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Sample records for chilensis philippi bivalvia

  1. Ophiuroidea das regiões antartica e subantartica: 2. variação em Gorgonocephalus chílensis (Philippi (Echinodermata, Ophiuroidea, Gorgonocephalidae Ophiuroidea from antarctic and subantarctic regions: 2. variation on Gorgonocephalus chilensis (Philippi (Echinodermata, Ophiuroidea, Gorgonocephalidae

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    Ana Maria Gouveia Monteiro

    1983-01-01

    Full Text Available Foram examinados 198 exemplares de Gorgonocephalus chilensis das regiões antártica e subantartica, tendo-se em vista a variação de caracteres morfológicos externos. Foi constatada uma grande variação nas características morfológicas externas, que parece independer de localização geográfica.A revision is presented on the variability of the ornamentation and other extermal morphological aspects of Gorgonocephalus chilensis. The samples were obtained along the period of 1962 to 1972 by the R/V "Hero" and "Eltanin" (USARP and by the R/V "Almirante Saldanha" from the Brazilian Navy.

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

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    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.

  3. Fauna Europaea: Mollusca - Bivalvia.

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    Araujo, Rafael; de Jong, Yde

    2015-01-01

    Fauna Europaea provides a public web-service with an index of scientific names (including important synonyms) of all living European land and freshwater animals, their geographical distribution at country level (up to the Urals, excluding the Caucasus region), and some additional information. The Fauna Europaea project covers about 230,000 taxonomic names, including 130,000 accepted species and 14,000 accepted subspecies, which is much more than the originally projected number of 100,000 species. This represents a huge effort by more than 400 contributing specialists throughout Europe and is a unique (standard) reference suitable for many users in science, government, industry, nature conservation and education. For the Mollusca-Bivalvia, data from 5 families (Margaritiferidae, Unionidae, Sphaeriidae, Cyrenidae, Dreissenidae) containing 55 species are included in this paper. European freshwater bivalves belong to the Orders Unionoida and Cardiida. All the European unionoids are included in the superfamily Unionoidea, the freshwater mussels or naiads. The European cardiids belong to the following three superfamilies: Cardioidea, Cyrenoidea and Dreissenoidea. Among the Unionoidea there are the most imperilled animal groups on the planet while the Cardioidea includes the cosmopolitan genus Pisidium, the Cyrenoidea the Asiatic clam (Corbiculafluminea) and the Dreissenoidea the famous invasive zebra mussel (Dreissenapolymorpha). Basic information is summarized on their taxonomy and biology. Tabulations include a complete list of the current estimated families, genera and species.

  4. A new species of Peltidium Philippi, 1839 (Crustacea, Copepoda, Harpacticoida) from the Pacific coast of Mexico.

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    Suárez-Morales, Eduardo; Jarquín-González, Jani

    2013-01-01

    During the analysis of phytal meiobenthic samples collected from a rocky-sandy beach in the state of Nayarit, in the Mexican Pacific, several specimens of harpacticoid copepods were obtained and taxonomically examined. These specimens were found to represent an undescribed species of the peltidiid genus Peltidium Philippi, 1839. The new species, Peltidium nayarit sp. n. is described herein. It resembles Peltidium nichollsi Geddes and Peltidium lerneri Geddes from Bahamas but also the widespread Peltidium speciosum Thompson & Scott and Peltidium purpureum Philippi. The new species from the Mexican Pacific differs from its known congeners by its possession of a unique combination of characters, including a modified pectinate seta on the antennary exopod, three terminal setae on the second endopodal segment of leg 1, third exopodal segment of leg 1 with three elements, inner terminal claw twice as long as outer claw, female fifth leg with 5 exopodal setae, exopodal setae I-III stout, spinulose and seta IV being as long as seta V. This is the second species of the family known to be distributed in the Eastern Tropical Pacific and in Mexico. Pending additional data, the distribution of this species appears to be restricted to this area of the Mexican Pacific.

  5. Valores hematológicos de referencia en tortuga terrestre argentina (Chelonoidis chilensis chilensis)

    OpenAIRE

    Troiano, Juan Carlos; M.C Silva

    1998-01-01

    Se tomaron muestras sanguíneas de 150 ejemplares sanos de tortuga terrestre argentina (Chelonoidis chilensis chilensis) por medio de punción de la vena coccígea superior. Las determinaciones que se realizaron incluyeron recuentos de glóbulos rojos, leucocitos y trombocitos, hematocrito, concentración de hemoglobina, índices hematimétricos y fórmulas leucocitarias relativas, las que se compararon con otras especies de Testudinidae. No se observaron cambios estadísticamente significativos en lo...

  6. Phytophthora austrocedri Elicitates Changes in Diterpene Profile of Austrocedrus chilensis.

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    Olate, Verónica Rachel; Vélez, María Laura; Greslebin, Alina; Schmeda-Hirschmann, Guillermo

    2015-08-18

    The populations of the Andean Cupressaceae Austrocedrus chilensis have been severely affected by a disease caused by the phytopathogenic fungus Phytophthora austrocedri. A study was undertaken to disclose changes in the resin composition of P. austrocedri-infected individuals, including naturally infected and artificially inoculated trees, compared with healthy A. chilensis trees. GC-MS and (1)H-NMR studies showed a clear differentiation among healthy and infected resins, with the diterpene isopimara-8(9),15-dien-19-ol as a relevant constituent in resins from infected trees. The effect of resin fractions from P. austrocedri infected trees on the pathogen was assessed by measuring the mycelial growth in agar plates. The most active fractions from resin obtained from infected trees inhibited fungal growth by nearly 50% at 1 mg/dish (35.37 µg/cm(2)). The main constituent in the active fractions were 18-hydroxymanool and the aldehyde torulosal. Both compounds are oxidation products of manool and can be a chemical response of the tree to the pathogen or be formed from the pathogen as a biotransformation product of manool by microbial oxidation. While the diterpene profiles from A. chilensis tree resins can easily differentiate healthy and P. austrocedri infected individuals, the possible conversion of manool to the antifungal derivatives 4 and 6 by the microorganism remains to be established.

  7. Phytophthora austrocedri Elicitates Changes in Diterpene Profile of Austrocedrus chilensis

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    Verónica Rachel Olate

    2015-08-01

    Full Text Available The populations of the Andean Cupressaceae Austrocedrus chilensis have been severely affected by a disease caused by the phytopathogenic fungus Phytophthora austrocedri. A study was undertaken to disclose changes in the resin composition of P. austrocedri-infected individuals, including naturally infected and artificially inoculated trees, compared with healthy A. chilensis trees. GC-MS and 1H-NMR studies showed a clear differentiation among healthy and infected resins, with the diterpene isopimara-8(9,15-dien-19-ol as a relevant constituent in resins from infected trees. The effect of resin fractions from P. austrocedri infected trees on the pathogen was assessed by measuring the mycelial growth in agar plates. The most active fractions from resin obtained from infected trees inhibited fungal growth by nearly 50% at 1 mg/dish (35.37 µg/cm2. The main constituent in the active fractions were 18-hydroxymanool and the aldehyde torulosal. Both compounds are oxidation products of manool and can be a chemical response of the tree to the pathogen or be formed from the pathogen as a biotransformation product of manool by microbial oxidation. While the diterpene profiles from A. chilensis tree resins can easily differentiate healthy and P. austrocedri infected individuals, the possible conversion of manool to the antifungal derivatives 4 and 6 by the microorganism remains to be established.

  8. Rodulfo Amando Philippi, el naturalista de mayor aporte al conocimiento taxonómico de la diversidad biológica de Chile

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    SERGIO A CASTRO

    2006-03-01

    Full Text Available Rodulfo Amando Philippi (1808-1904 es considerado uno de los naturalistas más influyentes en el desarrollo de las Ciencias Naturales en Chile. Entre las actividades científicas que desempeñó en el país está su dedicación al trabajo taxonómico y sistemático, que lo llevó a describir numerosas especies de plantas, animales y hongos. En este artículo se determina su contribución al conocimiento del patrimonio biológico de Chile, cuantificando el número y proporción de las especies actualmente válidas. De las especies descritas, 1.670 son consideradas válidas. Esta cifra equivale al 5,8 % de la diversidad biológica reconocida para Chile. Su mayor aporte se concentra en plantas vasculares, donde se encuentran vigentes 1.017 especies, que representan el 19 % de la flora vascular de Chile. Mención especial requiere el caso de algunos grupos, tales como anfibios, fasmatódeos, dermápteros y dípteros, cuya actual diversidad incluye 14, 30, 16 y 9 % de las especies de descritas por Philippi, respectivamente. De acuerdo a lo anterior y en comparación con otros taxónomos, Rodulfo Amando Philippi es el autor del mayor número de descripciones de especies válidas de la biota de ChileRodulfo Amando Philippi (1808-1904 is considered one of most influential in the development of natural sciences in Chile. Among his scientific endeavors, he contributed taxonomic descriptions of the biological diversity of Chile, encompassing organisms in three living kingdoms: plants, animals and fungi. In this article we examine his contribution to the knowledge of the biological wealth of Chile, quantifying the number and proportion of current valid species he described. Our findings indicate that Philippi described 1,670 valid species, equivalent to 5.8 % of the recognized biological diversity for Chile. His greatest contributions were in vascular plants with 1,017 species descriptions, which represent 19 % of the vascular flora of Chile. Special

  9. Community diversity of bacteria in digestive tract of mud snail (Bullacta exarata Philippi) and its rearing shoal

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    王国良; 郑天伦; 陆彤霞; 王一农; 於宏; 金珊

    2002-01-01

    The bacterial flora in the digestive tract of B. exarata Philippi and its rearing shoal were investigated, respectively. A total of 107 strains of heterotrophic bacteria, isolated from crop, stomach and intestine, mainly belong to genera Photobacterium, Bacillus, Pseudomonas and Vibrio. Varieties of bacteria in crop were significantly more than that in stomach and in intestine. A total of 173 strains of bacteria were isolated from the rearing shoal, belonging to 13 genera. The 5 predominant genera are Photobacterium, Bacillus, Pseudomonas, Vibrio and some genera of Enterobacteriaceae. The number of heterotrophic bacteria and Vibrio in rearing shoal changed in line with the alteration of the temperature, and were significantly affected by the use of pesticide.

  10. Bacteriological Analysis of the Digestive Tube of the Mud Snail (Bullacta exarata Philippi) and Its Rearing Shoal

    Institute of Scientific and Technical Information of China (English)

    WANG Guoliang; ZHENG Tianlun; LU Tongxia; WANG Yinong; YU Hong; JIN Shan

    2002-01-01

    The bacterial flora in the digestive tube of Bullacta exarata Philippi and its rearing shoal were investigated. A to-tal of 157 strains of heterotrophic bacteria, isolated from crop, stomach intestine and other parts of the digestive tube,mainly belong to the genera Photobacterium, Bacillus, Pseudomonas Vibrio and some genera of the family Enterobacteri-aceae. There are significantly more varieties of bacteria in crop than in stomach and intestine. A total of 173 strains of bacte-ria were isolated from the rearing shoal, belonging to 13 genera. The 5 predominant genera, such as Bacillus and Photobac-terium, are the same as those in the digestive tube, but greatly differ in percentages. The number of heterotrophic bacteriaand Vibrio in rearing shoal change in line with the alteration of the temperature, and are significantly affected by the use ofpesticides.

  11. Cell wall proteins in seedling cotyledons of Prosopis chilensis.

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    Rodríguez, J G; Cardemil, L

    1994-01-01

    Four cell wall proteins of cotyledons of Prosopis chilensis seedlings were characterized by PAGE and Western analyses using a polyclonal antibody, generated against soybean seed coat extensin. These proteins had M(r)s of 180,000, 126,000, 107,000 and 63,000, as determined by SDS-PAGE. The proteins exhibited a fluorescent positive reaction with dansylhydrazine suggesting that they are glycoproteins; they did not show peroxidase activity. The cell wall proteins were also characterized by their amino acid composition and by their amino-terminal sequence. These analyses revealed that there are two groups of related cell wall proteins in the cotyledons. The first group comprises the proteins of M(r)s 180,000, 126,000, 107,000 which are rich in glutamic acid/glutamine and aspartic acid/asparagine and they have almost identical NH2-terminal sequences. The second group comprises the M(r) 63,000 protein which is rich in proline, glycine, valine and tyrosine, with an NH2-terminal sequence which was very similar to that of soybean proline-rich proteins.

  12. New records of Protobranchia (Mollusca: Bivalvia in the Peruvian Sea

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    Carlos Paredes

    2014-06-01

    Full Text Available The following species of Bivalvia have been recorded for the first time for Peruvian waters: Nucula (Nucula iphigenia (Dall, 1908; Ennucula cardara (Dall, 1916; Nuculana (Nuculana extenuata (Dall, 1897; Orthoyoldia panamensis (Dall, 1908. These bivalves were collected in the platform and continental slope down to depths of 864 meters.

