacnídeos são habitantes conspícuos dos recifes da região do Indo-Pacífico e são cultivados e comercializados para os mercados alimentício e aquarista. No estudo apresentado foram determinadas as taxas de crescimento diário durante a primeira semana de vida da larva do bivalve ornamental Tridacna crocea. As matrizes foram induzidas à desova por meio de uma injeção intragonadal de serotonina realizada através do orifício bissal. Após desova, ovócitos foram coletados, fertilizados e mantidos em béqueres de vidro e tanques de fluxo contínuo tratados com antibióticos para evitar contaminação. Larvas foram alimentadas em duas ocasiões com a microalga Isochrysis galbana e zooxantelas foram oferecidas também por duas vezes. O comprimento larval foi medido através de mesa digitalizadora conectada em um microcomputador. A mortalidade larval foi exponencial durante as primeiras 48 horas de vida, diminuindo em seguida. A taxa média de crescimento foi de 11,3 μm dia-1, aumentando para 18,0 μm dia-1 após a adição de simbiontes. A sobrevivência aumentou para 75% após a adição de zooxantelas. Os resultados apresentam a curva de crescimento para a larva de T. crocea e sugerem que a aquisição de simbiontes pela larva pode ser importante para o crescimento larval e sobrevivência mesmo antes delas completarem a metamorfose.

  13. Assessing the morphological variability of Unio Delphinus spengler, 1783 (bivalvia : unionidae) using geometric morphometry

    OpenAIRE

    Morais, Pedro; Rufino, Marta M.; Reis, Joaquim; Dias, Ester; Sousa, Ronaldo Gomes

    2014-01-01

    The morphological variability of freshwater bivalve species, observed between and within river basins, may hamper their correct identification, even by experienced researchers. Classic morphometric measurements, i.e. shell length, height and thickness, or their ratios, are generally insufficient to distinguish populations and/or species. These issues may be overcome using a geometric morphometric method, which allows analysis of the overall shape of the individual, independently o...

  14. Influence of the invasive Asian clam Corbicula fluminea (Bivalvia: Corbiculidae) on estuarine epibenthic assemblages

    Science.gov (United States)

    Ilarri, M. I.; Souza, A. T.; Antunes, C.; Guilhermino, L.; Sousa, R.

    2014-04-01

    One of the most widespread invasive alien species (IAS) in aquatic ecosystems is the Asian clam Corbicula fluminea. Several studies have shown that C. fluminea can cause large-scale changes in macrozoobenthic assemblages; however, very few attempted to investigate the effects of this IAS on mobile epibenthic species, such as fishes and crustaceans. In this context, the influence of C. fluminea on epibenthic species was investigated during one year by comparing the associated epibenthic fauna in three nearby sites of the Minho estuary (NW of the Iberian Peninsula), wherein the abiotic conditions are similar but the density of the Asian clam is highly different. From a total of 13 species, six were significantly influenced by C. fluminea; five responded positively, namely the brown shrimp Crangon crangon, the European eel Anguilla anguilla, the common goby Pomatoschistus microps, the brown trout Salmo trutta fario and the great pipefish Syngnathus acus, whereas the shore crab Carcinus maenas was negatively influenced. However, stomach contents analysis revealed that fish and crustacean species do not feed on C. fluminea, suggesting that this IAS is still not a large component of the diet of higher trophic levels in this estuarine ecosystem. Our results suggest that the structure provided by C. fluminea shells is likely to be one of the main factors responsible for the differences observed. C. fluminea physical structure seems to influence the epibenthic associated fauna, when found in densities higher than 1000 ind./m2, with sedentary small-bodied crustaceans and fishes being mainly attracted by the increasing in habitat complexity and consequent enhancement of heterogeneity and shelter availability.

  15. Sensitivity of glochidial stages of freshwater mussels (Bivalvia: Unionidae) to copper

    Energy Technology Data Exchange (ETDEWEB)

    Jacobson, P.J.; Neves, R.J.; Cherry, D.S. [Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States); Farris, J.L. [Arkansas State Univ., State University, AR (United States). Dept. of Biological Sciences

    1997-11-01

    The sensitivity of glochidial stages of unionid mussels was evaluated in a series of exposures to aqueous copper. Glochidia held within marsupia of gravid Villosa iris exhibited no observable effect following a 30-d copper exposure at levels up to 19.1 {micro}g Cu/L. Similarly, transformation of encapsulated glochidia of Actinonaias pectoroso, Pyganodon grandis (Say, 1829), and V. iris to the juvenile stage was unaffected by 12- to 20-d copper exposures of largemouth bass, Micropterus salmoides (Lacepede), at levels up to 200 {micro}g Cu/L. In contrast, released glochidia of all species were sensitive to copper at comparatively low concentrations. The median lethal concentrations (24-h) for Lampsilis fasciola (Rafinesque, 1820) ranged from 26 to 48 {micro}g Cu/L, from 36 to 89 {micro}g Cu/L for V. iris, from 37 to 81 {micro}g Cu/L for Medionidus conradicus, from 42 to 132 {micro}g Cu/L for A. pectorosa, and from 46 to 347 {micro}g Cu/L for P. grandis. Copper sensitivity varied with changes in test conditions, including length of exposure, water temperature, and water hardness. Although sensitivity of released glochidia to copper was comparable to previously reported values for juvenile mussels, the juveniles may be at greater risk given their residency in benthic sediments where toxicants such as metals may be sequestered at high levels. An evaluation of this risk is an urgent priority for further research.

  16. Cytogenetics of Anodonta cygnea (Mollusca: Bivalvia) as possible indicator of environmental adversity

    Science.gov (United States)

    Carrilho, J.; Leitão, A.; Vicente, C.; Malheiro, I.

    2008-11-01

    Anodonta cygnea is a freshwater clam, belonging to the Unionidae family, which can be found in rivers and lagoons all over Europe and Northern America. As they appear as important case studies for ecological damage assessments, the various species of the Unionidae family have been submitted to a sort of recent studies on their chromosomal or cytogenetic status. In this study we confirmed the diploid chromosome number of 2 n = 38 for this species, and established for the first time the karyotype, which comprised six metacentric, 12 submetacentric and one subtelocentric chromosome pairs. We also found a high percentage of cells with an abnormal number of chromosomes. Considering that karyotype disturbances in Unionids have been previously related with exposure to chemicals, either natural or produced by human activity, we determined the aneuploidy index for our population. The aneuploidy index is an excellent marker for pollutant presence/effect. The animals acclimatized in tap water and in natural water from the lake where the individuals were collected showed different levels of aneuploidy. The higher values were found in tap water. Chromosome analysis techniques seem a suitable tool to study the impact of contaminants referred above, and making A. cygnea a suitable organism for assessment of an eugenic damage in aquatic systems. On the other hand, our results also point out to the importance of doing the acclimatizing process of the collected animals in their own natural water.

  17. Molecular Cytogenetics in Trough Shells (Mactridae, Bivalvia): Divergent GC-Rich Heterochromatin Content.

    Science.gov (United States)

    García-Souto, Daniel; Pérez-García, Concepción; Kendall, Jack; Pasantes, Juan J

    2016-01-01

    The family Mactridae is composed of a diverse group of marine organisms, commonly known as trough shells or surf clams, which illustrate a global distribution. Although this family includes some of the most fished and cultured bivalve species, their chromosomes are poorly studied. In this work, we analyzed the chromosomes of Spisula solida, Spisula subtruncata and Mactra stultorum by means of fluorochrome staining, C-banding and fluorescent in situ hybridization using 28S ribosomal DNA (rDNA), 5S rDNA, H3 histone gene and telomeric probes. All three trough shells presented 2n = 38 chromosomes but different karyotype compositions. As happens in most bivalves, GC-rich regions were limited to the nucleolus organizing regions in Spisula solida. In contrast, many GC-rich heterochromatic bands were detected in both Spisula subtruncata and Mactra stultorum. Although the three trough shells presented single 5S rDNA and H3 histone gene clusters, their chromosomal locations differed. Regarding major rDNA clusters, while Spisula subtruncata presented a single cluster, both Spisula solida and Mactra stultorum showed two. No evidence of intercalary telomeric signals was detected in these species. The molecular cytogenetic characterization of these taxa will contribute to understanding the role played by chromosome changes in the evolution of trough shells. PMID:27537915

  18. Abnormal features of Macoma balthica (Bivalvia) in the Baltic Sea: alerting symptoms of environmental adversity?

    Energy Technology Data Exchange (ETDEWEB)

    Sokolowski, Adam; Wolowicz, Maciej; Hummel, Herman; Smolarz-Gorska, Katarzyna; Fichet, Denis; Radenac, Gilles; Thiriot-Quievreux, Catherine; Namiesnik, Jacek

    2004-07-01

    Recent studies of the Baltic clam Macoma balthica (L.) from the southern Baltic (the Gulf of Gdansk) have revealed striking morphological, histological and cytogenetic features. Strong deformation of the shell, including elongation of the posterior end and the appearance of an easily visible flexure in this part, has been recorded. The population contribution of the deformed blunt shelled ('irregular') clams ranged from 0% to 65% and tended to increase with depth. The morphologically 'irregular' clams had higher accumulated tissue concentrations of trace metals (As, Ag, Cd, Pb, Cu and Zn), indicating a different metal handling ability. Adverse conditions in deeper water regions of the Gulf (e.g. hypoxia, hydrogen sulphide, elevated bioavailability of contaminants) have been suggested as inducers of the phenotypical changes (morphological deformation) in part of the population and, in parallel, of the specific physiological adaptations that result in higher metal accumulation in the 'irregular' clams. Cytogenetic and histological analyses showed the presence of tumours in gill cells and digestive system of the affected clams, the prevalence of disseminated neoplasia ranging from 0% to 94% depending on the site. The disease was manifested by a modified karyotype (i.e. an abnormal number and morphology of chromosomes), a higher activity of nucleolar organizer regions (AgNORs), and tissue lesions (enlarged cells, actively proliferative with pleomorphic nuclei). Bottom sediments showed acute toxicity and have been proposed as a source of an initialising carcinogenic factor. However, none of the ecotoxicological studies provided was successful in the clear demonstration of a single (or multifactorial) agent that can account for the disseminated neoplasia.

  19. Anatomy of Phyllodina persica (Bivalvia: Tellinidae, and its first occurrence in southeastern Brazilian waters

    Directory of Open Access Journals (Sweden)

    Rodrigo Cesar Marques

    2013-01-01

    Full Text Available This study presents a detailed anatomy of a rare Western Atlantic tellin, Phyllodina persica, under a comparative scenario. Some characters are shared with other tellinids such as the large hemipalps compared to gills; gills with outer demibranch with a single lamella absent from the pericardial region; the type-V stomach associated with the style sac conjoined with the proximal intestine, and distal intestine presenting a dorsal and ventral group of loops, separated by the transverse muscle. The stomach presents a laterally enlarged typhlosole, although shallow, without flange in the margins. This feature is not found in other tellinid species. Another noteworthy feature in the stomach is the aperture of both caeca, which are larger than the left pouch aperture, and as wide as the style sac aperture. Furthermore, there is an interesting small process in the anterior hinge, and a pair of oblique protractor muscles placed posteriorly to the anterior foot retractor muscle, being a new type of intrinsic muscle described in bivalves. In addition to anatomy, this study presents the southernmost record of P. persica, expanding its distribution to the southeastern region of Brazil.

  20. Microbial distribution and abundance in the digestive system of five shipworm species (Bivalvia: Teredinidae.

    Directory of Open Access Journals (Sweden)

    Meghan A Betcher

    Full Text Available Marine bivalves of the family Teredinidae (shipworms are voracious consumers of wood in marine environments. In several shipworm species, dense communities of intracellular bacterial endosymbionts have been observed within specialized cells (bacteriocytes of the gills (ctenidia. These bacteria are proposed to contribute to digestion of wood by the host. While the microbes of shipworm gills have been studied extensively in several species, the abundance and distribution of microbes in the digestive system have not been adequately addressed. Here we use Fluorescence In-Situ Hybridization (FISH and laser scanning confocal microscopy with 16S rRNA directed oligonucleotide probes targeting all domains, domains Bacteria and Archaea, and other taxonomic groups to examine the digestive microbiota of 17 specimens from 5 shipworm species (Bankia setacea, Lyrodus pedicellatus, Lyrodus massa, Lyrodus sp. and Teredo aff. triangularis. These data reveal that the caecum, a large sac-like appendage of the stomach that typically contains large quantities of wood particles and is considered the primary site of wood digestion, harbors only very sparse microbial populations. However, a significant number of bacterial cells were observed in fecal pellets within the intestines. These results suggest that due to low abundance, bacteria in the caecum may contribute little to lignocellulose degradation. In contrast, the comparatively high population density of bacteria in the intestine suggests a possible role for intestinal bacteria in the degradation of lignocellulose.

  1. Microbial Distribution and Abundance in the Digestive System of Five Shipworm Species (Bivalvia: Teredinidae)

    Science.gov (United States)

    Betcher, Meghan A.; Fung, Jennifer M.; Han, Andrew W.; O’Connor, Roberta; Seronay, Romell; Concepcion, Gisela P.; Distel, Daniel L.; Haygood, Margo G.

    2012-01-01

    Marine bivalves of the family Teredinidae (shipworms) are voracious consumers of wood in marine environments. In several shipworm species, dense communities of intracellular bacterial endosymbionts have been observed within specialized cells (bacteriocytes) of the gills (ctenidia). These bacteria are proposed to contribute to digestion of wood by the host. While the microbes of shipworm gills have been studied extensively in several species, the abundance and distribution of microbes in the digestive system have not been adequately addressed. Here we use Fluorescence In-Situ Hybridization (FISH) and laser scanning confocal microscopy with 16S rRNA directed oligonucleotide probes targeting all domains, domains Bacteria and Archaea, and other taxonomic groups to examine the digestive microbiota of 17 specimens from 5 shipworm species (Bankia setacea, Lyrodus pedicellatus, Lyrodus massa, Lyrodus sp. and Teredo aff. triangularis). These data reveal that the caecum, a large sac-like appendage of the stomach that typically contains large quantities of wood particles and is considered the primary site of wood digestion, harbors only very sparse microbial populations. However, a significant number of bacterial cells were observed in fecal pellets within the intestines. These results suggest that due to low abundance, bacteria in the caecum may contribute little to lignocellulose degradation. In contrast, the comparatively high population density of bacteria in the intestine suggests a possible role for intestinal bacteria in the degradation of lignocellulose. PMID:23028923

  2. Endogenous circatidal rhythm in the Manila clam Ruditapes philippinarum (Bivalvia: Veneridae)

    OpenAIRE

    Kim, W S; Huh, H.T.; Lee, J.-H.; Rumohr, Heye; Koh, C.H.

    1999-01-01

    Manila clams, Ruditapes philippinarum, removed from their natural environment and maintained for 9 weeks in continuously immersed conditions exhibited a clear endogenous circatidal rhythm in oxygen consumption. The clams exhibited a semidiurnal rhythmicity in oxygen consumption after showing a diurnal pattern in the first few days (5 to 7 d) of the experiment. The results of the present study indicate that activity rhythms of clams are controlled not only by exogenous factors, but also by an ...

  3. Life on wood - the carnivorous deep-sea mussel Idas argenteus (Bathymodiolinae, Mytilidae, Bivalvia

    DEFF Research Database (Denmark)

    Ockelmann, Kurt W.; Dinesen, Grete E.

    2011-01-01

    Deep-sea mussels associated with sunken wood are less well known in terms of anatomy, biology and evolution than their bathymodioline allies from cold seeps and hydrothermal vents. During the Danish 'Ingolf Expedition' (1895-96) to the Northeast Atlantic, two pieces of pinewood were collected fro...

  4. Efecto del sustrato en la intensidad del asentamiento de larvas de Argopecten purpuratus Lamarck, 1819 (Bivalvia, Pectinidae en ambiente controlado Effect of different susbstrates on the larval settlement of the scallop Argopecten purpuratus Lamarck, 1819 (Bivalvia, Pectinidae in laboratory condition

    Directory of Open Access Journals (Sweden)

    Lucio Encomendero

    2003-01-01

    Full Text Available Se estudió el efecto de diferentes tipos de sustrato y del biofilm formado sobre ellos, en la intensidad del asentamiento larval del ostión del norte Argopecten purpuratus. Se postula la hipótesis que sustratos de diferente naturaleza permiten la formación de diferentes biofilm a través del tiempo, los cuales originan distintas intensidades de asentamiento larval sobre ellos. Sustratos de netlón, malla mosquitera, concha de ostión y asbesto-cemento se sometieron a la formación de biofilm por períodos de 6, 12 y 18 días con flujo de agua filtrada a 50 mm. A cada sustrato con biofilm de diferentes edades (6, 12 y 18 días o sin él, contenidos en un recipiente con 300 mL de agua de mar filtrada, se le agregaron 200-300 larvas competentes. Después de 72 h en condiciones de laboratorio (15,3-18,6°C, se contó el número de larvas asentadas. Se determinó que el tipo de sustrato influye en la intensidad del asentamiento larval del ostión. Los mayores asentamientos se obtuvieron sobre asbesto-cemento (29,6-62,3%; seguidos por malla mosquitera (17,1-21,2% y concha de ostión (13-30%. Los niveles más bajos se obtuvieron sobre el netlón (4,3-15,2%. También se observó una relación directa entre el porcentaje de asentamiento larval y la edad del biofilm excepto en asbesto-cemento. El tipo de sustrato y la edad del biofilm mostraron un efecto sinérgico sobre la intensidad del asentamiento larvalThe effects of different types of substrate and of primary biofilm formed on them in relation to their capacity to attract settlement of competent larvae of the northern scallop Argopecten purpuratus, was studied. The hypothesis that different substrates permit the formation of different biofilm over time, which affect the intensity of scallop larval settlement on each different substrate, was tested. Substrates including Netlon @, fly screen, scallop shell, and asbestos-cement were incubated in 50 mm-filtered flowing sea water to allow formation of primary biofilm for periods of 6, 12, and 18 days. Each substrate, fouled for the time periods listed, was exposed to 200-300 competent scallop larvae in test volumes of 300 mL filtered seawater for periods of 72 h at ambient temperature (15.3-18.6°C, after which the numbers of larvae settled on each substrate were determined. The results showed that the type of substrate influenced the intensity of scallop larval settlement. The highest settlement occurred on the asbestos-cement (29.6-62.3%; intermediate levels of settlement were observed on the fly screen (17.1-21.2% and scallop shell (13.0-30.0%, and the lowest levels occurred on the Netlon (4.3-15.2%. A direct relationship was also observed between the percentage of larval settlement and the age of the biofilm, except for asbestos-cement. The type of substrate and age of the biofilm showed a synergistic effect on the intensity of larval settlement

  5. Efecto del sustrato en la intensidad del asentamiento de larvas de Argopecten purpuratus Lamarck, 1819 (Bivalvia, Pectinidae) en ambiente controlado Effect of different susbstrates on the larval settlement of the scallop Argopecten purpuratus Lamarck, 1819 (Bivalvia, Pectinidae) in laboratory condition

    OpenAIRE

    Lucio Encomendero; Enrique Dupré

    2003-01-01

    Se estudió el efecto de diferentes tipos de sustrato y del biofilm formado sobre ellos, en la intensidad del asentamiento larval del ostión del norte Argopecten purpuratus. Se postula la hipótesis que sustratos de diferente naturaleza permiten la formación de diferentes biofilm a través del tiempo, los cuales originan distintas intensidades de asentamiento larval sobre ellos. Sustratos de netlón, malla mosquitera, concha de ostión y asbesto-cemento se sometieron a la formación de biofilm por ...

  6. Cambios en el uso de la ostra perlera Pinctada mazatlanica (Bivalvia: Pteriidae en el Templo Mayor de Tenochtitlan Changes in the use of the pearl oyster Pinctada mazatlanica (Bivalvia: Pteriidae in the Great Temple of Tenochtitlan

    Directory of Open Access Journals (Sweden)

    Adrián Velázquez

    2007-10-01

    Full Text Available La concha del bivalvo panámico Pinctada mazatlanica fue ampliamente utilizada por las antiguas sociedades del México prehispánico; en las ofrendas enterradas en el Templo Mayor de Tenochtitlan se han encontrado alrededor de 600 objetos elaborados con ella, la mayor parte de los cuales proceden de la etapa constructiva IV (1440-1481, lo que llama la atención, ya que para entonces los mexicas no habían logrado conquistar emplazamientos en la costa del Pacífico. En los sucesivos agrandamientos arquitectónicos es notable el descenso en los objetos de la referida ostra, lo cual en principio se explicó por la mayor destrucción que éstos habían sufrido; sin embargo, el hallazgo de varios ricos depósitos en el predio conocido como Casa de las Ajaracas, correspondientes al reinado de Moctezuma II (1502-1521, en los que prácticamente se encuentra ausente la Pinctada mazatlanica, da lugar a nuevas interpretaciones. En el presente trabajo se presentan 2 posibles hipótesis para explicar el hecho anterior.The nacreous shell of the tropical Pacific mollusc Pinctada mazatlanica was widely used by the ancient inhabitants of Mexico. Around 600 pieces made of this shell have been found in offerings buried in the Great Temple of Tenochtitlan. Most of these objects come from the IVth construction stage (1440-1481, prior to the conquest of the Pacific Coast by the Aztecs. It was previously thought that the considerably smaller numbers found in the following stages were due to the greater degree of destruction suffered by the temple. Nevertheless, the almost complete absence of this material in nine offerings found recently corresponding to the VIIth construction stage (1502-1521, raise other possibilities. In this work two different hypotheses are presented to explain this observation.

  7. Biologia e anatomia funcional de Donax gemmula Morrison (Bivalvia, Donacidae do litoral de São Paulo, Brasil Biology and functional anatomy of Donax gemmula Morrison (Bivalvia, Donacidae from the littoral of São Paulo, Brazil

    Directory of Open Access Journals (Sweden)

    Flávio Dias Passos

    2004-12-01

    Full Text Available Donax gemmula Morrison, 1971 ocorre em praias arenosas da costa sudeste-sul do Brasil até o Uruguai. Espécimes foram coletados na Praia de Barequeçaba, São Sebastião, Estado de São Paulo, Brasil. O comportamento do animal foi registrado "in situ" e em aquários e a morfologia funcional a partir de espécimes dissecados sob estereomicroscópio; detalhes da anatomia foram obtidos a partir de cortes histológicos. A concha pequena, lisa, subglobosa, e o pé grande, muscular, provido de um par de músculos elevadores bem desenvolvidos, permitem escavação rápida, vital em praias sujeitas à intensa ação de ondas onde a espécie vive. Aparato bissal vestigial ocorre desde a fase juvenil à adulta e este donacídeo de vida livre, infaunal, não migra acompanhando o ritmo das marés. As margens do manto possuem prega mediana duplicada; além de tentáculos captados, as pregas medianas possuem tentáculos sensoriais filiformes, longos, estes últimos restritos à região posterior do animal. A espécie tem hábito alimentar suspensívoro seletivo, o qual é revelado pela presença de ctenídios grandes, completos e homorhábdicos, palpos labiais pequenos e muito seletivos, intestino curto, fracamente sinuoso, separado do saco do estilete cristalino, e tentáculos ramificados formando um crivo em torno da abertura inalante.Donax gemmula Morrison, 1971 is a small bivalve occurring on sandy beaches throughout the Southeastern Brazilian coast to Uruguai. Live specimens were collected from Barequeçaba Beach, São Sebastião, State of São Paulo, Brazil. The animal's behaviour was recorded in situ as well as in aquaria, and its functional morphology registered from specimens dissected under stereomicroscope; details of the anatomy were obtained from histological sections. The minute, smooth subglobose shell, and the large, muscular foot provided with a pair of well-developed elevator muscles allow fast burrowing, vital in the disturbed beach environment where the species lives. A vestigial byssal apparatus is present from juvenile through the adult form and this free-living infaunal donacid does not migrate following the rising and ebbing tides. The mantle margins have the middle fold duplicated; besides captate tentacles, the middle folds bear long, filiform, sensory tentacles, the latter restricted to the rear end of the animal. The presence of complete, large, homorhabdic ctenidia; small but very selective labial palps; short and few convoluted intestine, separated from the style sac; and straining tentacles encircling the inhalant aperture reveal the selective suspension feeding habit of the species.

  8. Gloquídio de Diplodon martensi (lhering (Mollusca, Bivalvia, Hyriidae e seu ciclo parasitário The glochidium of Diplodon martensi (lhering (Mollusca, Bivalvia, Hyriidae and its parasitic cycle

    Directory of Open Access Journals (Sweden)

    Maria Cristina Dreher Mansur

    1999-01-01

    Full Text Available Conchological and anatomical studies of the glochidium of Diplodon martensi (lhering, 1893 were performed on samples collected in a small river, tributary from the Caí River, that belong to the Jacuí River sub-basin in south-eastern Brazil. The parasitic development of the glochidium was observed in laboratory on a small cichlid fish Gymnogeophagus gymnogenys (Hensel, 1870.

  9. Early life history and spatiotemporal changes in distribution of the rediscovered Suwannee moccasinshell Medionidus walkeri (Bivalvia: Unionidae)

    Science.gov (United States)

    Johnson, Nathan A.; Mcleod, John; Holcomb, Jordan; Rowe, Matthew T.; Williams, James D.

    2016-01-01

    Accurate distribution data are critical to the development of conservation and management strategies for imperiled species, particularly for narrow endemics with life history traits that make them vulnerable to extinction. Medionidus walkeri is a rare freshwater mussel endemic to the Suwannee River Basin in southeastern North America. This species was rediscovered in 2012 after a 16-year hiatus between collections and is currently proposed for listing under the Endangered Species Act. Our study fills knowledge gaps regarding changes in distribution and early life history requirements of M. walkeri. Spatiotemporal changes in M. walkeri distribution were displayed using a conservation status assessment map incorporating metadata from 98 historical (1916–1999) and 401 recent (2000–2015) site surveys from museums and field notes representing records for 312 specimens. Recent surveys detected M. walkeri only in the middle Suwannee subbasin (n = 86, 22 locations) and lower Santa Fe subbasin (n = 2, 2 locations), and it appears the species may be extirpated from 67% of historically occupied 10-digit HUCs. In our laboratory experiments, M. walkeri successfully metamorphosed onPercina nigrofasciata (56.2% ± 8.9) and Etheostoma edwini (16.1% ± 7.9) but not on Trinectes maculatus, Lepomis marginatus, Notropis texanus, Noturus leptacanthus, Etheostoma fusiforme, orGambusia holbrooki. We characterize M. walkeri as a lure-displaying host fish specialist and a long-term brooder (bradytictic), gravid from fall to early summer of the following year. The early life history and distribution data presented here provide the baseline framework for listing decisions and future efforts to conserve and recover the species.

  10. Monoclonal antibody against a gill Rickettsiales-like organism of Pecten maxiumus (Bivalvia): application to indirect immunofluorescence diagnosis

    OpenAIRE

    Le Gall, Gyslaine; Mourton, Chantal; Boulo, Viviane; Paolucci, Francis; Pau, Bernard; Mialhe, Eric

    1992-01-01

    Using hybridoma technology, monoclonal antibodies (MABs) were prepared against a Rickettsiales-like organism (RLO) from the gills of the Saint-Jacques scallop Pecten maximus. The 5D7 MAB was then selected as a specific reagent suitable for an indirect immunofluorescence assay (IIFA) and evaluated for RLO diagnosis on P. maximus gill smears. Monoclonal antibody 5D7 showed no cross-reactivity with an RLO associated with a related pectinid species Chlamys opercularis.

  11. Estudio de la capacidad de acumulación de metales pesados en isognomon alatus (gmelin, 1791) (mollusca: bivalvia)

    OpenAIRE

    Romero Murillo, Patricia Emilce

    2012-01-01

    Los efectos ecológicos y fisiológicos, daños en los organismos hasta cambio en la funcionalidad de los ecosistemas, por la contaminación de metales pesados, natural o antropogénica, pueden ser monitoreados a través de la medida de acumulación de los metales en organismos sin efectos deletéreos. I. alatus, bivalvo del Caribe, asociado a Rhizophora mangle, grietas o rocas expuestas a corrientes de agua, con tallas entre 76-90 mm, madurez en seis meses y ciclo de vida superior al año, es indicad...

  12. Frequency, Magnitude, and Possible Causes of Stranding and Mass-Mortality Events of the Beach Clam Tivela mactroides (Bivalvia: Veneridae).

    Science.gov (United States)

    Turra, Alexander; Pombo, Maíra; Petracco, Marcelo; Siegle, Eduardo; Fonseca, Mariana; Denadai, Márcia R

    2016-01-01

    Stranding combined with mass-mortality events of sandy-beach organisms is a frequent but little-understood phenomenon, which is generally studied based on discrete episodes. The frequency, magnitude, and possible causes of stranding and mass-mortality events of the trigonal clam Tivela mactroides were assessed based on censuses of stranded individuals, every four days from September 2007 through December 2008, in Caraguatatuba Bay, southeastern Brazil. Stranded clams were classified as dying (closed valves did not open when forced) or dead (closed valves were easily opened). Information on wave parameters and the living intertidal clam population was used to assess possible causes of stranding. This fine-scale monitoring showed that stranding occurred widely along the shore and year-round, with peaks interspersed with periods of low or no mortality. Dead clams showed higher mean density than dying individuals, but a lower mean shell length, attributed to a higher tolerance to desiccation of larger individuals. Wave height had a significant negative relationship to the density of dying individuals, presumed to be due to the accretive nature of low-energy waves: when digging out, clams would be more prone to be carried upward and unable to return; while larger waves, breaking farther from the beach and with a stronger backwash, would prevent stranding in the uppermost areas. This ecological finding highlights the need for refined temporal studies on mortality events, in order to understand them more clearly. Last, the similar size structure of stranded clams and the living population indicated that the stranded individuals are from the intertidal or shallow subtidal zone, and reinforces the ecological and behavioral components of this process, which have important ecological and socioeconomic implications for the management of this population. PMID:26745804

  13. Frequency, Magnitude, and Possible Causes of Stranding and Mass-Mortality Events of the Beach Clam Tivela mactroides (Bivalvia: Veneridae.

    Directory of Open Access Journals (Sweden)

    Alexander Turra

    Full Text Available Stranding combined with mass-mortality events of sandy-beach organisms is a frequent but little-understood phenomenon, which is generally studied based on discrete episodes. The frequency, magnitude, and possible causes of stranding and mass-mortality events of the trigonal clam Tivela mactroides were assessed based on censuses of stranded individuals, every four days from September 2007 through December 2008, in Caraguatatuba Bay, southeastern Brazil. Stranded clams were classified as dying (closed valves did not open when forced or dead (closed valves were easily opened. Information on wave parameters and the living intertidal clam population was used to assess possible causes of stranding. This fine-scale monitoring showed that stranding occurred widely along the shore and year-round, with peaks interspersed with periods of low or no mortality. Dead clams showed higher mean density than dying individuals, but a lower mean shell length, attributed to a higher tolerance to desiccation of larger individuals. Wave height had a significant negative relationship to the density of dying individuals, presumed to be due to the accretive nature of low-energy waves: when digging out, clams would be more prone to be carried upward and unable to return; while larger waves, breaking farther from the beach and with a stronger backwash, would prevent stranding in the uppermost areas. This ecological finding highlights the need for refined temporal studies on mortality events, in order to understand them more clearly. Last, the similar size structure of stranded clams and the living population indicated that the stranded individuals are from the intertidal or shallow subtidal zone, and reinforces the ecological and behavioral components of this process, which have important ecological and socioeconomic implications for the management of this population.

  14. Golden mussel Limnoperna fortunei (Bivalvia: Mytilidae) distribution in the main hydrographical basins of Uruguay: update and predictions

    OpenAIRE

    Brugnoli Ernesto; Clemente Juan; Boccardi Lucía; Borthagaray Ana; Scarabino Fabrizio

    2005-01-01

    Limnoperna fortunei, an Asiatic rivers bivalve has become a worldwide problematic invasive species causing several water quality and macrofouling problems. In the Neotropical region it was first recorded in 1991 in the Río de la Plata coast, Buenos Aires province. Since this, it showed a quick upstream invasion into the principals aquatic systems of the Plata Basin. Nevertheless, there is not a study about its invasion and distribution process in aquatic systems of Uruguay. We describe the ne...

  15. Biochemical and fatty acid composition of Arca noae (Bivalvia: Arcidae from the Mali Ston Bay, Adriatic Sea

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    I. DUPCIC RADIC

    2014-09-01

    Full Text Available Biochemical and fatty acid composition of the bivalve Arca noae were investigated in the Mali Ston Bay in relation to environmental conditions. Sampling was carried out monthly, from December 2001 to November 2002. Wet shellfish meat consists on average of 77.61% water and 22.39% dry matter, while dry shellfish meat consists on average of 89.04% organic and 10.96% inorganic matter. PCA analysis identified temperature, nitrate, silicate, MICRO, Chl a and salinity as the most important environmental factors influencing biochemical composition of A. noae. An increase of dry weight content of A. noae was observed during the spring when both the sea temperature and food supply increased rapidly. Contents of protein (54.39-62.06% of dry weight, carbohydrate (4.13-8.07% of dry weight and lipid (3.46-8.58% of dry weight varied significantly during the year. Protein and lipid level reached the maximum value in June. The fatty acid profiles of total lipids extracted from A. noae showed high level of unsaturation (UNS/SAT 1.9-3.4. Total polyunsaturated fatty acids (PUFA represented the majority of total fatty acids (40.3-59.9% of total fatty acids and the most abundant were eicosapentaenoic (20:5n-3 and docosahexaenoic (22:6n-3 acid. n-3/n-6 PUFA ratio value varied between 2.1 and 5.0 and was the highest during the spring (April to June. Due to their low lipid and high percentages of healthy polyunsaturated fatty acids A. noae can be evaluated as a quality seafood product. The most suitable period of the year for its consumption is in the spring when it reaches its highest nutritional values.

  16. Characterization of an antimicrobial and neuroactive compound from pseudomonas plecoglossicida isolated from the gills of teredo somersi (Bivalvia: Teredinidae)

    International Nuclear Information System (INIS)

    Marine invertebrates have proven to be a prolific source of noteworthy marine natural products. Recent advances in the field have shown that the actual producers of the compounds were the bacteria associated with these organisms. Shipworms are soft-bodied marine bivalves known to thrive in wood which is their primary source of nutrition, their gills harbor a lot of associated bacteria and one of which may be Pseudomonas plecoglossicida, a known fish pathogen. This is the first report of the isolation of Pseudomonas plecoglossicida from the gill of a shipworm collected from Panglao, Bohol. In this study, secondary metabolites from seven day-old cultures of the bacteria were extracted using HP-20 Diaion resin and were found to have promising neuroactivity on primary cultures of dorsal root ganglion (DRG) neurons and an antimicrobial activity against Staphylococcus aureus (ATCC 12600). Using bioactivity assays as a reference the crude extract was further fractionated using LH-20 Sephadex and C18 open-column chromatography. Dowstream purification of the compound was done using reverse phase high pressure liquid chromatography (RP-HPLC). The neuroactive compound increasee the Ca2''+ influx in DRG neurons using a concentration of 20 μg/mL. Antimicrobial activity against S. aureus was observed using a concentration of 10 μg/mL. Spectroscopic analysis and structure elucidation using mass spectrometry and 1D and 2D Nuclear Magnetic Resonance (NMR) spectroscopy was utilized to generate a partial structure for the compounds. (author)

  17. Golden mussel Limnoperna fortunei (Bivalvia: Mytilidae distribution in the main hydrographical basins of Uruguay: update and predictions

    Directory of Open Access Journals (Sweden)

    Ernesto Brugnoli

    2005-06-01

    Full Text Available Limnoperna fortunei, an Asiatic rivers bivalve has become a worldwide problematic invasive species causing several water quality and macrofouling problems. In the Neotropical region it was first recorded in 1991 in the Río de la Plata coast, Buenos Aires province. Since this, it showed a quick upstream invasion into the principals aquatic systems of the Plata Basin. Nevertheless, there is not a study about its invasion and distribution process in aquatic systems of Uruguay. We describe the new records of Limnoperna fortunei in Uruguayan coast of Río de la Plata, Santa Lucía, Negro and Uruguay Rivers. With these results we aim to estimate its distributional limits for Uruguay main hydrographical basins. We also deal with the role of salinity as the main abiotic factor in limiting the east distribution of this mussel in Uruguayan coast of Río de la Plata and as a potential determinant of the "new" colonization on the Atlantic and the Merín Lagoon Basins. Its presence in the ecosystems not only can cause changes at the ecosystem level but also endanger the associated community, favoring the displacement and the disappearance of endemic species.Limnoperna fortunei, é um bivalve invasor de origem asiática que ocasiona problemas na qualidade d'água e poluição em diversas parte do mundo. Na região Neotropical foi registrado pela primeira vez na costa do Rio de la Plata, província de Buenos Aires. Desde então mostrou uma rápida invasão águas acima nos principais sistemas aquáticos da Bacia del Plata. Porém, ainda não existem estudos acerca do processo de invasão e distribuição nos ecossistemas aquáticos do Uruguai. O presente trabalho descreve os novos registros de Limnoperna fortunei na costa uruguaia do Rio de la Plata e dos Rios Santa Lucia e Uruguai. Os presentes resultados permitem avaliar seus limites de distribuição nas principais bacias hidrográficas do Uruguai. Discute-se o papel da salinidade como o principal fator abiótico limitante da distribuição deste mexilhão dourado na costa Uruguaia do Rio de la Plata e como potencial determinante na nova colonização nas bacias hidrográficas das Lagoas Merin e Atlântica. Sua presença nos ecossistemas aquáticos pode ocasionar não apenas mudanças a nível do ecossistema, mas também pôr em perigo as comunidades associadas favorecendo o desaparecimento das espécies endêmicas.

  18. Frequency, Magnitude, and Possible Causes of Stranding and Mass-Mortality Events of the Beach Clam Tivela mactroides (Bivalvia: Veneridae)

    OpenAIRE

    Alexander Turra; Maíra Pombo; Marcelo Petracco; Eduardo Siegle; Mariana Fonseca; Denadai, Márcia R.

    2016-01-01

    Stranding combined with mass-mortality events of sandy-beach organisms is a frequent but little-understood phenomenon, which is generally studied based on discrete episodes. The frequency, magnitude, and possible causes of stranding and mass-mortality events of the trigonal clam Tivela mactroides were assessed based on censuses of stranded individuals, every four days from September 2007 through December 2008, in Caraguatatuba Bay, southeastern Brazil. Stranded clams were classified as dying ...

  19. Corbicula fluminea (Bivalvia: Corbiculidae): a possible second molluscan intermediate host of Echinostoma cinetorchis (Trematoda: Echinostomatidae) in Korea

    OpenAIRE

    Chung, Pyung-Rim; Jung, Younghun; Park, Yun-Kyu; Hwang, Myung-Gi; Soh, Chin-Thack

    2001-01-01

    More than 1,500 clams of Corbicula fluminea, the most favorable food source of freshwater bivalves in Korea, were collected from 5 localities to examine cercarial and metacercarial infection with Echinostoma cinetorchis. Although 3 clams infected with suspicious E. cinetorchis metacercariae out of 200 specimens collected at Kangjin, Chollanam-do were detected, no cercarial and metacercarial infections with E. cinetorchis were observed in field-collected Corbicula specimens. In the susceptibil...

  20. Effects of anthracene on filtration rates, antioxidant defense system, and redox proteomics in the Mediterranean clam Ruditapes decussatus (Mollusca: Bivalvia).

    Science.gov (United States)

    Sellami, Badreddine; Khazri, Abdelhafidh; Louati, Héla; Dellali, Mohamed; Driss, Mouhamed Ridha; Aïssa, Patricia; Mahmoudi, Ezzeddine; Hamouda, Beyrem; Coelho, Ana Varela; Sheehan, David

    2015-07-01

    This study aimed at analyzing the impact of a toxic polyaromatic hydrocarbon (PAH), anthracene (ANT), on Ruditapes decussatus collected from a Tunisian coastal lagoon (Bizerte Lagoon). Filtration rates, several antioxidant enzymes--superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), and glutathione transferase (GST)--as well as indices of protein oxidation status were determined in various tissues of this bivalve. Specimens were exposed to 100 μg/L of ANT for 2 days. ANT levels were evaluated using HPLC and were detected in the gill and digestive gland at different amounts. ANT exposure altered the behavior of bivalves by changing the siphon movement and decreasing filtration rate significantly. The enzymatic results indicated that ANT exposure affected the oxidative stress status of the gills of R. decussatus. In addition, modification of proteins was detected in the gills using redox proteomics after ANT treatment. Three protein spots were successfully identified by matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry (MALDI-TOF-MS). These proteins can be roughly related to muscle contraction function. In contrast, no significant modification of enzymatic and protein responses was detected in the digestive gland after ANT treatment. These data demonstrate that combined behavioral and biochemical analyses are a powerful tool to provide valuable insights into possible mechanisms of toxicity of anthracene in R. decussatus. Additionally, the results highlight the potential of the gill as a valuable candidate for investigating PAH toxicity. PMID:25779113

  1. Devonia perrieri (Malard, 1903 (Bivalvia found in situ on the holothurian Leptosynapta inhaerens (Müller, 1776 in Norway

    Directory of Open Access Journals (Sweden)

    Glenn A. Bristow

    2010-12-01

    Full Text Available 800x600 Normal 0 21 false false false NO-BOK X-NONE X-NONE MicrosoftInternetExplorer4 The ectosymbiotic bivalve, Devonia perrieri, has earlier been found non-associated with its host in grab samples in Western Norway, but has never been found on its purported host, Leptosynapta inhaerens. Here we show it for the first time on its host, Leptosynapta inhaerens, in Norwegian waters. This confirms that the host in Western Norway is same as elsewhere in the bivalve’s distribution area.

  2. Biomonitoring study of an estuarine coastal ecosystem, the Sacca di Goro lagoon, using Ruditapes philippinarum (Mollusca: Bivalvia)

    International Nuclear Information System (INIS)

    Coastal lagoons are constantly subjected to releases of chemical pollutants, and so organisms may be exposed to such toxicants. This study investigated through a multivariate approach the physiological status of bivalve Ruditapes philippinarum, farmed in Sacca di Goro lagoon. Biomarkers at different levels of biological organization (catalase, superoxide dismutase, genotoxicity, reburrowing behavior) were evaluated at three sites exposed to different environmental conditions. A seasonal trend was observed, and micronucleus frequency was significantly lowest at the relatively pristine reference site. Enzymatic activity toward oxyradicals be quite efficient since variations in responsiveness were not consistent. However, behavioral impairment was observed in reburrowing rates. Sediment concentrations showed low PAH levels and high natural levels of trace metals Cr and Ni. DistLM statistical analysis revealed a non-significant relationship between selected biomarkers and xenobiotics. Therefore other potentially toxic compounds in admixture at low doses may be involved in driving differing spatial distribution of physiological impairment. -- Highlights: ► Health status assessment of bivalve Ruditapes philippinarum, from lagoon of Sacca di Goro. ► Multiparametric approach (chemical analysis, biochemical and behavioral biomarkers). ► Impairments of burrowing kinetics in the contaminated site. ► Micronucleus genotoxicity test to detect effects of contaminants complex mixture. ► Multiple stress of chemicals in estuarine costal ecosystem. -- The bivalve Ruditapes philippinarum as a bioindicator in monitoring pollution of estuaries

  3. Size-selective predation of the catfish Pimelodus pintado (Siluriformes: Pimelodidae on the golden mussel Limnoperna fortunei (Bivalvia: Mytilidae

    Directory of Open Access Journals (Sweden)

    João P. Vieira

    2013-02-01

    Full Text Available This paper describes the size-selective predation on Limnoperna fortunei (Dunker, 1857 by Pimelodus pintado (Azpelicueta, Lundberg & Loureiro, 2008 from the time it arrived at the Mirim Lagoon basin (2005. Sampling was carried out using bottom trawl in depths of 3-6 m, from January to November 2005, and from October to November 2008. Pimelodus pintado began to prey upon L. fortunei soon after its arrival (austral spring of 2005. On the spring of 2008, L. fortunei was found to be the most important food item of P. pintado. The variation in length of the mussels (0.7-3.2 cm, with a mode of 1.3 cm indicates that the species is now fully established in the system. Our data indicates that large individuals of P. pintado incorporate more mussels in their diets than small individuals. However, regardless of their size, P. pintado individuals predate only on small (<1.4 cm representatives of L. fortunei. This prey size corresponds to a phase when the mussel is more mobile and readily available for fish. Larger, more aggregated prey groups that are attached to hard substrates are avoided by fish predators.

  4. Size-selective predation of the catfish Pimelodus pintado (Siluriformes: Pimelodidae) on the golden mussel Limnoperna fortunei (Bivalvia: Mytilidae)

    OpenAIRE

    João P Vieira; Michelle N. Lopes

    2013-01-01

    This paper describes the size-selective predation on Limnoperna fortunei (Dunker, 1857) by Pimelodus pintado (Azpelicueta, Lundberg & Loureiro, 2008) from the time it arrived at the Mirim Lagoon basin (2005). Sampling was carried out using bottom trawl in depths of 3-6 m, from January to November 2005, and from October to November 2008. Pimelodus pintado began to prey upon L. fortunei soon after its arrival (austral spring of 2005). On the spring of 2008, L. fortunei was found to be the most ...

  5. Evidence for somatic transcription of male-transmitted mitochondrial genome in the DUI species Ruditapes philippinarum (Bivalvia: Veneridae).

    Science.gov (United States)

    Milani, Liliana; Ghiselli, Fabrizio; Iannello, Mariangela; Passamonti, Marco

    2014-08-01

    In species with doubly uniparental inheritance (DUI), males are heteroplasmic for two sex-linked mitochondrial genomes (M- and F-mtDNA). While a role of M-mtDNA in male gametogenesis and sperm function is evident, there is an ongoing debate on whether it is transcribed or not in male soma. In this work we report a qPCR analysis in the DUI species Ruditapes philippinarum, showing that M-mtDNA is transcribed in somatic tissues. We observed a correlation between DNA copy numbers of the two analyzed genes, cytochrome b and a novel male-specific mitochondrial gene thought to be involved in DUI (orf21), and between their transcription levels. No correlation between a transcript and its DNA copy number was found, supporting the existence of complex regulatory mechanisms of mitochondrial transcription. We found the highest amount of mtDNA and mtRNA in gonads, likely due to the intense cell proliferation and high energy request for gametogenesis, while the observed variation among specimens is probably related to their different stages of gonad development. Finally, orf21 showed a highly variable transcription in advanced stages of gametogenesis. We hypothesize a differential storage of orf21 transcripts in spermatozoa, representing different paternal contributions to progeny, possibly leading to different developmental outcomes. A transcriptional activity does not necessarily imply the translation of M-mtDNA genes, and studies on mitochondrial proteins and their localization are needed to definitively assess the functioning of male-transmitted mitochondria in male soma. All that considered, the male soma of DUI species may represent an intriguing experimental model to study cytoplasmic genetic conflicts. PMID:24562864

  6. Monitoring invasive quagga mussels, Dreissena rostriformis bugensis (Bivalvia: Dreissenidae, and other benthic organisms in a western US aqueduct

    Directory of Open Access Journals (Sweden)

    S. Mark Nelson

    2013-01-01

    Full Text Available A quagga mussel (Dreissena rostriformis bugensis Andrusov, 1897 invasion of an aqueduct in Arizona was monitored from 2007 – 2011using colonization substrates. As numbers increased, a filtering-collector caddisfly (Smicridea fasciatella McLachlan, 1871 declinedsignificantly in abundance. After two years of colonization, freshwater sponges were detected and associated with a decline in D. r. bugensisnumbers. Periphyton biomass increased considerably on substrates; perhaps partially, the result of decreased turbidity. Aqueduct biofoulerscould have major impacts on costs associated with aqueduct maintenance. From an operations viewpoint, mussels are undesirable due to flowrestriction associated with increased friction. Augmented sponge and periphyton biomass may also influence aqueduct operations andefficiencies.

  7. [Abundance and morphometry of tuberculosa Anadara and A. similis (Mollusca: Bivalvia) in the Manglar de Purruja, Dulce Gulf, Costa Rica].

    Science.gov (United States)

    Silva Benavides, A M; Bonilla Carrión, R

    2001-12-01

    The density, population, length, yield and sex proportion of the mollusks Anadara tuberculosa and A. similis were studied in Bahía de Golfito, Golfo Dulce, Pacific coast of Costa Rica from February 1998 to February 1999. A. tuberculosa was more abundant (0.9 units m(-2)), than A. similis (0.2 units m(-2)); the highest abundance was found at the canal mouths. The average lengths were 43.3 mm for A. tuberculosa and 42.8 mm for A. similis (both under the Costa Rican legal minimal length for exploitation: 47 mm). Maximum lengths were measured in the middle and upstream Canal Mayor, respectively: 43.0 mm and 43.4 mm. The correlation between length and fresh weight was 0.81 (Pearson). The average total weights were 26.2 g for A. tuberculosa and 19.1 g for A. similis. The condition index (a meat yield measurement) was higher in A. similis (21.2%) than in A. tuberculosa (17.2%). The maximum yield for both species lies in the 31-35 mm range. The male ratio was 43.7%. A species recovery plan is urgent because these results suggest both a decrease in density and illegal exploitation. PMID:15264545

  8. Mitogenomics of southern hemisphere blue mussels (Bivalvia: Pteriomorphia): Insights into the evolutionary characteristics of the Mytilus edulis complex.

    Science.gov (United States)

    Gaitán-Espitia, Juan Diego; Quintero-Galvis, Julian F; Mesas, Andres; D'Elía, Guillermo

    2016-01-01

    Marine blue mussels (Mytilus spp.) are widespread species that exhibit an antitropical distribution with five species occurring in the Northern Hemisphere (M. trossulus, M. edulis, M. galloprovincialis, M. californianus and M. coruscus) and three in the Southern Hemisphere (M. galloprovincialis, M. chilensis and M. platensis). Species limits in this group remain controversial, in particular for those forms that live in South America. Here we investigated structural characteristics of marine mussels mitogenomes, based on published F mtDNA sequences of Northern Hemisphere species and two newly sequenced South American genomes, one from the Atlantic M. platensis and another from the Pacific M. chilensis. These mitogenomes exhibited similar architecture to those of other genomes of Mytilus, including the presence of the Atp8 gene, which is missing in most of the other bivalves. Our evolutionary analysis of mitochondrial genes indicates that purifying selection is the predominant force shaping the evolution of the coding genes. Results of our phylogenetic analyses supported the monophyly of Pteriomorphia and fully resolved the phylogenetic relationships among its five orders. Finally, the low genetic divergence of specimens assigned to M. chilensis and M. platensis suggests that these South American marine mussels represent conspecific variants rather than distinct species. PMID:27241855

  9. Differences in sperm ultrastructure between Mytilus chilensis and Mytilus galloprovincialis (Bivalvia, Mytilidae: could be used as a taxonomic trait?

    Directory of Open Access Journals (Sweden)

    Pablo A Oyarzún

    2014-03-01

    Full Text Available The sperm ultrastructure has been used to solve several systematic and phylogenetic problems in marine invertebrates. The sperm ultrastructure of the Chilean mussel Mytilus chilensis and Mytilus galloprovincialis corresponds to the ect-aquasperm type. Sperm from both taxa measured 55-60 μm between head (acrosome + nucleus, midpiece (only 5 mitochondria and the flagellum which in its end piece has a smaller diameter tail. The differences between both taxa are clearly shown, in the structure of the acrosome and nucleus. Therefore, according to our results and those reported in the literature, we indicate that Chilean native mussel sperm is different from other species of the Mytilus complex (M. trossulus, M. galloprovincialis and M. edulis. These differences in sperm ultrastructure found in M. chilensis, are another trait that can be used to validate the taxonomic status of the species. Differences in sperm morphology are related with reproductive isolation, and probably will be useful to understand future data on speciation. Finally, we discussed the finding that Mytilus galloprovincialis sperm from Chile have an acrosome notoriously smaller than those reported for specimens from Europe and Africa, though they have a great similarity with specimens from Japan, as reported in the literature.

  10. Is the body condition of the invasive zebra mussel (Dreissena polymorpha) enhanced through attachment to native freshwater mussels (Bivalvia, Unionidae)?

    Science.gov (United States)

    Pilotto, Francesca; Sousa, Ronaldo; Aldridge, David C

    2016-05-15

    The invasion of zebra mussels, Dreissena polymorpha, into Western Europe and North America has driven widespread ecological change. Attachment of zebra mussels to the shell of native unionoid mussels has resulted in reductions in unionoid abundance and, in extreme cases, their localised extirpations. While the impacts of zebra mussels on infested unionoids are well documented, the possible benefits of the association to the zebra mussel have been little considered. We collected zebra mussels attached to unionoids and to inanimate structures. Zebra mussels attached to unionoids had significantly larger shells, higher standardized body mass and glycogen content than those attached to inanimate substrates, suggesting that D. polymorpha benefits from settling upon unionoids. The body condition of individual zebra mussels was negatively correlated with the number of zebra mussels attached to the unionoid, indicating intraspecific competition. Therefore, zebra mussels seem positively affected through attachment to unionoid mussels, but that these benefits decrease at higher densities of fouling. This association may offer advantages to the spread of zebra mussels within unionoid-rich systems, especially at sites with soft substrates and at the early stages of the invasion process where intraspecific competition is likely to be lower and benefits to the zebra mussels are higher. PMID:26925735

  11. The male and female complete mitochondrial genome sequences of the Endangered freshwater mussel Potomida littoralis (Cuvier, 1798) (Bivalvia: Unionidae).