  13. Sagitta chilensis nueva especie de quetognato en fiordos australes chilenos (Chaetognatha, Aphragmophora, Sagittidae) Sagitta chilensis a new species of chaetognath in Chilean fjords (Chaetognatha, Aphragmophora, Sagittidae)

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    Francisco Villenas; Sergio Palma

    2006-01-01

    Se describe por primera vez una nueva especie de quetognato del orden Aphragmophora, Sagitta chilensis n. sp., colectada en fiordos australes chilenos. Se analizaron 1065 ejemplares colectados entre la boca del Guafo y el canal Pulluche en noviembre de 2002. Estos ejemplares presentaron marcadas diferencias morfológicas con otras especies afines, como estructuras puntiagudas en el collarete y aletas, forma de aletas anteriores y posteriores, posición de las vesículas seminales y presencia de ...

  14. SIMULACIÓN MATEMÁTICA DEL PROCESO DE SECADO DE LA GRACILARIA CHILENA (GRACILARIA CHILENSIS) MATHEMATICAL SIMULATION OF DRYING PROCESS OF CHILEAN GRACILARIA (GRACILARIA CHILENSIS)

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    Antonio Vega Gálvez; Cristian Tello Ireland; Roberto Lemus Mondaca

    2007-01-01

    El objetivo de este trabajo es estudiar y modelar la cinética de secado por aire caliente del alga Gracilaria (Gracilaria chilensis) utilizando un secador convectivo diseñado y construido en la Facultad de Ingeniería de la Universidad de La Serena a cinco temperaturas de bulbo seco (30, 40, 50, 60 y 70ºC) y velocidad de aire de 2.0±0.2 m.s-1. Para el modelado matemático se utilizan tres modelos empíricos (Newton, Henderson-Pabis & Page). Durante el experimento se observa solamente el periodo ...

  15. Manganese speciation in Diplodon chilensis patagonicus shells: a XANES study

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    Soldati, A. L.; Vicente-Vilas, V.; Goettlicher, J.; Jacob, D. E.

    2009-04-01

    In addition to other types of climate archives, biogenic skeletons of a variety of different organisms (i.e. shells of bivalves, skeletal hard parts of corals or sponges) are increasingly used for high-resolution climate reconstructions. Bivalves are particularly suited for such analyses because they are geographically broadly distributed and have been shown to record climate and environmental information reliably and over long time intervals. Variation of environmental parameters such as food supply, substratum type, salinity, illumination, temperature, concentration of dissolved oxygen or oxygen/carbon dioxide ratio, among others, may affect growth pattern, shell structure, mineralogy, isotopic fractionation and chemistry. Thus, shell features, minor and trace element composition patterns and isotopic signals may serve as an archive of environmental history. In turn, palaeoclimatic parameters such as ambient temperature, precipitation gradients, seawater salinity and primary production can be reconstructed from the shells by means of sclerochronological and geochemical methods. However, the distribution of minor and trace elements in the biominerals is not only influenced by the environment or vital effects, but also by intrinsic biomineralisation parameters like the carbonate polymorphism and the mineral habit (Soldati et al., 2008a). Generally, it is assumed that the X2+ ions are replacing the Ca2+ ion in the calcium carbonate (CaCO3) structure, but newest findings show that amorphous (or disordered) phases may play a role in hosting some of the elements use as proxies (Meibom et al., 2008; and Finch and Allison, 2007). In this work we focused on the freshwater clam Diplodon chilensis patagonicus, a widely distributed inhabitant of lakes and rivers in southern South America. Thanks to its long life span and seasonal growth Diplodon mussels exhibit excellent characteristics to construct an accurate chronological archive, with time windows of up to around a

  16. SIMULACIÓN MATEMÁTICA DEL PROCESO DE SECADO DE LA GRACILARIA CHILENA (GRACILARIA CHILENSIS MATHEMATICAL SIMULATION OF DRYING PROCESS OF CHILEAN GRACILARIA (GRACILARIA CHILENSIS

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    Antonio Vega Gálvez

    2007-04-01

    Full Text Available El objetivo de este trabajo es estudiar y modelar la cinética de secado por aire caliente del alga Gracilaria (Gracilaria chilensis utilizando un secador convectivo diseñado y construido en la Facultad de Ingeniería de la Universidad de La Serena a cinco temperaturas de bulbo seco (30, 40, 50, 60 y 70ºC y velocidad de aire de 2.0±0.2 m.s-1. Para el modelado matemático se utilizan tres modelos empíricos (Newton, Henderson-Pabis & Page. Durante el experimento se observa solamente el periodo de velocidad decreciente, por lo que se utiliza la ecuación de la segunda Ley de Fick para el cálculo de la difusividad efectiva de agua. El proceso de secado presenta humedades finales entre 0.096 g agua/g m.s y 0.061 g agua/g m.s para 30ºC y 70ºC, respectivamente. Tanto la difusividad como los parámetros cinéticos k1, k2 y k3 de los modelos propuestos presentan dependencia con la temperatura y al evaluarlos con la ecuación de Arrhenius se obtienen energías de activación de 39.92, 33.85, 33.49 y 33.83 kJ·mol-1, respectivamente. De acuerdo a los análisis estadísticos que se utilizan (r2, SSE, RMSE y X², el modelo de Page muestra la mejor calidad de ajuste sobre los datos experimentales, otorgando así una buena herramienta para el modelado de la cinética de secado industrial de la Gracilaria chilensis y el cálculo del tiempo de secado a diferentes temperaturas, con el fin de alcanzar un contenido de humedad comercial aceptable internacionalmente.The aim of this research is to study and to model the hot air drying kinetics of Gracialaria algae (Gracilaria chilensis, using a convective drier -designed and built at the Faculty of Engineering of Universidad de La Serena- at five dry bulb temperatures (30, 40, 50, 60 and 70ºC and an air velocity of 2.0 ± 0.2 m.s-1. Three empirical models are used for the mathematic modeling (Newton, Henderson-Pabis & Page. During the experiment, only a falling rate period is observed, hence the Fick's second

  17. Ionising radiation as a quarantine treatment for controlling Brevipalpus chilensis (Acarina: Tenuipalpidae) in Thompson Seedless grapes

    International Nuclear Information System (INIS)

    Irradiation was investigated as a possible quarantine treatment against the false red vine mite, Brevipalpus chilensis, on Thompson Seedless grapes. The most resistant stage of B. chilensis was the adult. Irradiation doses required to cause 90% mortality of adults, nymphs and eggs were 1307, 970, and 328 Gy, respectively. The viability of eggs from irradiated adults decreased as irradiation dose increased. At doses between 450 and 600 Gy, adult females laid eggs but they were not viable. In dose response tests at 250, 300 and 350 Gy using adult mites on grapes, the minimum irradiation dose that prevented adult reproduction was 300 Gy. A large-scale confirmatory study demonstrated the effectiveness of 300 Gy using 8 042 adult mites. An irradiation dose of 200 Gy combined with 15 day cold treatment (simulating commercial shipping conditions) was also shown to be sufficient to stop reproduction in the mite, and this treatment combination was later confirmed with 5088 adult mites. The organoleptic properties of Thompson Seedless grapes irradiated at 600 Gy were not affected, nor were ripeness parameters altered relative to soluble solids and acidity; no phytotoxicity was detected in either berries or the stem. (author)

  18. Tamaño relativo encefálico e índices cerebrales en Vanellus c. chilensis (Aves: Charadriidae Relative encephalic size and cerebral indices of Vanellus c. chilensis (Aves: Charadriidae

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    ESTELA PISTONE

    2002-09-01

    Full Text Available Se analizó la composición cuantitativa encefálica y se estimaron índices cerebrales en Vanellus c. chilensis (tero o queltehue. Se estimó el volumen porcentual e índices cerebrales del encéfalo total y de siete de sus componentes, como así también los núcleos de relevo de las vías trigeminal, visual y acústica. El telencéfalo es el componente de mayor volumen relativo, siendo el neoestriado la estructura telencefálica de tamaño superior. El desarrollo del estriado propiamente dicho, tecto óptico y los núcleos de relevo de las vías visual y trigeminal concuerdan con la dieta carnívora de Vanellus c. chilensis. El tamaño relativo del Wulst y de los núcleos de la vía acústica se asocia a las complicadas tácticas que utiliza esta especie en la defensa del nido. Los índices cerebrales de las estructuras encefálicas analizadas indican que Vanellus c. chilensis es un ave progresivaThe quantitative encephalic composition and cerebral indices of Vanellus c. chilensis (southern lapwing were analyzed. The percentual volumes and cerebral indices for the whole encephalon and for seven components were calculated as well as relevous nuclei of the trigeminal, visual and acoustic pathways. The component of greater relative volume is the telencephalon. The neostriatum is the most developed encephalic structure. Developing of bulbus olfactorius, striatum, tectum opticum and relevous nuclei of visual and trigeminal pathways are according with the carnivorous diet of Vanellus c. chilensis. The relative size of Wulst and relevous nuclei of acoustic pathway appears associated with the complex tactics used by this species in the defense of nest. Cerebral indices of all the analyzed structures suggest that Vanellus c. chilensis is a progresive bird

  19. Phylogenetic relationships elucidate colonization patterns in the intertidal grazers Osilinus Philippi, 1847 and Phorcus Risso, 1826 (Gastropoda: Trochidae) in the northeastern Atlantic Ocean and Mediterranean Sea.

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    Donald, Kirsten M; Preston, Joanne; Williams, Suzanne T; Reid, David G; Winter, David; Alvarez, Raquel; Buge, Barbara; Hawkins, Stephen J; Templado, Jose; Spencer, Hamish G

    2012-01-01

    Snails in the closely related trochid genera Phorcus Risso, 1826 and Osilinus Philippi, 1847 are ecologically important algal grazers in the intertidal zone of the northeastern Atlantic Ocean and Mediterranean Sea. Here we present the first complete molecular phylogeny for these genera, based on the nuclear 28S rRNA gene and the mitochondrial 16S rRNA and COI genes, and show that the current classification is erroneous. We recognize nine species in a single genus, Phorcus: estimated by BEAST analysis, this arose 30 (± 10) Ma; it consists of two subgenera, Phorcus and Osilinus, which we estimate diverged 14 (± 4.5) Ma. Osilinus kotschyi, from the Arabian and Red Seas, is not closely related and is tentatively referred to Priotrochus Fischer, 1879. Our phylogeny allows us to address biogeographical questions concerning the origins of the Mediterranean and Macaronesian species of this group. The former appear to have evolved from Atlantic ancestors that invaded the Mediterranean on several occasions after the Zanclean Flood, which ended the Messinian Salinity Crisis 5.3 Ma; whereas the latter arose from several colonizations of mainland Atlantic ancestors within the last 3 (± 1.5) Ma. PMID:21945534

  20. Stand dynamics, spatial pattern and site quality in Austrocedrus chilensis forests in Patagonia, Argentina

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    S.L. Burns

    2013-07-01

    Full Text Available Aim of study: The objective of this study was to analyze the stand structure and spatial pattern of two A. chilensis stands with contrasting soil conditions and different site qualities in order to explore if these differences lead to patterns similar to the ones observed under different precipitation conditions.Area of study: The study was carried out in two stands located near the city of El Bolsón (41° 56’S - 71° 33’ W, Rio Negro, Argentina.Material and Methods: We evaluated age difference between canopy strata (upper and lower in two stands with different site qualities by means of a Mann-Whitney test. Dead individuals by diameter class were compared by means of a chi square test. Spatial distribution pattern was analyzed using the pair-correlation function and the mark-correlation function.Main results: Both sites exhibited a random spatial distribution of A. chilensis but different processes seem to underlie the patterns. In the low-quality site facilitation and continuous establishment led to a transient clumped spatial pattern. Mortality mediated by competition occurred mainly on small trees resulting in the current random pattern. On the other hand, spatial pattern in the high-quality site does not reflect a facilitation mediated recruitment. The upper strata established synchronously and subsequent regeneration was episodic.Research highlights: The results show that the differences in site quality may lead to different establishment spatial patterns, showing the importance of facilitation processes in sites with drier soil conditions and lower quality, although results may be site specific, due to the lack of replications.Keywords: Spatial analysis; regeneration; mortality; competition; facilitation.Abbreviations used:  LQ: low-quality site; HQ: high-quality site.

  1. Saxitoxin Modulates Immunological Parameters and Gene Transcription in Mytilus chilensis Hemocytes

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    Allisson Astuya

    2015-07-01

    Full Text Available Saxitoxin (STX is a neurotoxin produced by dinoflagellates in diverse species, such as Alexandrium spp., and it causes paralytic shellfish poisoning (PSP in humans after the ingestion of contaminated shellfish. Recent studies have suggested that the immune functions of bivalves could be affected by harmful algae and/or by their toxins. Herein, hemocytes are the main effector cells of the immune cellular response. In this study, we evaluated the response of hemocytes from the mussel Mytilus chilensis to STX exposure in a primary culture. Cell cultures were characterized according to size and complexity, while reactive oxygen species (ROS production was evaluated using a dichlorofluorescein diacetate (DCFH-DA assay. Finally, phagocytic activity was measured using both flow cytometry and fluorescence microscopy assays. Additionally, gene transcription of candidate genes was evaluated by qPCR assays. The results evidenced that exposures to different concentrations of STX (1–100 nM for 24 h did not affect cell viability, as determined by an MTT assay. However, when hemocytes were exposed for 4 or 16 h to STX (1–100 nM, there was a modulation of phagocytic activity and ROS production. Moreover, hemocytes exposed to 100 nM of STX for 4 or 16 h showed a significant increase in transcript levels of genes encoding for antioxidant enzymes (SOD, CAT, mitochondrial enzymes (COI, COIII, CYTB, ATP6, ND1 and ion channels (K+, Ca2+. Meanwhile, C-type lectin and toll-like receptor genes revealed a bi-phase transcriptional response after 16 and 24–48 h of exposure to STX. These results suggest that STX can negatively affect the immunocompetence of M. chilensis hemocytes, which were capable of responding to STX exposure in vitro by increasing the mRNA levels of antioxidant enzymes.

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

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    Tëmkin Ilya

    2010-01-01

    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 tr...

  3. The Potential of Algarrobo ( Prosopis chilensis (Mol.) Stuntz) for Regeneration of Desertified Soils: Assessing Seed Germination Under Saline Conditions

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    Westphal, Claus; Gachón, Paloma; Bravo, Jaime; Navarrete, Carlos; Salas, Carlos; Ibáñez, Cristian

    2015-07-01

    Due to their multipurpose use, leguminous trees are desirable for the restoration of degraded ecosystems. Our aim was to investigate seed germination of the leguminous tree Prosopis chilensis in response to salinity, one of the major abiotic challenges of desertified soils. Germination percentages of seed from 12 wild P. chilensis populations were studied. Treatments included four aqueous NaCl concentrations (150, 300, 450, and 600 mM). In each population, the highest germination percentage was seen using distilled water (control), followed closely by 150 mM NaCl. At 300 mM NaCl or higher salt concentration, germination was progressively inhibited attaining the lowest value at 450 mM NaCl, while at 600 mM NaCl germination remained reduced but with large variation among group of samples. These results allowed us to allocate the 12 groups from where seeds were collected into three classes. First, the seeds from Huanta-Rivadavia showed the lowest percent germination for each salt condition. The second group was composed of moderately salt-tolerant seeds with 75 % germination at 300 mM NaCl, followed by 50 % germination at 450 mM NaCl and 30 % germination at 600 mM NaCl. The third group from Maitencillo and Rapel areas was the most salt tolerant with an impressive seed germination level of 97 % at 300 mM NaCl, 82 % at 450 mM NaCl, and 42 % at 600 mM NaCl. Our results demonstrate that P. chilensis seeds from these latter localities have an increased germination capability under saline stress, confirming that P. chilensis is an appropriate species to rehabilitate desertified soils.

  4. A phylogenetic backbone for Bivalvia: an RNA-seq approach.

    Science.gov (United States)

    González, Vanessa L; Andrade, Sónia C S; Bieler, Rüdiger; Collins, Timothy M; Dunn, Casey W; Mikkelsen, Paula M; Taylor, John D; Giribet, Gonzalo

    2015-02-22

    Bivalves are an ancient and ubiquitous group of aquatic invertebrates with an estimated 10 000-20 000 living species. They are economically significant as a human food source, and ecologically important given their biomass and effects on communities. Their phylogenetic relationships have been studied for decades, and their unparalleled fossil record extends from the Cambrian to the Recent. Nevertheless, a robustly supported phylogeny of the deepest nodes, needed to fully exploit the bivalves as a model for testing macroevolutionary theories, is lacking. Here, we present the first phylogenomic approach for this important group of molluscs, including novel transcriptomic data for 31 bivalves obtained through an RNA-seq approach, and analyse these data with published genomes and transcriptomes of other bivalves plus outgroups. Our results provide a well-resolved, robust phylogenetic backbone for Bivalvia with all major lineages delineated, addressing long-standing questions about the monophyly of Protobranchia and Heterodonta, and resolving the position of particular groups such as Palaeoheterodonta, Archiheterodonta and Anomalodesmata. This now fully resolved backbone demonstrates that genomic approaches using hundreds of genes are feasible for resolving phylogenetic questions in bivalves and other animals.

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

    Directory of Open Access Journals (Sweden)

    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.

  6. Pipunculidae (Diptera da região neotropical: I. Redescrição de Chalarus chilensis Collin, comb. n. e descrição de duas espécies novas da Amazônia

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    J. A. Rafael

    1988-07-01

    Full Text Available Chalarus chilensis Collin, comb. n. é redescrito a partir do tipo e duas novas espécies da Bacia Amazônica, C. amazonensis e C. connexus, são descritas.Chalarus chilensis, comb. n. , is redescribed from the type and two species from the Amazon Basin, C. amazonensis and C. connexus, are described.

  7. Left-right asymmetries and shape analysis on Ceroglossus chilensis (Coleoptera: Carabidae)

    Science.gov (United States)

    Bravi, Raffaella; Benítez, Hugo A.

    2013-10-01

    Bilateral symmetry is widespread in animal kingdom, however most animal can deviate from expected symmetry and manifest some kind of asymmetries. Fluctuating asymmetry is considered as a tool for valuating developmental instability, whereas directional asymmetry is inherited and could be used for evaluating evolutionary development. We use the method of geometric morphometrics to analyze left/right asymmetries in the whole body, in two sites and totally six populations of Ceroglossus chilensis with the aim to infer and explain morphological disparities between populations and sexes in this species. In all individuals analyzed we found both fluctuating asymmetry and directional asymmetry for size and shape variation components, and a high sexual dimorphism. Moreover a high morphological variability between the two sites emerged as well. Differences in diet could influence the expression of morphological variation and simultaneously affect body sides, and therefore contribute to the symmetric component of variation. Moreover differences emerged between two sites could be a consequence of isolation and fragmentation, rather than a response to local environmental differences between sampling sites.

  8. [Use of mesquite cotyledon (Prosopis chilensis (Mol) Shuntz) in the manufacturing of cereal bars].

    Science.gov (United States)

    Estévez, A M; Escobar, B; Ugarte, V

    2000-06-01

    Cereal bars with peanut and walnut has shown to be snack foods of good organoleptic characteristics and high caloric value, due to their content of protein, lipids and carbohydrates. Cotyledons of mezquite seeds have a high protein content which biological quality improves with thermal processing like toasting, microwave or moist heat under pressure. The purposes of this research were to study the use of mezquite cotyledon (Prosopis chilensis (Mol) Stuntz) in cereal bars with two different levels of peanut or walnut; and to determine the effect of two thermal treatment applied on the cotyledon upon the bar characteristics. Twelve different kind of bars were developed through the combination of two levels of peanut or walnut (15% and 18%); the use of mezquite cotyledon (0% and 6%); and the application of two thermal processing to the cotyledon (microwave and toasting). Cereal bars were analysed for chemical, physical and sensory characteristics: moisture, water activity, proximate chemical composition, sensory quality and acceptability. Moisture content of bars with peanut ranged between 10.4% and 10.9%; and for those with walnut, between 10.5% and 12.3%. Protein content was higher in the bars with mezquite cotiledon, being higher those with peanut. Thermal processing did not have any effect on the chemical composition. Bars with mezquite cotyledon treated by microwave showed a higher acceptability.

  9. The reliability of morphometric discriminant functions in determining the sex of Chilean flamingos Phoenicopterus chilensis

    Institute of Scientific and Technical Information of China (English)

    Diego MONTALTI; Maricel GRA(N)A GRILLI; René E.MARAGLIANO; Guillermo CASSINI

    2012-01-01

    Monomorphic birds cannot be sexed visually and discriminant functions on the basis of external morphological variations are frequently used.Our objective was to evaluate the reliability of sex classification functions created from structural measurements of Chilean flamingos Phoenicopterus chilensis museum skins for the gender assignment of live birds.Five measurements were used to develop four discriminant functions:culmen,bill height and width,tarsus length and middle toe claw.The functions were tested on a sample of live flamingos from a zoo.The best classification for museum flamingos was given by a function using tarsus length,bill width and middle toe claw (97%).However,this function did not give the best classification for the zoo-based flamingos (81%) which had the best sex assignment by a function including measurements of tarsus,culmen and bill height and width (85%).This shows that a function giving good results in the sample from which it originated may not be as good when applied to another group of animals.Our study emphasizes the need for assessing the accuracy of a function by testing it with other methods to ensure its suitability when being applied.

  10. Seasonal variation and resin composition in the Andean tree Austrocedrus chilensis.

    Science.gov (United States)

    Olate, Verónica Rachel; Soto, Alex; Schmeda-Hirschmann, Guillermo

    2014-05-21

    Little is known about the changes in resin composition in South American gymnosperms associated with the different seasons of the year. The diterpene composition of 44 resin samples from seven Austrocedrus chilensis (Cupressaceae) trees, including male and female individuals, was investigated in three different seasons of the year (February, June and November). Twelve main diterpenes were isolated by chromatographic means and identified by gas chromatography-mass spectrometry and nuclear magnetic resonance (NMR). The diterpene composition was submitted to multivariate analysis to find possible associations between chemical composition and season of the year. The principal component analysis showed a clear relation between diterpene composition and season. The most characteristic compounds in resins collected in summer were Z-communic acid (9) and 12-oxo-labda-8(17),13E-dien-19 oic acid methyl ester (10) for male trees and 8(17),12,14-labdatriene (7) for female trees. For the winter samples, a clear correlation of female trees with torulosic acid (6) was observed. In spring, E-communic acid (8) and Z-communic acid (9) were correlated with female trees and 18-hydroxy isopimar-15-ene (1) with male tree resin. A comparison between percent diterpene composition and collection time showed p < 0.05 for isopimara-8(9),15-diene (2), sandaracopimaric acid (4), compound (7) and ferruginol (11).

  11. Seasonal Variation and Resin Composition in the Andean Tree Austrocedrus chilensis

    Directory of Open Access Journals (Sweden)

    Verónica Rachel Olate

    2014-05-01

    Full Text Available Little is known about the changes in resin composition in South American gymnosperms associated with the different seasons of the year. The diterpene composition of 44 resin samples from seven Austrocedrus chilensis (Cupressaceae trees, including male and female individuals, was investigated in three different seasons of the year (February, June and November. Twelve main diterpenes were isolated by chromatographic means and identified by gas chromatography-mass spectrometry and nuclear magnetic resonance (NMR. The diterpene composition was submitted to multivariate analysis to find possible associations between chemical composition and season of the year. The principal component analysis showed a clear relation between diterpene composition and season. The most characteristic compounds in resins collected in summer were Z-communic acid (9 and 12-oxo-labda-8(17,13E-dien-19 oic acid methyl ester (10 for male trees and 8(17,12,14-labdatriene (7 for female trees. For the winter samples, a clear correlation of female trees with torulosic acid (6 was observed. In spring, E-communic acid (8 and Z-communic acid (9 were correlated with female trees and 18-hydroxy isopimar-15-ene (1 with male tree resin. A comparison between percent diterpene composition and collection time showed p < 0.05 for isopimara-8(9,15-diene (2, sandaracopimaric acid (4, compound (7 and ferruginol (11.

  12. Microencapsulation of maqui (Aristotelia chilensis Molina Stuntz leaf extracts to preserve and control antioxidant properties

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    Leslie Vidal J

    2013-03-01

    Full Text Available Microencapsulation technology is an alternative to stabilize stress factors and protect food ingredients or additives, which include environmentally sensitive bioactive principles in protective matrices to increase their functionality and life span. The objective of this research was to study conditions to obtain microcapsules with antioxidant capacity from a maqui (Aristotelia chilensis [Molina] Stuntz, Elaeocarpaceae leaf extract by emulsification and subsequent retention after microencapsulation. Microcapsules were produced by water-in-oil emulsion (W/O using a phase of the aqueous maqui leaf extract and gum arabic, and a liquid vaseline phase. Maqui leaf extract antioxidant capacity was 99.66% compared with the aqueous phase of the emulsion at 94.38 and 93.06% for 5% and 15% gum arabic, respectively. The mean yield of maqui leaf extract microencapsulation with 5% gum arabic varied between 38 and 48%, whereas with 15% gum arabic it was 39%. Once the antioxidant microcapsules were formed, mean extract antioxidant capacity ranged between 30 and 35%. Both yields responded similarly to changes in gum arabic concentrations (5% and 15% in the aqueous phase of the emulsion; 5% concentration produced a microcapsule size from 1.0 to 10 urn. Maqui leaf extracts with high phenolic compound levels, which can be stabilized and protected by the microencapsulation process, produce new natural preservative systems as compared with their synthetic counterparts.

  13. Detailed analyses of fresh and dried maqui (Aristotelia chilensis (Mol.) Stuntz) berries and juice.

    Science.gov (United States)

    Brauch, J E; Buchweitz, M; Schweiggert, R M; Carle, R

    2016-01-01

    In this study, a detailed chemical characterization of nutritionally-relevant, quality-determining constituents in dried and fresh fruits as well as juices of maqui (Aristotelia chilensis (Mol.) Stuntz) is provided. A total of 8 glycosylated anthocyanins was characterized in maqui fruits, being composed of differently substituted cyanidin and delphinidin derivatives. During processing into juice, a substantial loss in total anthocyanin contents (TAC) was observed. TAC values were also reduced after drying of maqui berries. Likewise, the browning index (BI) of fresh fruits increased during processing. Being composed of flavonol glycosides and ellagic acids, 17 non-anthocyanin phenolics were characterized in all maqui samples. Besides characterizing phenolic compounds, antioxidant activities, total phenolics, major sugars, non-volatile organic acids, minerals and trace elements were quantitated. Moreover, total lipid contents and the fruits' mainly unsaturated fatty acid profiles are reported. The presented results indicate the high potential of maqui as so far under-utilized but extremely pigment-rich "superfruit". PMID:26212975

  14. Molecular evidence confirms that Proctoeces humboldti and Proctoeces chilensis (Digenea: Fellodistomidae) are the same species.