    Science.gov (United States)

    Froufe, Elsa; Gan, Han Ming; Lee, Yin Peng; Carneiro, João; Varandas, Simone; Teixeira, Amílcar; Zieritz, Alexandra; Sousa, Ronaldo; Lopes-Lima, Manuel

    2016-09-01

    Freshwater mussels of the family Unionidae exhibit a particular form of mitochondria inheritance called double uniparental inheritance (DUI), in which the mitochondria are inherited by both male and female parents. The (M)ale and (F)emale mitogenomes are highly divergent within species. In the present study, we determine and describe the complete M and F mitogenomes of the Endangered freshwater mussel Potomida littoralis (Cuvier, 1798). The complete M and F mitogenomes sequences are 16 451 bp and 15 787 bp in length, respectively. Both F and M have the same gene content: 13 protein-coding genes (PCGs), 22 transfer RNA (trn) and 2 ribosomal RNA (rrn) genes. Bayesian analyses based on the concatenated nucleotide sequences of 12 PCGs and 2 rrn genes of both genomes, including mitogenome sequences available from related species, were performed. Male and Female lineages are monophyletic within the family, but reveal distinct phylogenetic relationships. PMID:27158872

  12. Non-target trials with Pseudomonas fluorescens strain CL145A, a lethal control agent of dreissenid mussels (Bivalvia: Dreissenidae

    Directory of Open Access Journals (Sweden)

    Daniel P. Molloy

    2013-01-01

    Full Text Available In an effort to develop an efficacious and environmentally safe method for managing zebra mussels (Dreissena polymorpha and quaggamussels (Dreissena rostriformis bugensis, we initiated a research project investigating the potential use of bacteria and their naturalmetabolic products as biocontrol agents. This project resulted in the discovery of an environmental isolate lethal to dreissenid mussels,Pseudomonas fluorescens strain CL145A (Pf-CL145A. In previous published reports we have demonstrated that: 1 Pf-CL145A’s mode ofaction is intoxication (not infection; 2 natural product within ingested bacterial cells lyse digestive tract epithelial cells leading to dreisseniddeath; and 3 high dreissenid kill rates (>90% are achievable following treatment with Pf-CL145A cells, irrespective of whether thebacterial cells are dead or alive. Investigating the environmental safety of Pf-CL145A was also a key element in our research efforts, andherein, we report the results of non-target trials demonstrating Pf-CL145A’s high specificity to dreissenids. These acute toxicity trials weretypically single-dose, short-term (24-72 h exposures to Pf-CL145A cells under aerated conditions at concentrations highly lethal todreissenids (100 or 200 mg/L. These trials produced no evidence of mortality among the ciliate Colpidium colpoda, the cladoceran Daphniamagna, three fish species (Pimephales promelas, Salmo trutta, and Lepomis macrochirus, and seven bivalve species (Mytilus edulis,Pyganodon grandis, Pyganodon cataracta, Lasmigona compressa, Strophitus undulatus, Lampsilis radiata, and Elliptio complanata. Lowmortality (3-27% was recorded in the amphipod Hyalella azteca, but additional trials suggested that most, if not all, of the mortality couldbe attributed to some other unidentified factor (e.g., possibly particle load or a water quality issue rather than Pf-CL145A’s dreissenidkillingnatural product. In terms of potential environmental safety, the results of these invertebrate and vertebrate non-target trials areencouraging, but it would be unrealistic to think that dreissenids are the only aquatic organisms sensitive to Pf-CL145A’s dreissenid-killingnatural product. Additional testing is needed to better define Pf-CL145A’s margin of safety by identifying the sensitivity of other susceptibleorganisms. The results of these non-target safety trials – in combination with equally promising mussel control efficacy data – have now ledto Pf-CL145A’s commercialization under the product name Zequanox®, with dead cells as the product’s active ingredient. The commercialavailability of only dead-cell Zequanox formulations will eliminate the risk of any possible non-target infection by Pf-CL145A, furtherreducing environmental concerns. During the non-target project reported herein, the limited quantities of Pf-CL145A cells that we were ableto culture severely restricted the number and size of our trials. In contrast, the availability of Zequanox will now greatly expand theopportunities for non-target testing. The trials reported herein – exposing non-target organisms under aerated conditions to unformulated,laboratory-cultured cells – clearly point to Pf-CL145A’s potential for high host specificity, but non-target trials with Zequanox – using Pf-CL145A cells cultured, killed, and formulated using industrial-scale protocols – will be even more important as they will define the nontargetsafety limits of the actual commercial products under a wide range of environmental conditions.

  13. Numerical Quantification of Perkinsus Marinus in the American Oyster Crassostrea virginicata (Gmelin 1791) (Mollusca: Bivalvia) by Modern Stereology

    Science.gov (United States)

    Species of Perkinsus are responsible for high mortalities of bivalve molluscs world-wide. Techniques to accurately estimate parasites in tissues are required to improve understanding of perkinsosis. This study quantifies the number and tissue distribution of Perkinsus marinus in ...

  14. Recrutamento larval e crescimento de teredinidae (mollusca-bivalvia em região entremarés de manguezais

    Directory of Open Access Journals (Sweden)

    Sônia Godoy Bueno Carvalho Lopes

    1997-01-01

    Full Text Available O recrutamento larval e o crescimento de Teredinidae na região entremarés do manguezal da Praia Dura, Ubatuba, SP, foi acompanhado durante doze meses (08/84 a 08/85 utilizando coletores construídos com madeira de mangue. O tempo decorrido para se detectar a presença dos primeiros Teredinidae foi de aproximadamente sete meses após o início do experimento e o número de indivíduos por coletor foi muito reduzido no período de amostragem. Esses resultados contrastam com os obtidos por outros autores que instalaram coletores em ambiente marinho, mas são semelhantes aos obtidos por autores que instalaram coletores em regiões estuarinas do litoral brasileiro. Essas diferenças nos resultados talvez possam ser explicadas pelo fato da salinidade ser mais baixa e mais variável nos estuários que no ambiente marinho. A análise dos dados sobre o recrutamento larval, permite concluir que a espécie mais abundante foi Nausitora fustieula (Jeffreys, 1860, com principal época de instalação em março e taxa inicial de crescimento de 1,86 mm/day. As outras espécies de Teredinidae, Bankiaflmbriatula Moll & Roch, 1931, Bankia roehi Moll, 1931 e Neoteredo reynei (Bartsch, 1920, apresentaram pequeno número de indivíduos e em função disso, não foi possível determinar suas épocas de instalação e respectivas taxas de crescimento.The larval settlement and growth of Teredinidae in the intertidal region of the Praia Dura mangrove, Ubatuba, SP, were undertaken during one year (08/84 to 08/85 using colectors made from mangrove wood. The presence of the first Teredinidae was detected approximately seven month after the inicial experiment and the number of specimens per coletor was small during the sampling period. These results contrast with those obtained by other authors working in a marine environment, but are similar to those obtained in experiments developed in Brazilian estuaries. The differences between data obtained in marine and estuarine environments, might be explained by the lower and more variable salinity gradient in estuaries. Larval settlement data revealed that the most abundant species was Nausitora fustieula (Jeffreys,1860, which settles on wood prefrerably in March, and has an initial growth rate of 1.86 mm/day. The other Teredinidae species Banida fimbriatula Moll & Roch, 1931, Bankia rochi Moll, 1931 and Neoteredo reynei (Bartsch, 1920, occurred in a very small number of specimens and therefore, their time of settlement and growth rates could not be determined.

  15. A new species of Pulvinites (Mollusca: Bivalvia) from the upper Paleocene Paspotansa Member of the Aquia Formation in Virginia ( USA).

    Science.gov (United States)

    Ward, L.W.; Waller, T.R.

    1988-01-01

    Pulvinites lawrencei n.sp. is described from the upper Paleocene (Landenian Stage) Paspotansa Member of the Aquia Formation in Stafford County, Virginia. This is the first report of a member of the pteriacean family Pulvinitidae in the Tertiary on either side of the Atlantic, the only other post-Mesozoic records of Pulvinites being in the Paleocene of California and the present-day Pacific off southeast Australia. The stratigraphic setting and co-occurring molluscan assemblage of the new species indicate shallow-shelf, open-marine conditions with near normal salinities. -Authors

  16. New lucinid bivalves from shallow and deeper water of the Indian and West Pacific Oceans (Mollusca, Bivalvia, Lucinidae

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    John Taylor

    2013-08-01

    Full Text Available Four new species and a new genus of lucinid bivalves are described from shallow and deeper waters in the Indian and West Pacific Oceans. The new genus Scabrilucina (subfamily Lucininae includes the little-known S. victorialis (Melvill, 1899 from the Arabian Sea and S. vitrea (Deshayes, 1844 from the Andaman Sea as well as a new species S. melvilli from the Torres Strait off northeastern Australia. Ferrocina brunei new species (Lucininae was recovered from 60 m near oil drilling activities off Borneo; its anatomy confirmed the presence of symbiotic bacteria. Two unusual deeper water species of Leucosphaerinae are described, both species included in on-going molecular analyses; Gonimyrtea ferruginea from 400–650 m in the southwest Pacific and Myrtina reflexa from 200–825 m off Zanzibar and Madagascar.

  17. Effect of heavy metals (Cu, Cd and Pb) on aspartate and alanine aminotransferase in Ruditapes philippinarum (Mollusca: Bivalvia)

    International Nuclear Information System (INIS)

    The accumulation of cadmium, copper and lead and their effects on aspartate and alanine aminotransferases in digestive gland, gills, foot and soft body in the clam Ruditapes philippinarum were examined. The animals were exposed to different concentrations: Cd (200-600 μg·l-1), Pb (350-700 μg·l-1) and Cu (10-20 μg·l-1) for 7 days. The highest concentrations were found in digestive gland for cadmium and copper, and in gills for lead, and the lowest values were observed in the foot. Aspartate aminotransferase activity (AST), in general, was not inhibited by cadmium, lead or copper during the exposure. Only in clams exposed to cadmium (600 μg·l-1, 7 days) and copper (20 μg·l-1, 5 days) were observed significant differences (P-1. A significant correlation (P<0.05) was observed between ALT and metal accumulation for cadmium, copper and lead in gills. In the case of soft body, only cadmium and lead showed a significant correlation. In summary, R. philippinarum can be considered a bioindicator species for cadmium and lead accumulation and ALT could be useful as biomarker of sublethal stress for these metals in soft tissues and gills. Only gills can be considered an adequate target tissue for copper. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  18. The Effects of Mercury Exposure on the Surface Morphology of Gill Filaments in Perna perna (Mollusca: Bivalvia)

    International Nuclear Information System (INIS)

    This study investigated the possibility that changes in the surface morphology of mussel (Perna perna) gill filaments may be used to indicate the relative toxicity of pollutants in the marine environment. Healthy, adult P. perna were collected and immersed in 2 free-flow tanks. Mercury was added to seawater as it entered tank 1 to achieve a constant level of 50 μg/l-1 over 24 days. Uncontaminated seawater was circulated over the mussels in tank 2 (control) for the same period. A 25 mm2 area of gill filament was removed from each of the 5 specimens before and after 24 days immersion in tank 2, and after immersion for 1, 2, 4, 8, 16 and 24 days in tank 1. These were examined using a scanning electron microscope. The remaining soft tissues from each animal were analysed for mercury using an atomic absorption spectrometer. Mercury concentration increased from 0.13 (pre-immersion) to 87 μg/g after day 24. Surface morphology remained normal for all animals in tank 2 and for those exposed to Hg for up to 8 days. However, from 16 to 24 days exposure there was a gradual increase in the diameters of microvilli, a depletion of abfrontal cilia, an increase in abnormal, perhaps necrotic cells and an unusual increase in the number of cilia on the lateral surfaces. These results confirm that P. perna is an efficient bio-accumulator and suggest that their gill pathomorphology may be a useful indicator of toxicity

  19. Differences in absolute and relative growth between two shell forms of Pinna nobilis (Mollusca: Bivalvia) along the Tunisian coastline

    Science.gov (United States)

    Rabaoui, Lotfi; Tlig-Zouari, Sabiha; Katsanevakis, Stelios; Belgacem, Walid; Hassine, Oum Kalthoum Ben

    2011-08-01

    This study investigated the absolute and relative growth patterns of the fan mussel Pinna nobilis along the Tunisian coastline, taking into consideration both the variability among different areas and between the two shell forms "combed" and "straight and wide". Five subpopulations of the species were sampled, one from northern, two from eastern and two from southern Tunisia. Various assumptions on the growth patterns were tested based on an information theory approach and multi-model inference. For absolute growth, the assumption of different growth patterns between the two shell forms of P. nobilis and no difference among subpopulations was the most supported by the data. For the same age, "straight and wide" individuals gained on average greater lengths than the "combed" individuals. The absolute growth of the species was found to be asymptotic and the logistic model was the one most supported by the data. As for the relative growth, apart from the classical allometric model Y = aXb, more complicated models of the form ln Y = f(ln X) that either assumed non-linearities or breakpoints were tested in combination with assumptions for possible differences between the two forms and among subpopulations. Among the eight studied relationships between morphometric characters, the classical allometric model was supported in only two cases, while in all other cases more complicated models were supported. Moreover, the assumption of different growth patterns between the two forms was supported in three cases and the assumption of different growth patterns among subpopulations in four cases. Although precise relationships between the morphometric plasticity of the fan mussel and environmental factors have not been proven in this paper, local small scale constraints might be responsible of the different growth patterns observed in the same locality. A possible co-action of genetic factors should be evaluated in the future.

  20. Life cycle, population dynamics, growth and production of Abra segmentum (Mollusca, Bivalvia) at low salinities in a Mediterranean lagoon

    Science.gov (United States)

    Kevrekidis, Theodoros; Kasapis, K.; Kalpia, V.

    2009-12-01

    Aspects of the biology of Abra segmentum were investigated at low salinities in a Mediterranean coastal lagoon (Monolimni Lagoon, Northern Aegean Sea). Monthly samples were collected during the period from February 1998 to January 1999. Recruitment occurred from mid-spring to early autumn (0.3-5.7 psu) and recruits grew during summer and autumn (1.2-5.7 psu), while a major part vanished during next autumn, displaying a maximum life span of about 20 months. A positive correlation was found between the percentage of individuals having a shell length of ≤3.5 mm and temperature; age group 0 showed a growth rate of 0.97 mm per month, and the largest individual collected had a 19.76 mm shell length. The population density sharply increased during late spring (0.3-1.2 psu); this increase was followed by a decline during summer and, afterwards, a gradual increase up to late autumn. Secondary production calculated by the size-frequency method gave a mean annual density ( n) of 3,357 individuals m-2, a mean annual biomass ( B) of 21.98 g DW m-2, an annual production ( P) of 73.72 g DW m-2 and a P: B ratio of 3.35. A comparison of the present data with available data of A. segmentum populations from higher salinity habitats revealed that this bivalve in the study area showed a life history pattern similar to that of other populations of the species and a comparatively high growth rate, maximum body size, n, B, P and P: B ratio. Our findings suggest that the studied aspects of A. segmentum biology could not be markedly affected by low salinities.

  1. Integrative study of a new cold-seep mussel (Mollusca: Bivalvia) associated with chemosynthetic symbionts in the Marmara Sea

    Science.gov (United States)

    Ritt, Bénédicte; Duperron, Sébastien; Lorion, Julien; Sara Lazar, Cassandre; Sarrazin, Jozée

    2012-09-01

    Recently, small Idas-like mussels have been discovered living on carbonate crusts associated with cold-seeps in the Marmara Sea. These mussels, here referred to as Idas-like nov. sp., differ morphologically and genetically from another species identified as Idas aff. modiolaeformis, living in the same type of ecosystem in the Nile Deep-Sea Fan (eastern Mediterranean Sea). A phylogenetic analysis confirms the distinction between the two species, which belong to highly divergent lineages. Carbon stable isotope values, as well as the detection of thiotroph-related bacteria in the gill tissue, support the presence of a symbiotic, thiotroph-derived nutrition. In contrast, Idas aff. modiolaeformis displays six different types of symbionts. Finally our size-frequency data suggest that the recruitment is continuous in the examined area. The present study extends the documented distribution of symbiont-bearing mussels to the Marmara Sea, and contributes to the characterisation of biological communities in this recently explored area.

  2. Application of the morpho-functional analysis of hydrobionts ( Anadara sp. cf. Anadara inaequivalvis Bivalvia) to environmental monitoring

    Science.gov (United States)

    Kolyuchkina, G. A.; Miljutin, D. M.

    2013-03-01

    The population dynamics and morphological and functional characteristics (the concentration of hemocytes in the hemolymph and the level of histopathology) of the bivalve Anadara sp. cf. Anadara inaequivalvis were studied in 2005-2007 on the North Caucasian coast of the Black Sea. A drastic decline in the abundance of the bivalves simultaneously with cadmium's exceedence in their soft tissues and bottom sediments were recorded in May of 2007. Six months before the manifestation of the population effects, morphological and functional changes (a decrease in the content of hemocytes in the hemolymph and an increase in the content of brown cells in the connective tissue and lipofuscin-like pigment granules in the digestive gland epithelium) in the bivalves were detected that were the consequences of an external effect (presumably, cadmium intoxication). Thus, the morphological and functional changes of the individual Anadaras may be a promising tool for the early detection of the impact of pollutants on benthic ecosystems.

  3. Non-target trials with Pseudomonas fluorescens strain CL145A, a lethal control agent of dreissenid mussels (Bivalvia: Dreissenidae)

    OpenAIRE

    Molloy, Daniel P.; Denise A. Mayer; Michael J. Gaylo; Burlakova, Lyubov E.; Karatayev, Alexander Y.; Kathleen T. Presti; Paul M. Sawyko; John T. Morse; Eric A. Paul

    2013-01-01

    In an effort to develop an efficacious and environmentally safe method for managing zebra mussels (Dreissena polymorpha) and quaggamussels (Dreissena rostriformis bugensis), we initiated a research project investigating the potential use of bacteria and their naturalmetabolic products as biocontrol agents. This project resulted in the discovery of an environmental isolate lethal to dreissenid mussels,Pseudomonas fluorescens strain CL145A (Pf-CL145A). In previous published reports we have demo...

  4. Free amino acids in the clam Macoma balthica (L.) (Bivalvia, Mollusca) from brackish waters of southern Baltic Sea

    NARCIS (Netherlands)

    Sokolowski, A.; Wolowicz, M.; Hummel, H.

    2003-01-01

    Fourteen acidic and neutral free amino acids (FAA) were investigated in soft tissue of Macoma balthica from different depth zones of the Gulf of Gdansk (Baltic Sea) over a full seasonal cycle. The dry weight of the bivalves and physico-chemical parameters of overlying bottom water and surface sedime

  5. Plasticity of symbiont acquisition throughout the life cycle of the shallow-water tropical lucinid Codakia orbiculata (Mollusca: Bivalvia).

    Science.gov (United States)

    Gros, Olivier; Elisabeth, Nathalie H; Gustave, Sylvie D D; Caro, Audrey; Dubilier, Nicole

    2012-06-01

    In marine invertebrates that acquire their symbionts from the environment, these are generally only taken up during early developmental stages. In the symbiosis between lucinid clams and their intracellular sulfur-oxidizing bacteria, it has been shown that the juveniles acquire their symbionts from an environmental stock of free-living symbiont forms, but it is not known if adult clams are still competent to take up symbiotic bacteria from the environment. In this study, we investigated symbiont acquisition in adult specimens of the lucinid clam Codakia orbiculata, using transmission electron microscopy, fluorescence in situ hybridization, immunohistochemistry and PCR. We show here that adults that had no detectable symbionts after starvation in aquaria for 6 months, rapidly reacquired symbionts within days after being returned to their natural environments in the field. Control specimens that were starved and then exposed to seawater aquaria with sulfide did not reacquire symbionts. This indicates that the reacquisition of symbionts in the starved clams returned to the field was not caused by high division rates of a small pool of remaining symbionts that we were not able to detect with the methods used here. Immunohistochemistry with an antibody against actin, a protein involved in the phagocytosis of intracellular bacteria, showed that actin was expressed at the apical ends of the gill cells that took up symbionts, providing further evidence that the symbionts were acquired from the environment. Interestingly, actin expression was also observed in symbiont-containing cells of untreated lucinids freshly collected from the environment, indicating that symbiont acquisition from the environment occurs continuously in these clams throughout their lifetime. PMID:22672589

  6. Golden mussel Limnoperna fortunei (Bivalvia: Mytilidae) distribution in the main hydrographical basins of Uruguay: update and predictions.

    Science.gov (United States)

    Brugnoli, Ernesto; Clemente, Juan; Boccardi, Lucía; Borthagaray, Ana; Scarabino, Fabrizio

    2005-06-01

    Limnoperna fortunei, an Asiatic rivers bivalve has become a worldwide problematic invasive species causing several water quality and macrofouling problems. In the Neotropical region it was first recorded in 1991 in the Rio de la Plata coast, Buenos Aires province. Since this, it showed a quick upstream invasion into the principals aquatic systems of the Plata Basin. Nevertheless, there is not a study about its invasion and distribution process in aquatic systems of Uruguay. We describe the new records of Limnoperna fortunei in Uruguayan coast of Rio de la Plata, Santa Lucia, Negro and Uruguay Rivers. With these results we aim to estimate its distributional limits for Uruguay main hydrographical basins. We also deal with the role of salinity as the main abiotic factor in limiting the east distribution of this mussel in Uruguayan coast of Rio de la Plata and as a potential determinant of the "new" colonization on the Atlantic and the Merin Lagoon Basins. Its presence in the ecosystems not only can cause changes at the ecosystem level but also endanger the associated community, favoring the displacement and the disappearance of endemic species. PMID:15895160

  7. Seasonal abundance of the shipworm Neoteredo reynei (Bivalvia, Teredinidae in mangrove driftwood from a northern Brazilian beach

    Directory of Open Access Journals (Sweden)

    Carlos S. Filho

    2008-03-01

    Full Text Available Shipworms are important decomposers of wood, especially in mangrove forests where productivity is high. However, little emphasis has been given to the activity of shipworms in relation to the export of nutrients from mangroves to adjacent coastal areas. As a first step to obtaining such information, the frequency of colonized mangrove driftwood as well as shipworm density and length were studied by collecting washed up logs during a year at Ajuruteua beach, state of Pará, northern Brazil. A single species, Neoteredo reynei (Bartsch, 1920, was found colonizing driftwood. Although large colonized logs were most common on the beach, shipworm density was higher in small logs, especially during the dry season. In general, however, density was higher during the wet season (January to April and lowest in July. Overall shipworm mean length was 9.66cm. In large logs, mean length increased between the wet and dry seasons. However, there was no difference in length among log size categories. Mean shipworm length was similar throughout most of the year but tended to be greater in July. Although salinity varied between 10.9 and 40 during the year, no relationship was found between salinity and density or length. The results suggest that shipworm activity in driftwood logs is relatively constant throughout the year. Increased air humidity and rainfall may promote survival during the wet season. Large logs may take longer to colonize and thus have lower densities than small ones which are scarce probably because they are destroyed rapidly by shipworm activity. However, data on the disintegration of logs would be necessary to test this hypothesis. Larger size of shipworms in the dry season may be related to growth after an earlier recruitment period. Shipworms in large logs during the dry season may be better protected from dessication and high temperatures by the insulating properties of the larger volume of wood.

  8. Immunochemical localization of ribulose-1,5-bisphosphate carboxylase in the symbiont-containing gills of Solemya velum (Bivalvia : Mollusca)

    NARCIS (Netherlands)

    Cavanaugh, Colleen M.; Abbott, Marilyn S.; Veenhuis, Marten

    1988-01-01

    The distribution of the Calvin cycle enzyme ribulose-1,5-bisphosphate carboxylase (RbuP2Case; EC 4.1.1.39) was examined by using two immunological methods in tissues of Solemya velum, an Atlantic coast bivalve containing putative chemoautotrophic symbionts. Antibodies elicited by the purified large

  9. Cytogenetic characterisation of the razor shells Ensis directus (Conrad, 1843) and E. minor (Chenu, 1843) (Mollusca: Bivalvia)

    Science.gov (United States)

    González-Tizón, Ana M.; Rojo, Verónica; Vierna, Joaquín; Jensen, K. Thomas; Egea, Emilie; Martínez-Lage, Andrés

    2013-03-01

    The European razor shell Ensis minor (Chenu 1843) and the American E. directus (Conrad 1843) have a diploid chromosome number of 38 and remarkable differences in their karyotypes: E. minor has four metacentric, one metacentric-submetacentric, five submetacentric, one subtelocentric and eight telocentric chromosome pairs, whereas E. directus has three metacentric, two metacentric-submetacentric, six submetacentric, six subtelocentric and two telocentric pairs. Fluorescent in situ hybridisation (FISH) using a major ribosomal DNA probe located the major ribosomal genes on one submetacentric chromosome pair in both species; FISH with a 5S ribosomal DNA (5S rDNA) probe rendered one chromosomal (weak) signal for E. minor and no signal for E. directus, supporting a more dispersed organisation of 5S rDNA compared to the major ribosomal genes. The vertebrate telomeric sequence (TTAGGG) n was located on both ends of each chromosome, and no interstitial signals were detected. In this work, a comparative karyological analysis was also performed between the four Ensis species analysed revealing that the three European species studied so far, namely E. minor, E. siliqua (Linné 1758) and E. magnus Schumacher 1817 show more similarities among them than compared to the American species E. directus. In addition, clear karyotype differences were found between the morphologically similar species E. minor and E. siliqua.

  10. MARMARONIA ANGIOLINII, NEW GENUS AND NEW SPECIES OF BAKEVELLIIDAE (PTERIOIDA, BIVALVIA FROM THE MIDDLE PERMIAN OF CHIOS (GREECE

    Directory of Open Access Journals (Sweden)

    CRISTIANO LARGHI

    2002-11-01

    Full Text Available The Guadalupian (Middle Permian "Gymnocodiacean Limestones" cropping out in the north-eastern part of the Greek island of Chios (eastern Aegean Sea are amongst the most fossiliferous in the western Tethys. They contain rich assemblages of corals, brachiopods, molluscs, calcareous algae, foraminifers and ostracods. Scant attention was given till now to mollusc faunas compared with brachiopods and foraminifers. In the present paper the new genus Marmaronia, with type-species M. angiolinii n. sp., is established to distinguish some bivalves of the Bakevelliidae King, 1850, from the middle Guadalupian successions of the Marmaro locality in Chios Island. M. angiolinii n. gen. n. sp. is strongly inequivalve, with valves differing in convexity, umbo development and ornamentation. The left valve shows a radial furrow running from the anterior part of the umbonal region anteroventrally and is ornamented by strong radial costae; the right valve is ornamented by concentric sculpture and by thin rugae in the first growth stages of the posterior part of the shell. Both valves have a wide posterior wing. Two hypotheses concerning the epi- or endobyssate adaptation of Marmaronia are also discussed briefly in the present paper.   

  11. Unexpected co-occurrence of six bacterial symbionts in the gills of the cold seep mussel Idas sp (Bivalvia : Mytilidae)

    OpenAIRE

    Duperron, Sebastien; Halary, S.; Lorion, J; Sibuet, Myriam; F. Gaill

    2008-01-01

    Bathymodioline mussels occur in chemosynthesis-based ecosystems such as cold seeps, hydrothermal vents and organic debris worldwide. Their key adaptation to these environments is their association with bacterial endosymbionts which ensure a chemosynthetic primary production based on the oxidation of reduced compounds such as methane and sulfide. We herein report a multiple symbiosis involving six distinct bacterial 16S rRNA phylotypes, including two belonging to groups not yet reported as sym...

  12. Unexpected co-occurrence of six bacterial symbionts in the gills of the cold seep mussel Idas sp. (Bivalvia: Mytilidae).

    Science.gov (United States)

    Duperron, Sébastien; Halary, Sébastien; Lorion, Julien; Sibuet, Myriam; Gaill, Françoise

    2008-02-01

    Bathymodioline mussels occur in chemosynthesis-based ecosystems such as cold seeps, hydrothermal vents and organic debris worldwide. Their key adaptation to these environments is their association with bacterial endosymbionts which ensure a chemosynthetic primary production based on the oxidation of reduced compounds such as methane and sulfide. We herein report a multiple symbiosis involving six distinct bacterial 16S rRNA phylotypes, including two belonging to groups not yet reported as symbionts in mytilids, in a small Idas mussel found on carbonate crusts in a cold seep area located north to the Nile deep-sea fan (Eastern Mediterranean). Symbionts co-occur within hosts bacteriocytes based on fluorescence in situ hybridizations, and sequencing of functional genes suggests they have the potential to perform autotrophy, and sulfide and methane oxidation. Previous studies indicated the presence of only one or two symbiont 16S rRNA phylotypes in bathymodioline mussels. Together with the recent discovery of four bacterial symbionts in the large seep species Bathymodiolus heckerae, this study shows that symbiont diversity has probably been underestimated, and questions whether the common ancestor of bathymodioline mussels was associated with multiple bacteria. PMID:18093159

  13. Reproductive Biology of Amblema neislerii, Elliptoideus sloatianus, Lampsilis subangulata, Medionidus penicillatus, and Pleurobema pyriforme (Bivalvia: Unionidae): final report

    OpenAIRE

    O'Brien, Christine

    1997-01-01

    A study on the reproductive biology of Amblema neislerii, Elliptoideus sloatianus, Lampsilis subangulata, Medionidus penicillatus, and Pleurobema pyriforme was conducted from May 1995 to May 1997. The objectives of this study were as follows: 1) determine period of gravidity for each of the five mussel species, 2) determine host fish via laboratory experiments, 3) test whether unionid glochidia will transform on a nonidingenous fish, and 4) describe the glochidial morp...

  14. Association entre Montacuta ferruginosa (Montagu, 1808) et Echinocardium cordatum (Pennant, 1777)

    OpenAIRE

    Delongueville, C.; Scaillet, R.

    2003-01-01

    Description of the different steps to collect alive the bivalvia Montacuta ferruginosa (Montagu, 1808) together with his preferential host, the burrowing sand urchin Echinocardium cordatum (Pennant, 1777).

  15. Functional morphology, biology and sexual strategy of the circumboreal, adventitious crypt-building, Crenella decussata (Bivalvia Mytiloidea: Crenellidae)

    DEFF Research Database (Denmark)

    Morton, Brian; Dinesen, Grete E.; Ockelmann, Kurt W.

    2016-01-01

    The anatomy of Crenella decussata (Mytiloidea) is described. Individuals of this circumboreal species occupy granular crypts composed of sand grains held in place by mucus. The swollen basal region of the tubule is occupied by an individual, which connects to the sediment surface by two posterior...... the prodissoconch stage. Subsequently, these larvae are transferred to the exhalant tube of the crypt wherein they attach by a single fine byssal thread and are further brooded until the crawl-away juvenile stage is attained. Experimental studies of larval behaviour suggest that parental pheromones...... sustain the female/offspring bond. Newly hatched individuals responded to parental exhalant water by actively attaching themselves using a byssal thread. This response persisted for 28 days, but not after 55 days when, we suggest, the pheromonal response ceases and offspring are developed sufficiently to...

  16. Thriving and declining: Population dynamics of the macha (Mesodesma donacium, Bivalvia, Mesodesmatidae) along a latitudinal gradient of the Humboldt Current Upwelling System

    OpenAIRE

    Riascos, Jose M.

    2009-01-01

    The mass mortality of the highly dominant and abundant bivalve Mesodesma donacium along Peruvian sandy beaches represents one of the most conspicuous cases of impacts of strong El Nimo events (EN) in nearshore ecosystems, causing considerable shifts in the whole community. More than 25 years after EN-related mass mortalities began, the northern geographic distribution of this commercially important clam is still confined to northern Chile, illustrating its low ability to regain the former dis...

  17. Bioaccumulation and elimination of 60 Co and 137 Cs by Anomalocardia brasiliana (Gmelin, 1791) (Mollusca bivalvia). Remobilization of 60 Co, retained in marine sediment by microbial activity

    International Nuclear Information System (INIS)

    It was studied the capacity of a bi valve mollusc Anomalocardia brasiliana, which lives in the local bottom sediment, to remobilize 60 Co previously sorbed in the sediment. Laboratory experiments demonstrated that the transference of 60 Co from the sediment to the animal was insignificant (bioaccumulation factor (BF) of the order of 10-3). At the same time, the capacity of microorganisms, present in the bottom sediment, to remobilize 60 Co was studied. The results showed that this via of transference was important, considering the much greater microorganism biomass in relation to the biomass of bentonic organisms, as a whole. For 137 Cs the determined BF from water to the animal was 2.2. and, as in the case of 60 Co, the soft tissues concentrated more 137 Cs than shell. Remaining viscera showed the highest BFs. In another series of experiments, the loss of 60 Co or 137 Cs, previously accumulated by A. brasiliana, was followed in aquaria with or without sediment and the respective biological half-lives were calculated. Soft tissues retained 60 Co longer (biological half-life = 117 days) than shells, whereas for 137 Cs the opposite was observed and shells showed a biological half life of 38.5 days. The low values of 60 Co and 137 Cs BFS do not allow to classify A. brasiliana as good biological indicator for pollution by there radionuclides. However since A brasiliana is consumed by the local population and is commercialized to other areas, it was recommended that its contamination by 60 Co or 137 Cs should be monitored. (author)

  18. Spinaxinus (Bivalvia: Thyasiroidea) from sulfide biogenerators in the Gulf of Mexico and hydrothermal vents in the Fiji Back Arc: Chemosymbiosis and Taxonomy

    OpenAIRE

    Oliver, Graham; Rodrigues, Clara Lúcia Ferreira; Carney, Robert; Duperron, Sebastien

    2013-01-01

    Two new species of the thyasirid genus Spinaxinus (S. emicatus Oliver n. sp. and S. phrixicus Oliver n. sp.) are described from the Gulf of Mexico and the southwest Pacific, respectively. Both are compared with the type species of the genus, the eastern Atlantic S. sentosus Oliver and Holmes, 2006. Living specimens from the Gulf of Mexico were retrieved from artificial sulfide bio-generators on the upper Louisiana Slope. Gill morphology and molecular markers from the symbiotic bacteria confir...

  19. Description and morphology of the “Juan de Fuca vent mussel”, Benthomodiolus erebus sp. n. (Bivalvia, Mytilidae, Bathymodiolinae: “Phylogenetically basal but morphologically advanced”

    Directory of Open Access Journals (Sweden)

    P. Graham Oliver

    2015-08-01

    Full Text Available The Juan de Fuca vent mussel first found in 1990 is formally described as Benthomodiolus erebus sp. n. Comparisons are made with the three other species previously assigned to Benthomodiolus namely B. lignocola, B. geikotsucola and B. abyssicola. The anatomies of all four species are examined and are shown to share the arrangement of pedal and byssus musculature, having largely un-fused mantle margins and a hind gut with a very short loop. The ctenidia were examined using both light and scanning electron microscopy. B. erebus and B. geikotsucola were found to have lamellar filaments with extensive abfrontal expansion and fusion of the ascending and descending arms. In this there is similarity with Bathymodiolus. B. lignocola and B. abyssicola were found to have linear filaments with narrow abfrontal surfaces with little fusion. All four species were shown to have the abfrontal surfaces covered by polygonal cushions of microvilli although these were much less apparent in B. lignocola and B. abyssicola. Although Benthomodiolus was shown by a number of previous studies, using molecular data alone, to be phylogenetically basal to all other Bathymodiolinae the anatomy is highly adapted for chemosymbiosis. Species of Benthomodiolus are found on wood-falls, whale-falls and vent sites and thus mirror the habits of the Bathymodiolus/Idas clade.

  20. Integrated Use of Biomarkers (O : N Ratio and Acetylcholinesterase Inhibition) on Aulacomya ater (Molina, 1782) (Bivalvia: Mytilidae) as a Criteria for Effects of Organophosphate Pesticide Exposition

    OpenAIRE

    Eduardo Führer; Anny Rudolph; Claudio Espinoza; Rodrigo Díaz; Marisol Gajardo; Nuria Camaño

    2012-01-01

    The effect of residual concentrations of organophosphate pesticide chlorpyrifos (Lorsban 4E) on the activity of the acetylcholinesterase enzyme and oxygen : nitrogen ratio in the mussel Aulacomya ater was analyzed. Toxicity tests show a sensitivity to the pesticide in the bivalve estimated at 16 μg L-1 (LC50-96 hours). Concentrations between 0.2 and 1.61 μg L-1 were able to inhibit significantly the AChE activity, and concentrations between 0.8 and 1.61 μg L-1 stimulate ammonia excretion and ...

  1. Integrated Use of Biomarkers (O : N Ratio and Acetylcholinesterase Inhibition) on Aulacomya ater (Molina, 1782) (Bivalvia: Mytilidae) as a Criteria for Effects of Organophosphate Pesticide Exposition.

    Science.gov (United States)

    Führer, Eduardo; Rudolph, Anny; Espinoza, Claudio; Díaz, Rodrigo; Gajardo, Marisol; Camaño, Nuria

    2012-01-01

    The effect of residual concentrations of organophosphate pesticide chlorpyrifos (Lorsban 4E) on the activity of the acetylcholinesterase enzyme and oxygen : nitrogen ratio in the mussel Aulacomya ater was analyzed. Toxicity tests show a sensitivity to the pesticide in the bivalve estimated at 16 μg L(-1) (LC(50-96 hours)). Concentrations between 0.2 and 1.61 μg L(-1) were able to inhibit significantly the AChE activity, and concentrations between 0.8 and 1.61 μg L(-1) stimulate ammonia excretion and decrease oxygen : ammonia-N (O : N) ratio, with respect to the control group. A. ater proved to be a species sensitive to pesticide exposure and easy to handle in lab conditions. Thus, it is recommended as a bioindicator for use in programs of environmental alertness in the Eastern South Pacific coastal zone. PMID:22619673

  2. Integrated Use of Biomarkers (O : N Ratio and Acetylcholinesterase Inhibition on Aulacomya ater (Molina, 1782 (Bivalvia: Mytilidae as a Criteria for Effects of Organophosphate Pesticide Exposition

    Directory of Open Access Journals (Sweden)

    Eduardo Führer

    2012-01-01

    Full Text Available The effect of residual concentrations of organophosphate pesticide chlorpyrifos (Lorsban 4E on the activity of the acetylcholinesterase enzyme and oxygen : nitrogen ratio in the mussel Aulacomya ater was analyzed. Toxicity tests show a sensitivity to the pesticide in the bivalve estimated at 16 μg L-1 (LC50-96 hours. Concentrations between 0.2 and 1.61 μg L-1 were able to inhibit significantly the AChE activity, and concentrations between 0.8 and 1.61 μg L-1 stimulate ammonia excretion and decrease oxygen : ammonia-N (O : N ratio, with respect to the control group. A. ater proved to be a species sensitive to pesticide exposure and easy to handle in lab conditions. Thus, it is recommended as a bioindicator for use in programs of environmental alertness in the Eastern South Pacific coastal zone.

  3. A holistic approach to taxonomic evaluation of two closely related endangered freshwater mussel species, the oyster mussel Epioblasma capsaeformis and tan riffleshell Epioblasma florentina walkeri (Bivalvia: Unionidae)

    Science.gov (United States)

    Jones, J.W.; Neves, R.J.; Ahlstedt, S.A.; Hallerman, E.M.

    2006-01-01

    Species in the genus Epioblasma have specialized life history requirements and represent the most endangered genus of freshwater mussels (Unionidae) in the world. A genetic characterization of extant populations of the oyster mussel E. capsaeformis and tan riffleshell E. florentina walkeri sensu late was conducted to assess taxonomic validity and to resolve conservation issues for recovery planning. These mussel species exhibit pronounced phenotypic variation, but were difficult to characterize phylogenetically using DNA sequences. Monophyletic lineages, congruent with phenotypic variation among species, were obtained only after extensive analysis of combined mitochondrial (1396 bp of 16S, cytochrome-b, and ND1) and nuclear (515 bp of ITS-1) DNA sequences. In contrast, analysis of variation at 10 hypervariable DNA microsatellite loci showed moderately to highly diverged populations based on FST and R ST values, which ranged from 0.12 to 0.39 and 0.15 to 0.71, respectively. Quantitative variation between species was observed in fish-host specificity, with transformation success of glochidia of E. capsaeformis significantly greater (P<0.05) on greenside darter Etheostoma blennioides, and that of E. f. walkeri significantly greater (P<0.05) on fantail darter Etheostoma flabellare. Lengths of glochidia differed significantly (P<0.001) among species and populations, with mean sizes ranging from 241 to 272 ??m. The texture and colour of the mantle-pad of E. capsaeformis sensu stricto is smooth and bluish-white, whereas that of E. f. walkeri is pustuled and brown, with tan mottling. Based on extensive molecular, morphological and life history data, the population of E. capsaeformis from the Duck River, Tennessee, USA is proposed as a separate species, and the population of E. f. walkeri from Indian Creek, upper Clinch River, Virginia, USA is proposed as a distinct subspecies.

  4. Benthic communities on hard substrates covered by Limnoperna fortunei Dunker (Bivalvia, Mytilidae at an estuarine beach (Río de la Plata, Argentina

    Directory of Open Access Journals (Sweden)

    Fernando G. Spaccesi

    2012-01-01

    Full Text Available The structure and composition of benthic communities on hard substrates covered by the nonindigenous bivalve Limnoperna fortunei Dunker, the golden mussel, were quantified in the middle zone of the Río de la Plata Estuary (Argentina from April 2001 through March 2002. A total of 26 taxa were recorded. L. fortunei and Nematoda were the central and dominant groups, with a prodigious abundance of over 80%. The prevalence of L. fortunei, rather than the environmental variables, regulated the dynamics of the associated invertebrate fauna. The golden mussel alters both the structure and function of benthic native communities on hard substrates, allows a higher surface available for colonization and refuge, and provides food source to deposit-feeding organisms in the form of organic or residual material. The mussel also increases the abundance and diversity of taxa on hard substrata - such as Oligochaeta, Hirudinea, Tardigrada, Chironomidae, Copepoda, Tanaidacea, and Hydrachnidia. Similarities and nonparametric multidimensional-scaling analyses indicated that the benthic composition had a seasonal variation. L. fortunei has an environmental impact, an ability to invade new freshwater ambiences worldwide and ecological characteristic comparable to those of Dreissena polymorpha Pallas (the zebra mussel of North America and Europe.

  5. Analysis of trace elements in the shells of short-necked clam Ruditapes philippinarum (Mollusca: Bivalvia) with respect to reconstruction of individual life history

    International Nuclear Information System (INIS)

    Strontium (Sr) concentration in the shells of short-necked clams collected at different locations (Shirahama, warm area and Maizuru, cold area, Japan) was analyzed by two methods, PIXE and EPMA. The Sr concentration of external surface of shell umbo, which was made during short term at early benthic phase, was analyzed by PIXE, and was ranged from 1000 to 3500 ppm for individuals. The Sr concentration of clams collected at Shirahama showed positive correlation with shell length (SL) in individuals with SL < 31 mm, whereas clams collected at Maizuru did not show significant correlation. This result may be caused from the difference of the spawning seasons between two areas. The Sr concentration of cross section of shell umbo, which develops thicker continuously during their life to form faint stratum structure, was analyzed by EPMA along the line across the stratum structure. Some surges and long term waving patterns of the Sr concentration were observed. These results suggest that the life histories of individual clams could be recorded in the shell umbo cross sections as variations of trace elements and analyses of trace elements could clarify the histories of individual clams. (author)

  6. Estado del conocimiento de la durofagia en el registro fósil: interacción depredador-presa en moluscos marinos (Clases Gastropoda y Bivalvia)

    OpenAIRE

    Catalina Gómez-Espinosa; Raúl Gío-Argáez; Miriam Carreño de la Vega

    2015-01-01

    La depredación como un mecanismo evolutivo, de diversificación y biomineralización es un tópico de gran interés. Un tipo específico de depredación es la durofagia que se define como el hábito alimenticio de los animales que consumen organismos con un esqueleto duro mineralizado, ya sea concha o exoesqueleto. Los moluscos representan una fuente muy importante para examinar la depredación durófaga en el registro fósil debido a su distribución mundial, abundancia, buena preservación y a que ...

  7. Review of the functional morphology, biology and perturbation impacts on the boreal, habitat-forming horse mussel Modiolus modiolus (Bivalvia: Mytilidae: Modiolinae)

    DEFF Research Database (Denmark)

    Dinesen, Grete E.; Morton, Brian

    2014-01-01

    by the byssal gland and foot complex and becomes covered in sand grains held in place by a mucoid cement secreted by the dorsal mantle. The camouflaged shell at this vulnerable time probably serves as an anti-predator device. Individuals grow to maximum shell lengths of ∼60–213 mm, depending on depth...

  8. Scorched mussels (Brachidontes spp., Bivalvia: Mytilidae) from the tropical and warm-temperate southwestern Atlantic: the role of the Amazon River in their speciation.

    Science.gov (United States)

    Trovant, Berenice; Basso, Néstor G; Orensanz, José María; Lessa, Enrique P; Dincao, Fernando; Ruzzante, Daniel E

    2016-03-01

    Antitropicality is a distribution pattern where closely related taxa are separated by an intertropical latitudinal gap. Two potential examples include Brachidontes darwinianus (south eastern Brazil to Uruguay), considered by some authors as a synonym of B. exustus (Gulf of Mexico and the Caribbean), and B. solisianus, distributed along the Brazilian coast with dubious records north of the intertropical zone. Using two nuclear (18S and 28S rDNA) and one mitochondrial gene (mtDNA COI), we aimed to elucidate the phylogeographic and phylogenetic relationships among the scorched mussels present in the warm-temperate region of the southwest Atlantic. We evaluated a divergence process mediated by the tropical zone over alternative phylogeographic hypotheses. Brachidontes solisianus was closely related to B. exustus I, a species with which it exhibits an antitropical distribution. Their divergence time was approximately 2.6 Ma, consistent with the intensification of Amazon River flow. Brachidontes darwinianus, an estuarine species is shown here not to be related to this B. exustus complex. We suspect ancestral forms may have dispersed from the Caribbean to the Atlantic coast via the Trans-Amazonian seaway (Miocene). The third species, B rodriguezii is presumed to have a long history in the region with related fossil forms going back to the Miocene. Although scorched mussels are very similar in appearance, their evolutionary histories are very different, involving major historical contingencies as the formation of the Amazon River, the Panama Isthmus, and the last marine transgression. PMID:26929816

  9. New threats of an old enemy: the distribution of the shipworm Teredo navalis L. (Bivalvia: Teredinidae) related to climate change in the Port of Rotterdam area, the Netherlands.

    Science.gov (United States)

    Paalvast, Peter; van der Velde, Gerard

    2011-08-01

    The effects of four climate change scenarios for the Netherlands on the distribution of the shipworm upstream of the Rhine-Meuse estuary are described. Global warming will cause dry and warmer summers and decreased river discharges. This will extend the salinity gradient upstream in summer and fall and may lead to attacks on wooden structures by the shipworm. Scenarios including one or two degree temperature increases by 2050 compared to 1990 with a weak change in the air circulation over Europe will lead to an increased chance of shipworm damage upstream from once in 36 years to once in 27 or 22 years, respectively; however, under a strong change in air circulation, the chance of shipworm damage increases to once in 6 or 3 years, respectively. The upstream expansion of the distribution of the shipworm will also be manifested in other northwest European estuaries and will be even stronger in southern Europe. PMID:21641620

  10. The complete maternally and paternally inherited mitochondrial genomes of the endangered freshwater mussel Solenaia carinatus (Bivalvia: Unionidae and implications for Unionidae taxonomy.

    Directory of Open Access Journals (Sweden)

    Xiao-Chen Huang

    Full Text Available Doubly uniparental inheritance (DUI is an exception to the typical maternal inheritance of mitochondrial (mt DNA in Metazoa, and found only in some bivalves. In species with DUI, there are two highly divergent gender-associated mt genomes: maternal (F and paternal (M, which transmit independently and show different tissue localization. Solenaia carinatus is an endangered freshwater mussel species exclusive to Poyang Lake basin, China. Anthropogenic events in the watershed greatly threaten the survival of this species. Nevertheless, the taxonomy of S. carinatus based on shell morphology is confusing, and the subfamilial placement of the genus Solenaia remains unclear. In order to clarify the taxonomic status and discuss the phylogenetic implications of family Unionidae, the entire F and M mt genomes of S. carinatus were sequenced and compared with the mt genomes of diverse freshwater mussel species. The complete F and M mt genomes of S. carinatus are 16716 bp and 17102 bp in size, respectively. The F and M mt genomes of S. carinatus diverge by about 40% in nucleotide sequence and 48% in amino acid sequence. Compared to F counterparts, the M genome shows a more compact structure. Different gene arrangements are found in these two gender-associated mt genomes. Among these, the F genome cox2-rrnS gene order is considered to be a genome-level synapomorphy for female lineage of the subfamily Gonideinae. From maternal and paternal mtDNA perspectives, the phylogenetic analyses of Unionoida indicate that S. carinatus belongs to Gonideinae. The F and M clades in freshwater mussels are reciprocal monophyly. The phylogenetic trees advocate the classification of sampled Unionidae species into four subfamilies: Gonideinae, Ambleminae, Anodontinae, and Unioninae, which is supported by the morphological characteristics of glochidia.

  11. Incongruence between mtDNA and nuclear data in the freshwater mussel genus Cyprogenia (Bivalvia: Unionidae) and its impact on species delineation.

    Science.gov (United States)

    Chong, Jer Pin; Harris, John L; Roe, Kevin J

    2016-04-01

    Accurately identifying species is a crucial step for developing conservation strategies for freshwater mussels, one of the most imperiled faunas in North America. This study uses genetic data to re-examine species delineation in the genus Cyprogenia. Historically, Cyprogenia found west of the Mississippi River have been ascribed to Cyprogenia aberti (Conrad 1850), and those east of the Mississippi River were classified as Cyprogenia stegaria (Rafinesque 1820). Previous studies using mitochondrial DNA sequences indicated that C. aberti and C. stegaria were not reciprocally monophyletic groups, suggesting the need for systematic revision. We generated a novel dataset consisting of 10 microsatellite loci and combined it with sequence data from the mitochondrial ND1 gene for 223 Cyprogenia specimens. Bayesian analysis of the ND1 nucleotide sequences identified two divergent clades that differ by 15.9%. Members of these two clades occur sympatrically across most sampling locations. In contrast, microsatellite genotypes support recognition of three allopatric clusters defined by major hydrologic basins. The divergent mitochondrial lineages are highly correlated with the color of the conglutinate lures used by mussels to attract and infest host fishes, and tests for selection at the ND1 locus were positive. We infer that the incongruence between mtDNA and microsatellite data in Cyprogenia may be the result of a combination of incomplete lineage sorting and balancing selection on lure color. Our results provide further evidence that mitochondrial markers are not always neutral with respect to selection, and highlight the potential problems of relying on a single-locus-marker for delineating species. PMID:27066233

  12. Mitochondrial phylogenomics of the Bivalvia (Mollusca: searching for the origin and mitogenomic correlates of doubly uniparental inheritance of mtDNA

    Directory of Open Access Journals (Sweden)

    Bogan Arthur E

    2010-02-01

    Full Text Available Abstract Background Doubly uniparental inheritance (DUI is an atypical system of animal mtDNA inheritance found only in some bivalves. Under DUI, maternally (F genome and paternally (M genome transmitted mtDNAs yield two distinct gender-associated mtDNA lineages. The oldest distinct M and F genomes are found in freshwater mussels (order Unionoida. Comparative analyses of unionoid mitochondrial genomes and a robust phylogenetic framework are necessary to elucidate the origin, function and molecular evolutionary consequences of DUI. Herein, F and M genomes from three unionoid species, Venustaconcha ellipsiformis, Pyganodon grandis and Quadrula quadrula have been sequenced. Comparative genomic analyses were carried out on these six genomes along with two F and one M unionoid genomes from GenBank (F and M genomes of Inversidens japanensis and F genome of Lampsilis ornata. Results Compared to their unionoid F counterparts, the M genomes contain some unique features including a novel localization of the trnH gene, an inversion of the atp8-trnD genes and a unique 3'coding extension of the cytochrome c oxidase subunit II gene. One or more of these unique M genome features could be causally associated with paternal transmission. Unionoid bivalves are characterized by extreme intraspecific sequence divergences between gender-associated mtDNAs with an average of 50% for V. ellipsiformis, 50% for I. japanensis, 51% for P. grandis and 52% for Q. quadrula (uncorrected amino acid p-distances. Phylogenetic analyses of 12 protein-coding genes from 29 bivalve and five outgroup mt genomes robustly indicate bivalve monophyly and the following branching order within the autolamellibranch bivalves: ((Pteriomorphia, Veneroida Unionoida. Conclusion The basal nature of the Unionoida within the autolamellibranch bivalves and the previously hypothesized single origin of DUI suggest that (1 DUI arose in the ancestral autolamellibranch bivalve lineage and was subsequently lost in multiple descendant lineages and (2 the mitochondrial genome characteristics observed in unionoid bivalves could more closely resemble the DUI ancestral condition. Descriptions and comparisons presented in this paper are fundamental to a more complete understanding regarding the origins and consequences of DUI.

  13. Biomonitoring of Pb and Cd in two impacted watersheds in Southeast Brazil, using the freshwater mussel Anodontites trapesialis (Lamarck, 1819 (Bivalvia : Mycetopodidae as a biological monitor

    Directory of Open Access Journals (Sweden)

    Andréa C. Tomazelli

    2003-12-01

    Full Text Available Studies were carried out to investigate the contamination of Piracicaba and Mogi-Guaçu River basins (São Paulo State, Southeastern, Brazil for heavy metals (Cd and Pb, using the limnic bivalve Anodontites trapesialis as a biological monitor. The results showed that the concentrations of Pb were higher than the control group in both basins, showing the bioavailability of this non-essential element in the basins. The concentrations were higher in the Mogi-Guaçu than in the Piracicaba basin, and in the slightly contaminated sites in both basins. There was no correlation between the degree of human impact and Cd and Pb concentrations, it was not possible to infer about concentrations of these heavy metals in the bivalves based only in a broad evaluation of human impact.O principal objetivo deste estudo foi investigar a contaminação pelos metais pesados Cd e Pb nas bacias dos rios Piracicaba e Mogi-Guaçu (Estado de São Paulo, Brasil, utilizando o bivalve limnico Anodontites trapesialis como indicador biológico. As bacias estudadas apresentam diferentes graus de impacto, sendo a qualidade da água geralmente melhor na bacia do rio Mogi-Guaçu. Os teores de Pb detectados nos bivalves não podem ser considerados críticos, contudo, houve acúmulo em relação ao grupo de controle em ambas as bacias, especialmente na bacia do rio Mogi-Guaçu. As maiores concentrações dos elementos, especialmente Pb, foram observadas nos locais menos poluídos e na bacia menos degradada. Este fato sugere que estas concentrações não estão sendo afetadas apenas pelas atividades antrópicas nas bacias, mas deve-se considerar também fatores que afetem a biodisponibilidade ou fontes específicas e não pontuais.

  14. The reproductive cycle of Eurhomalea exalbida (Chemnitz, 1795) (Bivalvia: Veneridae) in Ushuaia Bay (54°50′ S), Beagle Channel (Argentina)

    OpenAIRE

    Morriconi, E.; Lomovasky, B.; Calvo, J.; Brey, Thomas

    2002-01-01

    The reproductive cycle of Eurhomalea exalbida (Chemnitz, 1795) in Ushuaia Bay, Beagle Channel, was studied from October 1998 to December 1999. Clams were collected monthly by SCUBA diving at 3 to 5 m water depth. The degree of sexual maturity was determined histologically (n=318). The sex ratio was 1:1 (Chi-squared p > 0.05). First sexual maturity occurred at 39 mm shell heigth in males and 40 mm in females (i.e. 4 years of age).Five distinct histological stages of sexual maturity could be es...

  15. Tasa de degradación de madera por el perforador de manglar Psiloteredo healdi (Bivalvia:Teredinidae) en el Lago de Maracaibo, Venezuela

    OpenAIRE

    José E. Rojas; Héctor Severeyn

    2000-01-01

    Con el propósito de evaluar la capacidad de degradar madera de los moluscos bivalvos perforadores de madera en comunidades de manglar, se realizó un estudio en el manglar Ana María Campos, Lago de Maracaibo, Venezuela, utilizando como sustratos bloques de madera de pino. Dos especie de teredos, Bankia fimbriatula y Psiloteredo healdi fueron encontradas en el manglar de la península Ana María Campos, siendo P. healdi la especie dominante. A pesar de estar presente durante todo el período de es...

  16. Inter- and intra-specimen variability masks reliable temperature control on shell Mg/Ca ratios in laboratory- and field-cultured Mytilus edulis and Pecten maximus (bivalvia)

    Science.gov (United States)

    Freitas, P. S.; Clarke, L. J.; Kennedy, H. A.; Richardson, C. A.

    2008-09-01

    The Mg/Ca ratios of biogenic calcite is commonly seen as a valuable palaeo-proxy for reconstructing past ocean temperatures. The temperature dependence of Mg/Ca ratios in bivalve calcite has been the subject of contradictory observations. The palaeoceanographic use of a geochemical proxy is dependent on initial, rigorous calibration and validation of relationships between the proxy and the ambient environmental variable to be reconstructed. Shell Mg/Ca ratio data are reported for the calcite of two bivalve species, Mytilus edulis (common mussel) and Pecten maximus (king scallop), which were grown in laboratory culturing experiments at controlled and constant aquarium seawater temperatures over a range from ~10 to ~20°C. Furthermore, Mg/Ca ratio data of laboratory- and field-grown M. edulis specimens were compared. Only a weak, albeit significant, shell Mg/Ca ratio temperature relationship was observed in the two bivalve species: M. edulis (r2=0.37, p<0.001 for laboratory-cultured specimens and r2=0.50, p<0.001 for field-cultured specimens) and P. maximus (r2=0.21, p<0.001 for laboratory-cultured specimens only). In the two species, shell Mg/Ca ratios were not found to be controlled by shell growth rate or salinity. The Mg/Ca ratios in the shells exhibited a large degree of variability among and within species and individuals. The results suggest that the use of bivalve calcite Mg/Ca ratios as a temperature proxy is limited, at least in the species studied to date. Such limitations are most likely due to the presence of physiological effects on Mg incorporation in bivalve calcite. The utilization is further limited by the great variability both within and among shells of the same species that were precipitated under the same ambient conditions.

  17. Inter- and intra-specimen variability masks reliable temperature control on shell Mg/Ca ratios in laboratory and field cultured Mytilus edulis and Pecten maximus (bivalvia

    Directory of Open Access Journals (Sweden)

    H. A. Kennedy

    2008-02-01

    Full Text Available The Mg/Ca ratios of biogenic calcites are commonly seen as a valuable palaeo-proxy for reconstructing past ocean temperatures. The temperature dependence of Mg/Ca ratios in bivalve calcite has been the subject of contradictory observations. The palaeoceanographic use of a geochemical proxy, like Mg/Ca ratios, is dependent on initial, rigorous calibration and validation of relationships between the proxy and the ambient environmental variable to be reconstructed. Shell Mg/Ca ratio data are reported for the calcite of two bivalve species, Mytilus edulis (common mussel and Pecten maximus (king scallop, for the first time grown in laboratory culturing experiments at controlled and constant aquarium seawater temperatures over a range from ~10 to ~20°C. Furthermore, Mg/Ca ratio data of laboratory-grown and field-grown M. edulis specimens were compared. Only a weak, albeit significant, shell Mg/Ca ratio–temperature relationship was observed in the two bivalve species: M. edulis (r2=0.37, pr2=0.50, pP. maximus (r2=0.21, p<0.001, laboratory cultured specimens only. In the two species, shell Mg/Ca ratios also were not found to be controlled by shell growth rate and salinity. Furthermore, measurement of Mg/Ca ratios in the shells of multiple specimens illustrated that a large degree of variability in the measured shell Mg/Ca ratios was significant at the species, inter- and intra-individual shell levels. The study data suggest the use of bivalve calcite Mg/Ca ratios as a reliable, precise and accurate temperature proxy still remains limited, at least in the species studied to date. Such limitations are most likely due to the presence of significant physiological effects on Mg incorporation in bivalve calcite, with such variability differing both within single shells and between shells of the same species that were precipitated under the same ambient conditions.

  18. Inter- and intra-specimen variability masks reliable temperature control on shell Mg/Ca ratios in laboratory- and field-cultured Mytilus edulis and Pecten maximus (bivalvia

    Directory of Open Access Journals (Sweden)

    H. A. Kennedy

    2008-09-01

    Full Text Available The Mg/Ca ratios of biogenic calcite is commonly seen as a valuable palaeo-proxy for reconstructing past ocean temperatures. The temperature dependence of Mg/Ca ratios in bivalve calcite has been the subject of contradictory observations. The palaeoceanographic use of a geochemical proxy is dependent on initial, rigorous calibration and validation of relationships between the proxy and the ambient environmental variable to be reconstructed. Shell Mg/Ca ratio data are reported for the calcite of two bivalve species, Mytilus edulis (common mussel and Pecten maximus (king scallop, which were grown in laboratory culturing experiments at controlled and constant aquarium seawater temperatures over a range from ~10 to ~20°C. Furthermore, Mg/Ca ratio data of laboratory- and field-grown M. edulis specimens were compared. Only a weak, albeit significant, shell Mg/Ca ratio–temperature relationship was observed in the two bivalve species: M. edulis (r2=0.37, p0.001 for laboratory-cultured specimens and r2=0.50, p0.001 for field-cultured specimens and P. maximus (r2=0.21, p0.001 for laboratory-cultured specimens only. In the two species, shell Mg/Ca ratios were not found to be controlled by shell growth rate or salinity. The Mg/Ca ratios in the shells exhibited a large degree of variability among and within species and individuals. The results suggest that the use of bivalve calcite Mg/Ca ratios as a temperature proxy is limited, at least in the species studied to date. Such limitations are most likely due to the presence of physiological effects on Mg incorporation in bivalve calcite. The utilization is further limited by the great variability both within and among shells of the same species that were precipitated under the same ambient conditions.

  19. Distribución, abundancia y aspectos biológicos de la almeja Polymesoda solida Phillippi, 1846 (Bivalvia: Corbiculidae en la Isla De Salamanca, Caribe Colombiano

    Directory of Open Access Journals (Sweden)

    Blanco Jacobo

    2006-06-01

    Full Text Available Con el propósito de evaluar el estado actual de la almeja estuarina Polymesoda solida como recurso ecológico y
    pesquero, se estudiaron diversos aspectos de la población en el sector occidental de la isla de Salamanca, en el Caribe colombiano. El muestreo se llevó a cabo mensualmente en cuatro ciénagas interconectadas de este Parque Natural, tres de ellas sometidas a explotación, entre abril y noviembre de 2004. Se estimó la densidad por metro cuadrado y se efectuaron mediciones de largo, alto y espesor de las conchas para obtener las distribuciones de tallas y relaciones morfométricas. Para conocer la condición física de los animales se estimaron índices de condición con base en los pesos de concha y partes blandas y se calculó el porcentaje de materia
    orgánica en los tejidos blandos. El estado reproductivo se determinó a partir de observaciones en fresco del material gonadal. Se llevaron a cabo análisis de correlación y de regresión múltiple para conocer el grado de influencia de diversas variables ambientales sobre aspectos biológicos de la almeja. Las condiciones ambientales en las ciénagas variaron en función de la distancia al río Magdalena y al mar, mostrando para ciertas variables un patrón marcadamente estacional, obedeciendo a las épocas climáticas. Se destacaron las diferencias en las características de P. solida entre sitios de muestreo, presentándose rangos de tallas, densidades, índices de condición y tipo de sustrato muy característico para cada ciénaga. La densidad varió inversamente con la talla, las longitudes de los ejemplares oscilaron entre 9,8 mm y 50 mm, predominando el rango de 25-30 mm. Se encontraron
    reclutas (<5mm ocasionalmente en orillas arenosas de algunos sectores. Las fluctuaciones en el índice de condición de los individuos se asociaron a los cambios en el estado fisiológico a lo largo del tiempo, muy dependientes del estado reproductivo. También se observaron diferencias entre ciénagas, señalándose la importancia de la salinidad, pH y transparencia del agua en las características biológicas de la población y por lo tanto se corroboró la importancia del régimen hídrico en su regulación. La mejor condición física de P. solida estuvo directamente relacionada con la menor salinidad a nivel espacial y temporal. Esto permitió establecer que la almeja en la zona de estudio posiblemente se adapta mejor a salinidades muy bajas en relación con lo encontrado
    en otros lugares del mundo. La gran variabilidad en las distribuciones de tallas y en la densidad de individuos
    se asoció a la heterogeneidad de un sistema estuarino altamente cambiante y a la explotación pesquera, debido
    al método de pesca selectivo, ocasionando discontinuidades en las distribuciones de tallas a nivel temporal y escasez de tallas muy pequeñas o muy grandes. Las diferencias espaciales en la relación talla-peso y en las relaciones morfométricas, así como la segregación de tallas y el reclutamiento en áreas diferentes a las de los adultos, sugieren que la población de P. solida se distribuye de acuerdo con criterios de modelos metapoblacionales y se resalta que su manejo como recurso, debe plantearse de acuerdo a tales criterios, pues de acuerdo con la información pesquera, la especie presenta varias señales de sobreexplotación.

  20. Megafauna recovered from a cold hydrocarbon seep in the deep Alaskan Beaufort Sea, including a new species of Axinus (Thracidae: Bivalvia: Mollusca)

    Science.gov (United States)

    Powell, C. L.; Valentich-Scott, P.; Lorenson, T. D.; Edwards, B. D.

    2011-12-01

    Several specimens of a new species of Axinus and a single well-worn gastropod columella provisionally assigned to the genus Neptunea (Buccinidae: Gastropoda: Mollusca) were recently recovered from at least two cores, the longest of which is 5.72 m long, from a large seafloor mound, informally named the Canning Seafloor Mound (CSM). The CSM is located at 2,530 m water depth on the Alaskan Beaufort Sea slope north of Camden Bay and is a fluid explosion feature containing methane hydrate and methane-saturated sediments overlying a folded and faulted deep basin. Only two modern species of Axinus are currently known. Axinus grandis (Verrill & Smith, 1885) is a northern Atlantic species and the recently described species, A. cascadiensis Oliver and Holmes (2007), is only known from Baby Bare Seamount, Cascadia Basin, northeastern Pacific Ocean. Common fragments, single valves, and a single articulated specimen represent this new Axinus species. These shells were distributed over nearly the entire length of the primary core. All specimens show wear and (or) dissolution. The age of these specimens is unknown and no living representatives were encountered. The genus Axinus has a fossil record back to the early Eocene in England and the Paleocene and Eocene in Egypt. Biogeographically the genus appears to have originated in the Tethys Sea and became established in the Atlantic Ocean during the Eocene, spreading across the Arctic Ocean in the late Tertiary. With the opening of the Bering Strait in the latest Miocene or early Pliocene the genus Axinus migrated southwest into the northeast Pacific. Interestingly, hydrocarbon seep deposits are also present on the adjacent North Slope of Alaska in the Marsh Anticline at Carter Creek, Camden Bay. These rocks, the Nuwok beds, contain abundant Thracidae bivalve of the genus Thracia, but not Axinus, however the rocks also represent cold seep deposits. These rocks have been variously dated from Oligocene to Pliocene and the exact age remains uncertain. Neptunea are a predatory snails well represented in the earliest Miocene to Holocene of the northern Pacific Ocean and in the late Pliocene to Holocene of the northern Atlantic. The presence of Neptunea at CSM, if identified properly, gives a maximum age for these deposits of latest Miocene or early Pliocene, after the opening of the Bering Strait, although they could be as young as Holocene.

  1. Large Vesicomyidae (Mollusca: Bivalvia) from cold seeps in the Gulf of Guinea off the coasts of Gabon, Congo and northern Angola

    Science.gov (United States)

    von Cosel, Rudo; Olu, Karine

    2009-12-01

    Two new genera and three new species of large Vesicomyidae are described from cold-seep sites on pockmarks and other sulfide-rich environments in the Gulf of Guinea (tropical east Atlantic) off Gabon, Congo (Brazzaville) and northern Angola, from 500 to 4000 m depth: " Calyptogena" (s.l.) regab n. sp., Wareniconcha (n.g.) guineensis (Thiele and Jaeckel 1931), Elenaconcha guiness n.g. n. sp., and Isorropodon atalantae n. sp. For two other species already taken by the R/V Valdivia in 1898, Calyptogena valdiviae (Thiele and Jaeckel 1931) and Isorropodon striatum (Thiele and Jaeckel 1931) new localities were discovered, and the species are rediscussed. E. guiness n.g. n.sp. is also recorded from off Banc d'Arguin, Mauritania, collected by commercial fishing vessels. The vesicomyid species here treated were encountered in different depth ranges along the Gabon-Congo-Angola margin, between 500 and 4000 m depth, and it was found that, in comparison with the dredge samples taken by the Valdivia expedition off southern Cameroon and off Rio de Oro (both at 2500 m), the same species occur in other depth ranges, in some cases with a vertical difference of more than 1000 m. .That means that the species are not confined to a given depth thought being typical for them and that the characteristics of the biotope are likely to play a major role in the distribution of the vesicomyids associated to cold seeps or other reduced environments along the West African margin.

  2. Threatened freshwater and terrestrial molluscs (Mollusca, Gastropoda et Bivalvia of Santa Catarina State, Southern Brazil: check list and evaluation of regional threats

    Directory of Open Access Journals (Sweden)

    2011-06-01

    Full Text Available A total of nineteen continental native mollusc species are confirmed for the Santa Catarina State (SC(organized in ten Genera and seven Families, one aquatic Prosobranchia/Caenogastropoda (Ampullariidae,six Pulmonata terrestrial gastropods (one Ellobiidae, three Megalobulimidae and two micro-snails –Charopidae and Streptaxidae and twelve freshwater mussels (eight Mycetopodidae and four Hyriidae. Thesespecies are designated by the International Union for Conservation of the Nature – IUCN as follows: seven as"Vulnerable", six "In Danger" and six “Without Category Established”. The general regional threats that thesespecies are subjected to are briefly analyzed.

  3. Genetic relationships among freshwater mussel species from fifteen Amazonian rivers and inferences on the evolution of the Hyriidae (Mollusca: Bivalvia: Unionida).

    Science.gov (United States)

    Santos-Neto, Guilherme da Cruz; Beasley, Colin Robert; Schneider, Horacio; Pimpão, Daniel Mansur; Hoeh, Walter Randolph; Simone, Luiz Ricardo Lopes de; Tagliaro, Claudia Helena

    2016-07-01

    The current phylogenetic framework for the South American Hyriidae is solely based on morphological data. However, freshwater bivalve morphology is highly variable due to both genetic and environmental factors. The present study used both mitochondrial (COI and 16S) and nuclear (18S-ITS1) sequences in molecular phylogenetic analyses of nine Neotropical species of Hyriidae, collected from 15 South American rivers, and sequences of hyriids from Australia and New Zealand obtained from GenBank. The present molecular findings support traditional taxonomic proposals, based on morphology, for the South American subfamily Hyriinae, currently divided in three tribes: Hyriini, Castaliini and Rhipidodontini. Phylogenetic trees based on COI nucleotide sequences revealed at least four geographical groups of Castalia ambigua: northeast Amazon (Piriá, Tocantins and Caeté rivers), central Amazon, including C. quadrata (Amazon and Aripuanã rivers), north (Trombetas river), and C. ambigua from Peru. Genetic distances suggest that some specimens may be cryptic species. Among the Hyriini, a total evidence data set generated phylogenetic trees indicating that Paxyodon syrmatophorus and Prisodon obliquus are more closely related, followed by Triplodon corrugatus. The molecular clock, based on COI, agreed with the fossil record of Neotropical hyriids. The ancestor of both Australasian and Neotropical Hyriidae is estimated to have lived around 225million years ago. PMID:27071805

  4. Passive biomonitoring study and effect biomarker in oysters Crassostrea brasiliana (Lamark, 1819. Mollusca, Bivalvia) in Santos and Cananeia Estuaries in Sao Paulo State, Brazil

    International Nuclear Information System (INIS)

    This study assessed the exposure and effects of trace elements in sentinel organisms, using the bivalve Crassostrea brasiliana in two estuarine areas in Sao Paulo State, Brazil: Santos Estuary and Cananeia Estuary, site of oyster farms, which was used as reference site. Oysters were evaluated for bioaccumulation of As, Co, Cr, Fe, Se and Zn by INAA and Cd, Pb and Hg by AAS. Effect biomarker was assessed by evaluation of lysosomal membrane stability. In the study of bioaccumulation of trace elements it was verified that Santos Channel presented the largest concentrations of elements studied in most cases. From the study of the cellular biomarker, it was verified that Santos Channel and winter showed higher stress to organisms in the present study. (author)

  5. Vanadium determination in Perna perna mussels (Linnaeus, 1758: Mollusca, Bivalvia) by instrumental neutron activation analysis using the passive biomonitoring in the Santos coast, Brazil

    International Nuclear Information System (INIS)

    Vanadium determination present in seawater is of great importance to evaluate marine contamination from industrial sources as well as to identify health hazards since mussels and other marine organisms are used as food. Besides, this evaluation in the Santos coast, SP, Brazil, is important, since this area is impacted by industrial and urban activities and discharges from ships and boats. In a previous study, V results obtained for transplanted mussel (active biomonitoring) were presented. This study aimed the V determination by passive biomonitoring by analyzing Perna perna mussels collected in natural environment, from three sites in Sao Paulo State coast: Cocanha Beach (reference site), Ponta de Itaipu and Palmas Island. Ninety individuals of mussels were collected in each site between September/08 and July/09 during the four seasons of the year. After shell removal and sample preparation, V was determined by instrumental neutron activation analysis. For analytical quality control, the NIST Standard Reference Material SRM 1566b Oyster Tissue was analyzed and the results presented good accuracy. The V concentrations in mussels on dry mass basis varied from 0.77 ± 0.02 to 3.56 ± 0.88 mg kg-1. Statistical tests were applied to the results showing differences on V concentrations among the sampling sites and season of sample collection. (author)

  6. First European record of the invasive brackish water clam Rangia cuneata (G.B. Sowerby I, 1831) (Mollusca: Bivalvia)

    OpenAIRE

    Verween, A; Kerckhof, F; Vincx, M.; Degraer, S.

    2006-01-01

    A population of Rangia cuneata (G.B. Sowerby I, 1831), an estuarine bivalve, has been recorded in the harbour of Antwerp, Belgium. This species is new to the European brackish water fauna. After initially finding only a few small individuals in August 2005, R. cuneata was encountered frequently in the pipes of the cooling water system of an industrial plant from February 2006 onwards. Before this present record, R. cuneata was only known from the Gulf of Mexico and the Atlantic coast of North...

  7. Evaluation of the levels of Br, Cl, K, Mg, Mn and V in Perna perna Mussels (Linnaeus, 1758: Mollusca, Bivalvia) collected in coast of Sao Paulo, Brazil

    International Nuclear Information System (INIS)

    In this study the content of Br, Cl, K, Mg, Mn and V was evaluated in samples of Perna perna mussels collected in coastal regions of Sao Paulo (Ponta de Itaipu and Palmas Island, in Santos) subjected to anthropogenic contamination, to compare these values with those of mussels from reference site of Cocanha Beach (in Caraguatatuba). The mussels were collected seasonally from September 2008 to July 2009. They were cleaned, ground, homogenized, lyophilized and then analyzed by Instrumental Neutron Activation Analysis (INAA). The INAA procedure consisted in the irradiation of the samples and synthetic elemental standards for 8 and 10 s, under a thermal neutron flux of 6.6 x 1012 n cm-2 s-1 in the IEA-R1 nuclear research reactor. For quality control of analytical results, certified reference materials NIST 1566b Oyster Tissue and NIST 2876 Mussel Tissue were analyzed and their results indicated good accuracy. The ranges of concentrations (dry basis) of the elements obtained in mussels collected for the four seasons of the year were: 173.80 to 358.99 mg kg-1 for Br; 45658 ± 1811 to 109166 ± 824 mg kg-1 for Cl; 7043 ± 856 to 12506 ± 675 mg kg-1 for K; 2774 ± 211 to 5691 ± 717 mg kg-1 for Mg; 7.01 ± 0.30 to 29.74 ± 3.32 mg kg-1 for Mn and 0.77 ± 0.02 to 3.43 ± 0.28 mg kg-1 for V. The seasonal and spatial variations of these element concentrations were in this study. (author)

  8. Evaluation of the levels of Br, Cl, K, Mg, Mn and V in Perna perna Mussels (Linnaeus, 1758: Mollusca, Bivalvia) collected in coast of Sao Paulo, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Daniele; Vasconcellos, Marina B.A.; Saiki, Mitiki; Catharino, Marilia G.M.; Moreira, Edson G., E-mail: danyseo@uol.com.br, E-mail: mbvascon@ipen.br, E-mail: mitiko@ipen.br, E-mail: mgcatharino@uol.com.br, E-mail: emoreira@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Sousa, Eduinetty C.P.M. de, E-mail: edvinett@usp.br [Universidade de Sao Paulo (IO/USP), Sao Paulo, SP (Brazil). Instituto Oceanografico. Laboratorio de Ecotoxicologia Marinha e Microfitobentos

    2013-07-01

    In this study the content of Br, Cl, K, Mg, Mn and V was evaluated in samples of Perna perna mussels collected in coastal regions of Sao Paulo (Ponta de Itaipu and Palmas Island, in Santos) subjected to anthropogenic contamination, to compare these values with those of mussels from reference site of Cocanha Beach (in Caraguatatuba). The mussels were collected seasonally from September 2008 to July 2009. They were cleaned, ground, homogenized, lyophilized and then analyzed by Instrumental Neutron Activation Analysis (INAA). The INAA procedure consisted in the irradiation of the samples and synthetic elemental standards for 8 and 10 s, under a thermal neutron flux of 6.6 x 10{sup 12} n cm{sup -2} s{sup -1} in the IEA-R1 nuclear research reactor. For quality control of analytical results, certified reference materials NIST 1566b Oyster Tissue and NIST 2876 Mussel Tissue were analyzed and their results indicated good accuracy. The ranges of concentrations (dry basis) of the elements obtained in mussels collected for the four seasons of the year were: 173.80 to 358.99 mg kg{sup -1} for Br; 45658 ± 1811 to 109166 ± 824 mg kg{sup -1} for Cl; 7043 ± 856 to 12506 ± 675 mg kg{sup -1} for K; 2774 ± 211 to 5691 ± 717 mg kg{sup -1} for Mg; 7.01 ± 0.30 to 29.74 ± 3.32 mg kg{sup -1} for Mn and 0.77 ± 0.02 to 3.43 ± 0.28 mg kg{sup -1} for V. The seasonal and spatial variations of these element concentrations were in this study. (author)

  9. Taxonomy, distribution and population structure of invasive Corbiculidae (Mollusca, Bivalvia in the Suquía River basin, Córdoba, Argentina

    Directory of Open Access Journals (Sweden)

    Paola B. Reyna

    2013-06-01

    Full Text Available Invasive species are one of the most significant causes of biodiversity loss and changes in ecosystem services, which underlines the importance of their detection and their study. The Asian clams (Corbiculidae are invasive organisms that accidentally entered the La Plata River, Argentina, presumably in the 1960s. The objectives of the present study were to identify the corbiculid species and to determine their distribution at several locations along the Suquía River basin, an extended area in central Argentina. In addition, population structure was evaluated monthly during one year, at a site in the city of Córdoba that is characterized by high human influence. The presence of Corbicula fluminea (Müller, 1774 and Corbicula largillierti (Philippi, 1844 in the Suquía River basin is reported for the first time. The former species was found only in a lentic environment (San Roque reservoir, while the latter was also found along the tributary rivers and brooks of the basin. Corbicula largillierti showed variations in average density between the different sites and also in biomass and size classes throughout the study period at the site at Córdoba city. The relative composition of the sediments, flow fluctuation and human pollution may be responsible for the observed differences.

  10. Intra-specific variability in life-history traits of Anadara tuberculosa (Mollusca: Bivalvia) in the mangrove ecosystem of the Southern coast of Ecuador.

    Science.gov (United States)

    Flores, Luis; Licandeo, Roberto; Cubillos, Luis A; Mora, Elba

    2014-06-01

    Anadara tuberculosa is one of the most important bivalves along the Western Pacific coast because of its commercial value. Nevertheless, the variability in growth, long-life span, natural mortality and reproductive parameters of this mangrove cockle has not yet been described. The aim of this study was to analyze these life-history traits in three areas of the Southern coast of Ecuador. Empirical and length-based methods were used to estimate these biological parameters. Body size data were collected from the commercial fishery between 2004 and 2011 in landing ports near to the Archipelago of Jambeli [Puerto Bolivar (PB), Puerto Jeli (PJ) and Puerto Hualtaco (PH)]. The von Bertalanffy growth parameters for combined sex were estimated between 70.87 to 93.45mm for L(infinity) and 0.22 to 0.80/year for k. The growth indices (PHI') ranged from 3.17 to 3.85, while the overall growth performance (OGP) ranged from 5.03 to 5.82. The mean of long-life span (t(max)), size and age at maturity (L50% and t50%) were estimated in 7.71 +/- 2.53 years, 39.13 +/- 2.24mm and 1.46 +/- 0.56 years for PB; 9.51 +/- 2.85 years, 37.78 +/- 1.95mm and 1.37 +/- 0.41 years for PJ and 5.81 +/- 2.11 years, 39.73 +/- 3.31mm and 0.94 +/- 0.41 years for PH. Natural mortality (M) ranged from 0.46 to 1.28/year. We concluded that significant intra-specific variation was observed in a temporal scale in PHI' and OGP indices as well as L50% and M. Therefore, temporal changes in these life-history traits should be taken into account when assessing the status of the mangrove cockle fishery. PMID:25102632

  11. Evaluation of magnesium and manganese in Perna perna mussels (Linnaeus, 1758: mollusca, bivalvia) collected in the cost of the state of Sao Paulo, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Daniele; Vasconcellos, Marina B.A.; Saiki, Mitiko; Cathartino, Marilia G.M.; Moreira, Edson G., E-mail: mbvascon@ipen.b, E-mail: mitiko@ipen.b, E-mail: emoreira@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Sousa, Eduinetty C.P.M. de, E-mail: edvinett@usp.b [Universidade de Sao Paulo (IO/USP), SP (Brazil). Inst. Oceanografico. Lab. de Ecotoxicologia Marinha e Microfitobentos

    2011-07-01

    The objective of the present study was to evaluate magnesium and manganese concentrations in Perna perna mussels by applying instrumental neutron activation analysis (INAA). The mussels were collected seasonally from September 2008 to July 2009 at Cocanha Beach in the city of Caraguatatuba (clean region), and at two sites in Santos Bay (Ponta de Itaipu and Palmas Island). The mussel samples were cleaned, grinded, homogenized, lyophilized and then analyzed by INAA. The INAA procedure consisted in the irradiation of the samples and synthetic elemental standards for 10 s, under a thermal neutron flux of 6.6 x 10{sup 12} n cm{sup -2} s{sup -1} in the nuclear research reactor of IPEN-CNEN/SP. The measurements of the gamma radioactivity of the samples and standards were carried out using a hyperpure semiconductor Ge detector, coupled to Digital Spectral Analyzer. The elemental concentrations were calculated by the comparative method. For quality control of analytical results, certified reference materials NIST SRM 1566b oyster tissue and NRC DORM-2 Dogfish Muscle were analyzed and their results indicated good accuracy. The element concentrations in mussels on dry mass basis varied from 2734 {+-} 205 to 5138 {+-} 507 mg kg{sup -1} for Mg and from 7.35{+-}0.57 to 29.06{+-}3.35 mg kg{sup -1} for Mn. The results obtained in mussel analysis indicated that the samples collected in Itaipu in the winter season presented higher accumulation of Mg than the other sites. For Mn, the highest concentrations were obtained for the mussels collected in Palmas in summer time. (author)

  12. Filter-feeding, food utilization, and nutrient remineralization by Corbicula fluminea (bivalvia) and its contribution to nutrient cycling in a North Carolina River

    International Nuclear Information System (INIS)

    The introduced Asiatic clam Corbicula fluminea is quite prolific, and since it is a filter-feeder, it can be expected to influence the cycling of nutrients within its habitat as a result of its feeding and excretory activities. Factors affecting filtration rates, food utilization, and excretion of metabolic wastes (ammonia and phosphate) were determined by laboratory experiments, and these physiological processes were then extrapolated to field estimates of Corbicula found in the upper Chowan River, N.C., to obtain an estimate of the potential impact the clams can have on nutrient cycling in the river. Clam filtration rates of four different 14C-labeled algae species (two greens, a blue-green, and a diatom) were similar, although partitioning of the ingested isotope showed significant differences between the algal foods. The diatom species was the most efficiently utilized by the clams, with more than 80% of the isotope ingested recovered in clam tissues. Corbicula freshly collected from the Chowan River excreted substantially more ammonia than phosphate, and rates of excretion of both nutrients were highest in summer. Clam excretion rates were much higher than sediment fluxes, and as a source of recycled nutrients, these clams could provide about one third of the nitrogen and phosphate requirements of the phytoplankton in the upper Chowan

  13. Preliminary assessment of heavy metal levels in Mytella falcata (Bivalvia, Mytilidae) from Bacanga River estuary, São Luis, State of Maranhão, Northeastern Brazil

    OpenAIRE

    CARVALHO G. P. de; CAVALCANTE P. R. S.; CASTRO A. C. L. de; ROJAS M. O. A. I.

    2000-01-01

    The concentrations of Cu, Zn, Pb, and Cd were determined in the mussel Mytella falcata from the Bacanga River estuary, in order to evaluate the potential role of domestic effluents released "in natura" on the quality of the estuarine environment with consequences to shellfish resources. Cu concentrations ranged from 5.2 mg.g-1 to 13.1 mg.g-1, while Zn concentrations ranged from 49.1 mg.g-1 to 76.3 mg.g-1. Pb and Cd showed concentrations lower than 2 mg.g-1. The results showed low concentratio...

  14. Characterization of nine microsatellite markers and development of multiplex PCRs for the Chinese huge musel Anodonta (Sinanodonta) woodiana Lea, 1834 (Mollusca, Bivalvia)

    Czech Academy of Sciences Publication Activity Database

    Popa, O. P.; Bartáková, Veronika; Bryja, Josef; Reichard, Martin; Popa, L. O.

    2015-01-01

    Roč. 60, June (2015), s. 234-237. ISSN 0305-1978 R&D Projects: GA ČR GA13-05872S Institutional support: RVO:68081766 Keywords : Invasive species * SSRs * Population genetics * Unionidae Subject RIV: EG - Zoology Impact factor: 0.967, year: 2014

  15. Descripción del desarrollo gonadal de Mesodesma Donacium (bivalvia: Mesodesmatidae), durante el periodo 2006 - 2014, en el litoral de Tacna

    OpenAIRE

    Gálvez Escudero, Marie Anne

    2015-01-01

    Mesodesma donacium (Lamarck, 1818), ha disminuido su abundancia durante los últimos 30 años, debido a los eventos El Niño más recientes y a la sostenida extracción sin medidas de control, lo que generado repercusiones sobre los grupos de pescadores que se dedicaban únicamente a la extracción de este recurso. Para lograr una recuperación y administración sostenible de este recurso, se requiere actualizar conocimientos biológicos básicos en temas reproductivos como el desarrollo gonadal y su va...

  16. Distribución del género Diplodon (Mollusca: Bivalvia: Hyriidae en territorio Argentino mediante el uso de Colecciones Biológicas

    Directory of Open Access Journals (Sweden)

    Santiago Hernán Torres

    2013-10-01

    Full Text Available Los bivalvos nacaríferos dulciacuícolas (“náyades”, son especies infaunales, endémicas de la RegiónNeotropical, pertenecientes a las familias Hyriidae (Swaison, 1840 y Etheriidae (Swaison, 1840. La alteración del ambiente y la competencia con especies invasoras como Corbicula fluminea (Müller, 1774 y Limnoperna fortunei (Dunker, 1857, impactan sobre las poblaciones naturales. En esta comunicación, se presenta el inicio de un Proyecto de investigación sobre la distribución geográfica de las especies del género Diplodon en la Argentina. Estas especies son un componente importante de la infauna de los cuerpos lóticos y lénticos, viviendo en fondos limosos, limo-arenosos, excepcionalmente en sustratos duros, con un régimen nutricio filtrador, teniendo un papel importante como recicladores de materia orgánica. Conocer la distribución de los bivalvos pertenecientes al género Diplodon en el territorio Argentino permitirá el reconocimiento de potenciales áreas prioritarias para su conservación. Sobre la base de la bibliografía disponible y los ejemplares de las especies del genero Diplodon depositados en la Colección Malacológica del Museo de La Plata (FCNyM-UNLP, se confeccionó una matriz de datos que incluye la identificación del ejemplar, la colección en que se encuentra depositado, el número de catálogo, la localidad y la fecha de colecta. Cada localidad fue ubicada mediante el uso de cartas geográficas de Argentina y revisiones bibliográficas en imágenes satelitales de GoogleEarth, asignando las coordenadas para cada punto. Como resultado del trabajo se obtiene la distribución de estas especies nativas y se discute el grado de solapamiento con las dos especies de bivalvos invasores y el impacto de actividades humanas. 

  17. Distribución, abundancia y aspectos biológicos de la almeja Polymesoda solida Phillippi, 1846 (Bivalvia: Corbiculidae) en la Isla De Salamanca, Caribe Colombiano

    OpenAIRE

    Blanco Jacobo; Hoz María Virginia de la; Campos Néstor

    2006-01-01

    Con el propósito de evaluar el estado actual de la almeja estuarina Polymesoda solida como recurso ecológico y
    pesquero, se estudiaron diversos aspectos de la población en el sector occidental de la isla de Salamanca, en el Caribe colombiano. El muestreo se llevó a cabo mensualmente en cuatro ciénagas interconectadas de este Parque Natural, tres de ellas sometidas a explotación, entre abril y noviembre de 2004. Se estimó la densidad por metro cuadrado y se efectuaron mediciones de ...

  18. A pesca e o manejo do berbigão (Anomalocardia brasiliana (Bivalvia: Veneridae na Reserva Extrativista Marinha do Pirajubaé, SC, Brasil

    Directory of Open Access Journals (Sweden)

    Paulo Ricardo Pezzuto

    2015-08-01

    Full Text Available The Marine Extractive Reserve of Pirajubaé (MER is located in the urban area of Florianópolis city (capital of Santa Catarina State, Southern Brazil, and has the bivalve known as “berbigão” (Anomalocardia brasiliana as its main fishing resource. Based on 100 daily surveys carried out during 2005, this paper describes the berbigão fishery and presents the history of its management. A hand dredge (“gancho” was used by 22 men and four women to catch the berbigão. The fishery is conducted predominantly in the morning and under water depths between 20 and 50 cm. On average, each fisherman swept 469.2 m2 with the dredge and caught 270.5 kilograms of live clams per fishing day, summing up 888.6 t landed in the RESEX along 2005. More than 97% of the individuals in the catch exceeded the minimum legal size (20 mm total length. However, both individual size and total biomass of the stock reduced significantly over time. Most of the catch was processed (i.e. cooked and unshelled and sold to very few buyers. Current management measures include: a maximum number of authorized fisherman; b days of the week and times of the day when the fishery is allowed; c minimum distance between the iron bars in the ganchos’ basket; d minimum legal size; e space-time rotation of fishing areas and, f reporting of daily production data. In spite of the large volume of scientific and traditional knowledge available and the existence of management rules discussed and approved on a participatory system, both the berbigão sustainability and the RESEX as a whole are threatened by administrative, social, economic, environmental and bureaucratic pressures. Neutralize such threats is a key challenge to be faced in this important federal conservation area of Southern Brazil.

  19. Colonization of Asian freshwaters by the Mytilidae (Bivalvia): a comparison of Sinomytilus harmandi from the Tonle-Sap River, Phnom Penh, Cambodia, with Limnoperna fortunei

    DEFF Research Database (Denmark)

    Morton, Brian; Dinesen, Grete E.

    2010-01-01

    belong to the Mytilidae (Pteriomorphia), as demonstrated in this study for S. harmandi and elsewhere for L. fortunei. Sinomytilus harmandi is likely endemic to the Mekong River where it is sympatric with L. fortunei, the latter species being widely distributed in Indochina, south of and including the...... China. Because L. fortunei has a Devonian (~345-395 mya) modioline ancestry and S. harmandi is derived from a Permo-Trias (~265–225 mya) ancient mytiline ancestor it appears that Asian freshwater systems have been colonized by representatives of the Mytilidae on two separate temporal occasions....

  20. Oyster culture in European countries

    OpenAIRE

    Heral, Maurice; Deslous-paoli, Jean-marc

    1991-01-01

    Three species of oysters have been or are cultivated in Europe: Crassostrea angulata, C. gigas, and Ostrea edulis. If we follow the taxonomic critera of Grassé, the European oysters belong to the group of Mollusca, class of Lamellibranchia or Bivalves, order of Filibranchia, family Ostreidae with two genera: C. angulata (Lamarck), Portuguese, cupped oyster; C. gigas, (Thunberg), Japanese or Pacific, cupped oyster; Ostrea edulis (Linné), fiat European oyster. Some authors think that C. gi...

  1. Allozymic variation in the clam genus Eurhomalea (Bivalvia: Veneriidae along southern South American coast Variación alozímica en el género de almejas Eurhomalea (Bivalvia: Veneriidae a lo largo de la costa sur de Sudamérica

    Directory of Open Access Journals (Sweden)

    M.H GALLARDO

    2003-09-01

    Full Text Available The correspondence between allozymic variation and specific differentiation was studied in four populations corresponding to the three nominal, allopatric species of clam genus Eurhomalea (E. rufa, E. lenticularis, E. exalbida described for southern South America. Allozyme variation scored in 12 loci was high as indicated by heterozygosity levels (15.8-20.7 % and by the presence of only three monomorphic loci (Hk-2, Icd-2, and Xdh-1. These high estimates of allelic variability were influenced by the low levels of interspecific genetic similarity (I = 0.64 and for the high conspecific values of genetic identity observed. The high estimates of substructuring found at the species level (F ST = 0.39 contrasted with the low differentiation (F ST = 0.027 and high migration rate (Nm = 9 existing among conspecific samples. Diagnostic allele fixation coinciding with specific recognition was recorded at locus Hk-1 whereas nearly-fixed differences at loci (Adh, alpha-Gpd, Icd-1, Ldh, Odh, Pgm-3 differed sharply in frequency among species. The Wagner procedure and the neighbor-joining algorithm produced a similar tree topology highly related to the geographic distance and to their taxonomic recognition. The lack of coincidence between patterns of allozymic variation and the two distinctive shell morphs (flat and globoid occurring in E. exalbida from Ushuaia bay do not support their taxonomic recognition.Se estudió la correspondencia entre la variación bioquímica y la diferenciación específica en cuatro poblaciones correspondientes a las tres especies nominales y alopátricas en las almejas del género Eurhomalea (E. rufa, E. lenticularis, E. exalbida descritas para la zona sur de Sudamérica. La variación alozímica registrada en 12 loci fue alta como lo indican los altos niveles de heterocigosidad (15,8-20,7 % y por la presencia de solo tres loci monomórficos (Hk-2, Icd-2 y Xdh-1. Esta alta estimación de variabilidad alélica influyó en los bajos niveles de similitud genética interespecífica (I = 0,64 y en los altos valores de identidad genética conespecífica observados. El alto grado de subestructuración poblacional interespecífica (F ST = 0,39 contrasta con la poca diferenciación (F ST = 0,027 y la alta tasa de migración (Nm = 9 existente a nivel intraespecífica. Coincidiendo con la situación específica de estas tres especies, se observó fijación alternativa de alelos en el locus Hk-1 mientras que los loci (Adh, alfa-Gpd, Idh-1, Ldh, Odh, Pgm-3 están fuertemente diferenciados en sus frecuencias. El procedimiento de Wagner y el algoritmo de Unión al Vecino produjeron topologías similares, altamente relacionadas con la distancia geográfica y con la situación taxonómica. La falta de coincidencia entre los patrones de variación y los dos morfos (planas y globosas presentes en E. exalbida de la bahía Ushuaia no apoyan su reconocimiento taxonómico como entidades genéticas discretas.

  2. O mexilhão Perna perna (Linnaeus) (Bivalvia, Mytilidae) em cultivo na Armação do Itapocoroy, Santa Catarina, Brasil The mussel Perna perna (Linnaeus) (Bivalvia, Mytilidae) in culture at the Armação of the Itapocoroy, Santa Catarina, Brazil

    OpenAIRE

    Adriano W. C. Marenzi; Branco, Joaquim O.

    2005-01-01

    Para verificar a viabilidade do cultivo do mexilhão, P. perna (Linnaeus, 1758) no sul do Brasil, duas experiências foram executadas na Armação de Itapocoroy. Das variáveis físicas e químicas foram analisadas a salinidade, temperatura e o oxigênio, que se mostraram ideais para esta espécie e, os macronutrientes também dentro dos níveis esperados para a região, não indicando poluição orgânica no local. O crescimento médio foi de 0,58 cm/mês e o aumento do peso foi de 2,57 g/mês. Curvas de cresc...

  3. Fases larvais do mexilhão dourado Limnoperna fortunei (Dunker) (Mollusca, Bivalvia, Mytilidae) na Bacia do Guaíba, Rio Grande do Sul, Brasil Larval stages of the golden mussel Limnoperna fortunei (Dunker) (Bivalvia, Mytilidae) in Guaíba Basin, Rio Grande do Sul State, Brazil

    OpenAIRE

    Cíntia P. dos Santos; Norma L. Würdig; Maria C. D. Mansur

    2005-01-01

    Desde o final de 1998, um pequeno bivalve invasor, o "mexilhão dourado", Limnoperna fortunei (Dunker, 1857), oriundo do sudeste asiático, está presente no sul do Brasil. Foi provavelmente transportado, não intencionalmente, através de água de lastro para a Bacia do Guaíba, Rio Grande do Sul, Brasil. Em nosso meio, este molusco vem causando problemas de "macrofouling" com grandes prejuízos econômicos e danos à fauna e flora. As coletas foram qualitativas e quantitativas quinzenais no período d...

  4. Ciclo gametogênico e comportamento reprodutivo de Iphigenia brasiliana (Mollusca, Bivalvia, Donacidae no estuário do rio Subaé, Baía de Todos os Santos, Bahia, Brasil Gametogenic cycle and reproductive behavior of Iphigenia brasiliana (Mollusca, Bivalvia, Donacidae in the Subaé river estuary, Todos os Santos Bay, Bahia, Brazil

    Directory of Open Access Journals (Sweden)

    Patrícia P. Silva

    2012-12-01

    Full Text Available Este estudo teve como objetivos descrever o ciclo gametogênico e o comportamento reprodutivo da população de Iphigenia brasiliana (Lamarck,1818 no estuário do rio Subaé, Baía de Todos os Santos, Bahia. Os bivalves foram coletados de novembro de 2001 a novembro de 2002. Um total de 244 espécimes foi medido (eixo anteroposterior, eviscerado, fixado, desidratado e incluído em parafina. O estudo histológico das gônadas foi realizado através de cortes seriados do tecido gonadal, de 5 mm de espessura, e corados pela HE. O tamanho médio mínimo da primeira maturação sexual (Lpm foi estimado a partir da distribuição das frequências relativas de jovens e adultos, por classe de comprimento dos indivíduos. As frequências relativas dos sexos em cada estádio de desenvolvimento foram consideradas conjuntamente para a análise do comportamento reprodutivo da população, e, em separado, para avaliar a sincronia do ciclo sexual entre machos e fêmeas. Foi observada uma variação de tamanhos entre 9,1 e 66,6 mm, com comprimento médio de 50,2 mm. O estudo não demonstrou diferença significativa entre os tamanhos de machos e fêmeas. Não foi possível observar a diferenciação de sexos em 2,1% dos indivíduos analisados. 51,6% dos indivíduos foram identificados como machos (M e 46,3% como fêmeas (F, não sendo constatadas diferenças significativas entre o número médio de machos e fêmeas, resultando numa proporção de M:F de 1,1:1. O Lpm foi estimado em 11,4 mm, mas apenas ao alcançarem comprimento médio de 34,4 mm, todos os indivíduos foram considerados adultos. Foram caracterizados quatro estádios de evolução do desenvolvimento gonadal em fêmeas e machos. A análise dos diferentes estádios permitiu a observação dos fenômenos de atresia e inversão sexual em fêmeas. O ciclo reprodutivo apresentou eliminação contínua de gametas, com maiores intensidades reprodutivas nos meses de novembro de 2001 a abril de 2002 e, também, no mês de outubro de 2002.This study aimed to describe the gametogenic cycle and reproductive behavior of the population of Iphigenia brasiliana (Lamarck, 1818 in the estuary of the Subaé river, Todos os Santos Bay, Bahia. The bivalves were collected from November 2001 to November 2002. A total of 244 specimens was measured (anteroposterior axis, gutted, fixed, dehydrated and embedded in paraffin. The histology of the gonads was performed by 5 mm thick serial sections of gonadal tissue, and stained with HE. The length at the beginning of gonadal maturation (Lpm was estimated from the distribution of the relative frequencies of youth and adults, by length class of individuals. The relative frequencies of the sexes at each stage of development were considered together for the analysis of the reproductive behavior of the population, and, separately, to assess the sexual cycle synchrony between males and females. We observed a variation of sizes between 9.1 and 66.6 mm, with a mean length of 50.2 mm. The study showed no significant difference between the sizes of males and females. There was no evidence of gender differentiation in 2.1% of subjects analyzed. 51.6% of subjects were identified as males (M and 46.3% as females (F, without significant differences among average number of male and female, resulting in the proportion of M:F ratio of 1,1:1. Lpm was estimated at 11.4 mm, but only to achieve average length of 34.4 mm, all subjects were considered adults. We characterized four stages of evolution of gonadal development in females and males. Analysis of different stages allowed the observation of the atresia phenomena and sex reversal in females. The reproductive cycle presents continuous elimination of gametes, with higher reproductive intensities in the months of November 2001 to April 2002 and also in October 2002.

  5. Ciclo gametogênico e comportamento reprodutivo de Iphigenia brasiliana (Mollusca, Bivalvia, Donacidae no estuário do rio Subaé, Baía de Todos os Santos, Bahia, Brasil Gametogenic cycle and reproductive behavior of Iphigenia brasiliana (Mollusca, Bivalvia, Donacidae in the Subaé river estuary, Todos os Santos Bay, Bahia, Brazil

    Directory of Open Access Journals (Sweden)

    Patrícia P. Silva

    2012-01-01

    Full Text Available Este estudo teve como objetivos descrever o ciclo gametogênico e o comportamento reprodutivo da população de Iphigenia brasiliana (Lamarck,1818 no estuário do rio Subaé, Baía de Todos os Santos, Bahia. Os bivalves foram coletados de novembro de 2001 a novembro de 2002. Um total de 244 espécimes foi medido (eixo anteroposterior, eviscerado, fixado, desidratado e incluído em parafina. O estudo histológico das gônadas foi realizado através de cortes seriados do tecido gonadal, de 5 mm de espessura, e corados pela HE. O tamanho médio mínimo da primeira maturação sexual (Lpm foi estimado a partir da distribuição das frequências relativas de jovens e adultos, por classe de comprimento dos indivíduos. As frequências relativas dos sexos em cada estádio de desenvolvimento foram consideradas conjuntamente para a análise do comportamento reprodutivo da população, e, em separado, para avaliar a sincronia do ciclo sexual entre machos e fêmeas. Foi observada uma variação de tamanhos entre 9,1 e 66,6 mm, com comprimento médio de 50,2 mm. O estudo não demonstrou diferença significativa entre os tamanhos de machos e fêmeas. Não foi possível observar a diferenciação de sexos em 2,1% dos indivíduos analisados. 51,6% dos indivíduos foram identificados como machos (M e 46,3% como fêmeas (F, não sendo constatadas diferenças significativas entre o número médio de machos e fêmeas, resultando numa proporção de M:F de 1,1:1. O Lpm foi estimado em 11,4 mm, mas apenas ao alcançarem comprimento médio de 34,4 mm, todos os indivíduos foram considerados adultos. Foram caracterizados quatro estádios de evolução do desenvolvimento gonadal em fêmeas e machos. A análise dos diferentes estádios permitiu a observação dos fenômenos de atresia e inversão sexual em fêmeas. O ciclo reprodutivo apresentou eliminação contínua de gametas, com maiores intensidades reprodutivas nos meses de novembro de 2001 a abril de 2002 e, também, no mês de outubro de 2002.This study aimed to describe the gametogenic cycle and reproductive behavior of the population of Iphigenia brasiliana (Lamarck, 1818 in the estuary of the Subaé river, Todos os Santos Bay, Bahia. The bivalves were collected from November 2001 to November 2002. A total of 244 specimens was measured (anteroposterior axis, gutted, fixed, dehydrated and embedded in paraffin. The histology of the gonads was performed by 5 mm thick serial sections of gonadal tissue, and stained with HE. The length at the beginning of gonadal maturation (Lpm was estimated from the distribution of the relative frequencies of youth and adults, by length class of individuals. The relative frequencies of the sexes at each stage of development were considered together for the analysis of the reproductive behavior of the population, and, separately, to assess the sexual cycle synchrony between males and females. We observed a variation of sizes between 9.1 and 66.6 mm, with a mean length of 50.2 mm. The study showed no significant difference between the sizes of males and females. There was no evidence of gender differentiation in 2.1% of subjects analyzed. 51.6% of subjects were identified as males (M and 46.3% as females (F, without significant differences among average number of male and female, resulting in the proportion of M:F ratio of 1,1:1. Lpm was estimated at 11.4 mm, but only to achieve average length of 34.4 mm, all subjects were considered adults. We characterized four stages of evolution of gonadal development in females and males. Analysis of different stages allowed the observation of the atresia phenomena and sex reversal in females. The reproductive cycle presents continuous elimination of gametes, with higher reproductive intensities in the months of November 2001 to April 2002 and also in October 2002.