    Science.gov (United States)

    Valdivia, I M; Cardenas, L; Gonzalez, K; Jofré, D; George-Nascimento, M; Guiñez, R; Oliva, M E

    2010-12-01

    Two species of Proctoeces Odhner, 1911 have been described in marine organisms from Chile: P. humboldti George-Nascimento & Quiroga (1983), parasitizing the gonads of keyhole limpets (Fissurella spp.), and P. chilensis Oliva (1984), an intestinal parasite of Sicyases sanguineus (Teleostei); both species were subsequently considered as P. lintoni Siddiqi & Cable (1960). To assist in the resolution of the taxonomic identification of Proctoeces species in marine organisms from Chile, phylogenetic studies using DNA sequences from the V4 region of the SSU rRNA gene were performed. Several specimens of P. lintoni were isolated from keyhole limpets (Fissurella spp.) and clingfish (S. sanguineus) from Bahia San Jorge (23°40'S) and Bahia Concepción (36°50'S). Phylogenetic analyses were conducted using three different approaches: a neighbour-joining (NJ), a maximum likelihood (ML) and Bayesian inference (BI). The phylogenetic analysis confirms that specimens of Proctoeces obtained from keyhole limpets and those specimens from the clingfish are in fact the same species. We prefer to consider our specimens as Proctoeces cf. lintoni, as the morphology of Proctoeces appears to be of doubtful value and genetic information about P. lintoni Siddiqi & Cable (1960) is not available. In addition, our results strongly suggest that there are at least three species in this genus.

  15. Short-term feeding response of the mussel Mytilus chilensis exposed to diets containing the toxic dinoflagellate Alexandrium catenella Respuesta alimentaria inicial del bivalvo Mytilus chilensis expuesto a dietas conteniendo el dinoflagelado tóxico Alexandrium catenella

    Directory of Open Access Journals (Sweden)

    JORGE M NAVARRO

    2008-03-01

    Full Text Available The short-term feeding response of the bivalve Mytilus chilensis was measured using four diets containing different proportions of the toxic dinoflagellate Alexandrium catenella. The diets containing the highest concentrations of the dinoflagellate showed the greatest effect on the feeding activity in the mussel, with clearance and ingestión rates significantly reduced during the first hours of exposure. After this period, M. chilensis demonstrated a capacity to acclimate to the toxic diets, with feeding parameters reaching values similar to those of untreated control organisms. It was not clear if the negative effect on the feeding behavior was caused by the presence of the paralytic toxin, or due to the larger size of the dinoflagellate cells in comparison with cells of Isochrysis galbana used in the control diet. However, parallel studies with diets containing the nontoxic dinoflagellate Alexandrium affine of similar size and shape to that of A. catenella, suggested the cell size was the main cause for impairment of feeding behavior. The capacity for acclimation to either toxin or cell size by M. chilensis makes it a good indicator species for the early detection of harmful PSP events, since its relative insensitivity to the toxin allows it to quickly recover normal feeding behavior and permits it to accumulate PSP in its tissues in a short timeLa respuesta inicial del bivalvo Mytilus chilensis fue medida bajo cuatro dietas que contenían diferentes proporciones del dinoflagelado tóxico Alexandrium catenella. Las dietas que contenían las concentraciones más altas de este dinoflagelado mostraron el mayor efecto durante las primeras horas de exposición. Después de este periodo inicial, M. chilensis demostró la capacidad para aclimatarse a estas dietas tóxicas, con parámetros de alimentación que alcanzaron valores similares a aquellos de los organismos controles. No fue claro si el efecto negativo sobre la conducta de alimentación fue

  16. Variabilidad genética y estructura poblacional del tunicado Pyura chilensis Molina, 1782, en la costa de Chile Genetic variability and population structure in tunicate Pyura chilensis Molina, 1782, in the coast of Chile

    Directory of Open Access Journals (Sweden)

    MARCELA P ASTORGA

    2006-12-01

    Full Text Available El tunicado Pyura chilensis se ha considerado una especie de importancia ecológica, por concentrar una gran diversidad biológica en sus agregaciones y de importancia económica por ser un recurso de extracción por pescadores artesanales. Sin embargo, se han detectado cambios en la distribución y abundancia de sus poblaciones adjudicados a su sobreexplotación. Para llegar a establecer medidas de conservación de un recurso, es necesario entre otras cosas, conocer su variabilidad genética y su estructura poblacional, estimando los patrones y sus causas. Por lo tanto, en el presente trabajo se determinó el grado de variabilidad genética aloenzimática del piure P. chilensis y su estructura poblacional en base a tres localidades (Antofagasta, Talcahuano y Puerto Montt en la costa chilena. Los loci polimórficos obtenidos fueron Mdh-1 y Pgi-1. Los valores de Fst mostraron leve estructuración poblacional entre localidades (Fst 0,019 al igual que la prueba exacta de diferenciación genética (P = 0,031. Se observó diferenciación para la localidad de Puerto Montt en relación a las otras dos localidades en algunos de los dos loci. Los niveles de variabilidad observados en esta especie corresponden a lo esperados para otras ascidias. La estructuración genética poblacional puede ser explicada por una combinación de diferentes factores, entre los que destacan: (i el tiempo del periodo larval de 12 a 24 h, lo cual no facilitaría una amplia dispersión a lo largo de 2.500 km de costa y (ii las condiciones oceanográficas diferenciales entre localidades, junto a patrones de circulación cerrados que podrían llegar a restringir el flujo génico. Por último, proponemos que un conocimiento adecuado del grado de variabilidad, estructura y dinámica genética de las poblaciones son aspectos esenciales para tomar medidas de conservación de recursos explotados, tanto en ambientes abiertos como en áreas de manejoThe ascidian Pyura chilensis is an

  17. 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.

  18. Espectro trófico de Chelonoidis chilensis (Chelonii: Testudinidae en la provincia fitogeográfica del monte (Mendoza, Argentina

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    Richard, Enrique

    1994-01-01

    Full Text Available Between 1983 and 1991, 83 field trips were made to the biogeographical province of Monte, in Mendoza province, Argentina, in order to study the trophic spectrum of Chelonoidis chilensis, among other ecoethological aspects. The trophic period extends from September to April. Adults are herbivorous in strict sense, but this may change according to the available resourees. Trophic spectrum is composed by 14 items (Families of vegetables. Some items have toxic or potentially toxit substances. Finally, the diet of Ch. chilensis is compared with the one of Ch. donosobarrosi and with other desert tortoises.

  19. Anatomía comparada del sistema digestivo de las rayas Urotrygon chilensis y Dasyatis sabina (Myliobatiformes) Comparative anatomy of the digestive system of the skates, Urotrygon chilensis and Dasyatis sabina (Myliobatiformes)

    OpenAIRE

    ABRAHAM KOBELKOWSKY

    2010-01-01

    La organización general del sistema digestivo de la raya pinta Urotrygon chilensis y la raya de espina Dasyatis sabina corresponde al patrón morfológico general de los Myliobatiformes. La dentición de estas especies muestra un dimorfismo sexual, consistente en dientes planos en las hembras y dientes puntiagudos en los machos. Entre los músculos mandibulares, el adductor mandibulae es el más complejo. Las cavidades bucofaríngea y visceral son aplanadas dorsoventralmente. El esófago es relativa...

  20. The Rho GTPase Family Genes in Bivalvia Genomes: Sequence, Evolution and Expression Analysis

    OpenAIRE

    Xue Li; Ruijia Wang; Xiaogang Xun; Wenqian Jiao; Mengran Zhang; Shuyue Wang; Shi Wang; Lingling Zhang; Xiaoting Huang; Xiaoli Hu; Zhenmin Bao

    2015-01-01

    Background Rho GTPases are important members of the Ras superfamily, which represents the largest signaling protein family in eukaryotes, and function as key molecular switches in converting and amplifying external signals into cellular responses. Although numerous analyses of Rho family genes have been reported, including their functions and evolution, a systematic analysis of this family has not been performed in Mollusca or in Bivalvia, one of the most important classes of Mollusca. Result...

  1. Evolutionary Patterns in Pearl Oysters of the Genus Pinctada (Bivalvia: Pteriidae)

    OpenAIRE

    Cunha, Regina L.; Blanc, Francoise; Bonhomme, Francois; Arnaud-Haond, Sophie

    2011-01-01

    Pearl oysters belonging to the genus Pinctada (Bivalvia: Pteriidae) are widely distributed between the Indo-Pacific and western Atlantic. The existence of both widely distributed and more restricted species makes this group a suitable model to study diversification patterns and prevailing modes of speciation. Phylogenies of eight out of the 11 currently recognised Pinctada species using mitochondrial (cox1) and nuclear (18S rRNA) data yielded two monophyletic groups that correspond to shell s...

  2. GENETIC DIVERSITY OF FIVE FRESHWATER MUSSELS IN GENUS ANODONTA (MOLLUSCA: BIVALVIA) REVEALED BY RAPD ANALYSIS

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Unionidae(Bivalvia)are distributed infreshwaters,and represent a significanttaxonof benthic community[1].In China,freshwater mussels are abundant resources[2].Since1949,substantial investigations onthe unionidfau-na had been undertakenin China[3—8].Withreference tooverseas research[9,10],a preliminary reorganization onthe Unionidae was performed accordingtosome classifica-tion characteristics such as shell shape,larvae character-istics,and breeding habit[11].Due tothe serious conver-gence of freshwater muss...

  3. Uncovering the Complex Transcriptome Response of Mytilus chilensis against Saxitoxin: Implications of Harmful Algal Blooms on Mussel Populations

    Science.gov (United States)

    Detree, Camille; Núñez-Acuña, Gustavo; Roberts, Steven; Gallardo-Escárate, Cristian

    2016-01-01

    Saxitoxin (STX), a principal phycotoxin contributing to paralytic shellfish poisoning, is largely produced by marine microalgae of the genus Alexandrium. This toxin affects a wide range of species, inducing massive deaths in fish and other marine species. However, marine bivalves can resist and accumulate paralytic shellfish poisons. Despite numerous studies on the impact of STX in marine bivalves, knowledge regarding STX recognition at molecular level by benthic species remains scarce. Therefore, the aim of this study was to identify novel genes that interact with STX in the Chilean mussel Mytilus chilensis. For this, RNA-seq and RT-qPCR approaches were used to evaluate the transcriptomic response of M. chilensis to a purified STX as well as in vivo Alexandrium catenella exposure. Approximately 800 million reads were assembled, generating 138,883 contigs that were blasted against the UniProt Mollusca database. Pattern Recognition Receptors (PRRs) involved in mussel immunity, such as Toll-like receptors, tumor necrosis factor receptors, and scavenger-like receptors were found to be strongly upregulated at 8 and 16 h post-STX injection. These results suggest an involvement of PRRs in the response to STX, as well as identifying potential, novel STX-interacting receptors in this Chilean mussel. This study is the first transcriptomic overview of the STX-response in the edible species M. chilensis. However, the most significant contribution of this work is the identification of immune receptors and pathways potentially involved in the recognition and defense against STX’s toxicity and its impact of harmful algae blooms on wild and cultivated mussel populations. PMID:27764234

  4. Actividad biológica del veneno de Anthothoe chilensis (Lesson, 1830 (Actiniaria: Sagartiidae

    Directory of Open Access Journals (Sweden)

    Fernando Retuerto

    2013-04-01

    Full Text Available El presente trabajo informa sobre características bioquímicas, actividad hemolítica, citotóxica y citolítica de tres fracciones del veneno de la anémona de mar Anthothoe chilensis. Los tentáculos de 78 ejemplares de A. chilensis, provenientes de la Isla Cabinza-San Lorenzo, Lima, fueron procesados obteniendo un filtrado, el cual se fraccionó por precipitación con tres puntos de saturación con acetona fría: I (20%, II (50%, III (80%. El filtrado mostró una concentración proteica de 1,8 mg/mL. Las pruebas de detección de carbohidratos totales demostraron la presencia de 1,401 mg de glucosa/ml de solución en el filtrado; mientras que la electroforesis en gel de poliacrilamida en presencia de dodecil sulfato de sodio (PAGE-SDS evidenció proteínas de 14 a 94 kDa, de las cuales la mayor parte fueron glicoproteínas. Se encontró actividad hemolítica sobre eritrocitos humanos en las fracciones I y II. La fracción III tuvo la actividad fosfolipásica más alta. Las tres fracciones tuvieron una ligera actividad proteolítica sobre caseína siendo la más activa la fracción I. Los efectos citotóxico y citológico fueron evaluados aplicando el Ensayo de Toxicidad en Embriones de Erizo de mar (SET. Las anormalidades morfológicas fueron evaluadas a las 48 horas de desarrollo. Las anormalidades citológicas fueron evaluadas en el estadio de gástrula tardía. Las tres fracciones acetónicas produjeron daños citotóxicos y citológicos importantes en los embriones de erizo de mar. Los efectos sobre los embriones fueron retrasar su desarrollo y producir anomalías morfológicas como lisis de blástulas y exogastrulación. Los daños citológicos observados fueron núcleos heteropicnóticos, núcleos gigantes y espacios celulares anormales. La fracción II fue la más citotóxica produciendo una mortalidad de 75,52 ± 5,5% en los primeros estadíos con 1,0 μg/mL. La fracción I produjo el mayor porcentaje de anomalías en los embriones

  5. Dietary fibre concentrate from Chilean algarrobo (Prosopis chilensis (Mol.) Stuntz) pods: purification and characterization.