  6. Avaliação da infestação e diversidade de Teredinidae (Mollusca - Bivalvia ao longo da costa do estado do Rio de Janeiro, Brasil Evaluation of the infestation and diversity of Teredinidae (Mollusca - Bivalvia along the coast of Rio de Janeiro State, Brazil

    Directory of Open Access Journals (Sweden)

    Andrea de O. R. Junqueira

    1989-01-01

    Full Text Available In order to evaluate the diversity and infestation level of Teredinidae wood-boring molluscs, ten satations were chosen along the coast of Rio de Janeiro State. Using five pine-wood panels in each station, it was possible to distinguish five areas according to species dominance. Ilha Grande Bay is characterized by the dominance of Lyrodus floridanus (Bartsch, 1922; Sepetiba Bay, by Bankia fimbriatula Moll & Roch, 1931, Tijuca Lagoon by Teredo navalis Linnaeus, 1758; Guanabara Bay by Notoredo knoxi (Bartsch, 1917 and Araruama Lagoon by Teredo furcifera Martens, 1894. Specific composition and dominance of these species were due mainly to abiotic factors such as salinity whereas infestation level was associated not only to salinity but also to other factors such as the quantity and quality of fouling, the presence of larval dispersion focus and the wood supply in each area.

  7. Allozymic variation in the clam genus Eurhomalea (Bivalvia: Veneriidae) along southern South American coast Variación alozímica en el género de almejas Eurhomalea (Bivalvia: Veneriidae) a lo largo de la costa sur de Sudamérica

    OpenAIRE

    M.H GALLARDO; González, C; Mena, C; Lomovasky, B.; Morriconi, E.; E CLASING

    2003-01-01

    The correspondence between allozymic variation and specific differentiation was studied in four populations corresponding to the three nominal, allopatric species of clam genus Eurhomalea (E. rufa, E. lenticularis, E. exalbida) described for southern South America. Allozyme variation scored in 12 loci was high as indicated by heterozygosity levels (15.8-20.7 %) and by the presence of only three monomorphic loci (Hk-2, Icd-2, and Xdh-1). These high estimates of allelic variability were influen...

  8. Ocorrência do molusco asiático Corbicula fluminea (Müller, 1774 (Bivalvia, Corbiculidae no baixo rio Negro, Amazônia central Occurrence of the Asian mollusc Corbicula fluminea (Müller, 1774 (Bivalvia, Corbiculidae in the lower Rio Negro, Central Amazon Region, Brazil

    Directory of Open Access Journals (Sweden)

    Daniel Mansur Pimpão

    2008-01-01

    Full Text Available O rio Negro é um dos maiores afluentes do rio Amazonas, mas poucos moluscos foram registrados até o momento para aquele rio, representados apenas por gastrópodes. Foi registrada a presença do molusco bivalve exótico Corbicula fluminea na margem esquerda do baixo rio Negro, no lago do Tupé e no Catalão - margem direita do rio Negro, todas localidades no município de Manaus, Brasil. O registro foi realizado por meio da coleta de conchas e espécimes vivos. É o primeiro registro de C. fluminea para o estado do Amazonas e Amazônia central.The Rio Negro is one of the biggest Rio Amazonas tributaries. Few molluscs have been registered to that river yet, represented only by gastropods. It is reported the occurrence of the exotic bivalve mollusc Corbicula fluminea in left bank margin of Rio Negro, Lago do Tupé and Catalão - right bank margin of Rio Negro, all localities in the municipality of Manaus, Brazil. The species is recorded by a collection of shells and specimens alive. This is the first occurrence of C. fluminea in the Amazon State and Central Amazon.

  9. 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

    Directory of Open Access Journals (Sweden)

    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.

  10. Dimensionamiento y configuración teórica de una línea de cultivo de ostra perla (Pinctada imbricata Mollusca: Bivalvia), en la bahía de Charagato, isla de Cubagua, Venezuela Sizing and theoretical configuration of a longline for growing pearl oysters (Pinctada imbricata Mollusca: Bivalvia) in the Bay of Charagato, Cubagua Island, Venezuela

    OpenAIRE

    Ernesto Trujillo; Guillermo Martínez; Luis León

    2007-01-01

    Se dimensionó una línea de cultivo mediante análisis teórico de la resistencia hidrodinámica del sistema y se configuró utilizando simulación análoga con la ayuda de modelos a escala. Se determinaron las variables de tensión en línea madre (TLM), la relación de aspecto (R A) del fondeo y el excursionamiento (P R) de la línea madre, cuyas resultantes fueron la tensión en el sistema de fondeo (T2) y el ángulo de ataque (α2); la tensión vertical en una sección de línea madre (TF) y el ángul...

  11. PHYSIOLOGICAL RESPONSES OF THE BROWN MUSSEL Perna perna (MOLLUSCA, BIVALVIA) EXPOSED TO THE ANIONIC SURFACTANT LINEAR ALKYLBENZENE SULPHONATE (LAS) = RESPOSTAS FISIOLÓGICAS DE MEXILHÃO Perna perna (MOLLUSCA, BIVALVIA) EXPOSTO AO SURFACTANTE ANIÔNICO ALQUILBENZENO SULFONATO LINEAR (LAS)

    OpenAIRE

    Marina Freitas Stefanoni; Denis Moledo de Souza Abessa

    2011-01-01

    The effects of the Linear Alkylbenzene Sulphonate (LAS) were evaluated on the mussel Perna perna, using physiological and genotoxic biomarkers. The Micronuclei (MN) assay was used to estimate effects at nuclear level, whereas the physiological effects were evaluated by measuring the oxygen consumption and ammonia excretion rates. Significant effects were observed for the MN assay and the ammonia excretion rate, even in low concentrations. The oxygen consumption was not affected in the tested ...

  12. PHYSIOLOGICAL RESPONSES OF THE BROWN MUSSEL Perna perna (MOLLUSCA, BIVALVIA EXPOSED TO THE ANIONIC SURFACTANT LINEAR ALKYLBENZENE SULPHONATE (LAS = RESPOSTAS FISIOLÓGICAS DE MEXILHÃO Perna perna (MOLLUSCA, BIVALVIA EXPOSTO AO SURFACTANTE ANIÔNICO ALQUILBENZENO SULFONATO LINEAR (LAS

    Directory of Open Access Journals (Sweden)

    Marina Freitas Stefanoni

    2011-01-01

    Full Text Available The effects of the Linear Alkylbenzene Sulphonate (LAS were evaluated on the mussel Perna perna, using physiological and genotoxic biomarkers. The Micronuclei (MN assay was used to estimate effects at nuclear level, whereas the physiological effects were evaluated by measuring the oxygen consumption and ammonia excretion rates. Significant effects were observed for the MN assay and the ammonia excretion rate, even in low concentrations. The oxygen consumption was not affected in the tested concentrations. For MN and ammonia excretion, the animals exposed to intermediate concentrations were not affected, but responded to the higher concentrations, indicating the existence of compensatory mechanisms at physiological level. However, parallel to this study other authors indicate the presence of progressive effects at the cellular level, suggesting that the organisms are not capable to recover of such increasing effects. Additionally, the results show that the levels of LAS observed for Brazilian coastal waters may chronically affect the biota. = Os efeitos do Alquilbenzeno Sulfonato de Sódio Linear sobre o mexilhão Perna perna foram avaliados por meio do uso de biomarcadores genotóxicos e fisiológicos. O ensaio da taxa de micronúcleos (MN foi conduzido para estimar o efeito ao nível nuclear, enquanto os efeitos fisiológicos foram avaliados através da medição da taxa de consumo de oxigênio e de excreção de amônia. Efeitos significativos foram observados para o ensaio do MN e para a taxa de excreção de amônia, mesmo em baixas concentrações. O consumo do oxigênio não foi afetado pelas concentrações dos ensaios. Para MN e excreção de amônia, os animais expostos às concentrações intermediárias não foram afetados, mas responderam às maiores concentrações, sugerindo a existência de mecanismos compensatórios em nível fisiológico. Contudo, paralelamente ao presente estudo, outros autores demonstraram haver efeitos progressivos em nível celular, sugerindo que os organismos não conseguem se recuperar dos efeitos crescentes da exposição. Os resultados ainda mostram que níveis de LAS presentes na costa brasileira podem afetar cronicamente a biota.

  13. Aspectos da reprodução e dinâmica populacional de Chione pubera (Bory Saint-Vicent) (Bivalvia, Veneridae) no sul do Brasil General features of the reproduction and population dynamics of Chione pubera (Bory Saint-Vicent) (Bivalvia, Veneridae) in South Brazil

    OpenAIRE

    Carlos Alberto Borzone; Kelly Midori Vargas; Paulo Ricardo Pezzuto; Yara Aparecida Garcia Tavares

    2001-01-01

    Material collected with a 2-meter wide beam trawl during eight surveys conducted from December 1995 to February 1997 was used for a first preliminary description of the reproduction and population dynamics of the edible venerid bivalve Chione pubera (Bory Saint-Vicent, 1827). Greatest catches were found between 30 to 35 meters depth, on fine sandy bottoms with a mud content lower than 10%. Dry weight meat condition index showed highest values during autumn and lowest values from winter to sum...

  14. Dimensionamiento y configuración teórica de una línea de cultivo de ostra perla (Pinctada imbricata Mollusca: Bivalvia, en la bahía de Charagato, isla de Cubagua, Venezuela Sizing and theoretical configuration of a longline for growing pearl oysters (Pinctada imbricata Mollusca: Bivalvia in the Bay of Charagato, Cubagua Island, Venezuela

    Directory of Open Access Journals (Sweden)

    Ernesto Trujillo

    2007-05-01

    Full Text Available Se dimensionó una línea de cultivo mediante análisis teórico de la resistencia hidrodinámica del sistema y se configuró utilizando simulación análoga con la ayuda de modelos a escala. Se determinaron las variables de tensión en línea madre (TLM, la relación de aspecto (R A del fondeo y el excursionamiento (P R de la línea madre, cuyas resultantes fueron la tensión en el sistema de fondeo (T2 y el ángulo de ataque (α2; la tensión vertical en una sección de línea madre (TF y el ángulo de ataque de la catenaria (α. Para la construcción del modelo del cabo de fondeo y de una sección de línea madre se utilizaron factores de escala lineal de 40 y de 18,86; y escalas de fuerza de 9.776,3 y de 1.233,13, respectivamente. Las mínimas tensiones T2 fueron obtenidas para RA de 1/4 y 1/5, a partir de la tensión teórica T1 de 777,15 kgf, con ángulos de ataque de 84,9° y 90°. Para una sección de una línea de cultivo de seis linternas, con organismos en fase adulta, las unidades centrales 3 y 4 alcanzaron una profundidad operacional de 7,37 m, una P R promedio de 93,6% y un ángulo de ataque de 55,86°. Se requiere validar in situ los resultados teóricos obtenidos, con ayuda de un tensiómetro, a fin de encontrar el equilibrio estructural del sistema con un mínimo de inversión y máximo rendimientoA farming longline was sized by theoretically analyzing the system’s hydrodynamic resistance and configured using analogue simulation with the help of scale models. The variables determined were mother line tension (TLM, the relationship of the anchoring aspect (R A, and movement (P R of the mother line. These resulted in anchoring system tension (T2 and attack angle (α2, and the vertical tension for a section of the mother line (TF and the attack angle of the catenary (α. The model of the anchor end and a section of the mother line were constructed using lineal scale factors of 40 and 18.86 and force scales of 9,776.3 and 1,233.13, respectively. The minimum tensions (T2 obtained for R A were 1/4 and 1/5 based on the theoretical tension (T1 777.15 kgf, with attack angles of 84.9° and 90°. A longline section with six lanterns and loaded with adult organisms had central units 3 and 4 at an operational depth of 7.37 m, an average P R of 93.6%, and an attack angle of 55.86°. A tensiometer should be used for an in situ validation of the theoretical results in order to determine the structural equilibrium of the system with minimum investment and maximum performance

  15. Use of clearance rate in Choromytilus chorus (Bivalvia: Mytilidae as a non-destructive biomarker of aquatic pollution El uso de la tasa de aclaramiento en Choromytilus chorus (Bivalvia: Mytilidae como biomarcador no destructivo de la polución acuática

    Directory of Open Access Journals (Sweden)

    BEATRIZ TORO

    2003-06-01

    Full Text Available Reduction in clearance rate was observed in the mussel Choromytilus chorus in relation to the degree of environmental pollution. Three sampling sites included the polluted San Vicente Bay, middling polluted Corral Bay, and weakly polluted Yaldad Bay in southern Chile. Pollution levels were estimated by quantitative analysis of polynuclear aromatic hydrocarbons (PAHs in mussel tissue from the three sites. Mussels from San Vicente showed lowest clearance rates and highest PAHs levels in both spring 1998 and summer 1999. Populations from Corral and Yaldad showed generally low levels of PAHs, so the mussels from Yaldad showed the highest rates of clearance in comparison to Corral and San Vicente populations. The significant negative relationship (P Se observó un deterioro de la tasa de aclaramiento en Choromytilus chorus de acuerdo al grado de polución ambiental. Se incluyeron tres sitios de muestreos, la bahía de San Vicente muy contaminada, la bahía de Corral con una polución intermedia y la bahía de Yaldad, al sur de Chile, con una baja contaminación. Los niveles de polución fueron estimados por análisis cuantitativos de hidrocarburos aromáticos polinucleares (HAPs en el tejido de los choros zapatos de los tres sitios de muestreo. Los choros zapatos de San Vicente mostraron la menor tasa de aclaramiento y altos niveles de HAPs, tanto en la primavera de 1998 como en el verano de 1999. Las poblaciones de Corral y Yaldad mostraron en general bajos niveles de HAPs, en tanto que los ejemplares de Yaldad presentaron altas tasas de aclaramiento en comparación con las poblaciones de Corral y San Vicente. La relación negativa significativa (P < 0,001 entre la polución en el tejido de los choros zapatos y sus tasas de aclaramiento, argumenta la utilidad del método como un biomarcador no destructivo para evaluar el impacto ambiental de la polución en las especies marinas

  16. THREE YEAR VARIATION IN SHELL GROWTH OF THEMUSSEL, ELLIPTIO WACCAMAWENSIS (LEA), IN LAKEWACCAMAW, A BAY LAKE IN NORTH CAROLINA

    Science.gov (United States)

    Freshwater mussels (Bivalvia: Unionidae) are one of the most endangered animal taxa in North America, and continued research on unionids will improve management decisions regarding their conservation. One unexplored aspect of unionid ecology is the magnitude of interannual variat...

  17. Bonamia sp. (Protozoa, Haplosporidia) parásito de Ostrea puelchana D’Orbigny, (Mollusca, Bivalvia) en el Golfo San Matías (Patagonia Argentina): Histopatología, identificación e infección

    OpenAIRE

    Kroeck, M.A.

    2005-01-01

    Los moluscos bivalvos son organismos sedentarios que establecen una relación íntima no sólo entre ellos, sino también con el espacio que ocupan y con sus condiciones fisicoquímicas. Sus poblaciones pueden ser hospedadoras de múltiples organismos patógenos (virus,bacterias, hongos, protistas y metazoos), cuya presencia es regulada eficazmente a niveles infra, meta y suprapoblacionales en ambientes silvestres, no provocando, salvo excepcionalmente, impactos severos. Los cultivos a escala come...

  18. Effect of zinc and benzene on respiration and excretion of mussel larvae (Perna perna) (Linnaeus, 1758) (Mollusca; Bivalvia) Bioenergética de larvas de mexilhão (Perna perna) (Linnaeus, 1758)

    OpenAIRE

    RADLVC. Jorge; D. Lemos; GS. Moreira

    2007-01-01

    The presence of pollutants in the ocean may affect different physiological parameters of animals. Oxygen consumption and ammonia excretion were evaluated in D-shaped larvae of mussels (Perna perna) exposed to zinc sulphate (ZnSO4) and benzene (C6H6). When compared to the control group, both pollutants presented a significant reduction in oxygen consumption. A reduction in the ammonia excretion was also observed, both for ZnSO4 and C6H6 and also in the oxygen consumption. The results indicate ...

  19. First report on the occurrence of the comb pen shell, Atrina pectinata (Linnaeus, 1767) (Bivalvia: Pinnidae) in Ulleungdo Island in the East Sea: Ecology and molecular identification of the species using COI gene sequence

    Science.gov (United States)

    Yang, Hyun-Sung; Kang, Hyun-Sil; Park, Heung-Sik; Noh, Choong Hwan; Jeong, Eui-Young; Choi, Kwang-Sik

    2015-12-01

    Pen shell is one of the largest marine bivalves inhabiting shallow subtidal soft bottoms in the west Pacific and Indian Oceans. In Korea, the comb pen shell Atrina pectinata fisheries has been established on the south and west coasts. Recently, a pen shell population has been discovered from a subtidal sand flat (25-30 m depth) in Ulleungdo Island located in the East Sea of Korea, suggesting a potential shellfish resource in this area. In the present study, we first surveyed the population density and size of the unique pen shell using SCUBA, and identified the pen shell to species level using mitochondrial cytochrome oxidase I gene (COI) sequence. An underwater survey carried out from July to September 2013 revealed that populations of pen shell patched on subtidal sand flat at a depth of 20-25 m. Grain size analysis indicated that sand particles accounted for 99% of the 600 × 700 m sand flat. The underwater survey also indicated that density of the pen shell ranged between 6-19 ind/m2, with a mean of 11 ind/m2. Shell height (i.e. longest axis of the shell) of the pen shell on the sand flat varied between 17.2 cm to 28.8 cm, with a mean of 25.1 cm, and the age was estimated to range between 1.5-7.5 yrs, with a mean of 5 yr. COI DNA sequence obtained from the pen shell in this study showed 98.9-99.2% similarity to Atrina pectinata (Linnaeus 1767) reported from Japan. In the cluster analysis, the COI DNA sequence of the pen shells from Ulleungdo Island was grouped with A. pectinata reported from Japan and China, indicating that the pen shell discovered in this study was A. pectinata, commonly distributed on the west and south coasts of Korea.

  20. Dinâmica da População de Anomalocardia brasiliana (Mollusca, Bivalvia, Veneridae no Estuário do Rio Paciência, no Município da Raposa, Estado do Maranhão

    Directory of Open Access Journals (Sweden)

    Juan Jethro Silva Santos

    2014-01-01

    Full Text Available A presença de moluscos no litoral maranhense é significativa, servindo de fonte de renda e subsistência para muitas comunidades. Um exemplo de molusco relacionado com esse potencial é a espécie Anomalocardia brasiliana (Gmelin 1791, que possui grande importância para a população do município da Raposa, na ilha do Maranhão. A presente pesquisa objetivou analisar a dinâmica dessa espécie em lotes naturais do próprio município, nos períodos locais caracterizados como seco e chuvoso. Coletas mensais foram realizadas no período de agosto a dezembro de 2010 e março a junho de 2011, onde foram efetuados levantamentos de informações importantes como variáveis biométricas, fator de condição e densidade. Os resultados encontrados mostraram que os organismos durante todo o período de coleta, exceto o mês de agosto, apresentaram tamanho satisfatório para o consumo, com média acima de 20 mm. Para outro caso, observou-se uma diminuição do fator de condição nos meses de agosto e dezembro, podendo estar relacionado com algum estresse no meio como: período de desova da espécie em questão ou pressão antrópica na região, tendo em vista que, esse organismo sofre forte extração local de forma não sustentável. A densidade dos organismos mostrou-se alta, em termos de biomassa, apresentando uma média de 3,16 toneladas em uma área de 6.007,5 m², que comparada com uma criação de gado extensiva, dependendo do manejo, torna-se mais produtiva, econômica e ecológica.

  1. Ion microprobe assessment of the heterogeneity of Mg/Ca, Sr/Ca and Mn/Ca ratios in Pecten maximus and Mytilus edulis (bivalvia shell calcite precipitated at constant temperature

    Directory of Open Access Journals (Sweden)

    H. Kennedy

    2009-01-01

    Full Text Available Small-scale heterogeneity of biogenic carbonate elemental composition can be a significant source of error in the accurate use of element/Ca ratios as geochemical proxies. In this study ion microprobe (SIMS profiles showed significant small-scale variability of Mg/Ca, Sr/Ca and Mn/Ca ratios in new shell calcite of the marine bivalves P. maximus and Mytilus edulis that was precipitated during a constant-temperature culturing experiment. Elevated Mg/Ca, Sr/Ca and Mn/Ca ratios were found to be associated with the deposition of elaborate shell features, i.e. a shell surface stria in P. maximus and surface shell disturbance marks in both species, the latter a common occurrence in bivalve shells. In both species the observed small-scale elemental heterogeneity most likely was not controlled by variable transport of ions to the extra-pallial fluid, but by factors such as shell Mg content influencing Sr and Mn heterogeneity, the influence of shell organic content and/or conditions at the shell crystal-solution interface. Invariant Mg/Ca ratios observed in the mid and innermost regions of the P. maximus shell suggests a potential application as a palaeotemperature proxy.

  2. Ion microprobe assessment of the heterogeneity of Mg/Ca, Sr/Ca and Mn/Ca ratios in Pecten maximus and Mytilus edulis (bivalvia shell calcite precipitated at constant temperature

    Directory of Open Access Journals (Sweden)

    P. S. Freitas

    2009-07-01

    Full Text Available Small-scale heterogeneity of biogenic carbonate elemental composition can be a significant source of error in the accurate use of element/Ca ratios as geochemical proxies. In this study ion microprobe (SIMS profiles showed significant small-scale variability of Mg/Ca, Sr/Ca and Mn/Ca ratios in new shell calcite of the marine bivalves Pecten maximus and Mytilus edulis that was precipitated during a constant-temperature culturing experiment. Elevated Mg/Ca, Sr/Ca and Mn/Ca ratios were found to be associated with the deposition of elaborate shell features, i.e. a shell surface stria in P. maximus and surface shell disturbance marks in both species, the latter a common occurrence in bivalve shells. In both species the observed small-scale elemental heterogeneity most likely was not controlled by variable transport of ions to the extra-pallial fluid, but by factors such as the influence of shell organic content and/or crystal size and orientation, the latter reflecting conditions at the shell crystal-solution interface. In the mid and innermost regions of the P. maximus shell the lack of significant small-scale variation of Mg/Ca ratios, which is consistent with growth at constant temperature, suggest a potential application as a palaeotemperature proxy. Cross-growth band element/Ca ratio profiles in the interior of bivalve shells may provide more promising palaeo-environmental tools than sampling from the outer region of bivalve shells.

  3. Ion microprobe assessment of the heterogeneity of Mg/Ca, Sr/Ca and Mn/Ca ratios in Pecten maximus and Mytilus edulis (bivalvia) shell calcite precipitated at constant temperature

    Science.gov (United States)

    Freitas, P. S.; Clarke, L. J.; Kennedy, H.; Richardson, C. A.

    2009-07-01

    Small-scale heterogeneity of biogenic carbonate elemental composition can be a significant source of error in the accurate use of element/Ca ratios as geochemical proxies. In this study ion microprobe (SIMS) profiles showed significant small-scale variability of Mg/Ca, Sr/Ca and Mn/Ca ratios in new shell calcite of the marine bivalves Pecten maximus and Mytilus edulis that was precipitated during a constant-temperature culturing experiment. Elevated Mg/Ca, Sr/Ca and Mn/Ca ratios were found to be associated with the deposition of elaborate shell features, i.e. a shell surface stria in P. maximus and surface shell disturbance marks in both species, the latter a common occurrence in bivalve shells. In both species the observed small-scale elemental heterogeneity most likely was not controlled by variable transport of ions to the extra-pallial fluid, but by factors such as the influence of shell organic content and/or crystal size and orientation, the latter reflecting conditions at the shell crystal-solution interface. In the mid and innermost regions of the P. maximus shell the lack of significant small-scale variation of Mg/Ca ratios, which is consistent with growth at constant temperature, suggest a potential application as a palaeotemperature proxy. Cross-growth band element/Ca ratio profiles in the interior of bivalve shells may provide more promising palaeo-environmental tools than sampling from the outer region of bivalve shells.

  4. Aspectos biológicos y ecológicos de Mytilopsis sallei (Recluz, 1849) (Bivalvia: Dreissenidae) en bancos de ostra de la Ciénaga Grande de Santa Marta, Caribe colombiano

    OpenAIRE

    Puyana, Mónica

    1995-01-01

    Mytilopsis sallei es una especie que se encuentra ampliamente distribuida sobre sustratos duros en la Ciénaga Grande de Santa Marta, siendo particularmente abundante sobre bancos de ostra de mangle (Crassostrea rhizophorae), donde alcanza densidades de hasta 5000 indiv/m2. Aunque posee una amplia tolerancia a variaciones en la salinidad y temperatura, prefiere aquellos lugares donde la afluencia de aguas dulces es constante. Puede además tolerar aguas turbias con un alto contenido de sediment...

  5. Ciclo gametogênico e comportamento reprodutivo de Iphigenia brasiliana (Mollusca, Bivalvia, Donacidae no estuário do rio Subaé, Baía de Todos os Santos, Bahia, Brasil

    Directory of Open Access Journals (Sweden)

    Patrícia P. Silva

    2012-12-01

    Full Text Available Este estudo teve como objetivos descrever o ciclo gametogênico e o comportamento reprodutivo da população de Iphigenia brasiliana (Lamarck,1818 no estuário do rio Subaé, Baía de Todos os Santos, Bahia. Os bivalves foram coletados de novembro de 2001 a novembro de 2002. Um total de 244 espécimes foi medido (eixo anteroposterior, eviscerado, fixado, desidratado e incluído em parafina. O estudo histológico das gônadas foi realizado através de cortes seriados do tecido gonadal, de 5 mm de espessura, e corados pela HE. O tamanho médio mínimo da primeira maturação sexual (Lpm foi estimado a partir da distribuição das frequências relativas de jovens e adultos, por classe de comprimento dos indivíduos. As frequências relativas dos sexos em cada estádio de desenvolvimento foram consideradas conjuntamente para a análise do comportamento reprodutivo da população, e, em separado, para avaliar a sincronia do ciclo sexual entre machos e fêmeas. Foi observada uma variação de tamanhos entre 9,1 e 66,6 mm, com comprimento médio de 50,2 mm. O estudo não demonstrou diferença significativa entre os tamanhos de machos e fêmeas. Não foi possível observar a diferenciação de sexos em 2,1% dos indivíduos analisados. 51,6% dos indivíduos foram identificados como machos (M e 46,3% como fêmeas (F, não sendo constatadas diferenças significativas entre o número médio de machos e fêmeas, resultando numa proporção de M:F de 1,1:1. O Lpm foi estimado em 11,4 mm, mas apenas ao alcançarem comprimento médio de 34,4 mm, todos os indivíduos foram considerados adultos. Foram caracterizados quatro estádios de evolução do desenvolvimento gonadal em fêmeas e machos. A análise dos diferentes estádios permitiu a observação dos fenômenos de atresia e inversão sexual em fêmeas. O ciclo reprodutivo apresentou eliminação contínua de gametas, com maiores intensidades reprodutivas nos meses de novembro de 2001 a abril de 2002 e, também, no mês de outubro de 2002.

  6. COⅠ -BASED DNA BARCODING IN MYTILIDAE SPECIES (MOLLUSCA: BIVALVIA)%基于线粒体COⅠ的DNA条形码技术在贻贝科种类鉴定中的应用

    Institute of Scientific and Technical Information of China (English)

    刘君; 李琪; 孔令锋; 陈军; 郑小东; 于瑞海

    2011-01-01

    DNA条形码(DNA barcoding)技术作为近年来发展起来的物种鉴定的一门新兴技术,已引起越来越多的关注.其原理是利用一段短DNA标准序列(对动物而言一般为线粒体细胞色素c氧化酶亚单位I,mitochondrial cytochrome c oxidase subunit Ⅰ,COⅠ)来实现物种鉴定[1].它的两大主要目的是鉴定已知种和发现新种[2,3].

  7. Variações no comprimento dos indivíduos de uma população do mexilhão dourado, Limnoperna fortunei (Mollusca: Bivalvia: Mytilidae), ao longo do ano, na Praia do Veludo, Lago Guaíba, Rio Grande do Sul, Brasil Length variation over a one-year period in specimens of the golden mussel, Limnoperna fortunei (Mollusca: Bivalvia: Mytilidae) from Veludo Beach, Guaíba Lake, Rio Grande do Sul, Brazil

    OpenAIRE

    Cintia P. dos Santos; Maria Cristina D. Mansur; Norma L. Würdig

    2008-01-01

    The individual size of Limnoperna fortunei (Dunker, 1857) was evaluated twice a month, for a year, based on samples from Veludo Beach (30º12'35"S, 51º11'68"W) in Guaiba Lake, southern Porto Alegre, Brazil. Physical and chemical data on water quality, such as temperature, transparency, depth, pH, dissolved oxygen, phosphorus, nitrogen, chlorophyll "a", and conductivity were also recorded. Adult samples were collected from underwater "sarandi" branches, Cephalanthus glabratus (Spreng) K. Schum ...

  8. Isognomon bicolor (C.B. Adams (Bivalvia, Isognomonidae: primeiro registro para o Brasil, redescrição da espécie e considerações sobre a ocorrência e distribuição de Isognomon na costa brasileira Isognomon bicolor (C.B. Adams (Bivalvia, Isognomonidae: first record to the Brazilian littoral, redescription of the species and comments on the occurrence and distribution of Isognomon in the Brazilian coast

    Directory of Open Access Journals (Sweden)

    Osmar Domaneschi

    2002-06-01

    Full Text Available The bivalve family Isognomonidae is represented in the Western Atlantic by the living genera Crenatula Lamarck, 1804 and Isognomon Solander, 1786. I. alatus (Gmelin, 1791 and I. radiatus (Anton, 1839 are the only Isognomonidae referred to the Brazilian malacofauna. The present work refers to the first record and geographic distribution of I. bicolor along the Brazilian littoral, and presents a re-description of the species based on shell characters, which include those of the prodissoconch. The occurrence of I. alatus and I. radiatus along the Brazilian littoral could not be confirmed, despite the intensive search for these Isognomonidae from Rio Grande do Norte through Rio Grande do Sul.

  9. determination of (Cd, As, Pb, Zn, Cr, and Cu) in the flesh tissues of some kinds of marine beings at the shore of Lattakia city by AAS

    International Nuclear Information System (INIS)

    Trace heavy metals in two sort of Bivalvia and five kind of fish has been determined in comparison with water samples using atomic absorption spectroscopy method. The results showed high concentration of studied elements (Cd, As, Pb, Zn, Cr, and Cu) in the animal samples compared with the water samples and is close to the concentration of some other elements , where these concentrations reached their highest value in the Bivalvia since it has the water filtration property. Nevertheless these concentrations are still approximate with their concentrations in other parts of the Mediterranean basin and within the known limits of these elements in the marine environment. (author)

  10. El aspecto progresivo en traducción : Una investigación sobre el gerundio español y su traducción sueca en La casa de los espíritus de Isabel Allende

    OpenAIRE

    Asp, Jenny

    2011-01-01

    El propósito de la tesina es investigar las traducciones suecas de la construcción estar + gerundio para ver si se ha mantenido el aspecto progresivo o no. Si se lo ha mantenido, ¿qué métodos han sido usados? Es un asunto interesante porque la lengua sueca no tiene un equivalente formal al gerundio español y tampoco existen muchos trabajos anteriores sobre esta cuestión. La novela La casa de los espíritus de Isabel Allende con su traducción sueca han servido como corpus y hemos usado cien eje...

  11. Trophic relationships between macroinvertebrates and fish in a pampean lowland stream (Argentina)

    OpenAIRE

    María V. López van Oosterom; Carolina S. Ocón; Florencia Brancolini; Maroñas, Miriam E.; Eduardo D. Sendra; Alberto Rodrigues Capítulo

    2013-01-01

    The diet and trophic relationships between the macroinvertebrates Phyllogomphoides joaquini Rodrigues Capítulo, 1992 and Coenagrionidae (Odonata), Chironomidae (Diptera), Diplodon delodontus (Lamarck, 1919) (Bivalvia: Hyriidae), and Pomacea canaliculata (Lamarck, 1822) (Gastropoda: Ampulariidae) and the fishes Pimelodella laticeps Eigenmann, 1917 (Heptapteridae) and Bryconamericus iheringii (Boulenger, 1887) (Characidae) in a temperate lowland lotic system in Argentina were assessed on the ba...

  12. The role of host specificity in explaining the invasion success of the freshwater mussel Anodonta woodiana in Europe

    Czech Academy of Sciences Publication Activity Database

    Douda, K.; Vrtílek, Milan; Slavík, O.; Reichard, Martin

    2012-01-01

    Roč. 14, č. 1 (2012), s. 127-137. ISSN 1387-3547 R&D Projects: GA AV ČR KJB600930802 Institutional research plan: CEZ:AV0Z60930519 Keywords : aquatic habitat * Bivalvia * host-parasite relationship * host specificity * Mollusca Subject RIV: EG - Zoology Impact factor: 2.509, year: 2012

  13. Contamination de l'estuaire et de la baie de Seine par le PCB-Bilan des etudes

    OpenAIRE

    Abarnou, Alain; Simon, S.

    1985-01-01

    This report is a synthesis of data concerning PCB concentrations in water, sediments and organisms (Bivalvia, Malacostraca, Pisces). Water analysis shows that Seine River is the primordial factor affecting PCB dispersion in the bay. Sediment contamination is higher near estuary along Calvados coast. PCB levels in Mytilidae and in Pectinidae set the problem of polluant origin, dispersion and effects on estuarine organisms.

  14. Determination of shell deposition rates of Arctica islandica from the New York Bight using natural 228Ra and 228Th and bomb-produced 14C

    International Nuclear Information System (INIS)

    Shell deposition rates of specimens of Arctica islandica (Mollusca: Bivalvia) from the New York Bight were determined using natural 228Ra and 228Th and bomb 14C. The specimens from deep (>55 m) offshore waters show annual growth banding. A shell obtained from the inner bight at <30-m depth seems to be younger than indicated by band counting

  15. La obra matemática de Luís A. Santaló

    OpenAIRE

    Vidal, Enrique

    1990-01-01

    Me resulta muy agradable poder comentar la obra matemática de un gran amigo, Luis A. Santaló, con quien me encontré por primera vez siendo los dos estudiantes en Madrid, y con el que siempre he mantenido una entrañable amistad.

  16. Análisis económico-financiero de las principales empresas del sector de la telefonía móvil en España

    OpenAIRE

    Fernández López, Aida

    2014-01-01

    El trabajo analiza la evolución seguida por el sector de la telefonía móvil en España desde sus inicios, analizando aspectos como la solvencia a corto y a largo plazo, el nivel de endeudamiento mantenido y la rentabilidad económica y financiera alcanzada por las principales empresas del sector

  17. Ciclo reprodutivo do mexilhão Perna perna (Linnaeus) (Molusca, Bivalvia) da Lagoa de Itaipu, Niterói, Rio de Janeiro, Brasil Reproductive cycle of Perna perna (Linnaeus) from Itaipu Lagoon, Niterói, Rio de Janeiro, Brazil

    OpenAIRE

    Eliana de Fátima Marques de Mesquita; Marta Guimarães de Abreu; Francisco Carlos de Lima

    2001-01-01

    The gametogenic aspects of mussel Perna perna (Linnaeus, 1758) from Itaipu Lagoon, Niterói, were studied through November 1998 to October 1999. Microscopic analysis was carried out at low and high dry magnifications, as well as under oil immersion. The animals collected showed variation of size from 4.8 to 9.1 cm in total length and from 2.0 to 3.9 cm in total width. Most advanced gonadal stage was detected through May, August and October of 1999 for female specimens. Male advanced gonadal st...

  18. GENETIC DIVERSITY OF FIVE FRESHWATER MUSSELS IN GENUS ANODONTA (MOLLUSCA: BIVALVIA ) REVEALED BY RAPD ANALYSIS%通过RAPD分析揭示五种淡水无齿蚌(软体动物门:双壳类)的遗传多样性

    Institute of Scientific and Technical Information of China (English)

    WEI Kai-Jian; XIONG Bang-Xi; ZHANG Gui-Rong

    2006-01-01

    Unionidae are an important group of benthic freshwater species. Due to the convergence phenomenon within freshwater mussels, there is still much controversy in the classification of Chinese Unionidae. In China, most studies on freshwater mussels emphasized resource investigation, biology and morphology, while little has been done in genetics, and particularly not in population genetic structure as well as genetic diversity. In order to further understand the status of genetic diversity of different species,random amplified polymorphic DNA (RAPD) markers were used to detect genetic diversity of populations in five species of the genus Anodonta : Anodonta arcaeformis , A . arcaeformis flavotincta , A .fluminea , A . woodiana woodiana and A . w . pacifica .DNA extraction method was based on phenol-chloroform and extracted genomic DNA from the adductor muscle and mantle tissues.Sixteen random primers were used for RAPD amplification and the polymorphism of amplified loci were analyzed. The results demonstrated that the percentage of amplified polymorphic loci for various populations ranged from 34.5% to 62.8%, the mean Shannon' s genetic diversity indices ranged from 0. 2021 to 0. 3552, and the mean intra-population Nei's genetic distance ranged from 0. 1386 to 0. 1713. In all populations of the five species, the genetic diversity for A. arcaeformis was the largest, and that of A. fluminea was the lowest. The inter-population genetic distance between A. w. woodiana and A. w. pacifica was 0.3186,so they can be considered as two sister species at the genetic angle.

  19. Early stage morphogenesis: an approach to problems of taxonomy, phylogeny and evolution in the Mytilidae (Mollusca: Bivalvia)%早期形态发生:一种解决贻贝科(软体动物门:双壳纲)分类、系统发育和进化问题的方法

    Institute of Scientific and Technical Information of China (English)

    George A. EVSEEV; Olga Ya. SEMENIKHINA; Natalya K. KOLOTUKHINA

    2005-01-01

    Sequence of appearance and transformations of morphological structures during larval and juvenile mytilids life histories have been examined. Ontogenies of about 60 taxa were typified into 4 morphogenetic patterns, or modes. Origin, developmental changes and homologies of the stage morphostructures were considered according to their location in three morphogenetic fields. The first, or central, field forms at the prodissoconch Ⅰ stage (PD-Ⅰ). It can be inherited by prodissoconch Ⅱ (PD-Ⅱ) and nepioconch (N) stages in one taxa, or PD-Ⅱ, N and dissoconch (D) stages in others. The second, or postero-dorsal, field appears at the N stage, and the third field, or antero-dorsal, at the D stage. The postero-dorsal field of the stage D inherits the N-morphostructures in one taxa, or D-stage in others. Central and postero-dorsal field morphostructures exhibit developmental sequences, or a system of characters which possess polarity, in contrast to adult characters applied in mytilid taxonomy. Based on early stage morphological characters of and well-known features studied previously but not used in taxonomy and phylogeny, a revaluation Soot-Ryen's system of supraspecific taxa and reconstruction of phylogenetic relationships among the Recent Mytilidae have been attempted. In the presented scheme, the subfamilies of Scarlato and Starobogatov (1984) form four phylogenetic lines beginning with the Modiolinae.%作者对贻贝科贝类的幼虫和幼贝期发育阶段形态结构的出现和变化顺序进行了研究,其约60个不同分类单元的个体发生可归纳为4种形态发生类型或模式.主要对3个形态发生区域的阶段形态结构的起源、发育变化和同源性做了研究.其一,即中央区域,开始形成于前双壳Ⅰ期(PD-Ⅰ),在某个分类单元它可以在前双壳Ⅱ期(PD-Ⅱ)和幼贝期(N)形成,而在其它分类单元则在前双壳Ⅱ期、幼贝期和双壳期(D)形成;第二区域,即背部后区,在幼贝期出现;第三区域,即背部前区,出现于双壳期.双壳期背部后区在某个分类单元起源于幼贝期的形态构造,在其它分类单元则可能起源于双壳期的形态构造.与在贻贝分类学上应用的成体特征相比,早期发育阶段中央和背部后区的形态结构显示出很明显的发育顺序或特征变化规律.根据以前人们熟知而尚未应用到分类和系统发育研究中的早期发育阶段形态特征,作者重新修订了Soot-Ryen的现生贻贝科种上阶元分类系统,重新提出了科内系统发育关系.修订的分类系统表明,Scarlato and Starobogatov (1984)提出的贻贝科各亚科由偏顶蛤亚科开始,沿4条系统发育路线演化发展,对应其早期发育阶段的4类形态发生类型或模式.

  20. Genetic analysis of the marine mussel Perna viridis (Bivalvia: Mytilidae) based on mitochondrial COI sequence and its phylogenetic relationship with other congeneric species%基于COI序列的翡翠股贻贝Perna viridis线粒体遗传特性分析及其近缘种间的系统关系探讨

    Institute of Scientific and Technical Information of China (English)

    位正鹏; 孔晓瑜; 吴相云; 喻子牛

    2009-01-01

    应用通用引物COIL 1490和COtH 2198对翡翠股贻贝Perna viridis的性腺和体细胞线粒体DNA进行PCR扩增,获得661bp长度的COI基因片段,经过比对性腺与体细胞的COI片段,发现雄性性腺与体细胞COI基因均为一个单倍型,即体内只有一种线粒体DNA类型,没有发现双单性遗传现象,雌、雄性腺的COI基因片段变异率很低(0.31%).应用 PAUP构建NJ树、MP树以及贝叶斯法构建了贝叶斯树,对股贻吡属3种间的系统关系进行了分析,结果表明,翡翠股贻贝P.viridis、p.canaliculus和P.perna之间的分化与分歧年代的估算是相吻合的.

  1. Invasive gobies in the Danube: invasion success facilitated by availability and selection of superior food resources

    Czech Academy of Sciences Publication Activity Database

    Polačik, Matej; Janáč, Michal; Jurajda, Pavel; Adámek, Zdeněk; Ondračková, Markéta; Trichkova, T.; Vassilev, M.

    2009-01-01

    Roč. 18, č. 4 (2009), s. 640-649. ISSN 0906-6691 R&D Projects: GA MŠk LC522 Grant ostatní: National Science Fund(BG) B-1510/05 Institutional research plan: CEZ:AV0Z60930519 Keywords : Apollonia * food availability * Bivalvia * invasion success * zebra mussel Subject RIV: EH - Ecology, Behaviour Impact factor: 1.512, year: 2009

  2. Biodiversity assessment of benthic macroinvertebrates in altitudinal lotic ecosystems of Serra do Cipó (MG, Brazil) Avaliação da biodiversidade de macroinvertebrados bentônicos em ecossistemas lóticos de altitude na Serra do Cipó (MG, Brasil)

    OpenAIRE

    GALDEAN N.; Callisto, M.; F. A. R. BARBOSA

    2001-01-01

    Five lotic systems of Serra do Cipó, south-east Brazil, were investigated in order to assess the existing diversity of benthic macroinvertebrates, habitats-microhabitats, and the available trophic resources. For each river it was analysed the communities of benthic macroinvertebrates and the composition of some taxonomic groups (Plecoptera, Ephemeroptera, Trichoptera and Diptera Chironomidae): the community with Bivalvia Sphaeriidae, Oligochaeta and Ephemeroptera Baetidae (being supposed a cl...

  3. Biodiversity assessment of benthic macroinvertebrates in altitudinal lotic ecosystems of Serra do Cipó (MG, Brazil)

    OpenAIRE

    GALDEAN N.; Callisto, M.; F. A. R. BARBOSA

    2001-01-01

    Five lotic systems of Serra do Cipó, south-east Brazil, were investigated in order to assess the existing diversity of benthic macroinvertebrates, habitats-microhabitats, and the available trophic resources. For each river it was analysed the communities of benthic macroinvertebrates and the composition of some taxonomic groups (Plecoptera, Ephemeroptera, Trichoptera and Diptera Chironomidae): the community with Bivalvia Sphaeriidae, Oligochaeta and Ephemeroptera Baetidae (being supposed a cl...

  4. Aspectos gerais sobre a alimentação do cangulo, Balistes vetula Linnaeus, 1758 (Pisces - Balistidae) no estado de Pernambuco - Brasil

    OpenAIRE

    Técio Luiz Macêdo Costa; Antônio de Lemos Vasconcelos Filho; Elza Maria Braga Galiza-Viana

    1987-01-01

    The Balistidae, especially Balistes vetula are commom fishes in tropical waters from Northeastern Brazil. Studies about these fishes captured at the coastal area of Recife between Pina; Boa Viagem, Piedade and Candeias beaches were carried out in order to determine the diet, and to verify a possible diet diversification between the sexes, and times of the year. Males and females had a food diet consisting mostly of molluscs belonging the classes Scaphopoda, Bivalvia, Gastropoda and crustacean...

  5. The Calyptogena magnifica chemoautotrophic symbiont genome

    Energy Technology Data Exchange (ETDEWEB)

    Newton, I.L.; Woyke, T.; Auchtung, T.A.; Dilly, G.F.; Dutton,R.J.; Fisher, M.C.; Fontanez, K.M.; Lau, E.; Stewart, F.J.; Richardson,P.M.; Barry, K.W.; Saunders, E.; Detter, J.C.; Wu, D.; Eisen, J.A.; Cavanaugh, C.M.

    2007-03-01

    Chemoautotrophic endosymbionts are the metabolic cornerstone of hydrothermal vent communities, providing invertebrate hosts with nearly all of their nutrition. The Calyptogena magnifica (Bivalvia: Vesicomyidae) symbiont, Candidatus Ruthia magnifica, is the first intracellular sulfur-oxidizing endosymbiont to have its genome sequenced, revealing a suite of metabolic capabilities. The genome encodes major chemoautotrophic pathways as well as pathways for biosynthesis of vitamins, cofactors, and all 20 amino acids required by the clam.

  6. Sequencing, De Novo Assembly, and Annotation of the Transcriptome of the Endangered Freshwater Pearl Bivalve, Cristaria plicata, Provides Novel Insights into Functional Genes and Marker Discovery

    OpenAIRE

    Bharat Bhusan Patnaik; Tae Hun Wang; Se Won Kang; Hee-Ju Hwang; So Young Park; Eun Bi Park; Jong Min Chung; Dae Kwon Song; Changmu Kim; Soonok Kim; Jun Sang Lee; Yeon Soo Han; Hong Seog Park; Yong Seok Lee

    2016-01-01

    Background The freshwater mussel Cristaria plicata (Bivalvia: Eulamellibranchia: Unionidae), is an economically important species in molluscan aquaculture due to its use in pearl farming. The species have been listed as endangered in South Korea due to the loss of natural habitats caused by anthropogenic activities. The decreasing population and a lack of genomic information on the species is concerning for environmentalists and conservationists. In this study, we conducted a de novo transcri...

  7. Disturbance of shallow marine soft-bottom environments and megabenthos assemblages by a huge tsunami induced by the 2011 M9.0 Tohoku-Oki earthquake.

    Directory of Open Access Journals (Sweden)

    Koji Seike

    Full Text Available Huge tsunami waves associated with megathrust earthquakes have a severe impact on shallow marine ecosystems. We investigated the impact of a tsunami generated by the 2011 M9.0 Tohoku-Oki earthquake on the seafloor and large benthic animals in muddy and sandy ria coasts (Otsuchi and Funakoshi bays in northeastern Japan. We conducted underwater field surveys using scuba equipment in water depths of <20 m before the tsunami (September 2010 and after the tsunami (September 2011 and September 2012. During the study period, episodic changes in topography and grain-size composition occurred on the seafloor of the study area. Megabenthos sampling revealed a distinct pattern of distribution succession for each benthic species. For example, the protobranch bivalve Yoldia notabilis (Bivalvia: Nuculanidae and the heterodont bivalve Felaniella usta (Bivalvia: Ungulinidae disappeared after the tsunami event, whereas the distribution of the venus clam Gomphina melanaegis (Bivalvia: Veneridae remained unchanged. In addition, the patterns of succession for a single species, such as the giant button top shell Umbonium costatum (Gastropoda: Trochidae and the heart urchin Echinocardium cordatum (Echinoidea: Loveniidae, varied between the two bays studied. Our data also show that reestablishment of some benthic animal populations began within 18 months of the tsunami disturbance.

  8. El «saber artístico» de un antropólogo y el estudio de la cultura en el Perú: A propósito de una obra olvidada de José María Arguedas

    Directory of Open Access Journals (Sweden)

    Juan Javier Rivera Andía

    2011-12-01

    Full Text Available Este breve texto intenta llamar la atención sobre ciertas preguntas en torno al carácter inédito que ha mantenido, por casi medio siglo, un archivo etnográfico acopiado por J. M. Arguedas. Entre ellas, nos preguntamos si tal condición estaría ligada a la forma en que Arguedas concebía el saber de la antropología.

  9. Variables predictoras de la actitud hacia los inmigrantes en la Región de Murcia (España)

    OpenAIRE

    Ramírez de la Fe, Mª Carmen; Rodríguez González, Ángel

    2006-01-01

    El presente estudio analiza la relación de distintas variables psicosociales con la actitud que mantienen los murcianos hacia los inmigrantes. Noventa y tres estudiantes de educación secundaria respondieron a instrumentos de medida de las siguientes variables: la similitud del exogrupo con el endogrupo, el contacto con los miembros del exogrupo (contacto presencial e interacción personal), el estereotipo mantenido hacia el exogrupo (valencia del estereotipo y amplitud del estereotipo), la per...

  10. Historia del modelo cosmológico estándar LCDM: la cosmología física tras del modelo del big bang

    OpenAIRE

    Luis Peña, Pilar Francisca

    2015-01-01

    Desde que el big bang se asentara como modelo cosmológico estándar han pasado 50 años. En este periodo, la cosmología ha mantenido abierta la cuestión de cuál es la evolución del universo y a través de la teoría inflacionaria ha enfrentado el p

  11. Aspectos reproductivos de la babilla Caiman crocodilus fuscus (Cope 1868, en condiciones de cautiverio

    Directory of Open Access Journals (Sweden)

    González Acosta Julio A.

    1996-06-01

    Full Text Available Observations were made on reproduction parameters of Caiman crocodilus tuscus in confimenet in the farm Saurus Ltd. during two periods of nesting and laying ( years 1992 - 1993 .Se realizaron observaciones sobre parámetros reproductivos en Caimsn crocodilus tuscus mantenidos en cautividad en el zoocriadero Saurus Ltda, durante dos épocas de anidación y postura (años 1992 - 1993.

  12. Construcción de una episteme desde la perspectiva ambiental compleja para la gestión en seguridad alimentaria y nutricional

    OpenAIRE

    Rodríguez Leyton, Mylene

    2010-01-01

    La seguridad alimentaria y nutricional, es una condición inherente a la vida; desde el inicio de la humanidad, cuando las guerras y las hambrunas deterioran la subsistencia, surge el interés por garantizar el autoabastecimiento de alimentos que se ha mantenido como un asunto prioritario en los programas de organismos internacionales y de los gobiernos. Hoy las transformaciones del concepto relacionan la seguridad alimentaria y nutricional con la disponibilidad, acceso, consumo, utilización...

  13. Sobrevivencia de Otocinclus spectabilis, en la etapa de levante, alimentado con dietas de diferente origen de la proteína

    OpenAIRE

    Lina M. Ardila - Meléndez; Jessica A. Albañil -Sanchez; José A. Arias Castellanos

    2012-01-01

    Los otocinclos son un grupo natural de peces loricaridos, que ocupan el segundo puesto dentro de los peces ornamentales de la captura que exporta Colombia. En la Orinoquia los alevinos y juveniles capturados de la especie son mantenidos cautivos en acuarios o estanques en tierra donde se les alimenta con raciones comerciales hasta conseguir la talla de venta, a esto último se le atribuye una de las principales causas de mortalidad. Con el propósito de explorar alternativas alimenticias que me...

  14. Crónica de la prensa salvadoreña: imaginarios que migran

    OpenAIRE

    Amparo Marroquín Parducci

    2008-01-01

    EL ARTÍCULO PRESENTA UN ESTUDIO DE LAS NARRATIVAS QUE LA PRENSA escrita ha venido construyendo en El Salvador en torno al fenómeno de la migración. Se argumenta que a través del tema de la migración se construye una poética de nación imaginada, y conjuntamente, se da la construcción de las alteridades que desde el discurso oficial se han mantenido vigentes.

  15. Behavioral analysis of Wistar rats fed with a flaxseed based diet added to an environmental enrichment Análisis del comportamiento de ratas Wistar alimentadas con una dieta a base de linaza añadidos a un enriquecimiento ambiental

    Directory of Open Access Journals (Sweden)

    J. Azevedo de Meneses

    2011-08-01

    ó dieta a base de linaza y fué mantenido en ambiente enriquecido; FSEG, que recibió dieta a base de linaza y fué mantenido en ambiente padrón; CEEG, que recibió dieta a base de caseína y fué mantenido en ambiente enriquecido; CSEG, que recibió dieta a base de caseína y fué mantenido en ambiente padrón; MCEEG, que recibió dieta a base de caseína con modificaciones de modo a proporcionar el mismo contenido de fibras y grasa encontrados en la dieta a base de linaza, y mantenido en ambiente enriquecido; MCSEG, que recibió dieta a base de caseína modificada y fué mantenido en ambiente padrón. Todos los animales tubieron temperatura ambiente controlada, jaulas colectivas (n = 3 y ciclo claro/oscuro (12 h, recibiendo água y ración ad libitum, excepto los grupos MCEEG y MCSEG que fueron sometidos a sistema pair feeding con los grupos FEEG y FSEG, respectivamente. El consumo y peso corporal de los animales fué medido dos veces por semana. Los animales fueron mantenidos en sus respectivos grupos a partir del primer mes de vida y hasta el segundo, cuando se inició un período de pruebas en el Open Field Test. Al término de las pruebas se sacrificaron los animales y se retiraron sus cerebros para calcular el peso relativo. Nuestros resultados muestran una interacción entre la linaza y el enriquecimiento ambiental en la habituación a un nuevo ambiente, haciendo que los animales sean mas manipulables y menos nerviosos.

  16. Benthic Macro-Fauna Composition and Abundance in Sombreiro River, Niger Delta, Nigeria

    Directory of Open Access Journals (Sweden)

    E.N. Ezekiel

    2011-04-01

    Full Text Available The benthic macro-fauna composition and abundance in sombreiro was studied for a period of two years (August 2007 - July2009. A total of twenty-eight species belonging to fourteen (14 families, six (6 classes and three (3 phyla were recorded in Sombreiro River. The phylum Annelida dominated with two classes (Oligochaeta and Polychaeta. Oligochaeta was represented by two families (Naididae and Lumbricidae and seven species having 25% by composition. Polychaeta was represented by seven families (Nereidae, Nepthyidae, Capitellidae, Eucinidae, Glyceridae, Arenicolidae and Syllidae and thirteen species having 46.4% by composition. The Phylum arthropoda was represented by two classes (Crustacea and inseita. Two families (Gammaridae and Penaidae having two species consisting of 7.2% were recorded, for the class crustacea. The class insecta was represented by one family (Chironomidae with one species consisting of 3.6%. The phylum Mollusca was represented by two classes (Gastropoda and Bivalvia. Gastropoda had two species with 7.2% composition and Bivalvia has three species with10.7% composition. Oligochaeta was the highest and constituted 62.0%. The others were Polychaeta (23.9%, Insecta (6.7%, Gastropoda (3.9%, Bivalvia (2.2% and Crustacea (1.3%. The mean diversity(S ranged between 11 species. Mean abundance of individuals (N was 985. Mean Margalef index (d value was 1.339. The mean value for Shannon-Wienner (H was 0.956. Mean Pielou’s index of relative density or evenness index (E was 0.986. Mean SimpsIn’s Dominance index (C was 0.623.

  17. Molecular identification, phylogeny and geographic distribution of Brazilian mangrove oysters (Crassostrea

    Directory of Open Access Journals (Sweden)

    Aline Grasielle Costa de Melo

    2010-01-01

    Full Text Available Oysters (Ostreidae manifest a high degree of phenotypic plasticity, whereby morphology is of limited value for species identification and taxonomy. By using molecular data, the aim was to genetically characterize the species of Crassostrea occurring along the Brazilian coast, and phylogenetically relate these to other Crassostrea from different parts of the world. Sequencing of the partial cytochrome oxidase c subunit I gene (COI, revealed a total of three species of Crassostrea at 16 locations along the Brazilian coast. C. gasar was found from Curuçá (Pará state to Santos (São Paulo state, and C. rhizophorae from Fortim (Ceará state to Florianópolis (Santa Catarina state, although small individuals of the latter species were also found at Ajuruteua beach (municipality of Bragança, Pará state. An unidentified Crassostrea species was found only on Canela Island, Bragança. Crassostrea gasar and C. rhizophorae grouped with C. virginica, thereby forming a monophyletic Atlantic group, whereas Crassostrea sp. from Canela Island was shown to be more similar to Indo-Pacific oysters, and either arrived in the Atlantic Ocean before the convergence of the Isthmus of Panama or was accidentally brought to Brazil by ship.

  18. Millennial-scale sustainability of the Chesapeake Bay Native American oyster fishery.

    Science.gov (United States)

    Rick, Torben C; Reeder-Myers, Leslie A; Hofman, Courtney A; Breitburg, Denise; Lockwood, Rowan; Henkes, Gregory; Kellogg, Lisa; Lowery, Darrin; Luckenbach, Mark W; Mann, Roger; Ogburn, Matthew B; Southworth, Melissa; Wah, John; Wesson, James; Hines, Anson H

    2016-06-01

    Estuaries around the world are in a state of decline following decades or more of overfishing, pollution, and climate change. Oysters (Ostreidae), ecosystem engineers in many estuaries, influence water quality, construct habitat, and provide food for humans and wildlife. In North America's Chesapeake Bay, once-thriving eastern oyster (Crassostrea virginica) populations have declined dramatically, making their restoration and conservation extremely challenging. Here we present data on oyster size and human harvest from Chesapeake Bay archaeological sites spanning ∼3,500 y of Native American, colonial, and historical occupation. We compare oysters from archaeological sites with Pleistocene oyster reefs that existed before human harvest, modern oyster reefs, and other records of human oyster harvest from around the world. Native American fisheries were focused on nearshore oysters and were likely harvested at a rate that was sustainable over centuries to millennia, despite changing Holocene climatic conditions and sea-level rise. These data document resilience in oyster populations under long-term Native American harvest, sea-level rise, and climate change; provide context for managing modern oyster fisheries in the Chesapeake Bay and elsewhere around the world; and demonstrate an interdisciplinary approach that can be applied broadly to other fisheries. PMID:27217572

  19. Complete mitochondrial DNA sequences of Saccostrea mordax and Saccostrea cucullata: genome organization and phylogeny analysis.

    Science.gov (United States)

    Volatiana, Josie Ancella; Fang, Shasha; Kinaro, Zachary Omambia; Liu, Xiao

    2016-07-01

    Classified in the phylum mollusks, oysters are bivalves which are found in estuaries and coastal zones. Because of their plastic shell, mitochondrial DNA analysis of this species becomes an interesting field, necessary to investigate their phylogenetic and evolution of relations. In our study, two oyster species: Saccostrea mordax and Saccostrea cucullata from Indian Ocean (Madagascar) were investigated. The complete sequence of Saccostrea mordax (16 512 bp) and Saccostrea cucullata (16 396 bp) were described and determined, with their mitogenomes deposited in the GenBank with accession number KP769562 and KP967577 respectively. Both mitochondrial genome sequences contained 12 protein-coding genes, 23 tRNAs, and two rRNAs, all encoded in the same heavy strand. High levels of similarity in the gene arrangement of the two Saccostrea species were evident. The phylogenetic analysis shows a closer relationship between the two Saccostrea species and confirms the strong relationship within Saccostrea, Crassostrea and Ostrea genus in taxonomy of Ostreidae family. PMID:26226596

  20. [The distribution of the radionuclides in the main components of lake ecosystems within the Chernobyl NPP exclusion zone].

    Science.gov (United States)

    2005-01-01

    The results of the studies devoted to the distribution of radionuclides 90Sr, 137Cs, 238Pu, 239 + 240Pu and 241Am in 1998-2003 in main components of Glubokoe Lake and Dalekoe-1 Lake located within Krasnensky flood lands of the Pripyat River (inner exclusion zone of the Chernobyl NPP) were analysed. The data about the radionuclide content in bottom sediments, in water, in seston, in macrozoobenthos (including bivalvia molluscs), in gasteropods molluscs, in higher aquatic plants and in fish are presented. PMID:16080615

  1. MOLLUSCAN FAUNA OF HARD SUBSTRATE ALONG THE COASTAL ZONE OF WESTERN LIBYA

    Directory of Open Access Journals (Sweden)

    Najla M Abushaala, Taher Shaibi* and Hassan M Howaege

    2014-08-01

    Full Text Available A total of 36 molluscs species were encountered along the western coast of Libya between Gout alruman and Tellil. Samples were collected during September and October 2004 using a 25 × 25 cm quadrate on a sectorial belt. Gastropoda was the most dominant class with 25 species followed by Bivalvia (10 species and one species of Polyplacophora. No significant differences in number of molluscan species were recorded between locations. The results showed a clear variations in the quantity of benthic animals in all studied station which ranged between 136 – 7276 individuals.

  2. First record of Corbicula fluminalis (Müller, 1774 in Lake Garda (Italy, living in sympatry with Corbicula fluminea (Müller, 1774

    Directory of Open Access Journals (Sweden)

    Cristina CAPPELLETTI

    2009-02-01

    Full Text Available The first record of Corbicula fluminalis (Müller, 1774 (Mollusca: Bivalvia: Veneroidea: Corbiculidae in Lake Garda (Italy is presented. This clam was observed in July 2008 along the lake shore, with a high number of shells; sampling of lake sediment revealed the presence of live specimens. C. fluminea (Müller, 1774 has already been recorded in Lake Garda since 2002. The need for further studies on the presence and the spread of the two clams and the biodiversity of the invertebrate community of the lake is underlined, in relation to recent records of other invasive species, such as Dikerogammarus villosus (Sowinsky, 1894.

  3. The first record of the Chinese pond mussel Sinanodonta woodiana (Lea, 1834 in Montenegro

    Directory of Open Access Journals (Sweden)

    Tomović Jelena

    2013-01-01

    Full Text Available Sinanodonta woodiana (Lea, 1834, Chinese pond mussel (Bivalvia: Unionoida: Unionidae is one of the most invasive aquatic macroinvertebrate species found in Europe. We report the Chinese pond mussel for the first time in Montenegro, in August 2012, in Lake Šasko (Adriatic part of the Central Mediterranean subarea. One specimen of the Chinese pond mussel was observed in a habitat with a predominantly silt-clay substrate. The main pathway of species introduction was evaluated to be via fish stocking. [Projekat Ministarstva nauke Republike Srbije, br. III 43002 i br. ON 173025

  4. Phylogenetic position of the genus Perkinsus (Protista, Apicomplexa) based on small subunit ribosomal RNA.

    Science.gov (United States)

    Goggin, C L; Barker, S C

    1993-07-01

    Parasites of the genus Perkinsus destroy marine molluscs worldwide. Their phylogenetic position within the kingdom Protista is controversial. Nucleotide sequence data (1792 bp) from the small subunit rRNA gene of Perkinsus sp. from Anadara trapezia (Mollusca: Bivalvia) from Moreton Bay, Queensland, was used to examine the phylogenetic affinities of this enigmatic genus. These data were aligned with nucleotide sequences from 6 apicomplexans, 3 ciliates, 3 flagellates, a dinoflagellate, 3 fungi, maize and human. Phylogenetic trees were constructed after analysis with maximum parsimony and distance matrix methods. Our analyses indicate that Perkinsus is phylogenetically closer to dinoflagellates and to coccidean and piroplasm apicomplexans than to fungi or flagellates. PMID:8366895

  5. Cytogenetic studies in green mussel, Perna viridis (Mytiloida: Pteriomorphia), from West Coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Iqbal, A.N.M.Z.; Khan, M.S.; Goswami, U.

    studies have received a little consideration than they actually deserve. Karyotypic details have been documented in several animal groups including a few Bivalvia species (Cornet and Soulard 1990; Wada and Komaru 1993; Insua et al. 1998; Martı´nez- Lage et... and methods Green mussels were collected from the Central West Coast of India. Live animals were brought to the laboratory and acclimatized for ten days in tanks containing aerated sea- water at 25C176C and fed upon phytoplankton Chaetocerous sp. Animals were...

  6. Macrobenthic communities of the coastal waters of Dabhol, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Ingole, B.S.; Rodrigues, N.; Ansari, Z.A.

    grab, covering an area of 0.04 m 2 and penetration of 10 cm. Sediment samples were col- lected from ten stations in Dec.1994 located in the three depth zones viz.: 5,10 and 20-meters (Fig. 1), while sediment samples in Dec. 1996 were collected only.... Composition and abundance of macrofauna Macrofauna comprised of Polychaeta, Amphipoda, Bivalvia, Oligochaeta and Gastropoda (Table 2). Al- though the macrofaunal composition did not show any major changes for both sampling periods, the percent occurrence...

  7. [Latin American malacology. Freshwater mollusks from Argentina].

    Science.gov (United States)

    Rumi, Alejandra; Gregoric, Diego E Gutiérrez; Núñez, Verónica; Darrigran, Gustavo A

    2008-03-01

    A report and an updated list with comments on the species of freshwater molluscs of Argentina which covers an area of 2 777 815 km2 is presented. Distributions of Gastropoda and Bivalvia families, endemic, exotic, invasive as well as entities of sanitary importance are also studied and recommendations on their conservation are provided. Molluscs related to the Del Plata Basin have been thoroughly studied in comparison to others areas of the country. This fauna exhibits relatively the biggest specific richness and keeps its affinity with the fauna of other regions of the basin in areas of Paraguay and Brasil. The 4 500 records of molluscs considered in this paper arise from the study of the collections of Museo Argentino de Ciencias Naturales "Bernardino Rivadavia", Buenos Aires; Museo de La Plata, La Plata and Fundación "Miguel Lillo", Tucumán. These institutions keep very important collections of molluscs in southern South America. Field information has recently been obtained and localities cited by other authors are also included in the data base. Until today, 166 species have been described, 101 belonging to 10 families of Gastropoda and 65 to 7 of Bivalvia. Families with highest specific richness are Lithoglyphidae (22) and Sphaeriidae (25), respectively. The number of endemic species (those present only in Argentina) by family is: Gastropoda: Ampullariidae (1), Cochliopidae (10), Lithoglyphidae (11), Thiariidae (3), Chilinidae (11), Lymnaeidae (2) and Physidae (2?); Bivalvia: Hyriidae (1?); Etheriidae (1?) and Sphaeriidae (10). Families with a distribution that comprise almost the whole country are: the Sphaeriidae and the gastropods Cochliopidae, Chilinidae and Lymnaeidae. Families Erodonidae and Solecurtidae (Bivalvia) were registered in mixohaline environments from Buenos Aires province. Gastropod families Thiaridae and Glacidorbiidae show a very restricted distribution. The rest of the families are present mainly in the center and north of the country

  8. The Distribution, Abundance and Seasonality of Benthic Macro Invertebrate in Okpoka Creek Sediments, Niger Delta, Nigeria

    OpenAIRE

    J.F.N. Abowei

    2010-01-01

    The distribution, abundance and seasonality of benthic macro invertebrates in Okpoka creeksediments were studied for a period of one year (January-December 2006). Polychaeta was highest andconstituted 82.8%. The others were Bivalvia (4.6%), Crustacea (4.5%) and Oligochaeta (3.9%), Gastropoda(2.1%) and Insecta (2.0%). From nineteen (19) species encountered in the area, all the species of the class(Polychaeta) with the exception of Nereis virens occurred in all the stations. The species found w...

  9. La transexualidad: asistencia multidisciplinar en el Sistema Público de Salud.

    Directory of Open Access Journals (Sweden)

    Trinidad Bergero Miguel

    2004-01-01

    Full Text Available La transexualidad constituye un importante problema de salud, que en nuestro país se ha mantenido al margen de las prestaciones sanitarias públicas hasta 1999, lo que ha dificultado la realización sistemática de estudios pormenorizados con poblaciones de transexuales españoles. En el presente trabajo se realiza de modo resumido una puesta al día de los conocimientos básicos sobre el tema, con el fin de facilitar un acercamiento al transexualismo y una mejor comprensión de esta patología

  10. Incidencia de agenesia dental en perros Beagle. Resultados preliminares(Dental agenesis incidence in Beagle dogs. Preliminary results

    Directory of Open Access Journals (Sweden)

    Rodríguez Sosa

    2011-11-01

    Full Text Available ResumenEn el presente trabajo se examinaron 49 perros Beagle procedentes del CENPALAB que fueron mantenidos bajo el mismo régimen de convivencia, alimentación y manejo en el Bioterio de la Facultad de Medicina “Victoria de Girón” tributarios todos a estudios de implantes dentales.AbstractForty-nine Beagle dogs coming from CENPALAB were maintained under the same coexistence, feeding and handling regime in the Bioterio of Medicine High School “Victoria de Girón” tributary to studies of dental implant all them.

  11. Criterios de esta edición

    OpenAIRE

    Laso, Francisco

    2015-01-01

    La mayor parte de los ensayos de Laso aparecieron originalmente en publicaciones periódicas. Estas se caracterizaban por llevarse a cabo con ajustados plazos de edición y como resultado del apuro, los textos llegaban a prensa cargados de errores. Con el fin de facilitar la lectura, hemos corregido dichos errores a la vez que modernizado y uniformizado el uso del lenguaje. En casos donde el error podría ser atribuido al autor, o donde existe duda acerca del sentido se ha mantenido el texto ori...

  12. El conductismo y algunas implicaciones de lo que significa ser conductista hoy

    OpenAIRE

    Camilo Hurtado

    2006-01-01

    Se discuten varios aspectos relacionados con el conductismo, sus múltiples versiones, una definición amplia de éste y a quienes se les puede denominar actualmente conductistas. Además, a partir de una anécdota se analiza, en términos de barreras epistemológicas, el rechazo a esta tradición de pensamiento y se discute como dicho rechazo está enraizado y mantenido en una serie de malentendidos y en las contradicciones que existen entre los principios del conductismo genérico y los de la llamad...

  13. La cartera de servicios en una organización de salud pública

    OpenAIRE

    Villalbí J.R.; Guix J.; Plasència A.; Armengou J.M.; Llebaría X.; Torralba L.

    2003-01-01

    La definición de la cartera de servicios ha sido uno de los elementos del proceso de mejora de la gestión de los servicios sanitarios en España, en curso, del que los servicios de salud pública se han mantenido en buena parte al margen. En este trabajo se analizan los servicios de salud pública a partir de la experiencia de la Agencia de Salud Pública de Barcelona. Se propone un esquema de categorización que permite distinguir entre los que son propiamente servicios productivos de salud públi...

  14. La cartera de servicios en una organización de salud pública Portfolio of services in a public health organization

    OpenAIRE

    J.R. Villalbí; J. Guix; A. Plasència; J.M. Armengou; X. Llebaría; L. Torralba

    2003-01-01

    La definición de la cartera de servicios ha sido uno de los elementos del proceso de mejora de la gestión de los servicios sanitarios en España, en curso, del que los servicios de salud pública se han mantenido en buena parte al margen. En este trabajo se analizan los servicios de salud p��blica a partir de la experiencia de la Agencia de Salud Pública de Barcelona. Se propone un esquema de categorización que permite distinguir entre los que son propiamente servicios productivos de salud públ...

  15. Regiones hidrogeológicas : República Argentina y provincias de Buenos Aires, Mendoza y Santa Fe

    OpenAIRE

    Auge, Miguel

    2004-01-01

    El incrementeo en la demanda global de agua, debido al aumento de la población, de la producción y del riego, es un problema que ha afectado, salvo raras excepciones, a todo el planeta. Esto lógicamente se ha manifestado con mayor intensidad en las regiones densamente pobladas, especialmente en las megalópolis. Si bien el volumen total de agua se ha mantenido prácticamente constante en la hidrósfera a través del tiempo, no ha sucedido lo mismo con su distribución espacial y temporal. En es...

  16. Un compromiso de servicio común: la carta de servicios de la biblioteca y del servicio de informática de la Universitat Pompeu Fabra

    OpenAIRE

    Alòs Marquès, Joan; Cabo Rigol, Mercè; Espinós Ferrer, Montserrat; Garreta Gambús, Mar; Grané Viadé, Teresa

    2010-01-01

    La Biblioteca y el Servicio de Informática de la Universitat Pompeu Fabra han mantenido, desde el inicio de su trayectoria, un fuerte compromiso para con la satisfacción de las necesidades de los usuarios y la mejora continua de la calidad de la prestación de los servicios. En el contexto de convergencia de prestación de servicios bibliotecarios, informáticos y audiovisuales de apoyo a la docencia, el aprendizaje y la investigación que se está llevando a cabo en la UPF, la B...

  17. Conocimientos y actitudes sobre sexualidad en adolescentes de primer curso de Grado en Educación Infantil y Primaria de la Universidad de Jaén

    OpenAIRE

    Rodríguez Mármol, María; Muñoz Cruz, Rafael; Sánchez Muñoz, Inés

    2016-01-01

    Objetivo: Conocer los conocimientos y actitudes sobre sexualidad en los adolescentes de primero de Grado en Educación de la Universidad de Jaén. Material y Método: Los datos se recogieron a través de un cuestionario anónimo, voluntario y autocumplimentado, el cual se aplicó a una muestra no probabilística por conveniencia de 151 sujetos estudiantes de primer curso de Grado en Educación Infantil y Primaria de la Universidad de Jaén. Resultados: 118 manifiestan haber mantenido re...

  18. Sensibilización y tolerancia a la violencia de parejas de novios en relaciones de noviazgo universitarias

    OpenAIRE

    Rodríguez Franco, Luis; Rodríguez Díaz, Francisco Javier; Antuña Bellerín, María De los Ángeles; López‐Cepero Borrego, Javier

    2010-01-01

    En nuestro estudio, se analiza la sensibilización y tolerancia a la violencia de pareja en estudiantes mujeres de entre 16 y 25 años que cursan sus estudios universitarios. El único requisito adicional para la formación de la muestra ha sido el haber mantenido una relación de noviazgo de, al menos, un mes de duración. La muestra se compone de un total de 1079 sujetos de las Universidades de Sevilla, Asturias, Huelva, A Coruña y Vigo a quienes se aplicó el Cuestionario de Violen...

  19. La Unión Europea ante la crisis Siria: limitaciones e incoherencias de la acción exterior europea en el mediterráneo

    OpenAIRE

    Ferrer Lloret, Jaume

    2014-01-01

    Hasta el estallido de la denominada “primavera árabe” en los primeros meses de 2011, la Unión europea había mantenido una política exterior condescendiente ante las vulneraciones graves y masivas de los derechos humanos responsabilidad del régimen sirio dirigido por el clan de los Al-Assad. Como respuesta al conflicto armado sirio y la comisión de crímenes contra la humanidad y crímenes de guerra atribuibles al Gobierno sirio, la UE ha aplicado toda una batería de medidas restrictivas, y ha d...

  20. Estudo comparativo do manejo das desovas de Caretta caretta (Testudines: Cheloniidae) no litoral do Espírito Santo, sudeste do Brasil

    OpenAIRE

    Barros Ribeiro, Leonardo; Souza, Bernardete María de

    2007-01-01

    Este estudio evaluó el éxito reproductivo de la tortuga marina Caretta caretta según el manejo aplicado por Projeto Tamar, entre los meses de septiembre de 2002 y enero de 2003, en la playa de Guriri, estado del Espírito Santo, sudeste del Brasil. Se aplicaron tres técnicas de manejo para proteger la población que anida en el área: nidos mantenidos en el mismo sitio de la postura (in situ), nidos transferidos en la propia playa, y nidos transferidos a cercos de incubación. Basado en la propor...

  1. Estudo comparativo do manejo das desovas de Caretta caretta (Testudines: Cheloniidae) no litoral do Espírito Santo, sudeste do Brasil

    OpenAIRE

    Barros Ribeiro, Leonardo; Souza, Bernardete María de

    2007-01-01

    Este estudio evaluó el éxito reproductivo de la tortuga marina Caretta caretta según el manejo aplicado por Projeto Tamar, entre los meses de septiembre de 2002 y enero de 2003, en la playa de Guriri, estado del Espírito Santo, sudeste del Brasil. Se aplicaron tres técnicas de manejo para proteger la población que anida en el área: nidos mantenidos en el mismo sitio de la postura (in situ), nidos transferidos en la propia playa, y nidos transferidos a cercos de incubación. Basado en la propor...

  2. Clinton-Lewinsky: el escándalo que comenzó en la Red

    Directory of Open Access Journals (Sweden)

    Dra. Claudia Quadros

    1999-01-01

    Full Text Available Internet fue el medio usado para publicar las primeras informaciones y rumores sobre la historia de que Mónica Lewinski, becaria de la Casa Blanca, había mantenido relaciones sexuales con el presidente de Estados Unidos, Bill Clinton. Matt Drudge, un periodista responsable de la edición de un panfleto digital sin credibilidad llamado 'The Drudge Report' (http://www.drudgereport.com fue el primero en difundir el escándalo. El hecho tuvo lugar el 18 de enero de 1998.

  3. Evaluación de una solución inmovilizadora para criopreservación del semen de Colossoma macropomum, “Gamitana”

    OpenAIRE

    Ehrlich Llasaca-Calizaya; Lorgio Verdi-Olivares; Jesús Nuñez-Rodriguez

    2015-01-01

    El objetivo del trabajo fue la criopreservacion de semen, que permitirá constituir un banco genético, para lo cual se buscó obtener una solución  inactivadora de colecta para el semen de Colossoma macropomum  “gamitana”, que permita obtener espermatozoides, con buena motilidad de activación después de la descongelación, en nitrógeno líquido. Se utilizó semen de reproductores mantenidos, del Instituto de Investigaciones de la Amazonía Peruana (IIAP) inducidos con Conceptal® y sin inducir mante...

  4. INFLUENCIA DE BACTERIOCINAS PRODUCIDAS POR Lactobacillus plantarum LPBM10 SOBRE LA VIDA ÚTIL DE FILETES DEL HÍBRIDO DE CACHAMA Piaractus brachypomus x Colossoma macropomum EMPACADO AL VACÍO: INFLUENCE OF BACTERIOCINS PRODUCED BY Lactobacillus plantarum LPBM10 ON SHELF LIFE OF CACHAMA HYBRID FILLETS Piaractus rachypomus x Colossoma macropomum VACUUM PACKAGED

    OpenAIRE

    Héctor SUÁREZ M.; Alicia DE FRANCISCO; Luiz H. Beirão

    2008-01-01

    El uso de algunos de los géneros de las bacterias ácidolácticas (BAL) como Lactobacillus, Leuconostoc, Lactococcus, o sus productos antimicrobianos como las bacteriocinas, son alternativas en la biopreservación de productos mínimamente procesados que son mantenidos bajo refrigeración. El potencial de biopreservación de un extracto crudo de bacteriocinas producidas por una cepa nativa de Lactobacillus plantarum LPBM10, se evalúa sobre filetes de híbrido de cachama Piaractus brachypomus x Colos...

  5. TASAS DE CONCEPCIÓN, FERTILIDAD Y PROLIFICIDAD EN OVEJAS DE PELO ALIMENTADAS CON DIETAS ENRIQUECIDAS CON ÁCIDOS GRASOS POLIINSATURADOS

    OpenAIRE

    G Cansino-Arroyo; J Herrera-Camacho; JR Aké-López

    2009-01-01

    Las tasas de concepción, de fertilidad y prolificidad fueron evaluadas en ovejas de pelo distribuidas al azar en: un grupo testigo que recibió 800 g MS de un concentrado comercial, un grupo melaza (n = 51) alimentado con 717.6 g MS del concentrado comercial + 80.25 g MS de melaza y un grupo aceite (n = 85) mantenido con 726.8 del concentrado comercial + 30.0 g de aceite de maíz como fuente de ácidos grasos poliinsaturados. Las tasas de concepción y fertilidad fueron similares entre los tratam...

  6. Estrategia innovadora enfocada en parejas del mismo sexo para disminuir la infección del VIH en hombres Latinos

    OpenAIRE

    Martinez, Omar; Wu, Elwin; Sandfort, Theo; Shultz, Andrew Z; Capote, Jonathan; Chávez, Silvia; Moya, Eva; DODGE, BRIAN; Morales, Gabriel; Porras, Antonio; Ovejero, Hugo

    2014-01-01

    El VIH es un problema de salud importante dentro de la comunidad latina de los Estados Unidos. Gracias a los esfuerzos de prevención, los niveles de contagio entre los latinos se han mantenido estables por más de una década. Sin embargo, esta población sigue siendo afectada a niveles muy altos, en particular entre hombres que tienen sexo con hombres (HSH), de origen latino y que hablan principalmente el idioma español. Existen varios factores que contribuyen a la transmisión del VIH entre est...

  7. Elecciones y resultados electorales en Guerrero 2011

    OpenAIRE

    Marco Antonio Adame Meza

    2011-01-01

    La pasada elección en Guerrero para elegir gobernador presentó características de alta polarización y confrontación entre las dos fuerzas políticas que han mantenido en las últimas elecciones la concentración de las preferencias de los electores. En el presente trabajo se explica grosso modo los últimos momentos de las campañas y se analizan los resultados electorales a partir de indicadores que nos muestran el comportamiento electoral, tales como concentración del voto, fragmentación y volat...

  8. Lesiones inducidas por contacto directo con antenas de radio en vehículos de Caballería

    OpenAIRE

    I. Díaz de Tuesta Revilla

    2014-01-01

    La exposición sostenida a emisiones de radio podría estar relacionada con lesiones en el tejido subcutáneo. Presentamos dos casos sucedidos en tiradores de vehículo explorador de Caballería (VEC) tras unas maniobras en zona de operaciones Líbano, consistentes en una inusual tumefacción del tejido adiposo en antebrazo derecho sin antecedente de contusiones, ni contactos químicos o irradiación conocida, y con piel íntegra, que coincide con zonas de posible contacto mantenido con la antena del v...

  9. La democracia débil ante el populismo de la privacidad : terror panóptico y secreto administrativo frente al periodismo de rastreo informático en España

    OpenAIRE

    Dader, José Luis

    2001-01-01

    La democracia ideal se asienta en el principio de la soberanía popular, cristalizada en una opinión pública. Esta opinión pública ha ejercido, al menos idealmente, una función de vigilancia crítica. Al mismo tiempo, los ámbitos de la vida privada y pública se han mantenido estructuralmente diferenciados. Pese a ello, a lo largo de los siglos XIX y XX, se percibe una paulatina interpenetación de estos ámbitos. La actual interrelación entre Estado y sociedad ha vaciado de significado específico...

  10. La etapa universitaria no favorece el estilo de vida saludable en las estudiantes granadinas

    OpenAIRE

    Gallardo-Escudero, A.; Mu??oz Alf??rez, Mar??a; Planells del Pozo, Elena Mar??a; L??pez Aliaga, Inmaculada

    2015-01-01

    Objetivo: La etapa universitaria conlleva una serie de cambios emocionales, fisiol??gicos y ambientales que van a determinar unas costumbres y h??bitos de riesgoque en muchos casos ser??n mantenidos a lo largo de la vida y repercutir??n en su estado de salud. El objetivo del presente estudio es analizar el estilo de vida (consumo de alcohol, tabaco y niveles de actividad f??sica) de mujeres estudiantes de la Universidad de Granada. Metodolog??a: Se trata de un estudio ...

  11. Participación popular y movimiento campesino aymara

    OpenAIRE

    Liendo, Roxana

    2009-01-01

    Bolivia es un país diverso, con fuerte sello indígena de sus alrededor de 36 pueblos y una cultura dominante criolla hispánica. Estas culturas que fueron subordinadas y excluidas a partir de la conquista española y que lo continuarían siendo en las diferentes etapas de la vida republicana. Como resultado, la responsabilidad de su sobrevivencia se debió a sus autoridades y organizaciones tradicionales. El pueblo aymara, ha mantenido, conceptos y prácticas propios: de desarrollo como "vivir bie...

  12. Mediación musical: Aproximación etnográfica al narcocorrido

    OpenAIRE

    Burgos Dávila, César Jesús

    2012-01-01

    El narcocorrido es una expresión musical popular, polémica, vigente y ampliamente difundida en México. El prefijo “narco” se refiere a los aspectos relacionados con la droga. El complemento “corridos” se refiere a una de las tradiciones musicales más antiguas que se ha mantenido a lo largo de la historia de México. Las composiciones contemporáneas se han adaptado a las condiciones actuales, donde imperan el narcotráfico, la inseguridad y la violencia. Las diferentes realidades de “la guerra ...

  13. Mejora del diagnóstico precoz de cáncer de mama en pacientes valencianas

    OpenAIRE

    Pastor Climente, Ismael Pascual

    2010-01-01

    INTRODUCCIÓN: El cáncer de mama adquiere cada vez mayor relevancia por ser la enfermedad maligna que afecta a mujeres más común del mundo desarrollado. Aunque la mortalidad por cáncer de mama ha descendido, en los últimos años la incidencia de cáncer de mama se ha mantenido estancada. Se vuelve, por tanto, fundamental realizar esfuerzos encaminados a la prevención de esta enfermedad, siendo necesario para ello conocer el perfil de la paciente diagnosticada de cáncer de mama en la actualidad ...

  14. ¿Existe una personalidad jaquecosa?.

    OpenAIRE

    Ramo, C.; E García Albea; I. Posada; A Rodríguez-Antigüedad; Félix Bermejo

    1985-01-01

    Se revisa brevemente el concepto actual de jaqueca y se analiza detalladamente la literatura existente sobre la personalidad jaquecosa. El concepto de personalidad jaquecosa fue mantenido por clínicos y autores de orientación psicoanalítica en las décadas de 1930-1950. los estudios recientes efectuados con criterios epidemiológicos (no basados en estudios hospitalarios) y realizados, empleando tests psicológicos estandarizados no son concordantes con la existencia de una personalidad jaquecos...

  15. POR UNA POLÍTICA FISCAL CONTRACÍCLICA

    OpenAIRE

    Eduardo Ramírez Cedillo

    2006-01-01

    La postura fiscal de las economías latinoamericanas y de muchas en desarrollo ha mantenido un carácter procíclico que ha jugado un papel importante en la inestabilidad que observan éstas, a diferencia de lo que sucede en los países desarrollados, que utilizan su política fiscal para atenuar las presiones del ciclo económico. A este respecto, en este trabajo se vierten algunas explicaciones, como: la exposición a la volatilidad de los capitales financieros y el uso inadecuado de la política de...

  16. Susceptibilidad y síntomas respiratorios asociados a la exposición a dióxido de carbono y dióxido de azufre provenientes del volcán Turrialba, Costa Rica

    OpenAIRE

    Marisol Yglesias-González; Horacio Alejandro Chamizo-García

    2014-01-01

    El volcán Turrialba ha mantenido en los últimos años una actividad de desgasificación, y paulatinamente se han mostrado los efectos de este dinamismo sobre la vegetación e infraestructuras de las comunidades aledañas. Entre las sustancias que conforman esta actividad de desgasificación se encuentra el dióxido de carbono y el dióxido de azufre que se han ido incrementando y son capaces de afectar la salud respiratoria de quienes se exponen a ellas. El objetivo de esta investigación es analiza...

  17. Comportamiento fisiológico y fisico-químico en la poscosecha de curuba de castilla (passiflora mollissima bailey) conservada en refrigeración y temperatura ambiente

    OpenAIRE

    Tellez, Claudia Patricia; Fischer, Gerhard; Quintero, Over

    2011-01-01

    Con el objetivo de evaluar las características fisico-quimicas y fisiológicas en postcosecha de dos cultivares nuevas de Curuba de Castilla, 'Ruizquin l' Y 'Ruizquin 2', promisorios para la exportación, los frutos fueron mantenidos unos a 8°C (cuarto frio) y otros a 20°C (temperatura ambiente). En general, durante los días de almacenamiento, se pudo determinar que el valor del pH aumenta ligeramente, mientras la acidez total titulable disminuye gradualmente; el peso del fruto y la consistenci...

  18. LA APERTURA COMERCIAL DE MÉXICO Y EL DECLIVE DE SU COMPETITIVIDAD UN ANÁLISIS COMPARATIVO CON COREA DEL SUR

    OpenAIRE

    Francisco Carlos Soto Ramírez; María de los Dolores Santarriaga Pineda

    2008-01-01

    Esto se logra a través de analizar lo que ha pasado con la apertura de México, el descenso en la productividad, sus bajos niveles de crecimiento económico y realizar una comparación con Corea del Sur en donde se observa un comportamiento inverso de su competitividad al experimentado por México, a pesar de que ambos países han mantenido un comportamiento similar en la tasa de crecimiento de las exportaciones.

  19. El Supercómputo en 2010

    OpenAIRE

    Luna René; Villa Luis; Ramírez Marco

    2011-01-01

    Las aplicaciones que dominan el mercado del software demandan mayor capacidad de cómputo de forma permanente en prácticamente todos los campos del conocimiento: multimedia, procesamiento digital de señales, 3D, aplicaciones dedicadas, reconocimiento de patrones, astrofísica, simulación. Esta relación que existe entre el desempeño de los procesadores y los requerimientos de las aplicaciones, ha sido un patrón que se ha mantenido desde que, en 1954, hizo su entrada estelar la primera computado...

  20. Enemigos de La Habana entre los patriotas gaditanos

    OpenAIRE

    Vázquez Cienfuegos, Sigfrido

    2009-01-01

    Con la expresión "enemigos de La Habana" los hacendados criollos cubanos hacían referencia a los intereses monopolísticos que, asentados en Cádiz y representados en el Consulado, trataban por todos los medios de mantener las prerrogativas exclusivistas que habían disfrutado durante años. Si bien esta pugna se había mantenido durante las últimas décadas del siglo XVIII, fue durante el periodo en que Cádiz encarnó la resistencia frente al invasor francés cuando el enfrentamiento alcanzó el grad...

  1. Maduración del fruto de feijoa (acca sellowiana berg) en los clones 41 (quimba) y 8-4 a temperatura ambiente en condiciones de la sabana de bogotá

    OpenAIRE

    Rodríguez, Mariela; Arjona, Harvey E.; Galvis, Jesús Antonio

    2010-01-01

    Con el propósito de seleccionar los mejores frutos de feijoa (Acca sellowiana Berg) para exportación, se realizó un estudio de maduración con los frutos de los clones 41 (Quimba) y 8-4, mantenidos a temperatura promedio de 16,3 oC y HR promedio de 65,1%. El clon 8-4 fue evaluado por 14 d y el clon 41 (Quimba) por 18 d. Diariamente se registraron las variables intensidad respiratoria, sólidos solubles totales, acidez total titulable, pH y pérdida de peso. La intensidad respiratoria se determin...

  2. LA REFORMA UNIVERSITARIA NICOLAITA 1971-1986

    OpenAIRE

    Lucio Rangel Hernández

    2008-01-01

    Este trabajo analiza el proceso de transformación académica, administrativa y normativa, operado en la Universidad Michoacana de 1971 a 1986, bajo el proyecto modernizador de la educación superior implementado por el presidente Luis Echeverría Álvarez y mantenido, con algunas variantes, por sus sucesores José López Portillo y Miguel de La Madrid Hurtado. Dicho proyecto se proponía modernizar a la universidad a fin de hacerla funcional, adecuarla a las exigencias de la nueva etapa del desarrol...

  3. Desarrollo de la especialidad en Psicología clínica en Costa Rica: perspectivas futuras

    OpenAIRE

    Roberto López-Core

    2013-01-01

    En este trabajo se describen los antecedentes históricos, evolución y desarrollo de la Especialidad en Psicología Clínica en Costa Rica. En el año 1957, se inició el ejercicio de esta disciplina y a partir del año 1979 se consolidó el programa de estudios adscrito al Convenio Marco firmado entre la Universidad de Costa Rica (UCR) y la Caja Costarricense de Seguro Social (CCSS). Desde entonces, ha mantenido una acción ininterrumpida en la formación de especialistas. Los y las residentes en ...

  4. COMO FOMENTAR EL DEPARTAMENTO DE RECURSOS HUMANOS A NIVEL INTERNO EN TIEMPOS DE CRISIS. EXPERIENCIA REAL.

    OpenAIRE

    ROSALES GUIJARRO, RAQUEL

    2013-01-01

    En este trabajo quiero mostrar cómo se puede potenciar el departamento de recursos humanos de una empresa a nivel interno a través de la implantación de un Plan de Marketing orientado a dicho departamento. Comencé con la empresa Colebega, S.A., pero por cuestiones de cambio accionarial el trabajo tuvo que paralizarse. He mantenido la esencia inicial del trabajo, pero centrándome en el sector de la hostelería en general y en particular en el subsector de la restauración, con el ...

  5. Prevención de úlceras por presión y lesiones musculoesqueléticas: paciente con ictus

    OpenAIRE

    Rodríguez Pappalardo, Fátima; Luque Moreno, Carlos; Peña Salinas, Marta; López Rodríguez, Luis

    2012-01-01

    Planteamos un caso clínico en el que enfermera y fisioterapeuta ponen en común procedimientos para mejorar la higiene postural de un paciente encamado con un accidente cerebrovascular y hemiplejia izquierda. Describimos analíticamente una intervención conjunta durante un mes. A pesar de que se ha mantenido el riesgo máximo de UPP objetivado inicialmente, durante este periodo no han aparecido úlceras, obteniendo un mantenimiento o aumento del rango de las articulaciones. Es impo...

  6. Prevención de úlceras por presión y lesiones musculoesqueléticas: paciente con ictus Pressure ulcer prevention and muscular and skeletal injuries: Patient with stoke

    OpenAIRE

    Carlos Luque Moreno; Marta Peña Salinas; Fátima Rodríguez Pappalardo; Luis López Rodríguez

    2012-01-01

    Planteamos un caso clínico en el que enfermera y fisioterapeuta ponen en común procedimientos para mejorar la higiene postural de un paciente encamado con un accidente cerebrovascular y hemiplejia izquierda. Describimos analíticamente una intervención conjunta durante un mes. A pesar de que se ha mantenido el riesgo máximo de UPP objetivado inicialmente, durante este periodo no han aparecido úlceras, obteniendo un mantenimiento o aumento del rango de las articulaciones. Es importante un traba...

  7. Tratamiento informativo de la Monarquia Española en la prensa digital. De las grandes cabeceras a los medios nativos digitales

    OpenAIRE

    Lluch Sánchez, Ana

    2014-01-01

    Actualmente, la monarquía española se encuentra en una situación complicada debido a los continuos escándalos acontecidos en los últimos años que han deteriorado la imagen de la institución. La confianza y simpatía en la corona decrece por momentos y por ello, desde el año 2011 hasta ahora (2014) tanto los cibermedios más consolidados, que se habían mantenido silenciados, como los nuevos medios nativos digitales han dedicado grandes espacios a desmenuzar los casos de corrupc...

  8. Servicios, patología y rehabilitación de muralla e instalaciones de recreo

    OpenAIRE

    Cuenca García, Juan Antonio; Fernández Grande, Jesús; Hernández, Jesús Antonio; Aracil Serrano, Jorge

    1985-01-01

    Not Available.El pueblo de Granadilla ha mantenido durante siglos su configuración de pueblo defensivo, sin extenderse fuera de sus murallas; esto dio lugar a la creación, por un lado, de un sistema de trazado urbanístico propio, basado en las directrices de toda ciudad árabe con recinto defensivo y, por otro lado, de una infraestructura en materia de servicios orientada hacia el autoabastecimiento, sobre todo, en tiempos de guerra y sitio. Hasta hace relativamente poco tiempo, en el pue...

  9. Los alimentos modificados. ??El omn??voro desculturalizado?

    OpenAIRE

    Contreras, Jes??s; Ribas, Joan

    2012-01-01

    Los avances cient??ficos y la innovaci??n tecnol??gica en el sector agroalimentario han dado lugar a una ruptura fundamental de las relaciones que los seres humanos hab??an mantenido f??sicamente con su medio. La 'industrializaci??n', percibida en gran medida como una 'artificializaci??n' de la alimentaci??n, ha dado lugar a la idea de que cada vez sabemos menos acerca de lo que comemos, a pesar de que nunca como hoy hab??amos tenido tantos conocimientos sobre los alimentos, las enfermedades...

  10. Resultados de intervenciones en adherencia al tratamiento farmacologico en pacientes con hipertensión arterial analizados desde el modelo de Dorothea Orem: una revisión integrativa

    OpenAIRE

    Herrera Olaya, Ginna Paola; Silva Torres, Jorge Mario

    2014-01-01

    La hipertensión arterial (HTA) sigue constituyendo un problema de salud pública tanto a nivel mundial como nacional. En Colombia, ocupó el séptimo lugar como causa de mortalidad general en 2013 y además aporta como factor de riesgo para un importante número de enfermedades de alta prevalencia. Para su control se han establecido diversas estrategias, sin embargo, la adherencia a estas se ha mantenido baja, determinando graves consecuencias para la calidad de vida de la población afectada. P...

  11. Apuntes para un modelo didáctico de la enseñanza del lenguaje musical en la etapa de infantil

    OpenAIRE

    Santamaría Herranz, Pablo

    2006-01-01

    Enseñar el lenguaje musical es siempre una tarea ardua que todos los profesores de música tenemos que abordar. Pero, ¿debemos enseñar el lenguaje musical en la escuela, y aún en la etapa de infantil? Aunque algunos pedagogos han mantenido una postura contraria, las investigaciones en psicología de la música apuntan a que no solo es posible, sino que además estaremos potenciando el desarrollo del lenguaje. El artículo propone una serie de canciones didácticas enfocadas hacia el aprendiza...

  12. Hispanismos y canarismos en un corpus de textos ingleses sobre Canarias

    OpenAIRE

    María-Isabel González-Cruz

    2013-01-01

    ResumenLas Islas Canarias (España) siempre han mantenido un estrecho contactocon el mundo anglosajón, lo que ha generado importantes consecuencias económicas, así como también socioculturales, lingüísticas y literarias. Un análisis de la bibliografía inglesa sobre Canarias revela, entre otros aspectos, la tendencia al uso de hispanismos y canarismos. Este trabajo ofrece el registro de esas voces que aparecen en un corpus de catorce obras tomadas de la extensa bibliografía anglocanaria. Tras r...

  13. Sobre los textos y sus derechos en la Biblioteca virtual 'Miguel de Cervantes' en la Universidad de Alicante

    Directory of Open Access Journals (Sweden)

    Rovira, José Carlos

    2001-05-01

    Full Text Available Cercanos ya a los dos años de su inauguración, quiero reflexionar en este artículo sobre la cuestión de derechos de autor en una Biblioteca Virtual, a partir de la experiencia que nosotros mismos hemos tenido. Mi marco de reflexión no es jurídico, aunque por supuesto parto de la Ley de Propiedad Intelectual, y del respeto escrupuloso a la misma que la biblioteca ha mantenido en su desarrollo. Hoy, más de cinco mil textos literarios en la red, junto a otros muchos recursos, avalan nuestra experiencia.

  14. Políticas de reparación: Reclamación y reentierro de restos indígenas. El caso de Gregorio Yancamil

    OpenAIRE

    Curtoni, Rafael Pedro; Chaparro, María Gabriela

    2014-01-01

    Introducción En las últimas décadas en la provincia de La Pampa se han desarrollado y mantenido diferentes acciones de homenaje, reconocimiento y restitución vinculadas con la problemática indígena como parte de las políticas estatales de “reparación histórica” con el pueblo rankülche. Desde la década de 1990, diversos monumentos y marcas conmemorativas fueron erigidos en la provincia con la finalidad de identificar y marcar lugares ancestrales y en consideración hacia la cultura rankülche (C...

  15. La arquitectura efímera de los kioscos para la música: memoria histórico-gráfica del Templete de la plaza "Carlos Navarro Rodrigo" de Alicante

    OpenAIRE

    Pérez del Hoyo, Raquel; Ferreiro Prieto, Juan Ignacio

    2012-01-01

    Gran número de construcciones temporales del pasado se han mantenido hasta nuestros tiempos, evolucionando desde la motivación religioso-festiva o político-representativa hacia la función simbólica o referencial. Otras, sin embargo, han llegado a desaparecer tras décadas de abandono, como es el caso del Templete de Benalúa que documenta este artículo, fruto de las investigaciones realizadas principalmente en el Archivo Histórico Municipal de Alicante, con el fin de contribuir a subsanar, de f...

  16. Perfil coproparasitológico de mamíferos silvestres en cautiverio en el estado de Pernambuco, Brasil COPROPARASITOLOGIC PROFILE OF CAPTIVE WILD MAMMALS IN PERNAMBUCO STATE, BRAZIL

    OpenAIRE

    MANUELA FIGUEIROA LYRA DE FREITAS; AQUELINE BIANQUE DE OLIVEIRA; MIRIAM DOWELL DE BRITO CAVALCANTI; RIVÂNIA ALVES OLIVEIRA; ANTÔNIO EVÊNCIO SOBRINHO

    2001-01-01

    A través de los métodos directo, de sedimentación y de flotación fueron analizadas muestras fecales de 62 mamíferos de las órdenes Artiodactyla (n=08), Carnivora (n=20), Perissodactyla (n=03), Primates (n=29) y Rodentia (n=02) mantenidos en cautiverio en el Parque Dois Irmãos, Recife, Pernambuco, Brasil. De los 62 animales analizados, 46 (74,2%) estaban parasitados de los cuales 22 (75,9%) pertenecían al orden Primates, 19 (95,0%) al orden Carnivora, 3 (37,5%) al orden Artiodactyla, y 2 (100%...

  17. Efecto de la mutación en el Gen Halotano sobre los inductores de contracción muscular a lo largo de la tenderización temprana. Papel del género

    OpenAIRE

    Pérez Martínez, Zulema

    2015-01-01

    La carne de cerdo es uno de los alimentos más consumidos. Para ello es necesario asegurar que la carne tiene una buena calidad y que el animal haya mantenido un bienestar adecuado. Para la realización de este proyecto se usaron 24 cerdos [(Large White x Landrace) x Pietrain],que fueron divididos en machos normales, machos portadores del gen halotano, hembras normales y hembras portadoras del gen halotano (6cerdos/grupo). Se criaron en una granja experimental donde fueron destetados a los 28 d...

  18. Factoría de aplicaciones web: PBLs pragmáticos

    OpenAIRE

    Camacho Ortega, Pedro Jesús; Galindo Muñoz, Alberto; Asenjo Álvarez, Felipe; Castilla Cebrian, Guillermo

    2014-01-01

    En este artículo se pretende describir la experiencia de colaboración entre diferentes Departamentos de la Universidad Europea, con el objetivo de crear aplicaciones web internas, con contenidos que puedan ser mantenidos por el usuario final. En concreto, se describen dos aplicaciones: La web del Congreso Apega 2014 y la Web de Aula Cero. Ambas aplicaciones han sido desarrolladas durante el curso académico 2013/2014 por el mismo grupo de alumnos del Módulo de Implantación de Aplicaciones Web,...

  19. Buenos Aires maraîchère : une Buenos Aires bolivienne ? Le complexe maraîcher de la Région métropolitaine à l'épreuve de nouveaux acteurs

    OpenAIRE

    Le Gall, Julie

    2011-01-01

    Buenos Aires hortícola: ¿una Buenos Aires boliviana? El complejo hortícola de la Región metropolitana a prueba de nuevos actores Resumen: Al estudiar el caso de Buenos Aires, esta tesis se interesa por la conservación de espacios de proximidad para alimentar las metrópolis: a pesar de presiones metropolitanas fuertes, la capital argentina ha mantenido sus espacios de producción y comercialización para abastecer en hortalizas frescas a sus 13 millones de habitantes. Siguiendo una línea reflexi...

  20. El impresionismo místico de " Camino de perfección "

    OpenAIRE

    Gómez Madrid, Benito

    2012-01-01

    La controversia en literatura entre tradición e innovación ha marcado decisivamente el discurso literario de la España post-imperial, cuando, como consecuencia de su progresiva pérdida de hegemonía, comenzó a sufrir la interferencia de una significativa reacción defensiva nacionalista por parte de sus intelectuales. Nacionalismo y literatura han mantenido una íntima relación en España a partir de entonces. Pío Baroja, consciente de su posición marginal, trata de conectarse con el impresionism...

  1. Plagio e integridad académica en Alemania

    OpenAIRE

    2016-01-01

    Alemania es quizá uno de los países europeos que, ya desde el siglo XVIII, ha mantenido un debate público más intenso sobre prácticas científicas y académicas deshonestas, relacionadas especialmente con tesis doctorales. Este debate fue especialmente productivo a finales del siglo XIX, dando lugar desde entonces, para evitar estas prácticas inaceptables, a la obligatoriedad de publicar todas las tesis doctorales, como requisito previo a la expedición del título de doctor por cualquier univers...

  2. Historia geopolítica de las enfermedades en Colombia

    Directory of Open Access Journals (Sweden)

    Hugo Armando Sotomayor

    2009-07-01

    sociales del país, el racismo, cargado de desprecio y subvaloración de lo "indio" y lo ~negro", y las guerras, de conquista, entre potencias coloniales, de Independencia, de defensa nacional y civiles, no pueden entenderse en toda su extensión si se estudian aisladamente. Ellos deben ser asociados, en su génesis y continuidad, a la historia de los intereses del poder político, social y de dominio territorial que introdujo el imperio español y a los que se han mantenido durante toda la vida republicana.

  3. DETERMINANTES FINANCIEROS Y OPERATIVOS DEL NIVEL DE INVENTARIOS EN EL SECTOR DE LA PRODUCCIÓN DE PAPEL EN COLOMBIA

    OpenAIRE

    Guillermo Buenaventura Vera; Elver Alfonso Bermeo Muñoz; Jorge Santiago Rosillo Corchuelo

    2001-01-01

    Se trata de establecer la influencia que el nivel de inventarios mantenido por las empresas del sector de producción del papel en Colombia tiene de factores investigados previamente en otros países; factores correspondientes a la Teoría Clásica como el nivel de ventas, y otros propios de la Teoría de la Agencia, como el flujo de caja, el nivel de la deuda y la utilidad operativa, entre otros. Resultados muy particulares y contundentes son obtenidos de una b...

  4. Trinidad, una historia económica basada en el azúcar, 1765-1848

    OpenAIRE

    Chaviano Pérez, Lizbeth Jhoanna

    2013-01-01

    Desde la sexta década del siglo XVIII el azúcar hizo su irrupción en Trinidad; en la última década del mismo siglo se consolidó como actividad económica fundamental. El contexto geopolítico, así como las particularidades del territorio, en especial su ubicación geográfica permitió que encontrara en las relaciones con sus vecinos caribeños los medios para hacerse del capital necesario para desarrollar su economía azucarera. El auge de esta actividad, mantenido hasta 1848, puede explicarse desd...