    Science.gov (United States)

    Estévez, Ana María; Figuerola, Fernando; Bernuy, Enrique; Sáenz, Carmen

    2014-12-01

    Prosopis species are generally fast-growing, drought-resistant, nitrogen-fixing trees or shrubs. Fruits of Prosopis spp are indehiscent pods, where pericarp is formed by the epicarp, light brown in colour, and fibrous nature; the mesocarp known as pulp, which is rich in sugars; and the endocarp. The aim of this work was to obtain a fibre concentrate from the pods of Prosopis chilensis Mol. (Stuntz) and to determine the chemical, physical, and technological properties of the pod flour (PF) and of a fibre concentrate or pod purified flour (PPF). Acetone, ethanol, and water at different conditions of time and temperature were used in the purification process. PF showed 53.7 g/100 g of total sugar content, 4.2 g/100 g of reducing sugar content, 41.8 g/100 g of total dietary fibre, 35.8 g/100 g of insoluble fibre, and 6.0 g/100 g of soluble fibre content. The PPF has a total sugar content of 3.8 g/100 g, reducing sugar content of 2.2 g/100 g, total dietary fibre content of 80.8 g/100 g, insoluble fibre content of 75.1 g/100 g, and soluble fibre content of 5.7 g/100 g. The scanning electron microscopy analysis showed the existence of voids in the structure of PPF flour, which reveals the efficiency of the purification process with a high decrease in the total sugar content.

  6. Dietary fibre concentrate from Chilean algarrobo (Prosopis chilensis (Mol.) Stuntz) pods: purification and characterization.

    Science.gov (United States)

    Estévez, Ana María; Figuerola, Fernando; Bernuy, Enrique; Sáenz, Carmen

    2014-12-01

    Prosopis species are generally fast-growing, drought-resistant, nitrogen-fixing trees or shrubs. Fruits of Prosopis spp are indehiscent pods, where pericarp is formed by the epicarp, light brown in colour, and fibrous nature; the mesocarp known as pulp, which is rich in sugars; and the endocarp. The aim of this work was to obtain a fibre concentrate from the pods of Prosopis chilensis Mol. (Stuntz) and to determine the chemical, physical, and technological properties of the pod flour (PF) and of a fibre concentrate or pod purified flour (PPF). Acetone, ethanol, and water at different conditions of time and temperature were used in the purification process. PF showed 53.7 g/100 g of total sugar content, 4.2 g/100 g of reducing sugar content, 41.8 g/100 g of total dietary fibre, 35.8 g/100 g of insoluble fibre, and 6.0 g/100 g of soluble fibre content. The PPF has a total sugar content of 3.8 g/100 g, reducing sugar content of 2.2 g/100 g, total dietary fibre content of 80.8 g/100 g, insoluble fibre content of 75.1 g/100 g, and soluble fibre content of 5.7 g/100 g. The scanning electron microscopy analysis showed the existence of voids in the structure of PPF flour, which reveals the efficiency of the purification process with a high decrease in the total sugar content. PMID:24003035

  7. Respuestas foliares de Aristotelia chilensis (Molina Stuntz (Elaeocarpaceae a la fragmentación del bosque maulino Leaf responses of Aristotelia chilensis (Molina Stuntz (Elaeocarpaceae to the fragmentation of the Maulino forest

    Directory of Open Access Journals (Sweden)

    FIORELLA REPETTO-GIAVELLI

    2007-12-01

    Full Text Available La fragmentación que ha sufrido el bosque nativo de Chile debido a la fuerte presión antrópica ha causado, además de la grave pérdida de habitat, la modificación del microclima de los parches de bosque remanente que alguna vez constituyeron un bosque continuo de especies nativas. Estos cambios generarían respuestas morfológicas, químicas y fisiológicas en plantas capaces de adaptarse a las nuevas condiciones. Este estudio tiene como objetivo identificar respuestas a nivel de las hojas ante el aumento de radiación solar y disminución de agua en el suelo que ocurre al interior de los fragmentos. Para esto utilizamos a Aristotelia chilensis, especie que crece tanto en fragmentos como en bosque continuo, y comparamos parámetros relacionados a su morfología foliar en bosque y fragmentos y medimos su repercusión en la capacidad fotosintética de A. chilensis. En términos morfológicos, se observó una disminución del área foliar y del área foliar específica en los fragmentos, siendo 1,2 veces menor que en el bosque continuo. En los fragmentos, el grosor de la epidermis y del parénquima esponjoso son más de 1,3 veces mas gruesos que en el bosque continuo. El grosor del parénquima en empalizada, en cambio, no se vio modificado. La cantidad de nitrógeno en las hojas es 1,2 veces mayor en el bosque continuo que en los fragmentos, mientras que el contenido de carbono no varía. La conductancia estomática en el bosque continuo fue 1,5 veces mayor que en los fragmentos. Aristotelia chilensis responde morfológica y fisiológicamente ante los cambios abióticos generados por la fragmentación de los bosques, lo que le permite sobrevivir tanto en ambientes de baja luminosidad como el bosque continuo y en ambientes de alta luminosidad y bajo contenido hídrico como los fragmentos de bosque, manteniendo tasas fotosintéticas semejantes en ambos ambientesFragmentation of the Maulino forest implies significant habitat loss, as well as the

  8. Genome sequence of Ensifer arboris strain LMG 14919(T); a microsymbiont of the legume Prosopis chilensis growing in Kosti, Sudan.

    Science.gov (United States)

    Reeve, Wayne; Tian, Rui; Bräu, Lambert; Goodwin, Lynne; Munk, Christine; Detter, Chris; Tapia, Roxanne; Han, Cliff; Liolios, Konstantinos; Huntemann, Marcel; Pati, Amrita; Woyke, Tanja; Mavrommatis, Konstantinos; Markowitz, Victor; Ivanova, Natalia; Kyrpides, Nikos; Willems, Anne

    2014-06-15

    Ensifer arboris LMG 14919(T) is an aerobic, motile, Gram-negative, non-spore-forming rod that can exist as a soil saprophyte or as a legume microsymbiont of several species of legume trees. LMG 14919(T) was isolated in 1987 from a nodule recovered from the roots of the tree Prosopis chilensis growing in Kosti, Sudan. LMG 14919(T) is highly effective at fixing nitrogen with P. chilensis (Chilean mesquite) and Acacia senegal (gum Arabic tree or gum acacia). LMG 14919(T) does not nodulate the tree Leucena leucocephala, nor the herbaceous species Macroptilium atropurpureum, Trifolium pratense, Medicago sativa, Lotus corniculatus and Galega orientalis. Here we describe the features of E. arboris LMG 14919(T), together with genome sequence information and its annotation. The 6,850,303 bp high-quality-draft genome is arranged into 7 scaffolds of 12 contigs containing 6,461 protein-coding genes and 84 RNA-only encoding genes, and is one of 100 rhizobial genomes sequenced as part of the DOE Joint Genome Institute 2010 Genomic Encyclopedia for Bacteria and Archaea-Root Nodule Bacteria (GEBA-RNB) project.

  9. The effect of Anonchocephalus chilensis Riggenbach (Eucestoda: Bothriocephalidea) on infracommunity patterns in Genypterus maculatus Tschudi (Osteichthyes: Ophidiidae).

    Science.gov (United States)

    Muñoz, S A; George-Nascimento, M

    2008-09-01

    The use of parasite body size (i.e. body mass) is a promising proxy to improve the study of patterns in parasite infracommunities, which are usually analysed using only numerical descriptors. This study deals with the importance and effect of the presence of a large endoparasite species, the cestode Anonchocephalus chilensis in a marine fish species, Genypterus maculatus, on the structure of the parasite infracommunities. Numerical and volumetric measures of aggregated properties of parasite infracommunities were compared and their correlation examined. The highly dominant presence of A. chilensis by volume causes a dramatic change in the patterns observed, including a smaller total volume of the remaining species when this volumetrically dominant species is present. However, C-scores and V-ratios, both indices based on null models of species occurrence, do not support the idea of communities structured by interspecific competition. Analyses reveal that numerical and volumetric community descriptors are complementary ways to search for patterns and to reveal processes within these systems. PMID:18394212

  10. 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

  11. Evaluación y comparación de la eficiencia de dos sistemas de incubación de huevos de Genypterus chilensis (Guichenot, 1848) Evaluation and comparison of the efficiency of two incubation systems for Genypterus chilensis (Guichenot, 1848) eggs

    OpenAIRE

    Rolando Vega; Miguel Pradenas; Juan Manuel Estrada; Diego Ramírez; Iván Valdebenito; Alfonso Mardones; Patricio Dantagnan; Denis Alfaro; Francisco Encina; Cristian Pichara

    2012-01-01

    Actualmente la tendencia de la acuicultura mundial está orientada hacia la diversificación de los cultivos, principalmente de especies nativas. El congrio colorado Genypterus chilensis es un pez nativo de alta demanda gastronómica y explotación estacional que lo proyecta como candidato para el desarrollo de su tecnología de cultivo. El objetivo de este trabajo fue evaluar la eficiencia de dos sistemas de incubación de masas de huevos de G. chilensis, uno con circuito cerrado de agua (SICC) y ...

  12. Crecimiento de juveniles de congrio colorado Genypterus chilensis en condiciones de cultivo

    Directory of Open Access Journals (Sweden)

    Rolando Vega

    2015-05-01

    Full Text Available El congrio colorado Genypterus chilensis (Guichenot, 1848 es un pez altamente demandado por el mercado chileno. Las capturas han disminuido y mantenido bajo 1.000 ton anuales en la década 2000-2010 con un precio de US$7 kg-1. El objetivo de este trabajo fue evaluar el crecimiento de juveniles de primera generación producida de padres silvestres en condiciones de cultivo. Se estimó el crecimiento de 128 juveniles durante cinco meses en el hatchery del CIMARQ, Valparaíso, Chile, distribuidos en cinco grupos de talla en estanques con agua marina (35 g L-1 y rango de temperatura de 12-14°C. Los pesos promedios iniciales variaron desde el grupo menor de 4 g (11 cm al mayor de 23 g (18 cm. Estos fueron alimentados con pellet comercial para peces marinos. Se midió mensualmente la longitud total (cm, peso (g y se estimó sus promedios, porcentaje de crecimiento en peso, tasa de crecimiento específico, coeficiente de crecimiento termal y factor de conversión. A los cinco meses el grupo menor alcanzó un peso promedio de 16 ± 7 g (16 ± 2 cm y el mayor 75 ± 17 g (27 ± 6 cm. Los pesos promedios mensuales se ajustaron con R² = 0,9 a las ecuaciones P = 3,845e0,300t y P = 20,63e0,240t. Los factores de conversión fluctuaron entre 8,6 y 0,3 al mes 5 para el grupo menor y de 0,6 a 0,2 para el mayor. Si se proyecta el crecimiento desde el peso inicial de 4 y 23 g hasta el peso de cosecha de 2 kg, éste se obtendría entre 26 y 18 meses para los grupos menor y mayor respectivamente.

  13. Exotic molluscs (Mollusca, Gastropoda et Bivalvia in Santa Catarina State, Southern Brazil region: check list and regional spatial distribution

    Directory of Open Access Journals (Sweden)

    A. Ignacio Agudo-Padrón

    2011-06-01

    Full Text Available A total of twenty-one exotic mollusc taxa were assessed for Santa Catarina State (SC, fifteen Gastropoda andsix Bivalvia (twelve terrestrial, five limnic/freshwater - three gastropods and two bivalves, and four marinebivalves. Of these, fourteen are confirmed as invasive species (nine terrestrial, three limnic/freshwater, andtwo marine.

  14. 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.

  15. Pharmacological reports about gastroprotective effects of methanolic extract from leaves of Solidago chilensis (Brazilian arnica) and its components quercitrin and afzelin in rodents.