  5. El Modelo Chileno desde una ética de justicia y de igualdad de las oportunidades humanas

    OpenAIRE

    Andrés Araya Rosales; Mauricio Gallardo Altamirano

    2015-01-01

    Tras más de dos décadas de democracia, en Chile, perdura el modelo económico desarrollado durante el régimen militar de Augusto Pinochet. Este modelo ha mostrado logros en materia económica, destacando sobre todo su ordenamiento macroeconómico, apoyado en una disciplina fiscal y una política monetaria que ha mantenido una inflación baja y estable. Se han logrado avances en el crecimiento económico, en disminución de la pobreza y en el mejoramiento del nivel de vida de los ciudadanos....

  6. Memoria 2010

    OpenAIRE

    CSIC-JA-USE - Instituto de Biomedicina de Sevilla (IBIS)

    2010-01-01

    Durante el año 2010 el IBIS ha continuado su evolución desde el punto de vista científico y organizativo. Las actividades generales comunes (ciclo de seminarios, máster/doctorado en Investigación Biomédica, etc.) se han mantenido con una aceptación y calidad más que notable. Igualmente, la producción científica, la generación y licencia de patentes y la captación de recursos externos han continuado en aumento. Junto a las aportaciones de las instituciones consorciadas, es destacab...

  7. EL PLAN DIRECTOR DE LA VEGA BAJA DE TOLEDO, ESPAÑA: PAISAJE PATRIMONIAL, ECOLÓGICO Y URBANO.

    OpenAIRE

    Agustín Hernández Aja; Fernando Roch Peña; Nerea Morán Alonso; Cristina Fernández Ramírez

    2014-01-01

    La Vega Baja de Toledo constituye un gran vacío urbano que, por avatares históricos, se ha mantenido al margen del crecimiento de la ciudad, rodeada por el casco histórico de Toledo, los barrios del ensanche norte y el río Tajo. Su localización privilegiada, junto a la riqueza patrimonial y ecológica del espacio, han sido las bases de la propuesta del Plan Director de la Vega Baja (PDVB). El objetivo del PDVB ha sido articular este vacío y abrirlo a la población, a la vez que proteger y re...

  8. Un análisis socio-geográfico de la oferta de "Entrentención para adultos" en la ciudad de Calama (Chile).

    OpenAIRE

    Marcelo Lufin Varas

    2015-01-01

    El objetivo principal del trabajo es describir los actores participantes y las características de la oferta espacial de “entretención para adultos” en la ciudad de Calama, y determinar qué tipo de negocio actúa como precursor de la formación de barrios rojos en dicha localidad. El trabajo utiliza información secundaria proveniente del registro de control sanitario mantenido por el Servicio de Salud, que incluye 791 prestadoras (incluyendo trabajadoras sexuales) en control desde el año 2006 a ...

  9. Fisiología y atributos de calidad de la guayaba “pera” (Psidium guajava cv.) en postcosecha

    OpenAIRE

    Nelson Gutiérrez Guzmán; Saul Dussan Sarria; Jennifer Castro Camacho

    2013-01-01

    El objetivo de este trabajo fue evaluar la fisiología de la madurez en frutos de guayaba “pera” (Psidium guajava cv.) cosechados al norte del departamento del Huila en Colombia, recolectados en tres estados de madurez, y mantenidos en dos condiciones de almacenamiento. Se evaluaron los índices de madurez hasta el momento de consumo.La pérdida de peso presentó una tendencia lineal y la firmeza una tendencia logarítmica; el contenido de sólidos solubles se incrementó y el contenido de ácido cít...

  10. ¿Para cuando llegará la paridad a la universidad?: situación de las mujeres investigadores en el Sistema de Ciencia y Tecnología español

    OpenAIRE

    San Segundo Manuel, Rosa

    2006-01-01

    Analiza la situación de las mujeres investigadoras en el Sistema de Ciencia y Tecnología español. Durante siglos las mujeres se han mantenido en un estado de postración cultural, y exclusión ciudadana, que en este contexto ha venido a denominarse genocidio cultural de las mujeres. Ya que estaban excluidas de todo el sistema de enseñanza, de la alfabetización, de las academias científicas y de las universidades. El libre acceso a la educación superior se produjo en 1910, pero con la pro...

  11. Análisis de los proyectos internacionales de ayuda al desarrollo en base a pasadas experiencias.

    OpenAIRE

    Gallardo, Juan. F.; Pajares, Silvia

    2009-01-01

    La presente comunicación se refiere a las experiencias habidas en varios Proyectos de investigación mantenidos con la Unión Europea (principalmente el Proyecto REVOLTOSO) y otras acciones de ayuda o colaboración con países iberoamericanos. Se realiza un análisis DAFO con el fin de agrupar las características, ventajas e inconvenientes de los Proyectos internacionales de ayuda al desarrollo. Se indican los productos evaluables y aquellos más evaluados en los medios académicos. Se concluye que ...

  12. La renovación de la Historia Militar. Coyunturas, interpretaciones, conceptos

    OpenAIRE

    Kühne, Thomas; Ziemann, Benjamin

    2012-01-01

    Durante décadas, la historia militar se ha mantenido apartada de las principales corrientes históricas y se convirtió básicamente en un reducto para los propios militares y eruditos que no compartían los avances historiográficos recientes y prolongaban la tradición positivista alemana. Sin embargo, en las últimas décadas la historia militar ha establecido un fructífero diálogo no sólo con escuelas como la historia social, la historia de la vida cotidiana, la historia oral y simila...

  13. Hemoglobinas anormales

    OpenAIRE

    German F Sáenz-Renauld

    2005-01-01

    Es notorio que en Costa Rica la frecuencia de las variantes más comunes de la hemoglobina (Hb) (S Y C) puede ser trazada desde África. Estas hemoglobinas son dos marcadores genéticos que han mantenido un equilibrado polimorfismo contra la presión selectiva de la malaria, en los países de origen o ancestrales. En la población caucásica son muy raras las mutantes estructurales de la Hb y se considera que nuestros indígenas no presentan ninguna alteración en elloci de la Hb. Un breve repaso antr...

  14. Entornos multimedia de realidad aumentada en el campo del arte.

    OpenAIRE

    Portales Ricart, Cristina

    2008-01-01

    La relación ente Ciencia y Arte ha mantenido a lo largo de la historia momentos de proximidad o distanciamiento, llegando a entenderse como dos culturas diferentes, pero también se han producido situaciones interdisciplinares de colaboración e intercambio que en nuestros días mantienen como nexo común la cultura digital y el uso del ordenador. Según Berenguer (2002) desde la aparición del ordenador, científicos y artistas están encontrando un espacio común de trabajo y entendimiento. Mediante...

  15. Poder heterosexual y movimientos socio-sexuales: tensiones no resueltas

    OpenAIRE

    Granados Barco, Adriana

    2012-01-01

    Desde la década de 1980 feministas lesbianas, afro-americanas y latino-americanas, desarrollan planteamientos críticos en torno al racismo, clasismo e imposición heterosexual mantenido dentro del movimiento feminista anglo-europeo. Algunos de estos planteamientos conciben la heterosexualidad como una norma, un régimen político, una institución, y especialmente una ideología asentada sobre la diferencia sexual. Teniendo en cuenta estas críticas, el presente trabajo aborda las tensiones y las d...

  16. Gestión económica y técnica del ganado bovino en régimen extensivo: dehesas.

    OpenAIRE

    Prieto Guijarro, Ángel

    1994-01-01

    Un equipo multidisciplinar incio una investigación de cuatro años financiada por la CEEsobre análisis técnico y económico del sitema agro-silvo-pastoral denominado "dehesa" en España y "montado" en Portugal. Este trabajo resume los resultados de la gestión del subsistema pasto natural-encinar 8quercus rotundifolia)-vacuno. El análisis realizado en dos dehesas durante 1991 y 1992 muestra la incidencia de los recursos de pastoreo, mantenido por la presión ganadera, en los costes y rentabilidad...

  17. Crónica de la prensa salvadoreña: imaginarios que migran

    Directory of Open Access Journals (Sweden)

    Amparo Marroquín Parducci

    2008-08-01

    Full Text Available EL ARTÍCULO PRESENTA UN ESTUDIO DE LAS NARRATIVAS QUE LA PRENSA escrita ha venido construyendo en El Salvador en torno al fenómeno de la migración. Se argumenta que a través del tema de la migración se construye una poética de nación imaginada, y conjuntamente, se da la construcción de las alteridades que desde el discurso oficial se han mantenido vigentes.

  18. Conductas sexuales en adolescentes de 12 a 17 años de Andalucía Sexual behavior in adolescents aged 12 to 17 in Andalusia (Spain)

    OpenAIRE

    José Rodríguez Carrión; Clara Isabel Traverso Blanco

    2012-01-01

    Objetivo: Describir los comportamientos y prácticas sexuales de los y las adolescentes de 12 a 17 años de edad en Andalucía (2007-2008). Método: La información se recogió mediante un cuestionario autocumplimentado, anónimo y voluntario, aplicado a una muestra aleatoria estratificada de 2.225 estudiantes de enseñanza secundaria obligatoria (ESO), en todas las provincias de Andalucía. Resultados: 388 adolescentes (18,2%) refirieron haber mantenido relaciones sexuales con penetración, sin difere...

  19. Competencia motriz del paciente urémico en el programa de hemodiálisis

    OpenAIRE

    Peña-Amaro, María-del-Pilar

    2006-01-01

    [ES]El paciente urémico en programa de hemodiálisis entra en una dinámica de inactividad física inducido por causas tanto de tipo biológico como psicológico o social y ello reduce su competencia motriz. esta inactividad física puede favorecer las alteraciones cardiovasculares y nutricionales ( de composición corporal) que se producen por causa tanto de la patología como de la técnica sustitutiva en la que se encuentran incluidos. Determinar si un ejercicio físico moderado pero mantenido tiene...

  20. Sistema integral de gestión de inmuebles online

    OpenAIRE

    Díaz Gil, Alberto

    2010-01-01

    Se requiere un sistema para la gestión de propiedades de una inmobiliaria con dos oficinas. Este sistema incluye una plataforma web y la gestión de una pantalla situada en el escaparate de una de las oficinas. La inmobiliaria disponía de un software que les permitía realizar todas las gestiones inmobiliarias, creado y mantenido por la empresa ASPgems, que es el que ha sido reemplazado por el proyecto objeto de esta memoria. La inmobiliaria necesita que exista: 0. Una web ...

  1. La alternancia en las elecciones municipales del Estado de México, 1996-2006

    OpenAIRE

    Manuel Ramírez Mercado; Jesús Alberto Palacios Espinosa

    2010-01-01

    En este artículo se realiza un análisis sobre las elecciones municipales en el Estado de México, para el periodo de 1996 a 2006, centrando la atención en las situaciones de alternancia continua y los casos en los cuales se ha mantenido un mismo partido político en el poder. De igual manera, el artículo incorpora las características socioeconómicas de la entidad y la de los municipios analizados, con lo cual se pretende ampliar los marcos de explicación hacia el impacto que pueden tener alguno...

  2. La defensa internacional del maíz contra la contaminación transgénica en su centro de origen

    OpenAIRE

    Ana de Ita

    2012-01-01

    Como ha podido documentarse, el gobierno mexicano ha mantenido una política de promoción del libre comercio y de las importaciones de maíz, y ha alentado el avance de los cultivos transgénicos. En el tlcan aceptó principios y condiciones que apoyan los intereses de Estados Unidos y Canadá [...]. No dio ninguna respuesta al hallazgo de maíz nativo contaminado con transgenes a pesar de ser el país centro de origen y diversidad del cereal [...]. Desoyó las demandas de científicos y de amplios se...

  3. Análisis histórico-legislativo de la organización de la escuela rural española en el período 1857-2012

    OpenAIRE

    Corchón Álvarez, Eudaldo (Coordinador); Raso Sánchez, Francisco; Hinojo Lucena, María Angustias

    2016-01-01

    El presente trabajo pretende, mediante el estudio detallado y exhaustivo de todas las leyes y textos oficiales que han regulado el sistema educativo formal en España desde 1857 hasta la actualidad, analizar y comprender, en la medida de lo posible, por qué la situación de marginalidad, olvido y desesperanza que sufre la escuela rural en nuestro país se ha mantenido a lo largo de un período de más de ciento cincuenta años de Historia. ¿Habrá llegado la hora del cambio para el mundo rural, ahor...

  4. Sumapaz

    OpenAIRE

    Gámez Alfonso, Javier

    2013-01-01

    Sumapaz es un texto concebido para el teatro de muñecos. La relación que he mantenido con esta forma particular de teatro durante varios años y el poder que le atribuyo como dispositivo teatral, han hecho que concentre mi atención y mi esfuerzo en esta tarea. He optado por el teatro de muñecos por una relación de auto-abandono, ausencia, distancia, vacío, que he percibido como característica de esta forma de arte escénico. En el teatro bunraku, por ejemplo, el titiritero se viste de negro est...

  5. VIGILANCIA CENTINELA PARA EL VIRUS DEL OESTE DEL NILO EN CULICIDOS Y AVES DOMÉSTICAS EN EL DEPARTAMENTO DE CÓRDOBA

    OpenAIRE

    Manolo Jaramillo; José Peña; Luis Berrocal; Nicholas Komar; Marco González; César Ponce; Katiuska Ariza; Salim Máttar

    2005-01-01

    El virus del Oeste del Nilo (VON) género Flavivirus, familia Flaviviridae, es mantenido en la naturaleza en un ciclo enzoótico ave-mosquito-ave. Las aves son los hospederos amplificadores primarios. Humanos y caballos son hospederos incidentales finales. En humanos las infecciones se manifiestan como enfermedad febril autolimitada. También puede presentarse encefalitis o meningoencefalitis. El virus se ha establecido en Norte América y se ha documentado su circulación en México, Jamaica, Repú...

  6. La paradoja de la violencia en los Estados Unidos: una perspectiva histórica.The paradox of American Violence: A historical appraisal.

    OpenAIRE

    Hugh Davis Graham

    2010-01-01

    El artículo presentado aquí es resultado de un trabajo más interpretativo que empírico. Se intenta explicar en éste la paradójica conclusión, desarrollada en el libro La Violencia en América —y sustentada por datos comparativos a nivel nacional— que señala que la historia de los Estados Unidos ha estado marcada por la violencia, sin embargo, gracias a la vitalidad de las instituciones públicas, ésta se ha mantenido en niveles seguros. Cuatro aspectos particulares de la experien...

  7. Efectos de la alcalosis metabólica inducida por la dieta en el rendimiento anaeróbico de alta intensidad Effects of the metabolic alkalosis induced by the diet in the high intensity anaerobic performance

    OpenAIRE

    O. Ríos Enríquez; E. Guerra-Hernández; B. Feriche Fernández-Castanys

    2010-01-01

    Objetivos: El propósito principal de este estudio es comparar el efecto de una alcalosis y acidosis inducidas por la dieta sobre el rendimiento en un esfuerzo anaeróbico láctico mantenido. Métodos: Para ello, trece sujetos activos se sometieron de forma cruzada a sendas dietas durante dos días y medio. Inmediatamente después realizaron una prueba de esfuerzo anaeróbica láctica máxima de estado estable hasta el agotamiento sobre cicloergómetro a 250 W. Resultados: La valoración de las dietas m...

  8. Fortalecimiento de las competencias didácticas y tecnológicas para la enseñanza a distancia y el autoaprendizaje de la especialidad de Información-Documentación en Mozambique

    OpenAIRE

    Moreiro González, José Antonio; Melo Alves, Fernanda María; Bueno-de-la-Fuente, Gema; García Zorita, Carlos; Bolaños Mejías, Carmen

    2012-01-01

    El compromiso con la cooperación al desarrollo en el ámbito de la Biblioteconomía y Documentación, mantenido durante cuatro años, entre la Universidad Carlos III de Madrid (UC3M) y la Universidad Eduardo Mondlane (UEM), con apoyo de acciones PCI de la AECID, pretende capacitar hacia el e-learning y la alfabetización informacional mediante el traspaso de experiencias, así como sentar las bases de la necesaria reforma educativa en los estudios de biblioteconomía y documentaciónpara adecuarse a ...

  9. Nuevas estrategias en la síntesis de compuestos de interés biológico: Estructuras terfenílicas y heterociclos nitrogenados fluorados enantioméricamente enriquecidos

    OpenAIRE

    Ibáñez Sánchez, Ignacio

    2015-01-01

    Actualmente, el descubrimiento y desarrollo de nuevos fármacos es un proceso lento y económicamente exigente. En los últimos 10 años, los gastos económicos destinados al descubrimiento de nuevos compuestos se han triplicado, mientras que el número de nuevas entidades moleculares (NMEs) se ha mantenido invariable en los últimos 50 años. Es por esta razón que la búsqueda de nuevas estructuras que posean una relevante actividad terapéutica permanece como objetivo primordial en química farmacéut...

  10. Beyşehir Gölü Zooplankton Türlerinin Aylık Dağılımı

    OpenAIRE

    DİDİNEN, Hakan; Yunus Ömer BOYACI

    2014-01-01

    Beyşehir Gölü'nde, Mayıs 2009-Nisan 2010 dönem aralığı aylık, 8 ayrı istasyondan su ve zooplankton örneklemesi yapılmıştır. Zooplankton olarak; Rotifera'ya ait 37, Copepoda'ya ait 5, Cladocera'ya ait 4 ve Bivalvia'ya ait 1 tür olmak üzere toplamda 47 tür tespit edilmiştir. Göl geneli toplam zooplankton yoğunluğuna göre; % 95,45'i Rotifera, % 3,66'sı Cladocera, % 0,89'u Copepoda ve < % 0,01'i Bivalvia'ya ait olduğu hesaplanmıştır. Zooplanktonun büyük bir kısmını mikro zooplankton temsil etmişt...

  11. ОЦЕНКА РАЗНООБРАЗИЯ СООБЩЕСТВА МОЛЛЮСКОВНАДСЕМ. PISIDIOIDEA (MOLLUSCA, BIVALVIA) КУЙБЫШЕВСКОГО ВОДОХРАНИЛИЩА ПО РЕЗУЛЬТАТАМ ИССЛЕДОВАНИЙ В 1984, 2002, 2005 ГГ

    OpenAIRE

    Загорская, Елизавета

    2012-01-01

    Антропогенное воздействие на экосистему Куйбышевского водохранилища отразилось на всех звеньях, в том числе на донных беспозвоночных моллюсков надсем. Pisidioidea. Приводятся данные по изменению структуры сообщества моллюсков Pisidioidea в разные периоды развития водохранилища.

  12. Macroepizoísmo em Libinia ferreirae (Crustacea, Brachyura, Majidae Macroepizoites on Libinia ferreirae (Crustacea, Brachyura, Majidae

    Directory of Open Access Journals (Sweden)

    Vanessa C. Winter

    2006-06-01

    Full Text Available Um estudo de distribuição dos macroepizóicos foi realizado numa população do caranguejo-aranha Libinia ferreirae Brito Capello, 1871 proveniente do litoral dos estados do Paraná e de Santa Catarina. O material biológico foi obtido junto aos pescadores, e faz parte do rejeito de pesca. Os caranguejos foram mensurados e os macroepizóicos identificados e contados. Os seguintes macroepizóicos sésseis foram registrados: Calliactis tricolor (Lesueur, 1817 (Cnidaria; Actiniaria (Cnidaria; Arca sp. (Mollusca; Ostreidae (Mollusca; Acanthodesia tenuis (Desor, 1848 (Bryozoa; Cirripedia e duas espécies tubícolas de Gammaridea (Crustacea. Além destes organismos ocorreram dois tubos desabitados e quatro animais vágeis. A anêmona C. tricolor foi a espécie mais abundante e freqüente, sendo, provavelmente, utilizada como mecanismo de camuflagem pelo caranguejo. O macroepizoísmo em L. ferreirae está relacionado com a idade ou tamanho do caranguejo, tendo maior incidência naqueles mais velhos ou de maior porte. Entretanto, a densidade dos macroepizóicos por caranguejo se mantém em torno de três. Não há relação entre o macroepizoísmo e o sexo do hospedeiro; somente fêmeas ovígeras utilizam desse recurso mais freqüentemente do que as não-ovígeras. Devido à maior área de fixação, os macroepizóicos colonizam principalmente a carapaça do caranguejo, enquanto nos pereiópodos há predominância de Bryozoa.A study of the distribution of the macroepizoites was carried out on a population of the spider crab Libinia ferreirae Brito Capello, 1871 from the Southern Brazilian coast. Crabs were obtained from shrimps and fishes by-catch. They were measured, and their macroepizoites were identified and counted. The following sessile macroepizoites were registered: Calliactis tricolor (Lesueur, 1817 (Cnidaria; Actiniaria (Cnidaria; Arca sp. (Mollusca; Ostreidae (Mollusca; Acanthodesia tenuis (Desor, 1848 (Bryozoa; Cirripedia and two species

  13. Depositional environment, foraminifer content and ESR ages of Quaternary Gediz Delta Sediments (Eastern Aegean Sea, İzmir-Western Turkey)

    Science.gov (United States)

    Gökçe Benli, Ekin; Aydın, Hülya; İşintek, İsmail; Engin, Birol; Şengöçmen, Berna

    2016-04-01

    Sediments and fossil content of Gediz Delta (Eastern Aegean Sea - İzmir) were examined based on the drilling core samples of the YSK-C and SK-246 drilling. W-SW part of the Delta is represented by continental delta sediments up to 6 meters and shallow marine detritic sediments up to 35 meters in the YSK-C drilling. Continental part consists of an soiled, graveled, muddy and sandy sediment in terms of rich organic substance. As for marine part, it consists of bioclast, muddy, fine graveled sand and by repetition of pebble, sand and bioclast bearing mud layers. Bioclasts comprise of bivalvia, echinoid, ostracod, gastropod, foramifer and bryozoa fragments. Benthic foraminiferal fauna determinated in the marine levels are represented by 55 bethic, 2 planktonic species. These foraminifers and bioclasts reflect that the W-SW part of the delta, has been occured in marine conditions between 8-31m deep. E-NE part of the delta is generally represented by continental sediments up to 43.5m in SK-246 drilling. In addition, it includes marine levels in 18-19 m, 23-24 m and 36-37,5 m intervals. Continental sediments of E-NE part is generally represented by calcareous and sandy mud rocks which mostly includes ash, tuff, and pebble derived from Neogene volcanic rocks. As for marine levels, it is composed of calcareous mud stones and calcareous clay stones including very thin gastropod, bivalvia and ostracod in 18- 19 and 36-37.5 meters whereas it is represented by sandy mud stones including a great deal of bentic foraminifer, bivalvia, bryozoa, echinoid, gastropod in 23-24 metres. Thus show that E-NE part of the delta is usually in continental condition but it is occasionally covered by sea. In aging studies of YSK-C core done by ESR method, age of 8-9 m interval is determined to be 11. 376 ± 0,067 Ka; however ages of 10-11m and 24-25 m intervals are revealed to be 16.466 ± 0,016 Ka and 15.344 ± 0,021 Ka respectively; finally age of 25-26 m interval is found to be 19.995 ± 0

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

    Science.gov (United States)

    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

  15. Manejo de primates en cautiverio: interpretación de marcadores etológicos de adaptación en Cebus libidinosus juveniles Management of Captive Primates: Ethological Bookmarks in Cebus libidinosus

    Directory of Open Access Journals (Sweden)

    A.M Giudice

    2011-06-01

    Full Text Available Los primates mantenidos en cautiverio, evidencian la necesidad de estimular su comportamiento natural y de promover su bienestar. Esta contribución describe los cambios en los marcadores etológicos en Cebus libidinosus (CLI juveniles (1 macho y 2 hembras mantenidos en cautiverio (ECAS, Berazategui, Argentina, bajo dos condiciones de alojamiento. Se utilizó el muestreo de barrido. Se evaluó la conducta "locomoción estereotipada". El tiempo total de observación fue de 290 horas. El nivel de locomoción estereotipada descendió y la jeraquía social se modifico. CLI mantenidos en cautiverio muestran: incremento en el comportamiento de interacción ambiente físico-social luego del cambio de recinto y la frecuencia de locomoción estereotipada se relacionó con las tareas de mantenimiento. Debido a la condición social de las especies de primates, el mantener grupos sociales formados según su estructura social en vida libre, resulta en un aumento de bienestar mayor que cambios en las condiciones físicas del alojamiento.The primates maintained in captivity, highlight the need to encourage their natural behavior and promote their welfare. In this paper we describe the changes in the ethological markers in Cebus libidinosus (CLI juvenile (1 male and 2 females kept in captivity (ECAS, Berazategui, Argentine, under two housing conditions. We used scan sampling. We evaluated the behavior "stereotyped locomotion". The total observing time was 290 hours. Stereotyped locomotion level decrease and the social hierarchy was modified. CLI maintained in captivity shows: an increase in the behavior of the physical environment and social interaction after the change of enclosure and frequency of stereotyped locomotion was associated with maintenance. Because the social status of the species of primates, maintaining in groups formed according to their social structure in the wild, resulting in a greater welfare benefit that changes in the physical conditions

  16. ASPECTS OF BIODETERIORATION OF LAPIDEOUS SUBMERGED ARTEFACTS: 3D METHODOLOGIES APPLICATION

    Directory of Open Access Journals (Sweden)

    S. Ricci

    2015-04-01

    Full Text Available Submerged stone archaeological artefacts are bioeroded by endolithic microbiota (cyanobacteria, algae and fungi and macroborers (Porifera, Bivalvia and Sipuncula. Optical microscope and SEM observations permit to analyse the bioerosion traces and to identify bioeroders. Data obtained with these techniques cannot be used to estimate volumes of material bioeroded. This aspect require the need to collect three-dimensional, close-range data from artefact. In this work we illustrate two 3D imaging techniques used to study bioerosion phenomena of underwater Cultural Heritage. In particular Digital Video Microscope permit the elaboration of 3D images, which are widely employed for close-range acquisitions. Underwater Laser Scanner documents the in situ degradation of submerged artefacts. This research aims to sensitize specialist figures in the study 3D offering a starting point for future collaborations that could lead to interesting results.

  17. Aspects of Biodeterioration of Lapideous Submerged Artefacts: 3d Methodologies Application

    Science.gov (United States)

    Ricci, S.; Antonelli, F.; Sacco Perasso, C.

    2015-04-01

    Submerged stone archaeological artefacts are bioeroded by endolithic microbiota (cyanobacteria, algae and fungi) and macroborers (Porifera, Bivalvia and Sipuncula). Optical microscope and SEM observations permit to analyse the bioerosion traces and to identify bioeroders. Data obtained with these techniques cannot be used to estimate volumes of material bioeroded. This aspect require the need to collect three-dimensional, close-range data from artefact. In this work we illustrate two 3D imaging techniques used to study bioerosion phenomena of underwater Cultural Heritage. In particular Digital Video Microscope permit the elaboration of 3D images, which are widely employed for close-range acquisitions. Underwater Laser Scanner documents the in situ degradation of submerged artefacts. This research aims to sensitize specialist figures in the study 3D offering a starting point for future collaborations that could lead to interesting results.

  18. Diversity of macrozoobenthos on Orlice river system

    International Nuclear Information System (INIS)

    There are 2 saprobiology monitoring profiles and 1 faunictic research profile on Orlice river, 5 saprobiology monitoring profiles and 2 faunictic research profile on Divoka Orlice river, 4 saprobiology monitoring profiles on Ticha Orlice river. It was collected 255 taxons of macrozoobentos on long therm research in years 1996-2002. Number of taxons: Turbellaria 3, Oligochaeta 13, Nematomorpha 1, Hirudinea 4, Gastropoda 6, Bivalvia 4, Malacostraca 3, Hydracarina 1, Odonata 4, Ephemeroptera 42, Plecoptera 28, Heteroptera 1, Megaloptera 2, Coleoptera 6, Trichoptera 70, Diptera 16, Diptera - Chironomidae 40, Diptera - Simuliidae 11. On locality Blesno - Orlice was discovered very rare plecoptera species Agnetina elegantula (KLAPALEK, 1905), on locality Chocen - Ticha Orlice was discovered rare chironomidae species Symposiocladius lignicola (KIEFFER, 1915). (authors)

  19. Ultrastructural description of the spore maturation stages of the clam parasite Minchinia tapetis (Vilela, 1951) (Haplosporida: Haplosporidiidae).

    Science.gov (United States)

    Azevedo, C

    2001-07-01

    The fine structure of maturing spores of a haplosporidian parasite found in the gill, mantle and foot tissues of Ruditapes decussatus L. (Mollusca, Bivalvia), a species of commercial importance in Portugal, is described. When observed free in suspension, immature spores exhibit one or two epispore cytoplasmic extensions (ECE) which constitute a projection of a portion of the exosporoplasm, sometimes without ultrastructural organisation, surrounded by the plasmalemma. Free spores observed by light microscopy (LM) after 3-5 days of incubation in filtered sea-water exhibit no ECE attached to the spore wall. The mature spore is ovoid to ellipsoid, operculate, uninucleate and measures c. 4.8 microm long and c. 3.9 microm wide. The spore shape and size and the identity of the host living in the same geographical region suggest that this species is the same as previously described using LM observations as Haplosporidium tapetis Vilela, 1951 and later transferred to Minchinia Labbé, 1896. PMID:11466479

  20. Food and feeding habits of king weakfish, Macrodon ancylodon (Bloch & Schneider, 1801 caught in the southern coast of Brazil (lat, 29º to 32ºs

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    Anastácio Afonso Juras

    1985-01-01

    Full Text Available Macrodon ancylodon was obtained from landings in Santos Port (São Paulo State of fish caught monthly by commercial vessels, on the southern coast of Brazil during September 1976 to August 1977. The measurements of total lenght, total weight determination of sex and maturity stages were made. The food items found in stomach contents were: shrimp (Artemesia longinaris, fishes (Paralonchurus brasiliensis, Macrodon ancylodon, Trichirus lepturus, Gadidae, Engraulidae, molluscs (Loliginidae, Bivalvia and Stomatopoda. Widening of food spectrum was observed in winter. The index of preponderance showed that immature females, immature and mature males fed predominantly on shrimp, while mature females fed mainly on fishes. During spring and summer (spawning season M. ancylodon exhibited relatively low percentage of full stomachs. Cannibalism was encountered more intensively for mature fish.

  1. Aspectos gerais sobre a alimentação do cangulo, Balistes vetula Linnaeus, 1758 (Pisces - Balistidae no estado de Pernambuco - Brasil

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    Técio Luiz Macêdo Costa

    1987-01-01

    Full Text Available The Balistidae, especially Balistes vetula are commom fishes in tropical waters from Northeastern Brazil. Studies about these fishes captured at the coastal area of Recife between Pina; Boa Viagem, Piedade and Candeias beaches were carried out in order to determine the diet, and to verify a possible diet diversification between the sexes, and times of the year. Males and females had a food diet consisting mostly of molluscs belonging the classes Scaphopoda, Bivalvia, Gastropoda and crustaceans and fishes. Echinoderms, foraminifera, bryozoa, sponges, polychaete worms, coelenterates and brachiopods were also observed in smaller proportions. Both males and females had a carnivorous benthic diet. Growth and changes in the seasons were not reflected by changes in the diet.

  2. The Bivalve Yangtzedonta is not the Brachiopod Xianfengella

    Institute of Scientific and Technical Information of China (English)

    YU Wen

    2005-01-01

    The alleged "holotype" of the bivalve Yangtzedontaprimitiva Yu, 1985 figured by Qian (2001) is a broken and distorted specimen of the brachiopod Xianfengella prima He and Yang, 1982 and not the holotype of Y. primitiva. Qian contends that the oldest recognized monoplacophoran, Maikhanella pristinis (Jiang, 1980), is neither a monoplacophoran nor the oldest molluscan fossil in the Meishucunian Stage of China. Furthermore, he considers that the oldest bivalve Xianfengoconcha elliptica Zhang, 1980 is an inarticulate brachiopod, not a mollusc. Watsonella yunnanensis (He and Yang, 1982), is associated with Yangtzedonta primitiva Yu but indicates no evolutionary relationship between the Classes Rostroconchia and Bivalvia in the Lower Cambrian Zhongyicun Member of the Yuhucun Formation. Qian's confusion in using non-molluscan fossils to discuss the early evolution of shelled molluscs also confuses the basic concepts of the respective groups.

  3. [Demography of the snail Plicopurpura pansa (Neotaenioglossa: Muricidae) and constitution of the associated mollusk community, in Guerrero, Mexico].

    Science.gov (United States)

    Flores-Garza, Rafael; Flores-Rodriguez, Pedro; García-Ibáñez, Sergio; Valdés-González, Arcadio

    2007-01-01

    We quarterly sampled the molluskan community of Playa Ventura, Guerrero, Mexico. Sample size (20 m2 in lm2 units) was determined by the spatial distribution pattern of Plicopurpura pansa using a negative binomial distribution. The density of the P. pansa was 5.19 snails/m2 and the sex ratio near 1:1. The average size was 20.10 mm (most females were 10.5 to 27.0 mm; most males 12.0 to 27.0 mm). Density was high and small sized dominated. Mean size varied with time. General mean weight was 1.79 g. Females weight varied more, maybe because of the reproductive cycle. Recruits were collected in five samplings. Most copulation activity was in March of 2001. The associated community includes 26 species of Gastropoda, five ofBivalvia and one of Polyplacophora, Brachidontes semilaevis being dominant. PMID:19086391

  4. Diet of Lipophrys pholis (L.) (Teleostei, Blenniidae) in Cantabrian coastal waters (Spain)

    Science.gov (United States)

    Mazé, Raquel A.; Domínguez, Josefa; Pérez-Cardenal, David

    1999-07-01

    Between February and December 1988, a total of 261 specimens of Lipophrys pholis were caught in eleven intertidal pools on the western coast of Asturias. This blenniid species mainly feeds on different groups of invertebrates, although algal remains also appear. Mollusca is the most highly represented taxon with the largest number of prey being Gastropoda, followed by Bivalvia and, to a lesser degree, Polyplacophora. Crustacea is well represented by Cirripedia. Isopoda also stands out and Amphipoda, Tanaidacea and Decapoda appear sporadically. Temporal diet analysis throughout the year shows no great differences. Likewise, a great similarity was observed among the feeding of L. pholis specimens collected in pools at a different tidal level, of variable size and with different algal cover. Changes in diet are appreciable as size increases, especially from a length of 6 cm on.

  5. Investigation of molluscan phylogeny on the basis of 18S rRNA sequences.

    Science.gov (United States)

    Winnepenninckx, B; Backeljau, T; De Wachter, R

    1996-12-01

    The 18S rRNA sequences of 12 molluscs, representing the extant classes Gastropoda, Bivalvia, Polyplacophora, Scaphopoda, and Caudofoveata, were determined and compared with selected known 18S rRNA sequences of Metazoa, including other Mollusca. These data do not provide support for a close relationship between Platyhelminthes (Turbellaria) and Mollusca, but rather suggest that the latter group belongs to a clade of eutrochozoan coelomates. The 18S rRNA data fail to recover molluscan, bivalve, or gastropod monophyly. However, the branching pattern of the eutrochozoan phyla and classes is unstable, probably due to the explosive Cambrian radiation during which these groups arose. Similarly, the 18S rRNA data do not provide a reliable signal for the molluscan interclass relationships. Nevertheless, we obtained strong preliminary support for phylogenetic inferences at more restricted taxonomic levels, such as the monophyly of Polyplacophora, Caenogastropoda, Euthyneura, Heterodonta, and Arcoida. PMID:8952075

  6. OIL DECONTAMINATION OF BOTTOM SEDIMENTS EXPERIMENTAL WORK RESULTS

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    Lushnikov Sergey V.

    2006-08-01

    Full Text Available This article presents the results of experimental work during 2004-2005 on oil decontamination of bottom sediments of Lake Schuchye, situated in the Komi Republic (Northern Russia. The cause of thecontamination were huge oil spills occurred after a series of accidental ruptures on the Harjaga-Usinsk and Vozej-Usinsk oil-pipe lines in 1994. Flotation technology was used for the cleaning of bottom sediments.157 tons of crude oil were removed during the course of 2-year experimental work from an area of 4,1 ha.The content of aliphatic and alicyclic oil hydrocarbons was reduced from 53,3 g/kg to 2,2 g/kg, on average.Hydrobiological investigations revealed that bottom sediments started to be inhabited by benthos organisms, dominantly Oligochaeta. Besides Oligochaeta, Chironomidae maggots and Bivalvia were detected. Theappearance of Macrozoobenthos organisms can serve as a bioindicator of water quality.

  7. Alterações na dieta de Pterodoras granulosus (Valenciennes, 1833) (Osteichthyes, Doradidae) devido a variação na abundância de uma espécie invasora de bivalve no reservatório de Itaipu, Brasil Alterations in the Pterodoras granulosus (Valenciennes, 1833) (Osteichthyes, Doradidae) diet due to the abundance variation of a bivalve invader species in the Itaipu Reservoir, Brazil

    OpenAIRE

    Angelo Antonio Agostinho; Fabiane Abujanra; Rosemara Fugi; Karla Danielle Gaspar da Luz

    2002-01-01

    Foram avaliadas as alterações na dieta de Pterodoras granulosus (Osteichthyes, Doradidae), no reservatório de Itaipu, no período de 1994 a 1998, associadas às alterações na abundância de um bivalve invasor, Corbicula fluminea, considerando-se dois eventos: (i) a explosão de C. fluminea no reservatório a partir de 1994, e (ii) a mortandade desse bivalvia em função das flutuações do nível de água a partir de julho/96. Os conteúdos estomacais, foram analisados pelos métodos de ocorrência e volum...

  8. Modulations in cell-mediated immunity of Mytilus edulis following the 'Sea Empress' oil spill

    International Nuclear Information System (INIS)

    The 'Sea Empress' oil tanker grounded outside Milford Haven (Wales, UK) in February 1996, spilling ∼ 70,000 tonnes of crude oil and contaminating over 100 km of coastline, causing mass mortalities and strandings of at least 11 mollusc species. Intensive field monitoring commenced after the spill, examining immunity and hydrocarbon levels in the mussel, Mytilus edulis (Mollusca: Bivalvia), a commercially-harvested species which can accumulate contaminants. Comparisons of mussels from oiled and reference sites revealed significant modulations in cell-mediated immunity. Elevations in blood cell (haemocyte) numbers and decreases in superoxide generation and phagocytosis were identified in contaminated animals. The immune response of contaminated mussels gradually improved and generally showed no significant differences compared with clean mussels after 11 weeks. By then, total hydrocarbon content in contaminated mussels had declined by 70-90%, while polycyclic aromatic hydrocarbon content had decreased by over 90%. (author)

  9. Influence of the flood of August 2002 on the freshwater mollusc fauna of the game preserve - Natural Monument Kralovska Obora in Prague

    International Nuclear Information System (INIS)

    15 species of freshwater Mollusca were recorded during two sampling days in the years 2001 and 2002 on some sites of the game preserve - natural monument Kralovska Obora (Stromovka) in Prague (Central Bohemia, 50 grad 06' 20'' N/14 grad 24' 58'' E). 203 specimens of 13 species in 2001 and 193 specimens of 10 species in 2002 (after a flood) were collected on one studied sampling site. An index of concentrated dominance (modification according to Simpson) from samples is 0.13 for 2001 and 0.28 for 2002. Jaccard's Index for species composition comparison is 64,3. The impact of the flood on aquatic malacofauna in Stromovka was greater in the case of snails that were living on water macrophytes. The benthic fauna (mainly Bivalvia) survived without large changes. (authors)

  10. Foods of Spectacled Eiders Somateria fischeri in the Bering Sea, Alaska

    Science.gov (United States)

    Petersen, M.R.; Piatt, J.F.; Trust, K.A.

    1998-01-01

    The winter diet of Spectacled Eiders living in marine habitats is known only from two individuals described by Cottam (1939). Here we examine marine diets from 36 stomachs collected near St. Lawrence Island, Bering Sea, Alaska, during May-June in 1987 and 1992. All Spectacled Eiders ate Mollusca, including Gastropoda (snails; frequency of occurrence 20.0%; sole taxon 0.0%) and Bivalvia (bivalves; 80.0%; 48.0%), and Crustacea (barnacles, amphipods and crabs; 30.6%; 0.0%). One bird ate a cod. The predominant species group eaten was Macoma Clams (72.0%; 36.0%). Prey species of Spectacled Eiders occur predominantly in waters 25-60 m deep in the Bering Sea. To obtain these prey, especially the bivalves, on the winter area Spectacled Eiders must forage in waters exceeding 40 m. We speculate that Spectacled Eiders regularly forage at depths of 45-70 m throughout winter.

  11. Molluscs associated with a Sardinian deep water population of Corallium rubrum (Linnι, 1758

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    F. CROCETTA

    2012-12-01

    Full Text Available Molluscan species living in association with Corallium rubrumcolonies are poorly known. Specimensfound on the branches of red coral colonies located off Capo Caccia (Alghero – SS, West Sardinia,Mediterranean Sea were studied by analyzing red coral branches collected at a depth of between 100 and120 m; their assemblage was made up of 44 species, all belonging to the classes Gastropoda and Bivalvia.Some data on the geographical distribution, ecology, taxonomy and dominance of these species, bothalive and dead, are given and the most interesting are commented on. Among the recorded species Triviamultilirata, Simnia purpurea, Coralliophila brevis, Ocinebrina paddeui, Pleurotomella demosia, Palliolumstriatum and Pseudamussium sulcatum deserve attention. Moreover, the second finding of livingspecimens of Asperarca secreta, described only on loose valves, is reported, and finally the prey-predatorrelationships among several gastropods and Cnidarians are confirmed.

  12. New Mediterranean Biodiversity Records (June 2012

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    A. NICOLAIDOU

    2012-12-01

    Full Text Available The present work reports on the extended distribution of nineteen species in the Mediterranean. These are: Upeneus pori(Fish:Turkey, Bursatella leachii (Mollusca, Opisthobranchia: eastern coast of Spain, Sparisoma cretense (Fish: Ionian coastof Greece, Pseudobryopsis myura (Chlorophyta: Turkey, Aplysia dactylomela (Mollusca, Opisthobranchia: Karpathos island,and Kyklades Archipelago, Greece, Asparagopsis armata and Botryocladia madagascariensis (Rhodophyta: South Peloponnesos,Greece, Oxynotus centrina (Fish: Greece, Caulerpa racemosa var. cylindracea (Chlorophyta , Stypopodium schimperi(Phaeophyta Siganus luridus and Stephanolepis diaspros (Fish Percnon gibbesi (Decapoda, Brachyura (Kyklades Archipelago,Greece, Cerithium scabridum (Mollusca, Prosobranchia: Anavissos: Greece and Cerithium renovatum (Mollusca, Prosobranchia:N. Κriti, Cassiopea andromeda (Scyphomedusa: Rhodos Island, Greece, Abra tenuis (Mollusca Bivalvia: VouliagmeniLake, Greece Lagocephalus lagocephalus (Fish: Calabrian coast, Italy and Plocamopherus ocellatus (Mollusca, Opisthobranchia:İskenderun Bay, Turkey.

  13. Radiological impact of TEPCO's Fukushima Dai-ichi Nuclear Power Plant accident on invertebrates in the coastal benthic food web

    International Nuclear Information System (INIS)

    Radioactive cesium (134Cs and 137Cs) concentrations in invertebrates of benthic food web (10 taxonomic classes with 46 identified families) collected from wide areas off Fukushima Prefecture (3–500 m depth) were inspected from July 2011, four months after the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident, to August 2013 to elucidate time-series trends among taxa and areas. Cesium-137 was detected in seven classes (77% of 592 specimens). Higher 137Cs concentrations within detected data were often found in areas near or south of the FDNPP, which is consistent with the reported spatial distribution of 137Cs concentrations in highly contaminated seawater and sediments after the FDNPP accident. Overall 137Cs concentrations in invertebrates, the maxima of which (290 Bq kg−1-wet in the sea urchin Glyptocidaris crenularis) were lower than in many demersal fishes, had decreased exponentially with time, and exhibited taxon-specific decreasing trends. Concentrations in Bivalvia and Gastropoda decreased clearly with respective ecological half-lives of 188 d and 102 d. In contrast, decreasing trends in Malacostraca and Polychaeta were more gradual, with longer respective ecological half-lives of 208 d and 487 d. Echinoidea showed no consistent trend, presumably because of effects of contaminated sediments taken into their digestive tract. Comparison of 137Cs concentrations in the invertebrates and those in seawater and sediments suggest that contaminated sediments are the major source of continuing contamination in benthic invertebrates, especially in Malacostraca and Polychaeta. - Highlights: • Radioactive cesium was measured in benthic invertebrates collected off Fukushima. • Results show taxon-specific and area-specific decreases in ecological half-lives. • Reasonable depuration of 137Cs concentration was found in Bivalvia and Gastropoda. • Slow depuration was observed in Polychaeta and Malacostraca. • Sediments are expected to be the major continued

  14. Investigation of molluscan phylogeny using large-subunit and small-subunit nuclear rRNA sequences.

    Science.gov (United States)

    Passamaneck, Yale J; Schander, Christoffer; Halanych, Kenneth M

    2004-07-01

    The Mollusca represent one of the most morphologically diverse animal phyla, prompting a variety of hypotheses on relationships between the major lineages within the phylum based upon morphological, developmental, and paleontological data. Analyses of small-ribosomal RNA (SSU rRNA) gene sequence have provided limited resolution of higher-level relationships within the Mollusca. Recent analyses suggest large-subunit (LSU) rRNA gene sequences are useful in resolving deep-level metazoan relationships, particularly when combined with SSU sequence. To this end, LSU (approximately 3.5 kb in length) and SSU (approximately 2 kb) sequences were collected for 33 taxa representing the major lineages within the Mollusca to improve resolution of intraphyletic relationships. Although the LSU and combined LSU+SSU datasets appear to hold potential for resolving branching order within the recognized molluscan classes, low bootstrap support was found for relationships between the major lineages within the Mollusca. LSU+SSU sequences also showed significant levels of rate heterogeneity between molluscan lineages. The Polyplacophora, Gastropoda, and Cephalopoda were each recovered as monophyletic clades with the LSU+SSU dataset. While the Bivalvia were not recovered as monophyletic clade in analyses of the SSU, LSU, or LSU+SSU, the Shimodaira-Hasegawa test showed that likelihood scores for these results did not differ significantly from topologies where the Bivalvia were monophyletic. Analyses of LSU sequences strongly contradict the widely accepted Diasoma hypotheses that bivalves and scaphopods are closely related to one another. The data are consistent with recent morphological and SSU analyses suggesting scaphopods are more closely related to gastropods and cephalopods than to bivalves. The dataset also presents the first published DNA sequences from a neomeniomorph aplacophoran, a group considered critical to our understanding of the origin and early radiation of the Mollusca

  15. Benthic macroinvertebrates as bioindicators of water quality in an Atlantic forest fragment

    Directory of Open Access Journals (Sweden)

    Augusto Oliveira

    2010-12-01

    Full Text Available The objective of this study was to evaluate benthic macroinvertebrate communities as bioindicators of water quality in five streams located in the "Reserva Particular do Patrimônio Natural" (RPPN Mata Samuel de Paula and its surroundings, in the municipality of Nova Lima near the city of Belo Horizonte, Minas Gerais State, southeastern Brazil. This region has been strongly modified by human activities including mining and urbanization. Samples were collected in the field every three months between August 2004 and November 2005, totaling six samplings in the rainy and dry seasons. This assessment identified one area ecologically altered while the other sampling sites were found to be minimally disturbed systems, with well-preserved ecological conditions. However, according to the Biological Monitoring Work Party (BMWP and the Average Score Per Taxon (ASPT indices, all sampling sites had excellent water quality. A total of 14,952 organisms was collected, belonging to 155 taxa (148 Insecta, two Annelida, one Bivalvia, one Decapoda, one Planariidae, one Hydracarina, and one Entognatha. The most abundant benthic groups were Chironomidae (47.9%, Simuliidae (12.3%, Bivalvia (7.5%, Decapoda (6.1%, Oligochaeta (5.2%, Polycentropodidae (3.7%, Hydropsychidae (2.5%, Calamoceratidae (1.8%, Ceratopogonidae (1.7%, and Libellulidae (1.2%. The assessment of the benthic functional feeding groups showed that 34% of the macroinvertebrates were collector-gatherers, 29% predators, 24% collector-filterers, 8% shredders, and 5% scrapers. The RPPN Mata Samuel de Paula comprises diversified freshwater habitats that are of great importance for the conservation of many benthic taxa that are intolerant to organic pollution.

  16. Brasil, América Latina e crise das reformas liberais

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    Luis Sergio Henriques

    2002-01-01

    Full Text Available En esta entrevista, concedida a la revista ESPACIOS (CINDES, Ecuador, y que se nos ha dado la primicia de su publicación, el autor opina críticamente sobre el futuro de Brasil, y de Latinoamérica en general, frente a las reformas liberales que la sociedad capitalista está implementando a nivel global. Brasil ha respondido a estas “reformas liberales”, entre dos escenarios que se han mantenido coexistiendo: por un lado, las fuerzas totalitarias y conservadoras que se adhieren al sistiema; por el otro, las fuerzas sociales disidentes de izquierda que se valen de la sociedad civil para demandar una democracia más participativa con el propóstio de combatir la hegemonía política y socio-cultural.

  17. La evolución de la política exterior China

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    Mario Esteban Rodríguez

    2016-01-01

    Full Text Available Este artículo sintetiza y analiza los principales cambios experimentados por la política exterior de la República Popular China desde su fundación en 1949 hasta la actualidad. Para explicar esas transformaciones se recurre fundamentalmente a tres variables (la política interna de China, las características del sistema internacional y el contexto de seguridad, que las autoridades chinas han interpretado influidas por tres componentes ideacionales: el comunismo, el nacionalismo y el pragmatismo. A modo de conclusión se subraya que, a pesar de sus vaivenes, la política exterior de Pekín ha mantenido tres objetivos fundamentales en las últimas siete décadas: modernización, reconocimiento internacional como gran potencia y reunificación nacional.

  18. Entre guerra y paz. América Latina frente a la tragedia del primer conflicto mundial

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    GRAZIANO PALAMARA

    2015-07-01

    Full Text Available El presente ensayo propone un análisis de las posturas latinoamericanas ante la Primera Guerra Mundial -Pgm-; la reflexión se fundamenta en un modelo interpretativo, que considera las guerras de alcance mundial, no solo como el punto de disgregación de un sistema internacional, sino como el momento fundante de un nuevo orden. Este modelo permite reflexionar en cuanto a la manera como Latinoamérica se acercó al declive del orden posnapoleónico y la conducta que adoptó, en 1917, al ingresar Estados Unidos al conflicto y la Revolución de Octubre en Rusia, cuando se abrió en el contexto de las relaciones internacionales una nueva época que habría mantenido intactas algunas de sus características, por lo menos hasta la caída del muro de Berlín.

  19. Crecimiento económico y demográfico regional en Colombia, 1985-2012

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    Luis Armando Galvis

    2015-12-01

    Full Text Available En el crecimiento económico y demográfico de Colombia han primado las grandes urbes, y en términos demográficos hoy es un país urbano. Este artículo examina la dinámica del crecimiento económico, en especial, la dinámica poblacional desde mediados de los ochenta. El análisis de las matrices de transición de Markov indica que el comportamiento demográfico de los municipios muestra signos de persistencia. Las principales ciudades mantienen su jerarquía y siguen siendo las más densamente pobladas. Los municipios con bajo nivel de densidad se han mantenido relativamente estancados en términos demográficos.

  20. Política fiscal y equidad: Estimación de la progresividad y capacidad redistributiva de los impuestos y el gasto público social en los países de la Comunidad Andina

    OpenAIRE

    Alberto Daniel Barreix; Jerónimo Roca; Luiz Arruda Villela

    2006-01-01

    En la Comunidad Andina (CAN), a excepción de Colombia, donde los indicadores de desigualdad se han mantenido estables, en todos los demás países de la región se ha deteriorado la distribución del ingreso respecto a inicios de los '90, con la peculiaridad de que el deterioro ha sido más pronunciado en aquellos países que presentaban, y aún presentan, una situación menos desigual: Venezuela y Perú, lo que ha llevado a una menor varianza de los coeficientes de desigualdad de la región en torno a...

  1. Proyecto LINK y Econometría de Alta Frecuencia: Las últimas aportaciones econométricas de Lawrence R. Klein

    OpenAIRE

    ADOLFO CASTILLA

    2015-01-01

    Lawrence R. Klein murió a los 93 años, el 20 de octubre de 2013. Su vida profesional ha sido larga y fructífera. Se mantuvo muy activo hasta los 87 años y el autor de este trabajo ha sido testigo directo de ello. Ha sido para él, maestro, mentor y amigo, y la colaboración de los dos se ha mantenido a lo largo de más de cuarenta años. Desde el punto de vista de la economía y de la econometría la carrera de Klein ha sido larga y variada, habiendo trabajado en áreas muy diversas. Como su vida y ...