    Science.gov (United States)

    de Barros, Mariel; Mota da Silva, Luisa; Boeing, Thaise; Somensi, Lincon Bordignon; Cury, Benhur Judah; de Moura Burci, Ligia; Santin, José Roberto; de Andrade, Sérgio Faloni; Monache, Franco Delle; Cechinel-Filho, Valdir

    2016-04-01

    Solidago chilensis Meyenmost (Asteraceae), popularly known as "Brazilian arnica" or "arnica-do-campo," is widely used in the folk medicine to treat gastric disorders. Based on this, the gastroprotective activity of S. chilensis methanolic extract was investigated. Besides, a phytochemical study allowed isolation of two flavonoids (quercitrin and afzelin). The gastroprotective effects were investigated in acute gastric ulcer models, and the antisecretory activity was assessed in vivo and in vitro. The adhered mucus levels, reduced glutathione (GSH) content and myeloperoxidase (MPO) activity were quantified in ulcerated tissues. The contribution of isolated compounds in extract effects was evaluated, and its doses were calculated according to its yield. To evaluate the in vivo healing properties of S. chilensis methanolic extract, a chronic gastric ulcer was induced in mice by 10 % acetic acid. Evaluation of tumor necrosis factor (TNF) levels was also performed at the site of the acetic acid-induced gastric ulcer. In parallel, effects on cell viability and cell proliferation of fibroblasts (L929 cells) were determined by in vitro trials. Firstly, the S. chilensis methanolic extract (100 or 300 mg/kg) reduced the ulcer area induced by ethanol/HCl in mice when compared to the vehicle group. Moreover, the S. chilensis extract (300 mg/kg) prevented the mucus depletion, the increase in MPO activity and the decrease in the GSH levels in the ulcerated gastric tissue. The S. chilensis extract also was able to decrease the indomethacin-induced gastric ulcer in rats at a dose of 100 mg/kg. The antisecretory effect of the extract (100 mg/kg, intraduodenal (i.d.)) was confirmed by the reduction in the volume and acidity in parallel to an increase in the pH of gastric content. In addition, quercitrin (1.38 mg/kg, but not 0.46 mg/kg) and afzelin (0.026 and 0.078 mg/kg) decreased the ethanol/HCl-induced gastric ulcer. In this model, quercitrin (1.38 mg/kg) prevented the depletion

  16. INFECCIÓN DE HYPOLOBOCERA CHILENSIS EIGENMANI POR METACERCARIAS DE PARAGONIMUS MEXICANUS (= PERUVIANUS EN EL DISTRITO DE CONDEBAMBA (CAJAMARCA, PERÚ

    Directory of Open Access Journals (Sweden)

    Alina Huiza F.

    2014-06-01

    Full Text Available Cangrejos de rio Hypolobocera chilensis eigenmanni fueron colectados de acequias durante el año 1997 en estación seca (mayo a diciembre en Chaquicocha, Área que pertenece al distrito de Condebamba (departamento de Cajamarca en la parte norte del Perú. Ciento treinta y un cangrejos colectados fueron transportados al Laboratorio de Parasitología y examinados por disección, 27 de 131 (20,6% estaban infectados por metacercarias de Paragonimus mexicanus(=peruvianus. La intensidad de la infección fue de 1 a 5 en la mayoría de los; casos (81,5% con un promedio de 4,85 por cangrejo. Estos datos son diferentes; a los de estudios anteriores; en la misma Área donde fueron más; altos, lo que indica una tendencia al decrecimiento del número de cangrejos infectados.

  17. Tracing the trans-pacific evolutionary history of a domesticated Seaweed (Gracilaria chilensis with archaeological and genetic data.

    Directory of Open Access Journals (Sweden)

    Marie-Laure Guillemin

    Full Text Available The history of a domesticated marine macroalga is studied using archaeological, phylogeographic and population genetic tools. Phylogeographic and population genetic analyses demonstrated that the cultivated red alga Gracilaria chilensis colonised the Chilean coast from New Zealand. Combining archaeological observations with phylogeographic data provided evidence that exchanges between New Zealand and Chile have occurred at least before the Holocene, likely at the end of the Last Glacial Maximum (LGM and we suggest that migration probably occurred via rafting. Furthermore, the remarkably low microsatellite diversity found in the Chilean populations compared to those in New Zealand is consistent with a recent genetic bottleneck as a result of over-exploitation of natural populations and/or the process of domestication. Therefore, the aquaculture of this seaweed, based essentially on clonal propagation, is occurring from genetically depressed populations and may be driving the species to an extinction vortex in Chile.

  18. Tracing the trans-pacific evolutionary history of a domesticated Seaweed (Gracilaria chilensis) with archaeological and genetic data.

    Science.gov (United States)

    Guillemin, Marie-Laure; Valero, Myriam; Faugeron, Sylvain; Nelson, Wendy; Destombe, Christophe

    2014-01-01

    The history of a domesticated marine macroalga is studied using archaeological, phylogeographic and population genetic tools. Phylogeographic and population genetic analyses demonstrated that the cultivated red alga Gracilaria chilensis colonised the Chilean coast from New Zealand. Combining archaeological observations with phylogeographic data provided evidence that exchanges between New Zealand and Chile have occurred at least before the Holocene, likely at the end of the Last Glacial Maximum (LGM) and we suggest that migration probably occurred via rafting. Furthermore, the remarkably low microsatellite diversity found in the Chilean populations compared to those in New Zealand is consistent with a recent genetic bottleneck as a result of over-exploitation of natural populations and/or the process of domestication. Therefore, the aquaculture of this seaweed, based essentially on clonal propagation, is occurring from genetically depressed populations and may be driving the species to an extinction vortex in Chile.

  19. Nutrient uptake efficiency of Gracilaria chilensis and Ulva lactuca in an IMTA system with the red abalone Haliotis rufescens

    Directory of Open Access Journals (Sweden)

    Juan Macchiavello

    2014-07-01

    Full Text Available The current study examined the nutrient uptake efficiency of Ulva lactuca and Gracilaria chilensis cultivated in tanks associated with the wastewater of a land-based abalone culture. The experiments evaluated different seaweed stocking densities (1200, 1900, 2600, and 3200 g m-2 and water exchange rates (60, 80, 125, and 250 L h-1. The results show that both U. lactuca and G. chilensis were efficient in capturing and removing all of the inorganic nutrients originating from the abalone cultivation for all of the tested conditions. Furthermore, an annual experiment was performed with U. lactuca, cultivated at a stocking density of 1900 g m-2 and at a water exchanged rate of 125 L h-1, in order to evaluate seasonal changes in the nutrient uptake efficiency, productivity, and growth rate associated with the wastewater of a land-based abalone culture. The results confirmed high uptake efficiency during the entire year, equivalent to a 100% removal of the NH4, NO3, and PO4 produced by the land-based abalone culture. The growth rate and productivity of U. lactuca presented a marked seasonality, increasing from fall until summer and varying from 0.5 ± 0.2% to 2.6 ± 0.2% d-1 and 10 ± 6.1% to 73.6 ± 8.4% g m-2 d-1 for sustainable growth rate and productivity, respectively. We conclude that there is sufficient evidence that demonstrates the high possibility of changing the traditional monoculture system of abalone in Chile, to a sustainable integrated multi-trophic aquaculture system, generating positive environmental externalities, including the use of U. lactuca as a biofiltration unit.

  20. Cadmium bioaccumulation and retention kinetics in the Chilean blue mussel Mytilus chilensis: Seawater and food exposure pathways

    Energy Technology Data Exchange (ETDEWEB)

    Herve-Fernandez, Pedro [Instituto de Geociencias, Universidad Austral de Chile, Castilla 567, Valdivia (Chile); Houlbreque, Fanny, E-mail: F.Houlbreque@iaea.org [International Atomic Energy Agency - Marine Environment Laboratories, 4 Quai Antoine 1er, 98000 Monaco (Monaco); Boisson, Florence [International Atomic Energy Agency - Marine Environment Laboratories, 4 Quai Antoine 1er, 98000 Monaco (Monaco); Mulsow, Sandor [Instituto de Geociencias, Universidad Austral de Chile, Castilla 567, Valdivia (Chile); Teyssie, Jean-Louis; Oberhaensli, Francois; Azemard, Sabine; Jeffree, Ross [International Atomic Energy Agency - Marine Environment Laboratories, 4 Quai Antoine 1er, 98000 Monaco (Monaco)

    2010-09-15

    The Chilean blue mussel (Mytilus chilensis, Hupe 1854) represents the most important bivalve exploited along the Chilean coast and is a major food source for the Chilean population. Unfortunately, local fish and shellfish farming face severe problems as a result of bioaccumulation of toxic trace metals into shellfishes. Blue mussels collected along the Chilean coasts contain levels of Cd above the regulatory limits for human consumption. In this study, we examined the bioaccumulation, depuration and organ distribution of Cd in the M. chilensis, from {sup 109}Cd-labelled bulk seawater and from feeding with {sup 109}Cd-labelled algae. The uptake of {sup 109}Cd via seawater displayed a simple exponential kinetic model suggesting that cadmium activity tends to reach an equilibrium value of 1.838 {+-} 0.175 ng g{sup -1} (mean {+-} asymptotic standard error, p < 0.001) after 78 {+-} 9 days. The depuration rate for {sup 109}Cd accumulated via seawater was slow, with only 21% of the total {sup 109}Cd accumulated in the whole mussel being eliminated after 52 days. Total elimination of Cd in mussels was adequately described by a double component kinetic model, in which the biological half-life for the long-lived component represents more than 6 months. In contrast, depuration after radiolabelled food uptake was fast, reaching only 20% of retention in 10 days. This knowledge of the long half-life of cadmium accumulated via seawater as well as the non-negligible level of cadmium accumulated into the shells is relevant to the management of Cd levels in this species and the refinement of detoxification processes in order to comply with authorized Cd levels.

  1. Synthesis of silver nanoparticles by coastal plant Prosopis chilensis (L.) and their efficacy in controlling vibriosis in shrimp Penaeus monodon

    Science.gov (United States)

    Kandasamy, Kathiresan; Alikunhi, Nabeel M.; Manickaswami, Gayathridevi; Nabikhan, Asmathunisha; Ayyavu, Gopalakrishnan

    2013-02-01

    The present work investigated the effect of leaf extract from coastal plant Prosopis chilensis on synthesis of silver nanoparticles using AgNO3 as a substrate and to find their antibacterial potential on pathogenic Vibrio species in the shrimp, Penaeus monodon. The leaf extract could be able to produce silver nanoparticles, as evident by gradual change in colour of the reaction mixture consisted of the extract and 1 mM AgNO3 to dark brown. The silver nanoparticles exhibited 2 θ values corresponding to the presence of silver nanocrystal, as evident by X-ray diffraction spectrum. The peaks corresponding to flavanones and terpenoids were found to be stabilizing agents of the nanoparticles, as revealed by Fourier transform infrared spectroscopy. The size of silver nanoparticles ranged from 5 to 25 nm with an average of 11.3 ± 2.1 nm and was mostly of spherical in shape, as confirmed by transmission electron microscopy. The silver nanoparticles were found to inhibit Vibrio pathogens viz., Vibrio cholerae, V. harveyi, and V. parahaemolyticus and this antibacterial effect was better than that of leaf extract, as proved by disc diffusion assay. The nanoparticles were then tested in the shrimp Penaeus monodon challenged with the four species of Vibrio pathogens for 30 days. The shrimps fed with silver nanoparticles exhibited higher survival, associated with immunomodulation in terms of higher haemocyte counts, phenoloxidase and antibacterial activities of haemolymph of P. monodon which is on par with that of control. Thus, the present study proved the possibility of using silver nanoparticles produced by coastal Prosopis chilensis as antibacterial agent in controlling vibriosis.

  2. Cadmium bioaccumulation and retention kinetics in the Chilean blue mussel Mytilus chilensis: Seawater and food exposure pathways

    International Nuclear Information System (INIS)

    The Chilean blue mussel (Mytilus chilensis, Hupe 1854) represents the most important bivalve exploited along the Chilean coast and is a major food source for the Chilean population. Unfortunately, local fish and shellfish farming face severe problems as a result of bioaccumulation of toxic trace metals into shellfishes. Blue mussels collected along the Chilean coasts contain levels of Cd above the regulatory limits for human consumption. In this study, we examined the bioaccumulation, depuration and organ distribution of Cd in the M. chilensis, from 109Cd-labelled bulk seawater and from feeding with 109Cd-labelled algae. The uptake of 109Cd via seawater displayed a simple exponential kinetic model suggesting that cadmium activity tends to reach an equilibrium value of 1.838 ± 0.175 ng g-1 (mean ± asymptotic standard error, p 109Cd accumulated via seawater was slow, with only 21% of the total 109Cd accumulated in the whole mussel being eliminated after 52 days. Total elimination of Cd in mussels was adequately described by a double component kinetic model, in which the biological half-life for the long-lived component represents more than 6 months. In contrast, depuration after radiolabelled food uptake was fast, reaching only 20% of retention in 10 days. This knowledge of the long half-life of cadmium accumulated via seawater as well as the non-negligible level of cadmium accumulated into the shells is relevant to the management of Cd levels in this species and the refinement of detoxification processes in order to comply with authorized Cd levels.

  3. Contenido energetico de algunos invertebrados bentonicos de la costa de Chile y fluctuación anual em Mytilus chilensis Hupe 1854

    Directory of Open Access Journals (Sweden)

    William E Duarte

    1980-12-01

    Full Text Available Caloric values, ash and hydric percentages were obtained from the most abundant benthic invertebrates of Corral Bay, from which this information was not previously available. The range of these values is not different to those of related taxonomic groups of other oceans. Annual fluctuations of these paramenters were studied in Mytilus chilensis so as to obtain a quantitative estimation of the variation of these values.

  4. Recruitment Dynamics of the Relict Palm, Jubaea chilensis: Intricate and Pervasive Effects of Invasive Herbivores and Nurse Shrubs in Central Chile

    OpenAIRE

    Marina Fleury; Wara Marcelo; Vásquez, Rodrigo A.; Luis Alberto González; Bustamante, Ramiro O.

    2015-01-01

    Shrubs can have a net positive effect on the recruitment of other species, especially relict species in dry-stressful conditions. We tested the effects of nurse shrubs and herbivory defoliation on performance (survival and growth) of nursery-grown seedlings of the largest living palm, the relict wine palm Jubaea chilensis. During an 18-month period, a total of more than 300 seedlings were exposed to of four possible scenarios produced by independently weakening the effects of nurse shrubs and...

  5. On the Evolutionary History of Uleiella chilensis, a Smut Fungus Parasite of Araucaria araucana in South America: Uleiellales ord. nov. in Ustilaginomycetes.

    Science.gov (United States)

    Riess, Kai; Schön, Max E; Lutz, Matthias; Butin, Heinz; Oberwinkler, Franz; Garnica, Sigisfredo

    2016-01-01

    The evolutionary history, divergence times and phylogenetic relationships of Uleiella chilensis (Ustilaginomycotina, smut fungi) associated with Araucaria araucana were analysed. DNA sequences from multiple gene regions and morphology were analysed and compared to other members of the Basidiomycota to determine the phylogenetic placement of smut fungi on gymnosperms. Divergence time estimates indicate that the majority of smut fungal orders diversified during the Triassic-Jurassic period. However, the origin and relationships of several orders remain uncertain. The most recent common ancestor between Uleiella chilensis and Violaceomyces palustris has been dated to the Lower Cretaceous. Comparisons of divergence time estimates between smut fungi and host plants lead to the hypothesis that the early Ustilaginomycotina had a saprobic lifestyle. As there are only two extant species of Araucaria in South America, each hosting a unique Uleiella species, we suggest that either coevolution or a host shift followed by allopatric speciation are the most likely explanations for the current geographic restriction of Uleiella and its low diversity. Phylogenetic and age estimation analyses, ecology, the unusual life-cycle and the peculiar combination of septal and haustorial characteristics support Uleiella chilensis as a distinct lineage among the Ustilaginomycotina. Here, we describe a new ustilaginomycetous order, the Uleiellales to accommodate Uleiella. Within the Ustilaginomycetes, Uleiellales are sister taxon to the Violaceomycetales. PMID:26790149

  6. On the Evolutionary History of Uleiella chilensis, a Smut Fungus Parasite of Araucaria araucana in South America: Uleiellales ord. nov. in Ustilaginomycetes.

    Directory of Open Access Journals (Sweden)

    Kai Riess

    Full Text Available The evolutionary history, divergence times and phylogenetic relationships of Uleiella chilensis (Ustilaginomycotina, smut fungi associated with Araucaria araucana were analysed. DNA sequences from multiple gene regions and morphology were analysed and compared to other members of the Basidiomycota to determine the phylogenetic placement of smut fungi on gymnosperms. Divergence time estimates indicate that the majority of smut fungal orders diversified during the Triassic-Jurassic period. However, the origin and relationships of several orders remain uncertain. The most recent common ancestor between Uleiella chilensis and Violaceomyces palustris has been dated to the Lower Cretaceous. Comparisons of divergence time estimates between smut fungi and host plants lead to the hypothesis that the early Ustilaginomycotina had a saprobic lifestyle. As there are only two extant species of Araucaria in South America, each hosting a unique Uleiella species, we suggest that either coevolution or a host shift followed by allopatric speciation are the most likely explanations for the current geographic restriction of Uleiella and its low diversity. Phylogenetic and age estimation analyses, ecology, the unusual life-cycle and the peculiar combination of septal and haustorial characteristics support Uleiella chilensis as a distinct lineage among the Ustilaginomycotina. Here, we describe a new ustilaginomycetous order, the Uleiellales to accommodate Uleiella. Within the Ustilaginomycetes, Uleiellales are sister taxon to the Violaceomycetales.

  7. Desarrollo del ensilado del alga Gracilaria chilensis para la alimentación del abalón rojo Haliotis rufescens

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    Alfonso Mardones

    2015-05-01

    Full Text Available En Chile, el principal insumo usado como alimento para abalones son las algas Gracilaria chilensis y Macrocystis pyrifera. Estas algas experimentan una notable baja de disponibilidad en otoño e invierno, lo cual trae consigo un aumento considerable de los precios, al tener que depender del abastecimiento desde áreas cada vez más alejadas de los centros de cultivo de abalones y, eventualmente, generando impactos ecológicos indirectos en sus poblaciones. El objetivo fue elaborar y evaluar un ensilado del alga G. chilensis para la alimentación de abalón rojo (Haliotis rufescens, determinando la cantidad de lixiviados generados durante el proceso, el cambio en la composición proximal del alga, la preferencia y consumo del abalón rojo de ensilado de G. chilensis. Se logró un producto ensilado de buenas características físicas, químicas y de conservación, así como una buena aceptación por parte del abalón.

  8. Non-selective in situ grazing of diatoms by juvenile Green Abalone (Haliotis fulgens Philippi, 1945 in the Baja California Peninsula Consumo in situ no selectivo de diatomeas por juveniles de abulón azul (Haliotis fulgens Philippi, 1945 en la Península de Baja California

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    Uri Argumedo Hernández

    2010-04-01

    Full Text Available For experimental or rearing purposes, young abalones are fed benthic diatoms successfully during their early life stages without considering if the diatoms provided are found in the abalone habitat, nor if grazing selectivity exists. Our aim in this study was to gather further evidence that would indicate whether young Haliotis fulgens graze diatoms in situ selectively. Thirty-four specimens of young H. fulgens were collected in a fishing site in BCS, México on two dates. We identified the diatoms in their gut contents (144 species and determined their relative abundances. Fourteen diatoms (80% of the total abundance were considered most important and twelve were among the most important in the diet of young abalone in BCS. The diversity values (H' of the diatoms in their guts ranged from 1.05 to 4.47, depending on dominance, which reflected the structure of diatom assemblages in situ. The above observations and the low similarity measured between samples show that species richness and equitability are similar even if the species composition of diatoms ingested by young abalone differs between specimens. The results lead us to conclude that grazing of diatoms by young H. fulgens is non-selective, and that the structure of diatom assemblages is more important than the particular taxa in their diet.Durante sus etapas tempranas de vida los abulones jóvenes son alimentados exitosamente con diatomeas bentónicas sin considerar si las especies suministradas se hallan en su medio natural, o si existe algún tipo de preferencia o selectividad por ciertas diatomeas. El objetivo de este estudio fue recabar evidencias acerca de si los juveniles de Haliotis fulgens Philippi presentan un consumo selectivo de diatomeas cuando se alimentan in situ. Se recolectaron treinta y cuatro juveniles de H. fulgens en un sitio de pesca de BCS, México en dos fechas. Se disecaron y se examinaron contenidos intestinales. Se identificaron 144 taxa de diatomeas y se

  9. Evaluación del potencial reproductivo del chorito (Mytilus chilensis de dos poblaciones naturales sometidas a diferentes temperaturas de acondicionamiento Assessment of the reproductive potential of the mussel (Mytilus chilensis from two natural populations subjected to different conditioning temperatures

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    Luis Lagos

    2012-07-01

    Full Text Available Mytilus chilensis tiene ciclos reproductivos que varían latitudinalmente. Presenta reducida diferenciación genética y morfológica debido a un gran potencial de dispersión. Se acondicionaron reproductores de bahía Yaldad (Chiloé y bahía Zenteno (Punta Arenas a 9 ± 0,5°C y 15 ± 0,5°C, alimentados con dieta (1:1 de Isochrysis galbana y Chaetoceros neogracile. Se espera dilucidar si el acondicionamiento a diferentes temperaturas produce variaciones en el potencial reproductivo de las poblaciones. El menor desarrollo gonadal se produjo en los reproductores acondicionados a 9°C, mientras que el mayor se produjo en los reproductores acondicionados a 15°C provenientes de Chiloé. La fecundidad de los reproductores de Yaldad fue mayor que los de Zenteno. El diámetro de los ovocitos fue mayor en los reproductores de Zenteno y en ambas poblaciones fue mayor a 9°C. Ni el porcentaje de huevos fecundados ni el porcentaje de eclosión de larvas D mostraron diferencias significativas entre las poblaciones a ninguna de las temperaturas de acondicionamiento. De acuerdo con estos resultados, no se logra establecer diferencias en el potencial reproductivo en las poblaciones y bajo las condiciones de este estudio.The reproductive cycles of Mytilus chilensis vary latitudinally. This species has reduced genetic and morphological differentiation due to its high potential for dispersal. Broodstocks from Yaldad Bay (Chiloé and Zenteno Bay (Punta Arenas were conditioned at 9 ± 0.5°C and 15 ± 0.5°C, and were fed a diet (1:1 of Isochrysis galbana and Chaetoceros neogracile. We expected to determine whether conditioning at different temperatures produces changes in the reproductive potential of the populations. Gonadal development was lowest in the broodstocks conditioned at 9°C, and highest in those conditioned at 15°C, from Chiloé. Fertility was greater in broodstocks from Yaldad than in those from Zenteno. Oocyte diameter was greater in broodstocks

  10. Size structure and sexual maturity of the golden crab (Chaceon chilensis exploited off Robinson Crusoe Island, Chile Estructuras de tallas y madurez en el cangrejo dorado (Chaceon chilensis explotado alrededor de la isla Robinson Crusoe, Chile

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    Aurora Guerrero

    2009-01-01

    Full Text Available Golden crab (Chaceon chilensis specimens were analyzed after being caught with traps by artisanal fishermen off Robinson Crusoe Island, Juan Fernández Archipelago, Chile. Of the 13,027 individuals caught between 300 and 1,000 m depth, 97.9% were male (12,754 and the rest female (273. The carapace length (CL of the sampled crabs was measured and, on average, the males (CL: 118.9 mm were larger than the females (CL: 94.3 mm. On the north side of the island, the specimens presented lower average sizes (112.2 mm whereas, in the remaining zones, the average carapace lengths were similar (CL: 117.1-119.5 mm. In bathymetric terms, an increasing trend was seen between average size and depth, with sizes over 123 mm CL found beginning at 750 m depth. A comparison of linear regressions between the carapace length and chela length of males revealed physical maturity at 100 mm CL, whereas a numerical analysis showed the size at first sexual maturity (SSM50% to be 109 mm CL.Se analizaron ejemplares de cangrejo dorado (Chaceon chilensis capturados mediante trampas por pescadores artesanales en torno a la isla Robinson Crusoe del archipiélago de Juan Fernández (Chile, entre 300 y 1.000 m de profundidad. Se midió la longitud cefalotorácica (LC de 13.027 individuos de los cuales 12.754 correspondieron a machos y únicamente 273 a hembras, con un claro predominio de machos (97,9%, fueron de talla promedio superior a las hembras (118,9 y 94,3 mm de LC, respectivamente. En el sector norte de la isla, se encontraron ejemplares con menor talla media (112,2 mm que en las zonas restantes, la longitud cefalotorácica media presentó valores similares (117,1 a 119,5 mm de LC. Se encontró una tendencia creciente entre la talla media y la profundidad, registrándose a partir del estrato de 750 m tallas promedio superiores a 123 mm de LC. Mediante la comparación de regresiones lineales entre la longitud cefalotorácica y la longitud de la quela, en machos se estableci

  11. Composición, riqueza de especies y abundancia de insectos defoliadores de actividad nocturna asociados a Aristotelia chilensis (maqui en el bosque maulino fragmentado Composition, species richness and abundance of nocturnal folivorous insects associated with Aristotelia chilensis (maqui in the fragmented Maulino forest

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    XAVIERA DE LA VEGA

    2008-06-01

    Full Text Available En el bosque maulino, la herbivoría sobre Aristotelia chilensis (maqui es negativamente afectada por la fragmentación del bosque, siendo mayor en el bosque continuo que en los fragmentos, particularmente a inicios de la temporada de crecimiento. Este fenómeno puede deberse a cambios en la dinámica de las poblaciones de defoliadores, esencialmente insectos. En este trabajo se evaluó la abundancia, riqueza de especies y composición de insectos defoliadores de actividad nocturna presentes en A. chilensis en un bosque continuo (600 ha y en ocho fragmentos remanentes (0,4-20 ha. Los muéstreos se realizaron mensualmente, entre agosto de 2005 y febrero de 2006, en 32 ejemplares adultos de A. chilensis en el bosque continuo y en 32 ejemplares en los fragmentos. Los insectos fueron muestreados durante las cinco primeras horas de la noche. Se recolectaron 890 insectos defoliadores, pertenecientes a 17 familias y 77 especies pertenecientes a los órdenes Coleóptera, Orthoptera y Lepidoptera, siendo todas nativas. La abundancia total no varió según el habitat. Sin embargo, la fragmentación incrementó o disminuyó la abundancia de algunas especies. La riqueza de especies por árbol tampoco fue afectada por la fragmentación del bosque, aunque el número total de especies fue considerablemente mayor en los fragmentos que en el bosque continuo. La similitud de especies fue mayor dentro del bosque continuo que entre el bosque continuo y los fragmentos o que entre los fragmentos. A principios de la temporada de crecimiento de A. chilensis (septiembre, la abundancia de Sericoides obesa fue significativamente mayor en el bosque continuo que en los fragmentos. Al avanzar en la temporada, Sericoides viridis se hizo más abundante en los fragmentos. Por el tamaño y la voracidad de los insectos del género Sericoides ellos serían los principales responsables de los patrones de defoliación de A. chilensis en el bosque maulino.At the Maulino forest

  12. [On the controversial questions of the taxonomy of Bivalvia (Mollusca): too many species or too few characters?].