  2. Origen de los Petroglifos gallego atlánticos

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    Ramón SOBRINO LORENZO-RUZA

    2009-10-01

    Full Text Available Desde la creación por el profesor Hugo Obermaier, en 1925, de la hipótesis sobre los grabados rupestres, insculturas o petroglifos del noroeste de España, expuesta en su trabajo Die Bronzezeitlichen Felsgravierungen von Nordwestspanien, Galizien, que fué aceptada, dado su prestigio internacional, en todos los medios científicos, no se ha vuelto a plantear seriamente ninguna otra hipótesis referente a los orígenes de dichos grabados. Cuevillas y Bouiza Brey, en Galicia, la han comentado aceptando el punto de vista mantenido por Obermaier en cuanto a los orígenes de los petroglifos. Mac White, denominando elemento megalitico al grupo más antiguo de Obermaier, lo acepta también.

  3. Actividad del virus del oeste del Nilo y otros flavivirus en cinco departamentos del Caribe colombiano

    Directory of Open Access Journals (Sweden)

    Jaime Álvarez

    2010-04-01

    Full Text Available El virus del oeste del Nilo (VON y el virus de la encefalitis de San Luis (VESL pertenece a la familia Flaviviridae, género Flavivirus y hacen parte del serocomplejo de la encefalitis japonesa (1. Estos virus se encuentran distribuidos en Estados Unidos, centro América y suramerica (2. Son mantenidos en la naturaleza en un ciclo enzoótico ave-mosquito-ave. Humanos, équidos y otros vertebrados se infectan por la picadura de mosquitos del genero Culex principalmente (1,2. En humanos se han identificado y descrito nuevos modos de transmisión de VON incluyendo infección a través de productos sanguíneos contaminados (3, transplante de órganos (4, transmisión a través de la leche materna (5, transmisión intrauterina (6, y exposición ocupacional (7.

  4. La línea rojinegra educativa del anarquismo español

    Directory of Open Access Journals (Sweden)

    Francisco José Cuevas Noa

    2010-02-01

    Full Text Available La educación anarquista española tiene entidad propia y ha lideradofrecuentemente este movimiento educativo a nivel internacional. Existen cuatro periodos en la evolución de la pedagogía libertaria en España: los primeros años del movimiento obrero, en el siglo XIX, el modelo de la Enseñanza Racionalista, las experiencias durante la Guerra Civil y, finalmente, los ensayos de educación anarquista desde 1975 hasta la actualidad. Aunque la pedagogía libertaria española ha cambiado adaptándose a los variados contextos, la esencia se ha mantenido: educar personas libres y rebeldes que trabajen por una sociedad nueva. Y esta continuidad histórica se debe a la estrecha vinculación entre pedagogía libertaria y movimiento anarquista.

  5. Eficiencia técnica y ambiental de la camaronicultura en Nayarit aplicando el índice de Malmquist

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    Francisco Javier Martínez-Cordero

    2015-01-01

    Full Text Available A partir de una base de datos no homogénea de 32 granjas de camarón en Nayarit para el periodo 2008-2011, el presente estudio aplica el índice de Malmquist para analizar su eficiencia técnica ET y ambientalmente ajustada EAA de una empresa o industria acuícola sostenible. Los resultados indican que los niveles de ET y EAA se han mantenido arriba de 0.80 y 0.75 en promedio, respectivamente. En general, los resultados confirman estudios regionales previos del cultivo de camarón, en función de que los rendimientos (kg/ha/año pueden ser decrecientes por causa de las enfermedades virales. Se recomienda aplicar estos indicadores de manera continua para asistir la planificación y toma de decisión tanto a nivel empresa como industria.

  6. Un análisis de la integración comercial entre los países de América del Sur

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    Vázquez Cueto, María José

    2008-01-01

    Full Text Available Los países que componen América del Sur vienen históricamente intentando unaintegración económica (CAN, MERCOSUR y Chile con mayor o menor fortuna. En estetrabajo se trata de analizar la evolución de la integración global entre ellos a través deindicadores que relacionan sus flujos comerciales, midiendo sus distintos grados de apertura yde conexión. Tomando como años de referencia 1996 y 2006, observamos los distintoscomportamientos de los países del lado de sus exportaciones. La evidencia empírica nosmuestra como el cambio en las relaciones que ha mantenido Venezuela con el resto, a nivel deexportaciones, han supuesto un freno hacia el proceso de integración comercial entre ellos

  7. CULTURA Y NATURALEZA: MONTAIGNE EN AMÉRICA

    OpenAIRE

    Vicente Raga Rosaleny

    2013-01-01

    El examen que del Nuevo Mundo llevó a cabo el escritor francés del Renacimiento tardío Michel de Montaigne, en alguno de sus más famosos ensayos, proporcionó un retrato de la condición humana que rompía con el paradigma aristotélico mantenido por, entre muchísimos otros, el humanista español Juan Ginés de Sepúlveda. Montaigne, usando las mismas fuentes que la mayoría de estudiosos escolásticos de su tiempo, se distanció de la dominante visión peripatética (cristianizada a lo largo de Edad Med...

  8. CULTURA Y NATURALEZA: MONTAIGNE EN AMÉRICA

    Directory of Open Access Journals (Sweden)

    Vicente Raga Rosaleny

    2013-12-01

    Full Text Available El examen que del Nuevo Mundo llevó a cabo el escritor francés del Renacimiento tardío Michel de Montaigne, en alguno de sus más famosos ensayos, proporcionó un retrato de la condición humana que rompía con el paradigma aristotélico mantenido por, entre muchísimos otros, el humanista español Juan Ginés de Sepúlveda. Montaigne, usando las mismas fuentes que la mayoría de estudiosos escolásticos de su tiempo, se distanció de la dominante visión peripatética (cristianizada a lo largo de Edad Media del hombre, ofreciendo una perspectiva alternativa que podríamos calificar de radicalmente moderna.

  9. Toxicidad y teratogénesis por arsénico en aguas en el pez cebra (Danio rerio)

    OpenAIRE

    F Prieto García; OA Báez Ramírez; W Scout; JC Gaytán Oyarzún; A Zúñiga Estrada

    2007-01-01

    El objetivo del trabajo fue estudiar los daños teratogénicos y la inducción de micronúcleos en células branquiales de peces cebra (Danio rerio) por presencia de arsénico en las aguas. Fueron mantenidos en aguas bicarbonatadas cálcicas magnésicas de un pozo de referencia y del pozo Zimapán 5, del Municipio Zimapán, Estado de Hidalgo, México. Este último, con un contenido de arsénico que varía de 0,395-0,630 mg/L. Para el estudio de genotoxicidad se evaluaron durante 180 dí...

  10. Toxicidad y teratogénesis por arsénico en aguas en el pez cebra (Danio rerio)

    OpenAIRE

    F Prieto García; OA Báez Ramírez; W Scout; JC Gaytán Oyarzún; A Zúñiga Estrada

    2007-01-01

    El objetivo del trabajo fue estudiar los daños teratogénicos y la inducción de micronúcleos en células branquiales de peces cebra (Danio rerio) por presencia de arsénico en las aguas. Fueron mantenidos en aguas bicarbonatadas cálcicas magnésicas de un pozo de referencia y del pozo “Zimapán 5”, del Municipio Zimapán, Estado de Hidalgo, México. Este último, con un contenido de arsénico que varía de 0,395-0,630 mg/L. Para el estudio de genotoxicidad se evaluaron durante 180 días en 3 tratamiento...

  11. Promoción de la detección del virus de la inmunodeficiencia humana en atención primaria Promoting routine human immunodeficiency virus testing in primary care

    OpenAIRE

    Rosa Martín-Cabo; Juan E. Losa-García; Higinio Iglesias-Franco; Rosario Iglesias-González; Angélica Fajardo-Alcántara; Asunción Jiménez-Moreno

    2012-01-01

    Objetivos: Promover la prueba diagnóstica frente al virus de la inmunodeficiencia humana (VIH) en atención primaria y describir su aceptación. Métodos: Estudio de intervención no aleatorizado en un centro de salud urbano sobre cinco médicos de atención primaria que atendían pacientes de 18 a 65 años de edad a quienes se iba a realizar un análisis de sangre por otro motivo. Se ofreció sistemáticamente la realización de la prueba del VIH si reconocían haber mantenido una relación sexual sin usa...

  12. Acheronta movebo : el Infierno y el Inconsciente; Virgilio y Freud

    OpenAIRE

    Petrella, Sabina

    2003-01-01

    Con la cita virgiliana que sirve de epígrafe a la Interpretación de los sueños, Freud quiso aludir a la represión. En este artículo, tras un análisis de las connotaciones semánticas que la idea del infierno ha ido asumiendo en la cultura europea cristiana, se enfoca la imagen de la furia Alecto, evocada por sinécdoque en el verso virgiliano y se estudia cómo sus ricas expansiones semánticas se han mantenido vivas hasta Freud. Se llega a la conclusión de que la antítesis Supe...

  13. Modelos contables y comprensión de la crisis financiera

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    Dirk J. Bezemer

    2012-06-01

    Full Text Available Este artículo muestra que los modelos macroeconómicos contables ayudaron a prever la crisis de crédito y la recesión económica, mientras que los modelos de equilibrio ubicuos en la formulación de política y la investigación de la corriente principal no. Explora los antecedentes intelectuales del enfoque contable como alternativa a la economía neoclásica y el ascenso y declive de los modelos de flujo de fondos durante la posguerra. Incluye estudios de caso actuales de ambos tipos de modelos y analiza por qué el enfoque contable se ha mantenido fuera de la corriente dominante. Hace recomendaciones constructivas para revisar los métodos de evaluación de la estabilidad financiera y aboga por una “contabilidad de la economía”.

  14. Periodismo ambiental y ecologismo, tratamiento informativo del vertido de Aznalcollar en El País, Edición Andalucia (1998-1999)

    OpenAIRE

    Fernández Reyes, Rogelio

    2001-01-01

    Siguiendo a Laurence Bardin, una hipótesis “es una afirmación provisional que se pretende verificar (confirmar o rechazar) recurriendo a procedimientos de análisis” y el objetivo “la intención general que se le da” (Bardin, 1986: 73-74). En nuestra investigación, hemos elaborado, basándonos en la intuición, una serie de hipótesis que se han mantenido abiertas hasta ir tanteando los resultados de algunos análisis. Bardin defiende que en el preanálisis no siempre están establecidas las hipó...

  15. Pequeño manual de inestética fílmica. Cine y filosofía en Alain Badiou

    OpenAIRE

    García Puchades, Wenceslao

    2015-01-01

    El filósofo francés Alain Badiou, al principio de su texto Arte y filosofía, utiliza el símil lacaniano del amo y la histérica para explicar la relación que la filosofía y el arte han mantenido a lo largo de la historia (Badiou, 2009, pp. 45-46). Desde su origen platónico, esta relación ha estado mediada por la pregunta del arte acerca su propia identidad: "Dime filosofía, tú que todo lo sabes, ¿en verdad, quién soy yo?". Por su parte, la filosofía, dividida entre su completo menosprecio y su...

  16. El concepto de 'recuperación' en Antropología : Ensayando ideas

    OpenAIRE

    Kalinsky, Beatriz; Carrasco, Morita

    1994-01-01

    En este artículo se muestran las vinculaciones conceptuales que ha habido entre cultura, diversidad sociocultural y el papel asumido por la Antropología en diferentes momentos históricos de la disciplina. Se pone el acento en los vaivenes ideológicos que han mantenido en relación a la idea de “recuperación, marcándose en todos los casos una tajante separación entre el ‘nosotros’ y el ‘otro-etnográfico’”. Concluimos presentando cómo en el momento actual, la dislocación política y el estallido ...

  17. Contención sin aislamiento

    OpenAIRE

    Mario Sánchez Gumiel

    2013-01-01

    En febrero de 2012 se cumplieron cuarenta años de la visita de Richard Nixon a China y, por tanto, de la reanudación de las relaciones sino-americanas que habían sido interrumpidas en 1949. Desde entonces, Estados Unidos y China han mantenido una recíproca política de contención y aislamiento, conscientes de sus diferencias, pero sabedores también de la necesidad de un entendimiento mutuo. Como consecuencia dicha política de contención y aislamiento, el océano Pacífico está transformándose, c...

  18. Peralta Ruiz, Víctor. La independencia y la cultura política peruana (1808-1821. Lima: Instituto de Estudios Peruanos / M.J. Bustamante de la Fuente, 2010, 385 pp.

    Directory of Open Access Journals (Sweden)

    Pilar García Jordán

    2015-06-01

    Full Text Available primeros tiempos de la revolución en unión con el ala urbana del movimiento 26 de Julio quisieron mermar los poderes de Castro. Los comunistas se fueron abriendo paso en el congreso. Los sindicalistas “mujalistas” y los independientes fueron depurados. El acercamiento de Castro a los comunistas recrudeció la guerra fría. Raúl Castro asumió el mando supremo de las fuerzas armadas, y Ernesto Guevara fue nombrado director del Banco Nacional. Este acercamiento de la revolución a los postulados comunistas hizo variar la postura de Estados Unidos, que había mantenido recelos importantes hacia la isla. Las presiones norteamericanas llevaron a Cuba a acercarse a la Unión Soviética, y en 1962 se produjo la crisis de los misiles, uno de los acontecimientos más duros de la guerra fría.

  19. La educación superior en México: un estudio comparativo

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    Juan Manuel Ocegueda Hernández

    2014-01-01

    Full Text Available Se analizan los logros del sistema de educación superior ( ses en México me - diante un ejercicio comparativo que considera cuatro naciones en desarrollo: Argentina, Brasil, Chile y Corea del Sur. Los resultados sugieren que México se ha rezagado en materia de cobertura y en su capacidad para ofrecer una educación superior de buena calidad debido a varios factores: la tendencia demográfica que ha mantenido alta la población de 19-24 años, limitaciones presupuestales como resultado de la baja participación privada en la atención de la demanda por estudios de educación superior y la dependencia del ses respecto al subsidio público, así como la falla de la política educativa para asegurar la calidad en los servicios que ofertan las ies .

  20. APUNTES SOBRE DESARROLLO TECNOCIENTÍFICO DESDE UNA PERSPECTIVA DE GÉNERO

    OpenAIRE

    Briseis Godinez Valdés; Mónica Cortina Castellanos

    2011-01-01

    Desde un enfoque de género, podría advertirse que de manera particular los análisis de la situación de la mujer en la tecnociencia, revelan las numerosas barreras que han mantenido a la mujer alejada del desarrollo científico-tecnológico, luchando sin más por el acceso a las instituciones y prácticas. El hecho del fracaso de muchos de los planes de integración de mujeres en la ciencia y la tecnología, develan como esta últimas, se revelan a menudo como instrumentos para la perpetuación de pro...

  1. Conducta de riesgo en infecciones de transmisión sexual y embarazo

    OpenAIRE

    Eligio Cándido Brito Méndez; Julia María Guerra Rosales; Raudel Rodríguez Báez

    2003-01-01

    Este trabajo, de corte transversal y descriptivo, abarcó a 239 adolescentes del Politécnico "Batalla de Guisa", Río Cauto, en el primer semestre del año 2001. Se les aplicó una encuesta anónima, se procesó la información por el conteo simple, y se representó en tablas estadísticas, con el consiguiente resultado. La mayoría de los adolescentes tuvieron su primera relación sexual entre los 11 y 16 años, y más de la mitad a partir de los 15. El 41 % ha mantenido relaciones sexuales con 2 o más p...

  2. Extracciones e indicaciones de extracciones dentales en población rural chilena de 11 a 30 años Extractions and indications of dental extractions in rural chilean population give 11 to 30 years

    OpenAIRE

    S. Olate; JP Alister; Soto, M.; R Alveal; J. Fuentes; D. Thomas

    2006-01-01

    Introducción: A pesar de la creciente tecnología odontológica y el progresivo aumento de la cantidad de odontólogos, el precario estándar de salud oral de la población rural se ha mantenido a lo largo del tiempo. El objetivo de esta investigación es describir y cuantificar las exodoncias de piezas dentarias permanentes en población rural. Metodología: Se realizó un estudio de tipo descriptivo seleccionando el 100% de los sujetos atendidos en el Consultorio Chol-Chol, (IX Región) de 11 a 30 añ...

  3. Los medios universitarios frente a la globalización de la cultura

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    Mauricio Andión Gamboa

    2005-01-01

    Full Text Available El presente ensayo revisa la relación que han mantenido las universidades con los medios de comunicación, como recursos tecnológicos útiles para ejercer sus funciones sustantivas; delínea la coyuntura histórica que vive el mundo, y explica el papel que los medios han cumplido en este proceso de transformación de los paradigmas culturales que habían guiado las prácticas académicas en Occidente. Aclara la forma en cómo las universidades están siendo obligadas a cambiar para ajustarse a las nuevas condiciones y presiones de su entorno; y finalmente, propone que el sentido del cambio debe darse a través del fortalecimiento de los programas de extensión universitaria, particularmente los de educación continua, a distancia y de difusión cultural.

  4. ¿Debate educativo en twitter?: el caso de los MOOC

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    Sonia Santoveña Casal

    2015-01-01

    Full Text Available Massive Open Online Course (MOOC ha supuesto una nueva forma de entender la educación, lo que ha potenciado un debate abierto en el ámbito académico, no solo a través de publicaciones científicas, sino también a través de las redes sociales. En este artículo se presenta un estudio del debate, relativo a este concepto, mantenido en Twitter. Se ha realizado un análisis descriptivo y un análisis de contenido. Se obtiene una muestra de 9.023 tweets. Se concluye que no se ha registrado un debate en Twitter relativo a lo que significa el concepto MOOC o su implicación en la educación.

  5. Historiografía, eurocentrismo y universalidad en enrique dussel

    OpenAIRE

    Pachón Soto, Damian

    2012-01-01

    Se exponen las críticas de Enrique Dussel a la historiografía de la filosofía tradicional y a la visión hegemónica de la modernidad y su eurocentrismo, que han ocultado la participación de otros pueblos en la constitución de Europa. Esta crítica abre las puertas a una nueva comprensión de la actualidad, donde la filosofía europea puede entrar en diálogo con otras tradiciones filosóficas para construir lo que el autor llama una “transmodernidad filosófica”. Este propósito crítico es mantenido ...

  6. Comparabilidade da informação contábil em empresas brasileiras após a adoção das normas internacionais de contabilidade

    Directory of Open Access Journals (Sweden)

    Diane Rossi Maximiano Reina

    2014-01-01

    Full Text Available Esta investigación tiene como objetivo analizar los niveles de comparabilidad de los informes financieros de las empresas que componen el Índice Brasil 50 - IBrX - 50 después de la adopción de las Normas Internacionales de Contabilidad. Es una investigación descriptiva, cualitativa y cuantitativa, referente a los Pronunciamientos Técn icos CPCs 16, 27, 04 e 38, calculados por el índice de comparabilidad T Index. Los resultados manifiestan un nivel de comparabilidad promedio en el CPC 16 de 0,34; CPC 27 de 0,90; CPC 04 de 0,92; y CPC 38 de 0,15 (mantenidos para la venta. Los índices pro medio de comparabilidad son críticos sobre el método de mensuración y evaluación de los stocks, instrumentos financieros .

  7. Publicaciones en Educación Matemática. La experiencia de "una empresa docente"

    OpenAIRE

    Gómez, Pedro; Fernández, Felipe; Carulla, Cristina; Andrade, Luisa

    1998-01-01

    Uno de los factores centrales para el desarrollo de la comunidad de educación matemática en un país es su producción editorial. Desde su creación, "una empresa docente" ha mantenido una actividad editorial con estos propósitos. En este artículo se describe la experiencia que hemos vivido en este campo. Se presenta el proceso de creación de la unidad de auto-edición del centro y la forma como se convirtió en un sello editorial a nivel internacional. Se discute sobre la problemática de la produ...

  8. De la hegemonía a la multipolaridad en el comercio internacional desde la posguerra

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    Hernández Adolfo

    1987-06-01

    Full Text Available EI presente artículo se propone interpretar los cambios que en el curso de la posguerra han sufrido las participaciones de unos cuantos países y grupos de países en el comercio mundial desde la posguerra. Algunas de estas se han mantenido relativamente estables; otras han experimentado variaciones abruptas, lo que plantea interrogantes acerca de tres cuestiones cruciales de la economía mundial: las relaciones entre las naciones capitalistas avanzadas y las subdesarrolladas; la participación de los países de economía planificada en el comercio de Occidente, y la competencia entre países capitalistas avanzados.

  9. Posicionamiento en Google Académico y en la WEB de la Revista Ciencias Holguín

    OpenAIRE

    Jorge González-Alonso; Jhony Fabián-Pazmiño; Yudeisy Pérez-González

    2015-01-01

    Se caracterizó la presencia en Google Scholar y en la Web de 635 artículos de la Revista Ciencias Holguín publicados entre 1995 y el 2015. La revista ha mantenido un promedio de 4.85 citas por año y de 0.15 citas por artículo. Se realizó el agrupamiento por clústeres con el algoritmo de DB-Scan lo que permitió caracterizar cuatro grupos en función del número de citas. En uno de los clúster se agruparon 577 artículos (91% del total analizado) que no han sido referenciados en otras publicacione...

  10. Evaluation of reactivity monitoring techniques at the Yalina – Booster subcritical facility

    OpenAIRE

    Bécares Palacios, Vicente

    2014-01-01

    La gestión de los residuos radiactivos de vida larga producidos en los reactores nucleares constituye uno de los principales desafíos de la tecnología nuclear en la actualidad. Una posible opción para su gestión es la transmutación de los nucleidos de vida larga en otros de vida más corta. Los sistemas subcríticos guiados por acelerador (ADS por sus siglas en inglés) son una de las tecnologías en desarrollo para logar este objetivo. Un ADS consiste en un reactor nuclear subcrítico mantenido e...

  11. Evaluación de una solución inmovilizadora para criopreservación del semen de Colossoma macropomum, “Gamitana”

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    Ehrlich Llasaca-Calizaya

    2015-01-01

    Full Text Available El objetivo del trabajo fue la criopreservacion de semen, que permitirá constituir un banco genético, para lo cual se buscó obtener una solución  inactivadora de colecta para el semen de Colossoma macropomum  “gamitana”, que permita obtener espermatozoides, con buena motilidad de activación después de la descongelación, en nitrógeno líquido. Se utilizó semen de reproductores mantenidos, del Instituto de Investigaciones de la Amazonía Peruana (IIAP inducidos con Conceptal® y sin inducir mantenidos en el Centro de Acuicultura Nuevo Horizonte del Fondo Nacional de Desarrollo Pesquero (CANH - FONDEPES. El semen fue colectado en soluciones inactivadoras de 9% y 10% de NaCl, añadiendo 2 g/L, 4 g/L y 8 g/L de NaHCO3,  soluciones de sacarosa (300 mM, 400 mM y 500 mM sola o con 1,5 g/L, 1 g/L y 0,5 g/Lde NaCl. Se concluye que el tratamiento de 400 mM de sacarosa dio el mejor resultado, con una motilidad del 80% y 40 segundos de duración. También se evaluó la motilidad, después de una hora de almacenamiento a temperatura ambiente, con 60% de motilidad después de la activación y 20 segundos de duración. Este trabajo permitirá desarrollar  un protocolo de criopreservación para lotes de semen inmovilizados, con tiempo suficiente para preparar las pajuelas, congelarlas en nitrógeno líquido y optimizar el manejo de reproductores.

  12. Comparación de los efectos cardiovasculares del propofol, tiopental y de la mezcla propofol-tiopental en un grupo de caninos sanos premedicados con hidromorfona

    Directory of Open Access Journals (Sweden)

    Camilo Padilla Peñuela

    2013-12-01

    Full Text Available El objetivo de la investigación fue determinar las diferencias en el desempeño cardiovascular de caninos sanos premedicados con hidromorfona e inducidos y mantenidos con tres diferentes protocolos anestésicos. Se evaluaron quince caninos sanos entre uno y seis años de edad, los cuales no presentaban afecciones cardiacas o que generaran dolor, y con un riesgo anestésico clasificado como ASA I. Los pacientes se distribuyeron en tres grupos y cada uno fue inducido y mantenido en un plano anestésico (estadio III, plano 2 con un protocolo según el grupo al que se habían incorporado (tiopental, propofol o la mezcla propofol-tiopental. En cada paciente se realizó ecocardiografía (fracción de acortamiento y fracción de eyección y se midió el lactato plasmático y la presión arterial por el método oscilométrico. Las mediciones se realizaron en tres periodos de tiempo diferentes (T1, antes de premedicar; T2, después de premedicar y T3, después de la inducción. Se observó una diferencia muy significativa en la frecuencia cardiaca de los pacientes anestesiados con propofol (p = 0,0004 con tendencia a la bradicardia, y la presión arterial se mostró disminuida en este grupo; sin embargo, la diferencia no logró ser significativa (p = 0,08. En cuanto a los demás parámetros (fracción de eyección, fracción de acortamiento y lactato tampoco se observaron diferencias.

  13. Estrutura da Comunidade de Invertebrados Bentônicos do Rio Piranhas-Assu, Rio Grande do Norte, Nordeste do Brasil

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    Jansen Fernandes Medeiros

    2008-12-01

    Full Text Available Esse trabalho teve como objetivo conhecer os invertebrados bentônicos, bem como caracterizar os grupos tróficos funcionais existentes no rio Piranhas-Assu, município de Alto do Rodrigues, Rio Grande do Norte. As coletas foram realizadas nos meses de maio (chuva, julho e setembro (seca de 2002, em trechos diferentes do rio. Foi medida a velocidade da correnteza, a largura, profundidade do rio e temperatura da água. Foram coletados 3525 indivíduos de Insecta e outras classes (Malacostraca, Gastropoda, Bivalvia, Arachnida, Ostracoda e Copepoda. A maior abundância da classe Insecta ocorreu no mês de setembro (seca. A vazão apresentou correlação com a abundância com na Classe Insecta, já a velocidade superficial da água para outras classes. Entre os Insecta observou-se uma maior abundância de predadores, seguida dos coletores, já para as outras classes os raspadores foram mais abundantes.Structure of benthic invertebrate’s community with focus in the aquatic insects of the Piranhas-Assu river, State of Rio Grande do Norte, Northeast, BrazilAbstract. The aim of this work was to verify the benthonic invertebrates, and to identify the functional trophic groups that exist in the Piranhas-Assu, in Alto do Rodrigues municipality, Rio Grande do Norte State. The samples were carried taken on May (rain season, July and September (dry season from 2002, in different sites in the river. The measurements of water speed, wide, temperature and river deep where made. It was collected 3525 individuals of Insecta and other classes (Malacostraca, Gastropoda, Bivalvia, Arachnida, Ostracoda and Copepoda. Insecta showed a higher abundance in September (dry season. The river discharge showed significant correlation with Insecta classe abundance, and the superficial water speed had correlation with other classes. The insects showed a highest abundance of predators, followed by collectors, in the other classes, the scrappers were the most abundant.

  14. Implicaciones etologicas y significado de la estereotipicidad de Oichnus Bromley durante el plioceno en la cuenca del bajo Guadalquivir (SO España

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    Mayoral, E.

    1990-08-01

    Full Text Available The analysis of the stereotypy in the Oichnus-type borings on Bivalvia (epi and infaunal from different Pliocene stratigraphic horizons in the Southwestern sector of the Guadalquivir Basin, has allowed to show sorne changes about the predatory behaviour. These have an effect on two levels: on a small scale, when the changes between juvenil and mature state of the preys are considered and on a larger scale, when the environmental conditions of every stratigraphic horizons are estimated. The variability on the first case are due to internal factors to the predatory-prey system: morphology, size and ornamentation of the preys. On the second one, are related with loss or increase in external factors on system: environmental selective pressure (kind of substrate, energy, ecologic competition. Wel1 defined behaviour patterns have been revealed by differences in the stereotypy of several Oichnus-type (O. paraboloides Bromley and O. simplex Bromley. This fact establish also various trace-makers for the latter.El estudio de la estereotipicidad de las perforaciones del tipo Oichnus Bromley, realizado sobre representantes de Bivalvia (epi e infauna en diferentes horizontes estratigráficos del Plioceno del sector SO de la Cuenca del Guadalquivir ha permitido evidenciar cambios en la conducta depredadora de los organismos. Estas variaciones se detectan a pequeña escala al considerar los cambios que se producen en el desarrollo del estado juvenil al estado adulto de las presas y a una escala mayor, cuando se estiman las transformaciones medioambientales inherentes a cada uno de los horizontes estratigráficos estudiados. En el primer caso, las variaciones están en función de factores internos al sistema depredador- presa: morfología, tamaño y ornamentación de estas últimas. En el segundo caso se relacionan con la pérdida o adquisición de factores externos al sistema: presión selectiva ambiental (naturaleza del sustrato, energía, competición ecol

  15. Trophic relationships between macroinvertebrates and fish in a pampean lowland stream (Argentina Relaciones tróficas entre los macroinvertebrados y peces en un arroyo de la llanura pampeana (Argentina

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    María V. López van Oosterom

    2013-03-01

    Full Text Available The diet and trophic relationships between the macroinvertebrates Phyllogomphoides joaquini Rodrigues Capítulo, 1992 and Coenagrionidae (Odonata, Chironomidae (Diptera, Diplodon delodontus (Lamarck, 1919 (Bivalvia: Hyriidae, and Pomacea canaliculata (Lamarck, 1822 (Gastropoda: Ampulariidae and the fishes Pimelodella laticeps Eigenmann, 1917 (Heptapteridae and Bryconamericus iheringii (Boulenger, 1887 (Characidae in a temperate lowland lotic system in Argentina were assessed on the basis of gut contents and stable-isotope analyses. The feeding strategies were analyzed by the AMUNDSEN method. Relative food items contribution for the taxa studied indicated a generalist-type trophic strategy. In macroinvertebrates, in general, the values of stable isotope confirmed the result of the analysis of gut contents. With the fish, stable-isotope analysis demonstrated that both species are predators, although B. iheringii exhibited a more omnivorous behaviour. These feeding studies allowed us to determine the trophic relationships among taxa studied. Detritus and diatoms were a principal source of food for all the macroinvertebrates studied. In La Choza stream the particulate organic matter is a major no limited food resource, has a significant influence upon the community.Se evaluó la dieta y las relaciones tróficas entre los macroinvertebrados Phyllogomphoides joaquini Rodrigues Capítulo, 1992 y Coenagrionidae (Odonata, Chironomidae (Diptera, Diplodon delodontus (Lamarck, 1919 (Bivalvia: Hyriidae, Pomacea canaliculata (Lamarck, 1822 (Gastropoda: Ampulariidae y los peces Pimelodella laticeps Eigenmann, 1917 (Heptapteridae y Bryconamericus iheringii (Boulenger, 1887 (Characidae en un ecosistema lótico pampásico, sobre la base del contenido estomacal y el análisis de isótopos estables. La estrategia alimentaria fue analizada mediante el método de AMUNDSEN. La contribución relativa de cada categoría alimenticia para los taxa estudiados indicó que

  16. Conductas sexuales en adolescentes de 12 a 17 años de Andalucía Sexual behavior in adolescents aged 12 to 17 in Andalusia (Spain

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    José Rodríguez Carrión

    2012-12-01

    Full Text Available Objetivo: Describir los comportamientos y prácticas sexuales de los y las adolescentes de 12 a 17 años de edad en Andalucía (2007-2008. Método: La información se recogió mediante un cuestionario autocumplimentado, anónimo y voluntario, aplicado a una muestra aleatoria estratificada de 2.225 estudiantes de enseñanza secundaria obligatoria (ESO, en todas las provincias de Andalucía. Resultados: 388 adolescentes (18,2% refirieron haber mantenido relaciones sexuales con penetración, sin diferencias estadísticamente significativas entre chicos (18,0% y chicas (18,5%. Sí se encontró una mayor precocidad de los chicos en la edad de su inicio (14 años frente a 14,4, comienzo en la masturbación (11,3 años frente a 12,7, sexo oral (13,8 años frente a 14,6 y masturbación a la pareja (13,7 años frente a 14,4. También se hallaron diferencias en el número de parejas sexuales (2 los chicos y 1,6 las chicas, mantener relaciones sexuales en la actualidad (menos ellos, haber mantenido relaciones sexuales a través de Internet (más los chicos, haber usado un anticonceptivo en el primer coito (menos los chicos y conocimiento del doble método y de las infecciones de transmisión sexual (mayor en las chicas. Conclusiones: Uno de cada seis estudiantes de ESO de Andalucía ha mantenido relaciones sexuales con penetración; de ellos, dos tercios las mantienen en la actualidad, sobre todo las chicas. Valorado junto con un escaso conocimiento (menos del 50% del doble método y de las infecciones de transmisión sexual, nos lleva a considerar necesario incluir la educación sexual como específica dentro del currículo de la enseñanza secundaria.Objective: To describe sexual behavior and activity among adolescents aged 12-17 years old in Andalusia (Spain in 2007-2008. Method: The data for this study were collected through an anonymous questionnaire distributed to a stratified random sample of 2,225 secondary school students in Andalusia

  17. Are Predators Limiting Zebra Mussel Colonization of Unionid Mussels in Great Lake Coastal Wetlands?

    Science.gov (United States)

    de Szalay, F. A.; Bowers, R.

    2005-05-01

    Although many native mollusc populations have been eliminated in the Laurentian Great Lakes by the exotic zebra mussel, recent surveys have found abundant unionid (Bivalvia: Unionidae) populations in some coastal wetlands. Unionid burrowing in soft sediments and predation by fish have been shown to reduce numbers of attached zebra mussels, and we tested these factors in a Lake Erie coastal wetland. In 2002, we held live unionids (Leptodea fragilis, Quadrula quadrula) and Pyganodon grandis shells in exclosures with wire mesh bottoms that were buried to sediment depths of either 5, 10, or 20 cm. After 2 months, numbers of attached dreissenids on unionids were significantly higher inside all exclosure treatments than outside exclosures. This indicated that either unionid burrowing was prevented in all sediment depth treatments or molluscivores were excluded by exclosures. In 2004, we measured dreissenid colonization on Q. quadrula and PVC plates in bottomless exclosures with different mesh sizes. After 6 months, dreissenid numbers on PVC plates and on Q. quadrula in 2.5 cm X 2.5 cm and 5 cm X 10 cm mesh exclosures were significantly higher than in open exclosures. These data suggest that molluscivores are important in limiting dreissenids in Great Lake coastal wetlands.

  18. Chromosome mutagenesis in populations of aquatic biota in the Black Sea, Aegean Sea and Danube and Dnieper rivers, 1986-1989

    International Nuclear Information System (INIS)

    We studied the level of structural mutagenesis in the reproductive and somatic cells of aquatic biota of various taxa from natural populations of neustic and benthic communities in the Black and Aegean Seas and the Dnieper and Danube rivers between 1986 and 1989. The cytogenetic research covered embryos, larvae and adult worms of Nereidae, Naididae, Tubificidae and Turbellaria, adult Sagitta setosa, young Bivalvia molluscs, embryos of Mysidacea, and growing roe of Engraulis encrasicholus, Sprattus sprattus, Diplodus annularis, Mullus barbatus, Trachurus trachurus, Scophthalmus maeoticus, Abramis brama, Blicca bjoerkna, Rutilus rutilus and Stizostedion lucioperca. It was established that aquatic biota in the open waters of the Black and Aegean Seas had a lower level of chromosome mutagenesis than representatives of the fluvial communities. The intensity of mutagenesis was compared with the data published in the literature on radioactive contamination/chemical pollution of the aqueous medium in these areas. The paper sets out statistical regularities in chromosome mutagenesis (inter-individual variability in the chromosome aberration rate and distribution of chromosome damage in cells), noting different patterns of chromosome aberration distribution among cells. On the basis of a large quantity on our own data from field and experimental cytogenetic studies involving aquatic biota, the paper considers the possibility of using - for the purposes of radiochemical-ecological monitoring - chromosome damage distribution in cells as an indicator of whether mutagens are radiation-related or not. (author)

  19. Colwellia and sulfur-oxidizing bacteria: An unusual dual symbiosis in a Terua mussel (Mytilidae: Bathymodiolinae) from whale falls in the Antilles arc

    Science.gov (United States)

    Duperron, Sébastien; Gros, Olivier

    2016-09-01

    Seven individuals of a single morphotype of mussels (Bivalvia: Mytilidae) were found attached to a naturally sunken whale intervertebral disk collected in Guadeloupe (Caribbean) at 800 m depth. These specimens resemble small Idas mussels which are found worldwide at cold seeps and hydrothermal vents, and typically harbor ectosymbiotic bacteria on their gills upon which they depend for nutrition. Based on multi-locus gene sequencing, these specimens appear to belong to a new species closely related to two species now included within the genus Terua. Unexpectedly, its closest relatives are found in the Pacific, questioning how this species has reached the Antilles arc. Based on marker gene sequence analysis, electron and fluorescence microscopy, Terua n. sp. harbors two distinct and abundant extracellular bacterial symbionts located between microvilli at the apical surface of host gill epithelial cells. One is a sulfur-oxidizing bacterium similar to the symbionts previously identified in several deep-sea mussels, while the other is related to Colwellia species, a group of cold-adapted heterotrophic bacteria able to degrade organic compounds. This study provides the first evidence for the existence of a dual symbiosis in mussels from whale fall ecosystems in the Caribbean. The evolutionary history of Terua n. sp. and potential role of its Colwellia symbionts are discussed.

  20. Mollusc fauna associated with the Cystoseira algal associations in the Gulf of Trieste (Northern Adriatic Sea

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    V. PITACCO

    2014-07-01

    Full Text Available Mollusc assemblages associated with Cystoseira associations were sampled in the southern part of the Gulf of Trieste during the summers of 2008 and 2012. Samples were collected by SCUBA diving in the infralittoral belt (from 1 to 4 m depth. The surface within frames of 20 x 20 cm was scraped off with samples were collected by hand or with an air-lift sampler. Four erected algal species were found: Cystoseira barbata, C. compressa, C. corniculata and Halopithys incurva. A total of 69 species of molluscs were identified in those associations. Gastropoda were dominant, with the highest species richness and abundance, followed by Bivalvia and Polyplacophora. A large number of juveniles were found, proving the importance of Cystoseira associations for mollusc recruitment. Differences in composition, structure and abundance of mollusc assemblages were found for sites dominated by different algal species, and correspond to different morphology and degree of development of canopy-forming species. The present study confirms that the dominant algal species within Cystoseira associations strongly influence, although at different levels, abundance and distribution of mollusc assemblages in the Northern Adriatic Sea.

  1. Perna perna (LINNAEUS, 1758) mussels irradiated by 60CO gamma rays cytotoxicity evaluation

    International Nuclear Information System (INIS)

    The aim of the present work was the study of ionizing radiation effects on aquatic biota regarding the location of nuclear facilities nearby coastal areas assuming the risk of leaks and nuclear accidents. Bivalve mollusks have been widely used in the monitoring of aquatic environment studies mainly for their sessile habit and pollutants bioconcentration ability. So marine mussel Perna perna (Bivalvia: Mytilidae) was used as organism test in this study. The study of radioactive toxicity was performed by cytotoxicity test exposing the organisms to 11Gy gamma radiation dose. After radiation the neutral red retention assay evaluated the lysosomal membrane integrity in the mussel hemocytes. 50% lethal dose assay (LD50) of gamma radiation on Perna perna mussels was carried out by exposure the organisms to 60Co gamma rays at doses ranging from 0 to 3000 Gy. The result of gamma radiation LD50 for these mussels was 1068 Gy and the neutral red retention time of irradiated organisms was about 47% lower than the control, non irradiated organisms. With the obtained results is expected to contribute in the study to identify the range of ionizing radiation doses which can cause toxic effects in marine invertebrates. (author)

  2. Eco-environmental impact assessment of pre-leisure beach nourishment on the benthic invertebrate community at Anping coast

    Science.gov (United States)

    Shih, Chun-Han; Kuo, Yi-Yu; Chu, Ta-Jen; Chou, Wen-Chieh; Chang, Wei-Tse; Lee, Ying-Chou

    2011-06-01

    In recent years, owing to global warming and the rising sea levels, beach nourishment and groin building have been increasingly employed to protect coastal land from shoreline erosion. These actions may degrade beach habitats and reduce biomass and invertebrate density at sites where they were employed. We conducted an eco-environmental evaluation at the Anping artificial beach-nourishment project area. At this site, sand piles within a semi-enclosed spur groin have been enforced by use of eco-engineering concepts since 2003. Four sampling sites were monitored during the study period from July 2002 to September 2008. The environmental impact assessment and biological investigations that we conducted are presented here. The results from this study indicate that both biotic (number of species, number of individual organisms, and Shannon-Wiener diversity) and abiotic parameters (suspended solids, biological oxygen demand, chemical oxygen demand, dissolved inorganic nitrogen, dissolved inorganic phosphorus, total phosphorus, total organic carbon, median diameter, and water content) showed significant differences before and after beach engineering construction. Biological conditions became worse in the beginning stages of the engineering but improved after the restoration work completion. This study reveals that the composition of benthic invertebrates changed over the study period, and two groups of organisms, Bivalvia and Gastropoda, seemed to be particularly suitable to this habitat after the semi-enclosed artificial structures completion.

  3. Wetland macroinvertebrates of Prentiss Bay, Lake Huron, Michigan: diversity and functional group composition

    Science.gov (United States)

    Merritt, R.W.; Benbow, M.E.; Hudson, P.L.

    2002-01-01

    The Great Lakes support many fish and waterbirds that depend directly or indirectly on coastal wetlands during some portion of their life cycle. It is known that macroinvertebrates make up an important part of wetland food webs and ecosystem function; however, our understanding of species distribution within and among wetlands has only recently received attention. We investigated the macroinvertebrates of a freshwater marsh (Prentiss Bay) in the Les Chenaux Island Area of Northern Lake Huron, Michigan. Macroinvertebrate taxa diversity and functional feeding group composition were compared between two habitats. A shallow depositional habitat with higher vegetation diversity and little wave action was compared to a deeper erosional habitat with fewer plant species and more wave action. A total of 83 taxa were collected over the summer of 1996, representing two phyla (Arthropoda and Mollusca) and five classes (Arachnida, Bivalvia, Malacostraca, Gastropoda and Insecta). A total of 79 genera were identified, with 92% being insects (39 families composed of at least 73 genera). Of the total, 42 insect genera were common to both habitats,while relatively fewer were collected exclusively from the erosional compared the depositional habitat. When habitats were pooled, predators comprised about 50% of the functional group taxa, while gathering collectors and shredders each were about 20%. Filtering collectors and scrapers each represented functional groups were lower. These data suggest that vegetation diversity, depth and wave action affect taxa composition and functional group organization of the Prentiss Bay marsh.

  4. Caracterização sedimentológica da planície intertidal da parte sul do saco do Limoeiro (Ilha do Mel - Paraná - Brasil: I. implicações ecológicas

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    Erminda da Conceição Guerreiro Couto

    1998-01-01

    Full Text Available Sediment cores 40 cm depth were taken in triplicate at nine points along an unvegetable intertidal flat, to assess the ecological implications of sedimentological characteristics. Each core was sectioned in 5 cm depht layers. In these sub-samples temperature, pH, water, organic matter and carbonate content were determined. Granulometric analysis, porosity, qualitative and quantitative identification of sediment components were also carried. The sediments presented low water (15.6 - 37.2 %, organic matter (0.7 - 5.0 % and carbonates (0.3 - 1.0 % contents, prevailing fine to very fine sand at surface. Statistical analysis showed a strong horizontal homogeneity regarding sedimentological and physiochemical parameters. Organic matter exhibit a general trend of increase with depth, while carbonate content follow an inverse behavior, refleting the higher contribution of bioclastic calcareous. Textural features and qualitative sediment analysis suggest that the biological mechanism of shell crushing is predominant over physical ones in the grinding till sand size. Amongst the involved organisms there is a sponge Clione celata, the mollusks Nassarius vibex and Thais haemastoma floridana (Gastropoda, Martesia striata (Bivalvia, and the spionid polychaete Polydora socialis and P. websteri.

  5. Eco-Environmental Impact Assessment of Pre-Leisure Beach Nourishment on the Benthic Invertebrate Community at Anping Coast

    Institute of Scientific and Technical Information of China (English)

    Chun-Han SHIH; Yi-Yu KUO; Ta-Jen CHU; Wen-Chieh CHOU; Wei-Tse CHANG; Ying-Chou LEE

    2011-01-01

    In recent years, owing to global warming and the rising sea levels, beach nourishment and groin building have been increasingly employed to protect coastal land from shoreline erosion. These actions may degrade beach habitats and reduce biomass and invertebrate density at sites where they were employed. We conducted an eco-environmental evaluation at the Anping artificial beach-nourishment project area. At this site, sand piles within a semi-enclosed spur groin have been enforced by use of eco-engineering concepts since 2003. Four sampling sites were monitored during the study period from July 2002 to September 2008. The environmental impact assessment and biological investigations that we conducted are presented here. The results from this study indicate that both biotic (number of species, number of individual organisms, and Shannon-Wiener diversity) and abiotic parameters (suspended solids, biological oxygen demand, chemical oxygen demand, dissolved inorganic nitrogen, dissolved inorganic phosphorus, total phosphorus, total organic carbon, median diameter, and water content) showed significant differences before and after beach engineering construction. Biological conditions became worse in the beginning stages of the engineering but improved after the restoration work completion.This study reveals that the composition of benthic invertebrates changed over the study period, and two groups oforganisms, Bivalvia and Gastropoda, seemed to be particularly suitable to this habitat after the semi-enclosed artificial structures completion.

  6. Comparative analysis of riverscape genetic structure in rare, threatened and common freshwater mussels

    Science.gov (United States)

    Galbraith, Heather S.; Zanatta, David T; Wilson, Chris C.

    2015-01-01

    Freshwater mussels (Bivalvia: Unionoida) are highly imperiled with many species on the verge of local extirpation or global extinction. This study investigates patterns of genetic structure and diversity in six species of freshwater mussels in the central Great Lakes region of Ontario, Canada. These species vary in their conservation status (endangered to not considered at risk), life history strategy, and dispersal capabilities. Evidence of historical genetic connectivity within rivers was ubiquitous across species and may reflect dispersal abilities of host fish. There was little to no signature of recent disturbance events or bottlenecks, even in endangered species, likely as a function of mussel longevity and historical population sizes (i.e., insufficient time for genetic drift to be detectable). Genetic structure was largely at the watershed scale suggesting that population augmentation via translocation within rivers may be a useful conservation tool if needed, while minimizing genetic risks to recipient sites. Recent interest in population augmentation via translocation and propagation may rely on these results to inform management of unionids in the Great Lakes region.

  7. Perna perna (LINNAEUS, 1758) mussels irradiated by {sup 60}CO gamma rays cytotoxicity evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Martini, Gisela A.; Pusceddu, Fabio H.; Rogero, Sizue O.; Rogero, Jose Roberto, E-mail: gisela.martini@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    The aim of the present work was the study of ionizing radiation effects on aquatic biota regarding the location of nuclear facilities nearby coastal areas assuming the risk of leaks and nuclear accidents. Bivalve mollusks have been widely used in the monitoring of aquatic environment studies mainly for their sessile habit and pollutants bioconcentration ability. So marine mussel Perna perna (Bivalvia: Mytilidae) was used as organism test in this study. The study of radioactive toxicity was performed by cytotoxicity test exposing the organisms to 11Gy gamma radiation dose. After radiation the neutral red retention assay evaluated the lysosomal membrane integrity in the mussel hemocytes. 50% lethal dose assay (LD50) of gamma radiation on Perna perna mussels was carried out by exposure the organisms to {sup 60}Co gamma rays at doses ranging from 0 to 3000 Gy. The result of gamma radiation LD50 for these mussels was 1068 Gy and the neutral red retention time of irradiated organisms was about 47% lower than the control, non irradiated organisms. With the obtained results is expected to contribute in the study to identify the range of ionizing radiation doses which can cause toxic effects in marine invertebrates. (author)

  8. A seasonal comparison of zooplankton communities in the Kara Sea - With special emphasis on overwintering traits

    Science.gov (United States)

    Kosobokova, Ksenia Nikolaevna; Hirche, Hans-Juergen

    2016-06-01

    Siberian marginal seas cover large parts of the marine Arctic and host unique zooplankton communities. Detailed knowledge of their community structure and life history traits is a prerequisite to predict their response to ongoing and future climate and anthropogenic changes although winter data is extremely rare. Here data are presented from winter samples (February and April) in four biogeographic regions of the Kara Sea. Comparison of community composition and zooplankton abundance/biomass with data collected during summer showed lower diversity in winter, mainly due to the absence of freshwater species. In contrast to many other northern regions, seasonal biomass differences were relatively small. Year-round high biomass is maintained through a large share of small copepod species and constantly high share of the chaetognath Parasagitta elegans. An advanced state of gonad maturation and reproduction was observed in winter in herbivorous, omnivorous, and carnivorous species, e.g. the copepods Calanus glacialis, Drepanopus bungei, Limnocalanus macrurus, Oithona similis, Pseudocalanus major, Pseudocalanus minutus/acuspes, Paraeuchaeta glacialis, Microcalanus pygmaeus, and euphausiids, hydromedusae, and pteropods. Meroplanktonic larvae of nudibranchia, polychaeta and bivalvia were also registered. Close to the Yenisei mouth, abundance of eggs and larvae of various taxa exceeded older stages. Our data show that the brackish-water zone of the Kara Sea hosts specific communities with omnivorous species efficiently exploiting local resources during the winter and utilizing them for winter reproduction.

  9. Amundsen Sea Mollusca from the BIOPEARL II expedition

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    Camille Moreau

    2013-04-01

    Full Text Available Information regarding the molluscs in this dataset is based on the epibenthic sledge (EBS samples collected during the cruise BIOPEARL II / JR179 RRS James Clark Ross in the austral summer 2008. A total of 35 epibenthic sledge deployments have been performed at five locations in the Amundsen Sea at Pine Island Bay (PIB and the Amundsen Sea Embayment (ASE at depths ranging from 476 to 3501m. This presents a unique and important collection for the Antarctic benthic biodiversity assessment as the Amundsen Sea remains one of the least known regions in Antarctica. Indeed the work presented in this dataset is based on the first benthic samples collected with an EBS in the Amundsen Sea. However we assume that the data represented are an underestimation of the real fauna present in the Amundsen Sea. In total 9261 specimens belonging to 6 classes 55 families and 97 morphospecies were collected. The pecies richness per station varied between 6 and 43. Gastropoda were most species rich 50 species followed by Bivalvia (37, Aplacophora (5, Scaphopoda (3 and one from each of Polyplacophora and Monoplacophora.

  10. Ross Sea Mollusca from the Latitudinal Gradient Program: R/V Italica 2004 Rauschert dredge samples.

    Science.gov (United States)

    Ghiglione, Claudio; Alvaro, Maria Chiara; Griffiths, Huw J; Linse, Katrin; Schiaparelli, Stefano

    2013-01-01

    Information regarding the molluscs in this dataset is based on the Rauschert dredge samples collected during the Latitudinal Gradient Program (LGP) on board the R/V "Italica" in the Ross Sea (Antarctica) in the austral summer 2004. A total of 18 epibenthic dredge deployments/samplings have been performed at four different locations at depths ranging from 84 to 515m by using a Rauschert dredge with a mesh size of 500μm. In total 8,359 specimens have been collected belonging to a total of 161 species. Considering this dataset in terms of occurrences, it corresponds to 505 discrete distributional records (incidence data). Of these, in order of abundance, 5,965 specimens were Gastropoda (accounting for 113 species), 1,323 were Bivalvia (accounting for 36 species), 949 were Aplacophora (accounting for 7 species), 74 specimens were Scaphopoda (3 species), 38 were Monoplacophora (1 species) and, finally, 10 specimens were Polyplacophora (1 species). This data set represents the first large-scale survey of benthic micro-molluscs for the area and provides important information about the distribution of several species, which have been seldom or never recorded before in the Ross Sea. All vouchers are permanently stored at the Italian National Antarctic Museum (MNA), Section of Genoa, enabling future comparison and crosschecking. This material is also currently under study, from a molecular point of view, by the barcoding project "BAMBi" (PNRA 2010/A1.10). PMID:24146597

  11. Phylogenomics reveals deep molluscan relationships.

    Science.gov (United States)

    Kocot, Kevin M; Cannon, Johanna T; Todt, Christiane; Citarella, Mathew R; Kohn, Andrea B; Meyer, Achim; Santos, Scott R; Schander, Christoffer; Moroz, Leonid L; Lieb, Bernhard; Halanych, Kenneth M

    2011-09-22

    Evolutionary relationships among the eight major lineages of Mollusca have remained unresolved despite their diversity and importance. Previous investigations of molluscan phylogeny, based primarily on nuclear ribosomal gene sequences or morphological data, have been unsuccessful at elucidating these relationships. Recently, phylogenomic studies using dozens to hundreds of genes have greatly improved our understanding of deep animal relationships. However, limited genomic resources spanning molluscan diversity has prevented use of a phylogenomic approach. Here we use transcriptome and genome data from all major lineages (except Monoplacophora) and recover a well-supported topology for Mollusca. Our results strongly support the Aculifera hypothesis placing Polyplacophora (chitons) in a clade with a monophyletic Aplacophora (worm-like molluscs). Additionally, within Conchifera, a sister-taxon relationship between Gastropoda and Bivalvia is supported. This grouping has received little consideration and contains most (>95%) molluscan species. Thus we propose the node-based name Pleistomollusca. In light of these results, we examined the evolution of morphological characters and found support for advanced cephalization and shells as possibly having multiple origins within Mollusca. PMID:21892190

  12. Ross Sea Mollusca from the Latitudinal Gradient Program: R/V Italica 2004 Rauschert dredge samples

    Directory of Open Access Journals (Sweden)

    Claudio Ghiglione

    2013-10-01

    Full Text Available Information regarding the molluscs in this dataset is based on the Rauschert dredge samples collected during the Latitudinal Gradient Program (LGP on board the R/V “Italica” in the Ross Sea (Antarctica in the austral summer 2004. A total of 18 epibenthic dredge deployments/samplings have been performed at four different locations at depths ranging from 84 to 515m by using a Rauschert dredge with a mesh size of 500µm. In total 8,359 specimens have been collected belonging to a total of 161 species. Considering this dataset in terms of occurrences, it corresponds to 505 discrete distributional records (incidence data. Of these, in order of abundance, 5,965 specimens were Gastropoda (accounting for 113 species, 1,323 were Bivalvia (accounting for 36 species, 949 were Aplacophora (accounting for 7 species, 74 specimens were Scaphopoda (3 species, 38 were Monoplacophora (1 species and, finally, 10 specimens were Polyplacophora (1 species. This data set represents the first large-scale survey of benthic micro-molluscs for the area and provides important information about the distribution of several species, which have been seldom or never recorded before in the Ross Sea. All vouchers are permanently stored at the Italian National Antarctic Museum (MNA, Section of Genoa, enabling future comparison and crosschecking. This material is also currently under study, from a molecular point of view, by the barcoding project “BAMBi” (PNRA 2010/A1.10.

  13. On the benthic molluscs of Banco Inglés (Río de la Plata, Uruguay

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    Carranza, A.

    2007-12-01

    Full Text Available We describe the specific richness and community structure of benthic molluscs on a shallow-water sandy bank (Banco Inglés in the Río de la Plata estuary. From a total of 25 macroinvertebrate taxa collected, that included one ophiuroid, one bryozoan, fourcrustaceans and four polychaete species, molluscs were the dominant taxon, with 15 species recorded. These were one species of Polyplacophora, eight Bivalvia and six Gastropoda (one exotic, representing 11families and 11 genera. In terms of mean relative abundance, the molluscan assemblage was dominated by the deposit-feeder bivalve Corbula caribaea, averaging ca. 30% of the individuals of the macroinfauna. The alien species Rapana venosa was noted in two stations, represented by one and four specimens. We used null model analysis to test for nonrandomness in the structure of the molluscan communities of the area. The analysis supported the null hypothesis that co-occurrence patterns could not be distinguished from those that might arise by random processes.

  14. Amundsen Sea Mollusca from the BIOPEARL II expedition.

    Science.gov (United States)

    Moreau, Camille; Linse, Katrin; Griffiths, Huw; Barnes, David; Kaiser, Stefanie; Glover, Adrian; Sands, Chester; Strugnell, Jan; Enderlein, Peter; Geissler, Paul

    2013-01-01

    Information regarding the molluscs in this dataset is based on the epibenthic sledge (EBS) samples collected during the cruise BIOPEARL II / JR179 RRS James Clark Ross in the austral summer 2008. A total of 35 epibenthic sledge deployments have been performed at five locations in the Amundsen Sea at Pine Island Bay (PIB) and the Amundsen Sea Embayment (ASE) at depths ranging from 476 to 3501m. This presents a unique and important collection for the Antarctic benthic biodiversity assessment as the Amundsen Sea remains one of the least known regions in Antarctica. Indeed the work presented in this dataset is based on the first benthic samples collected with an EBS in the Amundsen Sea. However we assume that the data represented are an underestimation of the real fauna present in the Amundsen Sea. In total 9261 specimens belonging to 6 classes 55 families and 97 morphospecies were collected. The species richness per station varied between 6 and 43. Gastropoda were most species rich 50 species followed by Bivalvia (37), Aplacophora (5), Scaphopoda (3) and one from each of Polyplacophora and Monoplacophora. PMID:23794869

  15. Complete sequences of the highly rearranged molluscan mitochondrial genomes of the Scaphopod Graptacme eborea and the bivalve Mytilus edulis.

    Science.gov (United States)

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

    2004-08-01

    We have determined the complete sequence of the mitochondrial genome of the scaphopod mollusk Graptacme eborea (14,492 nts) and completed the sequence of the mitochondrial genome of the bivalve mollusk Mytilus edulis (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 it 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 noncoding nucleotides than any other mtDNA studied to date, with the largest noncoding region 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 it 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. PMID:15014161

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  17. Molecular approaches to bivalve population studies: a review

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    Dragomir-Cosmin David

    2011-12-01

    Full Text Available This paper presents a literature review concerning the importance of molecular approaches in bivalve’s population study. The class Bivalvia counts more than 20,000 species with a wide distribution both in freshwater and marine environment. Given their importance especially in aquaculture as a source of food, they have also a strong economic impact upon human society. This review encompasses best practices in bivalve studies from field sampling to laboratory analyses, addressing questions about molecular methods and tools commonly used by specialized researchers. Molecular tools specifically deals with phylogeography, population genetics, biology, ecology and taxonomy. In all these fields, molecular markers play an important role by completing some unanswered questions such as the role of the bivalves in the ecosystems in relation to anthropogenic and global change issues. Numerous genetic markers were developed for specific problems, thereferore we identify as a major issue the absence of uniform and universally recognized methods. The various sections of the paper emphasize from peer reviewed literature literature which are considered the most useful markers, costs and benefits of different methodology, major gaps of knowledge.in bivalve population studies. By reviewing virtually all genetic markers employed during nearly half a century of bivalve molecular research, in our opinion two are the best option “tools: the mitochondrial COI (cytochrome oxidase subunit I and nuclear ITS2 (internal transcribed spacer 2.

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

    Science.gov (United States)

    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. PMID:26487042

  19. Distribution of molluscan remains in the sediment of the Chukchi Sea and its vicinity, the Arctic

    Institute of Scientific and Technical Information of China (English)

    Gao Aiguo; Xu Fengshan; Sun Haiqing; Li Lon

    2003-01-01

    The result of an analysis of mollusca remains collected from the Chukchi Sea, Beaufort Sea and Bering Sea in the First Chinese National Arctic Research Expedition, from July to September,1999 is presented. Seventeen species of mollusca have been identified, which belong to two classes: Bivalvia and Gastropoda. The compositions of the mollusca are very simple. According to the distribution pattern two groups may be distinguished among molluscan species. The Pan-Arctic and circumboreal group comprises Nuculana pernula, N. radiata, Nucula bellotii, Astarte montagui, Seripes groenlandicus, Macoma calcarea, M. moesta alaskana, Liocyma fluctuosa, Mya pseudoarenaria and Turritella polaris. Three species, Cyclocardia crebricos tata, Trichotrois coronata and Argobuccinum oregonense are components of the Pan-Arctic and Pacific boreal group. With regard to feeding habits, detritus feeders dominate. There are 7 species of detritus feeders, i.e. , Nuculana pernula, N. radiata,Nucula bellotii , Macoma calcarea , M. moesta alaskana , Macoma sp. and Trichotropis coronata . Detritus feeders are dominant with regard to the numbers of species as well as to the frequency of occurrence. Macoma calcarea is the most abundant species.

  20. A phenological shift in the time of recruitment of the shipworm, Teredo navalis L., mirrors marine climate change.

    Science.gov (United States)

    Appelqvist, Christin; Havenhand, Jonathan N

    2016-06-01

    For many species, seasonal changes in key environmental variables such as food availability, light, and temperature drive the timing ("phenology") of major life-history events. Extensive evidence from terrestrial, freshwater, and marine habitats shows that global warming is changing the timings of many biological events; however, few of these studies have investigated the effects of climate change on the phenology of larval recruitment in marine invertebrates. Here, we studied temperature-related phenological shifts in the breeding season of the shipworm Teredo navalis (Mollusca, Bivalvia). We compared data for the recruitment period of T. navalis along the Swedish west coast during 2004-2006 with similar data from 1971-1973, and related differences in recruitment timing to changes in sea surface temperature over the same period. We found no significant shift in the timing of onset of recruitment over this ~30-year time span, but the end of recruitment was an average of 26 days later in recent years, leading to significantly longer recruitment periods. These changes correlated strongly with increased sea surface temperatures and coincided with published thermal tolerances for reproduction in T. navalis. Our findings are broadly comparable with other reports of phenological shifts in marine species, and suggest that warmer sea surface temperatures are increasing the likelihood of successful subannual reproduction and intensifying recruitment of T. navalis in this region. PMID:27516852

  1. Měkkýši Českého lesa – IV. Nové údaje pro jižní část Českého lesa Molluscs of the Český Les Mts. – IV. New data for the southern partof the Český Les Mts.

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    Libor Dvořák

    2008-10-01

    Full Text Available Data on recent molluscan fauna in the southern part of the Český Les Mts., with additional data from the phytogeographic district of the Plzeňská Pahorkatina hills, are presented. Altogether, 63 species (62 species of Gastropoda and 1 species of Bivalvia were recorded at 22 selected sites. The author‘s collecting activity was focused on ruderal sites and abandoned villages along the state border. There is spruce plantation dominating in the woodlands with scarce malacofauna. The common forest species dominate there, with the presence of montane and submontane elements, such as Clausilia cruciata, Vertigo substriata, and Discus ruderatus, which occur in the rest of preserved deciduous forests. The record of Atlantic Oxychilus alliarius species is the fifth known in Czech Republic. The montane snail of Clausilia cruciata was found at one site at very low altitude of 550 m a.s.l. A slug species Arion alpinus, never found in this area before, was recorded at five sites. Its occurrence here is the westernmost one in the Czech Republic. The elements of open habitats presented by xerotherm sites and open wetlands were not recorded, except for the species Vallonia costata and Vallonia excentrica occurring only at the ruins of abandoned villages and their surroundings.

  2. Development and application of the mollusc Arctica islandica as a paleoceanographic tool for the North Atlantic Ocean

    Energy Technology Data Exchange (ETDEWEB)

    Weidman, C.R.

    1995-09-01

    Until now there has been no tool comparable to corals for reconstructing long term high-resolution geochemical time-series for the colder, higher-latitude oceans. In this thesis, the long-lived (+100 years) boreal mollusc (Bivalvia) Arctica islandica is shown to be practical for this purpose in the northern North Atlantic Ocean. The evidence, compiled here, demonstrates that the carbonate shell of this species faithfully records the ambient dissolved inorganic carbon`s (DIC) radiocarbon ({Delta}{sup 14}C) concentration and accurately reflects the ambient temperature in its stable oxygen isotope ({delta}{sup 18}O) composition. However, the stable carbon isotope ({delta}{sup 13}C) composition of the A. islandica shell likely is not a good recorder of ambient DIC {delta}{sup 13}C, and likely responds to physiological controls. Four {Delta}{sup 14}C time histories are reconstructed from the annual bands of A. islandica shells for the higher-latitudes of the northern North Atlantic Ocean (from 41{degree}N to 70{degree}N).

  3. Quantitative proteomics of heavy metal stress responses in Sydney rock oysters.

    Science.gov (United States)

    Muralidharan, Sridevi; Thompson, Emma; Raftos, David; Birch, Gavin; Haynes, Paul A

    2012-03-01

    Currently, there are few predictive biomarkers in key biomonitoring species, such as oysters, that can detect heavy metal pollution in coastal waterways. Several attributes make oysters superior to other organisms for positive biomonitoring of heavy metal pollution. In particular, they are filter feeders with a high capacity for bioaccumulation. In this study, we used two proteomics approaches, namely label-free shotgun proteomics based on SDS-PAGE gel separation and gas phase fractionation, to investigate the heavy metal stress responses of Sydney rock oysters. Protein samples were prepared from haemolymph of oysters exposed to 100 μg/L of PbCl(2), CuCl(2), or ZnCl(2) for 4 days in closed aquaria. Peptides were identified using a Bivalvia protein sequence database, due to the unavailability of a complete oyster genome sequence. Statistical analysis revealed 56 potential biomarker proteins, as well as several protein biosynthetic pathways to be greatly impacted by metal stress. These have the potential to be incorporated into bioassays for prevention and monitoring of heavy metal pollution in Australian oyster beds. The study confirms that proteomic analysis of biomonitoring species is a promising approach for assessing the effects of environmental pollution, and our experiments have provided insights into the molecular mechanisms underlying oyster stress responses. PMID:22539440

  4. Trophic relationships between macroinvertebrates and fish in a pampean lowland stream (Argentina

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    María V. López van Oosterom

    2013-03-01

    Full Text Available The diet and trophic relationships between the macroinvertebrates Phyllogomphoides joaquini Rodrigues Capítulo, 1992 and Coenagrionidae (Odonata, Chironomidae (Diptera, Diplodon delodontus (Lamarck, 1919 (Bivalvia: Hyriidae, and Pomacea canaliculata (Lamarck, 1822 (Gastropoda: Ampulariidae and the fishes Pimelodella laticeps Eigenmann, 1917 (Heptapteridae and Bryconamericus iheringii (Boulenger, 1887 (Characidae in a temperate lowland lotic system in Argentina were assessed on the basis of gut contents and stable-isotope analyses. The feeding strategies were analyzed by the AMUNDSEN method. Relative food items contribution for the taxa studied indicated a generalist-type trophic strategy. In macroinvertebrates, in general, the values of stable isotope confirmed the result of the analysis of gut contents. With the fish, stable-isotope analysis demonstrated that both species are predators, although B. iheringii exhibited a more omnivorous behaviour. These feeding studies allowed us to determine the trophic relationships among taxa studied. Detritus and diatoms were a principal source of food for all the macroinvertebrates studied. In La Choza stream the particulate organic matter is a major no limited food resource, has a significant influence upon the community.

  5. Bioavailability of PAHs in aluminum smelter affected sediments: evaluation through assessment of pore water concentrations and in vivo bioaccumulation.

    Science.gov (United States)

    Ruus, Anders; Bøyum, Olav; Grung, Merete; Næs, Kristoffer

    2010-12-15

    Bioaccumulation of polycyclic aromatic hydrocarbons (PAHs) from coal tar pitch polluted sediments was predicted by (1) a generic approach based on organic carbon-water partitioning and Gibbs linear free energy relationship (between K(OW) and K(OC)), and (2) measurements of freely dissolved concentrations of PAHs in the sediment pore water, using passive samplers and solid phase extraction. Results from these predictions were compared with those from in vivo bioaccumulation experiments using Nereis diversicolor (Polychaeta), Hinia reticulata (Gastropoda), and Nuculoma tenuis (Bivalvia). Measured sediment/water partition coefficients were higher than predicted by the generic approach. Furthermore, predicted biota-to-sediment accumulation factors (BSAFs) derived from measured pore water concentrations were more in agreement with the bioaccumulation observed for two of the three species. Discrepancies associated with the third species (N. tenuis) were likely a result of particles remaining in the intestine (as shown by microscopic evaluation). These results indicate the importance of conducting site-specific evaluations of pore water concentrations and/or bioaccumulation studies by direct measurements to accurately provide a basis for risk assessment and remediation plans. The importance of knowledge regarding specific characteristics of model organisms is emphasized. PMID:21077669

  6. Měkkýši v nivě Milešovského potoka Molluscs of the Milešovský Potok floodplain (Northwest Bohemia, Czech Republic

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    Lucie Juřičková

    2011-06-01

    Full Text Available This paper presents a research of mollusc assemblages in the Milešovský Potok floodplain (Northwest Bohemia, Czech Republic. Altogether, 72 mollusc species (70 species of Gastropoda, 2 species of Bivalvia have been recorded at the selected sites during previous and recent researches in 1947–2010 representing 29% of the total Czech malacofauna. Widespread forest species dominate there (40% of all recorded species with some less common woodland species such as Platyla polita, Oxychilus glaber, Macrogastra ventricosa, Sphyradium doliolum, and Perforatella bidentata. The rest of malacocoenoses is formed by mesophile species (22%, hydrophilous species (6%, species of wetlands (8%, freshwater habitats (8% and species of open habitats (10%. Vertigo angustior, a rare wetland species protected by the NATURA system, and Helicella itala, endangered species of open habitats, were also found. The malacofauna of the Milešovský Potok stream can be used as a model of mollusc assemblages of natural floodplain environment in warm areas of Central Europe.

  7. El nuevo ciclo de movilización mapuche en Chile: la emergencia de la CAM y el proyecto autonomista para una región plurinacional

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    José Marimán

    2015-01-01

    Full Text Available El artículo pone en contexto histórico el nuevo ciclo de movilizaciones mapuches, que se ha intensificado en la última década. El movimiento mapuche es el principal movimiento en Chile a favor del poder territorial autónomo, que resiste el sistema político presidencialista homogenizador, que es centralista y nacionalista. El artículo explica el despojo territorial a dicho pueblo/nación por el Estado chileno, y la lógica de minorización a la que se le ha mantenido en la nueva democracia, con políticas sectoriales pero sin autonomía y poder político. También se da cuenta de la complejidad del movimiento mapuche en la reivindicación de tierras a partir del año 1997, explicando la complejidad de la violencia en los territorios de La Araucanía, y la lucha con las empresas forestales. La principal propuesta de solución política del conflicto es aceptar la idea de región autónoma plurinacional, con un parlamento con cuotas indígenas, devolución de recursos, derecho indígena y recuperación de la lengua.

  8. Un enfoque sistémico

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    Carlos Rodríguez Monroy

    2006-01-01

    Full Text Available Este artículo es resultado de un trabajo de investigación, cuyo objetivo establece la determinación y análisis de los factores que inciden en la competitividad de la manufacturera textil y del vestido. Aplicando el modelo de competitividad sistémica, se profundizó en los distintos factores que influyen en los niveles sistémicos (micro, meso, macro y meta, con el fin de proponer las condiciones necesarias para generar el desarrollo del sector. La infraestructura productiva textil se integra en 99,5% de micro, pequeñas y medianas empresas (MIPYMES, que revelan diferentes problemáticas y no logran interactuar debidamente con las instituciones de apoyo. Por su parte el Estado ha mantenido un entorno propicio para la competitividad y ha establecido políticas industriales dirigidas a un cambio en los tipos de organización industrial (clusters y empresas integradoras. Pero para participar con éxito en los nuevos sistemas de competencia internacional se deben lograr consensos entre actores sociales que permitan hacer los cambios necesarios para encauzarse hacia una competitividad sostenida en la industria textil.

  9. Fisiología y atributos de calidad de la guayaba “pera” (Psidium guajava cv. en postcosecha

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    Nelson Gutiérrez Guzmán

    2013-04-01

    Full Text Available El objetivo de este trabajo fue evaluar la fisiología de la madurez en frutos de guayaba “pera” (Psidium guajava cv. cosechados al norte del departamento del Huila en Colombia, recolectados en tres estados de madurez, y mantenidos en dos condiciones de almacenamiento. Se evaluaron los índices de madurez hasta el momento de consumo.La pérdida de peso presentó una tendencia lineal y la firmeza una tendencia logarítmica; el contenido de sólidos solubles se incrementó y el contenido de ácido cítrico disminuyó; la tasa respiratoria en condiciones ambientales osciló entre 60 y 100 mL CO2 • kg-1 • h-1 y la crisis climatérica inició a las 50 horas, mientras que en almacenamiento refrigerado se presentó entre las 75 y 90 horas, produciendo entre 15 y 20 mL CO2 • kg-1 • h-1.

  10. Respuesta fenológica de la vegetación arbórea de las lomas del sur del Perú (Mejía -Arequipa EN relación con el evento "El Niño 1997-98"

    Directory of Open Access Journals (Sweden)

    Carmelo Talavera

    2014-06-01

    Full Text Available Este trabajo presentó la evaluación del comportamiento fenológico de la vegetación arbórea con el fin de determinar su probable utilización como indicadores biológicos de la ocurrencia de eventos "El Niño". Los árboles evaluados fueron Caesalpinea spínosa, Duranta armata, Caríca candícans y Citharexylum flexuosum. Los resultados indican una alta variación en las respuestas fenológicas. C. spinosa por ejemplo en 1995 y 1996 inició la floración antes que el brote; en 1997 inicio mucho antes, pero tuvo una corta duración, yen 1998, se ha presentado en forma tardía y breve, mientras que la cubierta foliar se ha mantenido en forma constante. En el caso de D. armata y C. flexuosum la floración se presenta posterior al brote, pero en ambos casos durante la ocurrencia del evento en 1998 no presentaron floración; y C. candícans presenta floración antes que el brote, pero con alta variabilidad en el tamaño de la floración.

  11. El lugar extraterritorial de Miguel Labordeta en la poesía española. Claves para una comprensión crítica de su obra

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    Vicente Francisco Vives Pérez

    2013-03-01

    Full Text Available A pesar de su calidad estética y capacidad de trangresión, la poesía de Miguel Labordeta (Zaragoza, 1921-1969 no ha sido suficientemente atendida en nuestra historia literaria. El conjunto de su obra ha permanecido al margen de las consideraciones críticas que sí han tenido otros autores coetáneos del período de la posguerra. Posiblemente el sentido innovador de su escritura y su complejo universo simbólico han mantenido los libros del poeta aragones al margen de una valaoración crítica que afirme la singularidad de su lírica dentro de un panorama poético caracterizado por una sumisión a los mensajes del realismo. El presente artículo se encarga de esclarecer algunos aspectos que pongan en valor la escritura poética de Miguel Labordeta.

  12. Modos de discurso y actitudes En grupos de discusión. Un estudio comparativo de mujeres y hombres

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    María Jesús Cala Carrillo

    2005-01-01

    Full Text Available El objetivo fundamental de este trabajo es el de analizar cómo la relación entre factores comoel género y la experiencia educativa afectan a las actitudes que mantienen hombres y mujeressobre temas como la situación de las mujeres y los hombres y la educación de hijas e hijos. Paraello hemos realizado un análisis de las actitudes en el marco del discurso, adoptando para ellouna aproximación alternativa a la que tradicionalmente se ha mantenido en este campo. Uno denuestros mayores esfuerzos se ha ido encaminado a la elaboración de herramientas metodológicasque nos permitan analizar las actitudes de manera exhaustiva y que nos posibiliten conocer ycomprender a través de qué mecanismos argumentativos se están defendiendo actitudes más omenos igualitarias con respecto a las mujeres y a las prácticas en las que éstas participan o debenparticipar y cómo las diferencias entre mujeres y hombres están mediadas por la experienciaeducativa. En últimas, asumimos que este tipo de experiencia cultural puede favorecer nuevosmodos de discurso y, consecuentemente, nuevos modos de pensamiento.

  13. y migración laboral

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    Joaquín Peña Piña

    2005-01-01

    Full Text Available A través de un análisis histórico se revisa el caso de una comunidad indígena mam de la región Sierra-Soconusco del estado de Chiapas, México. En esa región, la economía agrícola regional vinculada al café ha mantenido una relación permanente con la migración laboral a las fincas cafetaleras, lo que ha contribuido a conformar un escenario desigual del desarrollo regional. En este artículo se analiza cómo el proceso de cambio social mediado por la producción de café, la migración extrarregional y las acciones de obra pública han repercutido en la capitalización de los grupos domésticos y la comunidad, así como en la situación de las mujeres

  14. Hacia una concepción del hombre simbionte

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    Camilo Rodríguez

    2005-10-01

    Full Text Available Durante la historia de nuestra especie, el ser humano ha mantenido en muchas ocasiones una actitud arrogante y prepotente hacia la naturaleza, sintiéndose el dominador de toda forma viviente y de su entorno. Debemos analizar la historia de la vida para entender cuál debe ser el roldel hombre en la Tierra. Desde que se formó la primera célula en el planeta, se estableció la simbiosis como mecanismo evolutivo principal; la cooperación mutua en todos los niveles favorece la adaptación al medio ambiente y la supervivencia de las especies. Cuando el ser humano aparece, conoce su realidad simbiótica; sin embargo, de la mano con su evolución cultural, pasa a ser dominador del planeta, con consecuencias negativas y posiblemente funestas para su especie y muchas otras formas de vida. En este artículo se trazan las pautas para retomar nuestro horizonte simbiótico, con la aplicación de los principios bioéticos de justiciay beneficencia, para un futuro mejor del humano y el planeta tierra.

  15. Evaluación de la campaña de vacunación en Cantabria dos años de evolución epidemiológica

    Directory of Open Access Journals (Sweden)

    González de Aledo Alvaro

    2000-01-01

    Full Text Available Se presentan los resultados de la campaña de vacunación antimeningocócica realizada en Cantabria en febrero-marzo de 1997. A corto plazo, la campaña tuvo el efecto de disminuir la tasa de incidencia en el grupo de riesgo desde 21,33/100.000 en los 12 meses previos, a cero en los 12 meses posteriores. A medio plazo (2 años y medio después, la incidencia se ha mantenido un 80% más baja en el grupo de riesgo y un 77,3% más baja en el conjunto de la población. La efectividad vacunal en el tercer año tras la campaña se mantiene por encima del 91% en todas las edades, aunque algunos sesgos comentados en el trabajo hacen que esta efectividad esté infraestimada. Por otra parte, la efectividad vacunal es muy superior a los porcentajes de seroprotección medidos por la tasa de anticuerpos bactericidas, especialmente en las edades menores. Los casos clínicos en vacunados han tenido un curso clínico benigno.

  16. Cómo hacer atractiva una firma en un país en crisis: Caso Allianz – AGF- Colseguros

    Directory of Open Access Journals (Sweden)

    Freddy Grijalva

    2005-12-01

    Full Text Available El caso Allianz-Agf-Colseguros forma parte del proyecto «Empresas que perduran en Colombia», el cual busca caracterizar algunas prácticas de gestión y organización de empresas que se han mantenido a través del tiempo en el país. Se sigue un diseño metodológico de estudio de caso múltiple; la información ha sido recabada mediante una guía constituida por 10 categorías y 43 variables de análisis; triangulación de información, entrevistas en profundidad y búsqueda de Información secundaria, garantizan la validez de los resultados. En las conclusiones se enfatiza en el perfil de equipos gerenciales interculturales como medio para hacer más atractiva la firma para los inversionistas extranjeros, en un país en crisis.

  17. Pigmentación inusual del paladar asociada a imatinib: reporte de caso clínico

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    J. López-Labady

    2013-12-01

    Full Text Available Existen diversos factores que pueden inducir pigmentaciones en la mucosa bucal, entre ellos algunos fármacos tienen la capacidad de estimular la producción de melanina en el epitelio oral. Recientemente se ha demostrado que el mesilato de imatinib (Glivec® usado como droga antineoplásica es capaz de producir como efecto adverso pigmentación de la mucosa bucal muy especialmente la del paladar. Se reporta el caso de una paciente de 56 años de edad bajo terapia con imatinib desde hace 8 años por padecer de leucemia mieloide crónica. Al examen clínico se observó una hiperpigmentación color azul grisácea en la totalidad del paladar óseo que al estudio histopatológico mostró acúmulo de melanina principalmente en el corion. La paciente se ha mantenido con la lesión en paladar bajo observación, sin cambios clínicos ni histopatológicos. Para establecer la asociación de este fármaco con la pigmentación en la mucosa bucal es necesario descartar otros factores inductores de melanosis además de considerar las características clínicas como coloración y ubicación de la lesión.

  18. Estudios sobre leishmaniasis tegumentaria en el Perú. I. Infección experimental de perros con cepas de leishmanias procedentes de casos de Uta

    Directory of Open Access Journals (Sweden)

    Arístides Herrer

    1951-01-01

    Full Text Available Se han inoculado varias series de perros con cepas de leishmanias procedentes de la forma clínica de la leishmaniasis tegumentaria conocida en el Perú con el nombre de uta, usando con tal objeto material tomado directamente de las lesiones utosas así como también cultivos del parásito. Los principales resultados obtenidos en tales inoculaciones son los siguientes: 1. Ha sido imposible infectar al perro con cultivos mantenidos solamente in vitro por espacio de cinco a ocho años, no obstante de haberse ensayado en tres series distintas de inoculaciones. 2. Se ha conseguido infecciones experimentales en el 87 por ciento de los perros que fueron inoculados con cultivos de reciente aislamiento. Aunque las inoculaciones fueran hechas bajo las mismas circunstancias en el dorso del hocico y la cara interna de una de las orejas, la infección se ha obtenido principalmente en el hocico. 3. También se ha logrado infectar perros inoculándoles material tomado directamente de las lesiones leishmaniásicas, ya sea de casos de uta o de lesiones producidas experimentalmente en otros perros.

  19. Mercosur y Unasur: posturas de la Argentina frente a ambos procesos – sólo un ejemplo = Mercosul and Unasul: Argentina’s attitude in relation to both processes – just a exemple

    Directory of Open Access Journals (Sweden)

    Vilosio, Laura E.

    2010-01-01

    Full Text Available El Mercosur y la Unasur constituyen dos procesos de integración internacional que, en la actualidad, tienden a otorgar gobernabilidad a Sudamérica con un posible grado de convergencia en sus objetivos. Pero los procesos de integración requieren que cada uno de sus integrantes los jerarquice como prioritarios a la hora de diseñar e implementar su política exterior, así como a la de resolver sus conflictos. En este trabajo se analiza con un método teórico descriptivo la actitud asumida por la Argentina frente a estos dos procesos a través de tres acontecimientos que consideramos ilustrativos: la incorporación de Venezuela al Mercosur, la falta de articulación estratégica en el plano comercial externo por parte de Argentina y Brasil y el conflicto sobre las papeleras mantenido por Argentina con el Uruguay. Este estudio permite observar la forma en que este estado, al igual que el resto de los integrantes de estos procesos de integración, no insiste en propiciar el privilegio de los espacios de integración como ámbitos adecuados para la concertación de estrategias políticas, económicas y ni siquiera comerciales comunes que permitan potenciar la competitividad de todos y cada uno de sus miembros.

  20. Insecticides authorized for use on olive trees and the relationship between their registration and residues in olive oil

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    Lentza-Rizos, Ch.

    1996-12-01

    Full Text Available In order to eliminate losses due to insect attack, several insecticides are used on olive trees. Their residues in olive oil constitute an important parameter of its quality and must be monitored regularly and kept as low possible in order to ensure consumer protection. In this paper the insecticides authorized for use on olive trees are listed and their ADIs and Codex Alimentarius MRLs reported. The existing registrations are discussed from the point of view of their residues in oil.

    Diversos insecticidas son usados para eliminar las pérdidas debidas al ataque de insectos en olivos. Sus residuos en el aceite de oliva constituyen un parámetro importante de su calidad y deben ser controlados con regularidad y mantenidos tan bajos como sea posible en orden a asegurar la protección del consumidor. En este artículo se incluyen los distintos insecticidas autorizados para su uso en olivos así como los valores de ingesta diaria aceptable para el hombre y los límites máximos autorizados de los mismos. Los registros existentes se discuten desde el punto de vista de sus residuos en el aceite.

  1. El Desarrollo Web: Portal Holguín como el camino hacia una metáfora visual

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    Edith Guerra Ávila

    2007-01-01

    Full Text Available Se aborda panorámicamente el Proyecto Territorial Portal Holguín como un proyecto de desarrollo Web, analizando algunos aspectos que lo caracterizan: estructura y funcionamiento durante 5 años. Se ofrece información de cómo se ha mantenido el trabajo a través de la metodología NexoDigital y la evaluación permanente de este proyecto y su constante actualización. Se valoran algunos elementos que contribuyen al logro de que el portal sea usable, visible y recuperable por los buscadores y de la red de redes. Se resume la remodelación del sitio de la ciencia como parte del nuevo proyecto y la creación del sitio del Centro de Investigaciones y Servicios Ambientales y Tecnológicos de Holguín (CISAT. Se llegan a conclusiones y se hacen algunas recomendaciones, sobre lo valorado durante la experiencia.

  2. Efectos del sistema de conservación sobre la fertilidad de oocitos de yamú (Brycon amazonicus) durante cortos períodos de almacenamiento

    DEFF Research Database (Denmark)

    Velasco-Santamaría, Yohana M.; Corredor-Santamaría, Wilson; Cruz-Casallas, Pablo E.

    2006-01-01

    El objetivo fue evaluar los efectos del sistema de conservación sobre la fertilidad de oocitos de yamú (Brycon amazonicus) durante cortos períodos de almacenamiento. Se utilizaron hembras y machos adultos tratados con extracto de hipófisis de carpa para estimular la ovulación y aumentar el volumen...... seminal. Oocitos obtenidos de la misma hembra fueron sometidos a tres sistemas de conservación: in situ (IS, mantenidos dentro de la cavidad ovárica), ex situ a temperatura ambiente (T°A) y ex situ a temperatura de refrigeración (T°R). El diámetro ovocitario (DO) y la viabilidad fueron evaluados a los 0...... larvas. Bajo los tres sistemas de conservación, DO aumentó con el tiempo, siendo mayor (p<0.001) que el control a partir de los 15 min de almacenamiento. Los mayores DO fueron observados en oocitos conservados a T°R (p<0.05). Hasta 60 min de almacenamiento, en los sistemas de conservación IS y a T°A, la...

  3. Factores de competitividad de la agroindustria de la caña de azúcar en México

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    Noé Aguilar Rivera

    2011-01-01

    Full Text Available La industria azucarera de México integra actividades agrícolas de crecimiento, cosecha y transporte de caña a la producción de azúcar estándar y refinada, con otros productos y subproductos. Para competir en una economía global, es importante establecer criterios de desempeño para reducir costos de producción en términos de competitividad técnica, productividad y eficiencia en aspectos como rendimientos, caña de azúcar y agroindustrial por hectárea y de fábrica. En este artículo se discuten algunos indicadores de competitividad económica y técnica de la industria de caña de azúcar mexicana, con metodologías de benchmarking y diamante de Porter. Los resultados mostraron que son numerosos los factores técnicos y económicos que limitan el crecimiento, debido a que la industria mexicana se ha mantenido no competitiva y requiere mejorar e innovar en la reducción de costos, sobre todo en materia prima, cosecha y transporte. También está la diversificación, con base en los subproductos, como residuos de cosecha, bagazo, melazas, lodo de filtros y vinazas; esto es de gran importancia como fuente renovable de energía y materias primas.

  4. La justificación de los recursos administrativos

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    José Luis Benavides

    2012-12-01

    Full Text Available Durante la elaboración del Código de Procedimiento Administrativo y de lo Contencioso Administrativo fue discutida la idea de suprimir el requisito de los recursos administrativos previos, que podría carecer de utilidad y ser, por el contrario, un obstáculo al acceso al juez. Con una argumentación somera, el sistema anterior fue mantenido con algunos retoques. ¿Por qué? ¿Se justifica que la administración no pueda ser demandada directamente? Los orígenes de la vía gubernativa permiten determinar las funciones originalmente atribuidas al sistema. Ello no significa que los recursos administrativos no hayan adquirido, con el tiempo, funciones diferentes que justificarían su pervivencia, tales como la consolidación de la decisión administrativa, la protección de los administrados y la lucha contra la congestión de la justicia.

  5. El modelo pedagógico de la reforma instruccionista de 1870 en el Estado Soberano de Santander: un modelo para la formación de ciudadanos

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    Rolando Humberto Malte Arévalo

    2011-05-01

    Full Text Available El texto se propone describir el contenido pedagógico de la reforma instruccionista de 1870 nacida y aplicada en el Estado Soberano de Santander entre 1865 y 1885. Pese a que la reforma ha captado la atención de numerosos investigadores, aún no hay estudios que hablen de los cambios pedagógicos promovidos por esta reforma. Así pues, la presente investigación intentará develar cada uno de los aspectos que la caracterizaron, para mostrar que en efecto la reforma instruccionista liberal, tal como lo han señalado algunos investigadores, constituyó un programa político que propendía por la modernización de la sociedad colombiana. Para lograr este propósito se apela al concepto modelo pedagógico, tomado de la teoría pedagógica contemporánea, como herramienta que le ayude al observador de hoy en día a develar los rasgos de un fenómeno que se ha mantenido oculto en los documentos. Las fuentes tratadas son todas de orden oficial, pues la reforma fue puesta en marcha precisamente por quienes controlaban en aquel momento el poder político.

  6. Los repositorios de acceso abierto en Argentina: situación actual Open access repositories in Argentine: an update

    Directory of Open Access Journals (Sweden)

    Carolina De Volder

    2008-12-01

    Full Text Available Se llevó a cabo una caracterización básica y descriptiva de los repositorios argentinos de acceso abierto. Se identificaron quince repositorios: siete institucionales pertenecientes a cinco universidades nacionales; cuatro temáticos; tres de tesis y disertaciones y una biblioteca digital exclusivamente de revistas. De la investigación, se desprende que en nuestro país no hay políticas públicas ni mandatos relacionados con el acceso abierto; sí proyectos aislados surgidos y mantenidos en general por la iniciativa y el trabajo de los bibliotecarios, sobre todo en el ámbito universitario.A basic and descriptive characterization of the Argentinean repositories of open access was carried out. Fifteen repositories were identified: seven institutional belonging to five national universities; four thematic; three of thesis and dissertations and a digital library exclusively of journals. The results show that Argentina has not public policies or mandates in relation to open access. However, it has only isolated projects generally supported by the initiative and work of librarians, most of them in the university field.

  7. Desarrollo de la especialidad en Psicología clínica en Costa Rica: perspectivas futuras

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    Roberto López-Core

    2013-06-01

    Full Text Available En este trabajo se describen los antecedentes históricos, evolución y desarrollo de la Especialidad en Psicología Clínica en Costa Rica. En el año 1957, se inició el ejercicio de esta disciplina y a partir del año 1979 se consolidó el programa de estudios adscrito al Convenio Marco firmado entre la Universidad de Costa Rica (UCR y la Caja Costarricense de Seguro Social (CCSS. Desde entonces, ha mantenido una acción ininterrumpida en la formación de especialistas. Los y las residentes en el proceso formativo tienen una doble condición: son funcionarios/as del sistema de salud de la CCSS y estudiantes de posgrado de la UCR. Se mencionan las perspectivas futuras y la inserción de esta disciplina en la implementación de la Política Nacional de Salud Mental en Costa Rica (2012. Se menciona, además, la relación e interacción con disciplinas afines como la Psiquiatría, la Neuropsicología, las Neurociencias y la rehabilitación psicosocial. Se hace referencia a las perspectivas futuras de su participación en otras áreas, como la Psicogeriatría, Psicooncología, Psicología de enlace, cuidados paliativos y la salud sexual y reproductiva.

  8. Espacios para el arte: lugares en continua redefinición

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    Eloísa Alisal

    2007-12-01

    Full Text Available Através de la historia del museo y del coleccionismo han ido proliferando una gran variedad de espacios en los que se cobijan, conservan, resguardan o almacenan los objetos de interés cultural y, a pesar de esto, el patrimonio artístico de las comunidades ha continuado siendo soporte de su memoria como colectividad. Desde los santuarios griegos dedicados a las Musas hasta los museos y centros de arte actuales, las colecciones artísticas cobijadas se han transformado en soporte para la transmisión de ideas y de conocimientos. Tanto los espacios físicos (templos, academias, galerías, palacios y salones como los espacios virtuales (museos y galerías en red han mantenido la misma finalidad: conservar, estudiar y difundir las manifestaciones artísticas de las culturas. Han pasado más de dos siglos desde la creación del primer museo de arte contemporáneo concebido como lugar de conservación, estudio y difusión del arte creado en su contemporaneidad; y más de un siglo desde que Duchamp incluyera su obra “Fuente” en el Armory Show, desde entonces el museo de arte se redefine junto al objeto que debería cobijar.

  9. La calidad de los aprendizajes en la enseñanza secundaria

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    Enrique Bono Santos

    2011-01-01

    Full Text Available Se defiende la hipótesis de que hoy es muy deficiente el nivel de calidad del aprendizaje real que consiguen la mayoría de las alumnas y alumnos de toda la Secundaria y últimos cursos de Primaria. Calidad difícil de evaluar (Litwin, 1998 pero implica que lo que enseñamos,independientemente de que se "apruebe" o no, se transforme en un aprendizaje eficaz, aplicable, mantenido en el tiempo, personalmente reconstruido, y de esta manera desarrolle y amplíe el espacio cognitivo así como enriquezca las capacidades intelectuales de todos nuestros alumnos y alumnas. Esta mejora de calidad está siendo demandada por la sociedad del conocimiento, por los receptores laborales y académicos de nuestro alumnado, así como por bastantes profesores, directivos e inspectores de nuestros Institutos de Secundaria. Se justifica que el aceptar esta realidad por parte del profesorado es el primer paso para cualquier innovación de la enseñanza.

  10. GHL Comfort Hotel Los Héroes. Historia Empresarial

    Directory of Open Access Journals (Sweden)

    Natalia Álvarez

    2008-11-01

    Full Text Available En un contexto administrativo, la historia empresarial marca la presencia de un lenguaje en donde se procede a describir, explicar y evaluar la toma de decisiones en el ambiente empresarial. Esta toma de decisiones se convierte entonces en una política, que tomará como base el entorno en el cual se desenvuelve. Es así que resulta imprescindible el comportamiento a nivel interno y externo de la organización, de esta manera se evalúa qué papel juega el control administrativo en la producción, el bienestar y desarrollo no sólo de la empresa, sino además de su personal. En este artículo estableceremos la importancia del análisis y descripción de los procesos claves de éxito que se realizan puntualmente en GHL comfort hotel los héroes, organización que se ha mantenido en el mercado y en su corta vida ha logrando no sólo un posicionamiento, sino además ser una empresa estable e innovadora.

  11. Diabetes tipo 2 y pionefrosis: una complicación potencialmente fatal. Presentación de un caso

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    Miguel Ángel Serra Valdés

    2013-09-01

    Full Text Available La infección bacteriana del tracto urinario es un problema común en la práctica médica diaria. Son complicaciones agudas muy frecuentes y severas en pacientes diabéticos. La motivación a la presentación de este caso radica en su importancia para la docencia, e invita a la reflexión de cómo se está realizando la práctica clínica de esta entidad. Se presenta el caso de una paciente que hacía 2 meses había comenzado con dolor en la región lumbar izquierda, que se irradiaba a la parte anterior del abdomen de ese lado hasta el muslo, este era un dolor mantenido, intenso, punzante, que se aliviaba con calmantes y algunas veces al flexionar la pierna de ese sector. Además presentaba decaimiento, inapetencia, nauseas, fiebres de 38-39˚C, ardor miccional con orinas frecuentes de poca cantidad y de color oscuro. El examen físico planteó la posibilidad diagnóstica que fue corroborada por la tomografía axial computarizada de pionefrosis obstructiva. Se realizó tratamiento médico y se efectuó nefrectomía radical izquierda.

  12. Reforma agraria y señorío urbano en el liberalismo decimonónico. El movimiento campesino de los "Montes de Toledo"

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    Luis m. LORENTE TOLEDO

    2010-02-01

    Full Text Available El primer tercio del siglo XIX es el marco idóneo para entender el dilema ideológico o ambivalente doctrinal que encierra en sí y se desprende, al mismo tiempo, de la gran corriente de pensamiento denominada Romanticismo. Pues, además de ser soporte del conservadurismo restaurador del Congreso de Viena, fue génesis de una ideología adversa a ésta de tendencia medievalizante, por la plena aceptación del nuevo espíritu liberal y de defensa de las nacionalidades. El espíritu de aventuras, el gusto por la acción violenta, el potenciar la actividad creadora del individuo, la exaltación de la rebeldía contra toda clase de esquemas previos —caracteres todos ellos y esenciales del movimiento romántico— conducirán necesariamente hacia un nuevo fenómeno ideológico de defensa de las libertades en todas sus manifestaciones. Es pues, en este sentido, como el Romanticismo se convertirá en soporte ideológico de la principal fuerza opositora al entramado geopolítico establecido en Viena y mantenido por su brazo armado, es decir, dará contenido a la nueva corriente política del Liberalismo y sentido en su férrea lucha contra la Restauración.

  13. REDQUELI-INIA, NUEVO CULTIVAR SINTÉTICO DE TRÉBOL ROSADO Redqueli-INIA, new red clover synthetic cultivar

    Directory of Open Access Journals (Sweden)

    Fernando Ortega K.

    2003-04-01

    Full Text Available Redqueli-INIA es un nuevo cultivar diploide de trébol rosado (Trifolium pratense L. seleccionado para mejorar, en relación al cultivar chileno Quiñequeli-INIA, la sobrevivencia de plantas, rendimiento de forraje y persistencia. Redqueli-INIA es un cultivar sintético generado a partir de siete plantas madres de época de floración intermedia. Se diferencia morfológicamente de Quiñequeli-INIA fundamentalmente por presentar plantas de corona más ancha, un menor porcentaje de plantas con marcas en las hojas, y menor proporción de plantas con flores rosado claro. El cultivar es mantenido por semilla de primera generación almacenada a baja temperatura en los bancos de germoplasma del Instituto de Investigaciones Agropecuarias (INIA de Chile.Redqueli-INIA is a new diploid red clover (Trifolium pratense L. cultivar selected to improve the survival of plants, forage yield and persistence compared to the Chilean diploid cultivar Quiñequeli-INIA. Redqueli-INIA is a synthetic of seven mother plants with intermediate flowering time. The main morphological differences compared to Quiñequeli-INIA are its wider crowns, a lower percentage of plants with leaf marks, and a lower proportion of plants with light pink flowers. The cultivar is maintained by cold storage of first generation seeds in the genebanks of the Institute of Agricultural Research (INIA of Chile.

  14. Crecimiento y desarrollo regional de México y Corea del Sur: un análisis comparativo de las leyes de Kaldor

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    Luis Quintana Romero

    2013-01-01

    Full Text Available El crecimiento y desarrollo económico de México y Corea del Sur han seguido trayectorias diferentes en las últimas décadas. Desde los ochenta, la economía mexicana ha mantenido un avance lento, lo que no le ha permitido entrar a una senda de crecimiento acelerado como sí le ha sucedido a Corea. La evidencia empírica muestra que en este último país el crecimiento está determinado de forma endógena; el sector manufacturero sirve de pivote para el desarrollo al encabezar el crecimiento sectorial y de la productividad del trabajo. En México, caso contra- rio, la evidencia empírica señala que no existe un crecimiento endógeno. No hay un liderazgo sectorial que amplíe y mantenga un mercado local robusto, lo que influye en su trayectoria de crecimiento de largo plazo. Asimismo, el crecimiento manufacturero coreano da lugar a efectos de derrama en un conjunto de regiones, lo que ocasiona externalidades espaciales positivas, mientras que en México, el lento crecimiento del sector no se ha traducido en una fuente del crecimiento regional en el período 1998-2008.

  15. "En la boca de las nubes" (A la boca dels núvols y con los pies en el suelo. Ramon Vinyes: contra la literatura, la vida

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    Jordi Marrugat i Doménech

    2005-01-01

    Full Text Available Este artículo propone una lectura unitaria del volumen de narraciones de Ramon Vinyes En la boca de las nubes (1946. Además, va a las fuentes de las cuales surge la estética del libro —la narrativa catalana y europea de los años 20-30 y el pensamiento teórico de Vinyes— para explicar como el autor decadentista de La ardiente cabalgata (1909 acaba por escribir un libro tan alejado de los posicionamientos que había mantenido durante el Modernismo. Y es que si en 1909 Vinyes decantaba la balanza de la dicotomía artevida hacia el primero de estos términos, en 1946, después de haber vivido una guerra civil y dos guerras mundiales, la decanta radicamente hacia el segundo. Así, el lector podrá encontrar sugestivas comparaciones entre Vinyes y escritores como T. Gautier, Villiers de l’Isle-Adam, Gabriele d’Annunzio o Gabriel Alomar por lo que se refiere a su época modernista; entre Vinyes y Malraux, Saint-Exupéry, V. Woolf, Joan Oliver o Salvador Espriu, por lo que se refiere a los años 30; y entre Vinyes i Pere Calders o Lluís Ferran de Pol, por lo que se refiere al exilio

  16. Lesiones inducidas por contacto directo con antenas de radio en vehículos de Caballería

    Directory of Open Access Journals (Sweden)

    I. Díaz de Tuesta Revilla

    2014-09-01

    Full Text Available La exposición sostenida a emisiones de radio podría estar relacionada con lesiones en el tejido subcutáneo. Presentamos dos casos sucedidos en tiradores de vehículo explorador de Caballería (VEC tras unas maniobras en zona de operaciones Líbano, consistentes en una inusual tumefacción del tejido adiposo en antebrazo derecho sin antecedente de contusiones, ni contactos químicos o irradiación conocida, y con piel íntegra, que coincide con zonas de posible contacto mantenido con la antena del vehículo. La causalidad no es determinante por tratarse de una relación observacional, pero los hallazgos sugieren que deberían tomarse medidas en relación con la reducción del riesgo de exposición a radiaciones electromagnéticas en operarios de carros con antenas plegables.

  17. (SIGLA: Sistema de Información Geográfica del Litoral de Andalucia

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    Jose Ojeda Zujar

    2006-01-01

    Full Text Available Se presenta el diseño y funcionalidades de un visor desarrollado inicialmente para proporcionar un fácil acceso a la información contenida en el SIGLA (Sistema de Información Geográfica del Litoral Andaluz, mantenido por la Consejería de Obras Publicas de la Junta de Andalucía (Vuelo interactivo del litoral Andaluz. El visor presenta dos versiones según el usuario: (i para un usuario no especialista permite la visualización 2D y 2,5D, así como vuelos virtuales, sobre información geográfica georreferenciada en varios formatos (tif, jpg, ecw, msid, shp, dxf, bip…, teniendo acceso a la información alfanumérica asociada en el caso de los «shapes». Permite igualmente el acceso a información multimedia georreferenciada (fotos, videos, etc…; (ii Para usuarios técnicos, a las funcionalidades anteriores se le añaden la posibilidad de generar videos (.avi e imágenes tridimensionales, así como digitalizar puntos, líneas y polígonos en formato shape, editando los atributos alfanúmericos. Igualmente el visor permite, en tiempo real, calcular parámetros derivados del Modelo Digital de Elevaciones utilizado (pendientes, sombras, zonas ocultas, etc..

  18. A comunidade remanescente de quilombo do Engenho Siqueira: territorialidade, identidade quilombola e potencialidade da agroecologia

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    Marli Gondim de Araújo

    2012-01-01

    Full Text Available La comunidad negra rural campesina del Engenho Siqueira practica modos de producción agrícola y de pesca heredados de sus antepasados. Se pretende explicar en este texto las compatibilidades culturales y técnicas entre los actuales modos de producción desarrollados y la agroecología. La agricultura tradicional como actividad principal de esta comunidad constituye una de las referencias en el manejo sostenible de los ecosistemas de esta región costera. Fueron hechas catorce entrevistas semiestructuradas con habitantes más antiguos del ingenio y agricultores(as. Los resultados indican que esa población no demuestra haber mantenido recientemente vínculo subalterno con el sistema del monocultivo de la caña de azúcar, tanto en la forma de asalariar en las fábricas cercanas como en el cultivo de caña en la comunidad. Por otra parte, las prácticas agrícolas y de pesca allí desarrolladas presentan gran potencialidad agroecológica, como se demostró durante el estudio.

  19. Crisis y recuperación económica: el papel de la política fiscal

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    Moritz Cruz

    2012-01-01

    Full Text Available Desarrollamos un análisis comparativo de cinco economías que experimentaron crisis financieras recientemente (México 1994, Corea del Sur 1997, Rusia 1998, Brasil 1998 y Argentina 2001, con el fin de identificar el papel que la política económica jugó durante la crisis y el posterior proceso de recuperación económica. Nuestro análisis indica que únicamente México enfrentó y mantuvo su política económica, incluida la fiscal, sujeta a las restricciones del modelo económico que originó la crisis. Aunque Brasil hizo lo mismo para enfrentar la crisis, durante su proceso de recuperación rompió con dicha restricción. Finalmente, Argentina, Corea y Rusia se caracterizaron por romper desde la misma crisis, aunque en diferentes grados, con la restricción de política económica, postura que se ha mantenido desde entonces.

  20. Labor de la enfermera en la atención a gestantes cardiópatas

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    Maritza Miclín Velázquez

    1999-04-01

    Full Text Available Se indica el desarrollo alcanzado en los últimos años en la atención a los pacientes cardiópatas. Se hizo un estudio descriptivo y retrospectivo de 51 gestantes cardiópatas atendidas en el Servicio de Perinatología del Hospital de Maternidad Norte "Tamara Bunke" de Santiago de Cuba, durante 1994, con el propósito de valorar la importancia de la labor de Enfermería durante el embarazo, parto y puerperio de estas pacientes, de donde se derivó que los cuidados especiales mantenidos garantizaron que la enfermedad cardíaca no repercutiera sobre la tasa de morbilidad y mortalidad maternoperinatales, que las complicaciones fueran mínimas en las madres y que no se produjeran defunciones.The development achieved during the last years in the attention of cardiacs is stressed. A descriptive and retrospective study of 51 pregnant women attended at the Perinatology Service of the "Tamara Bunke" North Maternal Hospital, in Santiago de Cuba, during 1994, was conducted aimed at assessing the importance of the nurse´s work during the pregnancy, delivery and puerperium of these patients. It was concluded that thanks to the special care given, the heart disease did not influence on the maternal and perinatal morbidity and mortality rate, mothers´ complications were minimal, and there were no deaths.