    Science.gov (United States)

    Rizhinashvili, A L

    2011-01-01

    Problems emerging in the course of taxonomic studies and species diagnostics of freshwater bivalves are discussed by the example of one of the bivalve groups (the family Unionidae). It is shown that one of the causes of the current, diametrically opposing views on specific and generic systematics of Bivalvia is the fact that researchers revising taxonomic groups ignore complex analysis of several independent characters (conchological, anatomical, biochemical, genetic, etc.).

  13. [Are the contours of the frontal section of shell valves in Bivalvia specific?].

    Science.gov (United States)

    Voroshilova, I S

    2013-01-01

    The diagnostic importance of the character of curvature of the frontal section of shell valves in Bivalvia on the basis of determining the constant angle of the logarithmic spiral is discussed. The contours of the frontal section of shell valves in several species of mollusks of the families Margaritiferidae and Sphaeriidae have been analyzed. It is shown that in different species of the family Sphaeriidae, the values of constant angles coincide. While performing graphic constructions, it was established that the contours of the frontal section of all studied species of pearl mussels and some spheriids do not correspond to the segment of the logarithmic spiral. It was noted that the hypothesis of the species specificity of this character was not confirmed; therefore, the curvature of the frontal section of shell valves cannot be used as the main character for the systematics and species identification of bivalves.

  14. Distribution patterns of the Jurassic ostreids (Bivalvia) from Tanggula of China

    Institute of Scientific and Technical Information of China (English)

    沙金庚

    2001-01-01

    Distribution of the Jurassic ostreids (Bivalvia) from Tanggula area of China includes three patterns, which are (1) Tethys: containing Liostrea birmanica and Eligmus rollandi, (2) western Europe and northern Tethys: consisting of Gryphaea (Bilobissa) bilobata; and (3) Global: composed of Actinostreon gregareum and Nanogyra nana. However, they are all limited between palaeolatidudes 60° South and North. Actinostreon gregareum originated in the Sinemurian of northern Chile and it entered Kenya and Madagascar in the Toarcian, but there is no reliable Si-nemurian-Toarcian A. gregareum fossil record in continental margins between Chile and Kenya and Madagascar. Such distribution patterns and dispersal processes have demonstrated that (1) during the Jurassic all seas and oceans were connected to each other; (2) the Tethys and the western European epicontinental seas did produce some endemic taxa; (3) the distribution of these ostreids was most likely controlled by latitudes and creature ecology; and (4) A, gr

  15. Domestication and sustainable production of wild crafted plants with special reference to the Chilean Maqui berry (Aristotelia chilensis

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    Vogel, Hermine

    2016-07-01

    Full Text Available The principle threats for sustainable production of wild collected medicinal plants are related to ecological factors, such as endemism, and botanical factors critical for survival, such as the collection of roots or barks or slow growing species. The sustainable way to produce raw material on a large scale would be species specific management of the wild resources that guarantees conservation of biodiversity, or bringing the species under cultivation. A checklist proposed by WHO, UICN and WWF (1993 indicates that domestication of any medicinal plant concerns plant selection and breeding, studies about propagation, cultivation techniques, plant protection, time of harvest, among others. The different domestication steps are illustrated for the Chilean maqui (Aristotelia chilensis, a wild tree whose fruits are demanded in increasing volumes by the international market because of its high antioxidant capacity. High yielding plants with good fruit quality have been selected from wild populations and accessions have been cultivated under different environmental conditions to select the most suitable genotypes for the establishment of commercial orchards.

  16. Histopathological survey of the mussel Mytilus chilensis (Mytilidae and the clam Gari solida (Psammobiidae from southern Chile

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    Florencia Cremonte

    2015-03-01

    Full Text Available A total of 175 specimens of mussels, Mytilus chilensis (Mytilidae, and 56 specimens of clams, Gari solida (Psammobiidae, were collected in natural beds and culture sites of southern Chile. Juvenile mussel specimens (3 cm of maximum length were free of parasites and diseases, whilst the commercial sized populations was parasitized by intracellular inclusions of bacteria-like organisms in the digestive gland epithelium and in the gills, by ciliates in the gills, turbellarians similar to Paravortex (Rhabocoela in the intestine lumen and copepods attached to the gills. In addition, the disseminated neoplasia disease was also present although in low prevalences. In the clam, G. solida, prokariotic inclusions were found in the digestive gland epithelium and bacteria-like organisms in the gills, often encapsulated by haemocytes; oocysts containing up to 8 sporozoites similar to Nematopsis (Apicomplexa in the connective tissue, causing haemocytic infiltration when the intensity of infection was high; ciliates belonging to two different species (one of them similar to Trichodina inhabiting the gills; and a turbellarian similar to Paravortex in the lumen of digestive system without apparent host reaction. The populations of the bivalve species here studied were devoid of serious pathogens.

  17. Isolation and identification of Vibrio toranzoniae associated with diseased red conger eel (Genypterus chilensis) farmed in Chile.

    Science.gov (United States)

    Lasa, Aide; Avendaño-Herrera, Ruben; Estrada, Juan M; Romalde, Jesús L

    2015-09-30

    The present study deals with the first isolation of Vibrio toranzoniae from cultured red conger eel (Genypterus chilensis). During the summer season of 2011, mortalities were observed in young red conger eel at one aquaculture experimental rearing system in Quintay, Valparaiso, Chile. The microbiological analysis of the diseased fish resulted in the isolation of three dominant and representative isolates, designated as R.17, R.18 and R.19, which were obtained from gill, fin and external lesions from three different fish, respectively. All isolates were identified as V. toranzoniae by means of a polyphasic taxonomic approach, including phenotypic characterization, sequencing of 16S rRNA and housekeeping genes, and DNA-DNA hybridization. Inoculation of a representative strain (R18) in turbot as model fish species demonstrated the pathogenic potential for fish of the Chilean isolates. Results obtained indicate that the geographical and host distribution of V. toranzoniae is wider than expected, and that this species may have negative incidence in the culture of marine organisms. PMID:26072371

  18. The Rho GTPase Family Genes in Bivalvia Genomes: Sequence, Evolution and Expression Analysis.

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    Xue Li

    Full Text Available Rho GTPases are important members of the Ras superfamily, which represents the largest signaling protein family in eukaryotes, and function as key molecular switches in converting and amplifying external signals into cellular responses. Although numerous analyses of Rho family genes have been reported, including their functions and evolution, a systematic analysis of this family has not been performed in Mollusca or in Bivalvia, one of the most important classes of Mollusca.In this study, we systematically identified and characterized a total set (Rho, Rac, Mig, Cdc42, Tc10, Rnd, RhoU, RhoBTB and Miro of thirty Rho GTPase genes in three bivalve species, including nine in the Yesso scallop Patinopecten yessoensis, nine in the Zhikong scallop Chlamys farreri, and twelve in the Pacific oyster Crassostrea gigas. Phylogenetic analysis and interspecies comparison indicated that bivalves might possess the most complete types of Rho genes in invertebrates. A multiple RNA-seq dataset was used to investigate the expression profiles of bivalve Rho genes, revealing that the examined scallops share more similar Rho expression patterns than the oyster, whereas more Rho mRNAs are expressed in C. farreri and C. gigas than in P. yessoensis. Additionally, Rho, Rac and Cdc42 were found to be duplicated in the oyster but not in the scallops. Among the expanded Rho genes of C. gigas, duplication pairs with high synonymous substitution rates (Ks displayed greater differences in expression.A comprehensive analysis of bivalve Rho GTPase family genes was performed in scallop and oyster species, and Rho genes in bivalves exhibit greater conservation than those in any other invertebrate. This is the first study focusing on a genome-wide characterization of Rho GTPase genes in bivalves, and the findings will provide a valuable resource for a better understanding of Rho evolution and Rho GTPase function in Bivalvia.

  19. 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

  20. Polyphenol content and antioxidant activity of maqui (Aristotelia chilensis Molina Stuntz) during fruit development and maturation in Central Chile Contenidos de polifenoles y actividad antioxidante de maqui (Aristotelia chilensis Molina Stuntz) durante el desarrollo y maduración de frutos en Chile Central

    OpenAIRE

    Carolina Fredes; Gloria Montenegro; Juan Pablo Zoffoli; Miguel Gómez; Paz Robert

    2012-01-01

    Maqui (Aristotelia chilensis Molina Stuntz, Elaeocarpaceae) is a Chilean native species which produces small berries that are mainly collected from the wild. The health benefits of maqui fruit are attributed to their high polyphenol content as well as their wide variety of anthocyanins and flavonols. One of the main factors that affect the polyphenol content in fruit is the maturity stage at harvest. The objective of this study was to determine total phenol and total anthocyanin content and a...

  1. RETINAL MORPHOLOGY AND ELECTRORETINOGRAPHY IN TWO VISUALLY FORAGING CHARADRIIFORMES BIRDS WITH DIFFERENT FEEDING ACTIVITY RHYTHMS: THE DOUBLE-STRIPED THICK-KNEE (BURHINUS BISTRIATUS WAGLER, 1829 AND THE SOUTHERN LAPWING (VANELLUS CHILENSIS L., 1758

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    Liliana Figueroa R

    2012-06-01

    Full Text Available Our study compares the visual function of the Double-striped Thick-knee (Burhinus bistriatus Wagler,1829, which forages primarily during dusk and at night, and the Southern Lapwing (Vanellus chilensis L., 1758, which is known to forage during daytime and occasionally at night, analyzing morphological and electrophysiological aspects of their retina. The fact that thick-knees have large eyes and are nocturnally actives suggest that, compared with the diurnal lapwing, they should have a very sensitive retina under low light intensity. Electroretinograms (ERGs were obtained from anesthetized live birds at different light intensities in photopic and scotopic conditions, and the retinae were subsequently processed for histological analysis. The scotopic ERG b-waves of B. bistriatus, at all light intensities, were always of larger amplitude than those of V. chilensis. However, the a-waves of both species were of similar amplitude. Under photopic conditions, V. chilensis yield highest a- and b-wave amplitudes than B. bistriatus. The latter has a larger dialated pupil diameter and a greater axial length/equatorial diameter ratio than V. chilensis. Likewise, the rod density of B. bistriatus significantly exceeds that of V. chilensis. In the latter, cone density tends to be higher than in B. bistriatus while the rods:cones ratio were lower. Rod outer segments of B. bistriatus strongly exceed in length those of any other Charadriiformes species studied so far, but are thinner than those of V. chilensis. In contrast, the latter has thicker cone outer segments and outer and inner plexiform layers than B. bistriatus. Similarly, ganglion cells are more abundant per unit area in V. chilensis. Our combined results reveal a higher retinal sensitivity of B. bistriatus under low light conditions, in accordance with their crepuscular and nocturnal foraging strategies. V. chilensis, although mainly active during daylight, appears to have a moderate retinal

  2. Sporothrix chilensis sp. nov. (Ascomycota: Ophiostomatales), a soil-borne agent of human sporotrichosis with mild-pathogenic potential to mammals.

    Science.gov (United States)

    Rodrigues, Anderson Messias; Cruz Choappa, Rodrigo; Fernandes, Geisa Ferreira; de Hoog, G Sybren; de Camargo, Zoilo Pires

    2016-02-01

    A combination of phylogeny, evolution, morphologies and ecologies has enabled major advances in understanding the taxonomy of Sporothrix species, including members exhibiting distinct lifestyles such as saprobes, human/animal pathogens, and insect symbionts. Phylogenetic analyses of ITS1/2 + 5.8s sequences split Sporothrix genus in two well-defined groups with dissimilar ecologies. Species embedded in the Sporothrix schenckii complex are frequently agents of human and animal sporotrichosis, and some of these are responsible for large sapronoses and zoonoses around the warmer temperate regions of the world. At the other extreme, basal saprophytic species evolved in association with decaying wood and soil, and are rarely found to cause human disease. We propose to create a new taxa, Sporothrix chilensis sp. nov., to accommodate strains collected from a clinical case of onychomycosis as well as from environmental origins in Chile. Multigene analyses based on ITS1/2 + 5.8s region, beta-tubulin, calmodulin and translation elongation factor 1α revealed that S. chilensis is a member of the Sporothrix pallida complex, and the nearest taxon is Sporothrix mexicana, a rare soil-borne species, non-pathogenic to humans. The ITS region serves as a primary barcode marker, while each one of the protein-coding loci easily recognized species boundaries providing sufficient information for species identification. A disseminated model of murine sporotrichosis revealed a mild-pathogenic potential, with lung invasion. Although S. chilensis is not a primary pathogen, accidental infection may have an impact in the immunosuppressed population. With the introduction of distinct species with similar routes of transmission but different virulence, identification of Sporothrix agents at the species level is mandatory.

  3. Pesca artesanal de cangrejo dorado (Chaceon chilensis en el archipiélago de Juan Fernández, Chile Artisanal fishing for golden crab (Chaceon chilensis off the Juan Fernández archipelago, Chile

    Directory of Open Access Journals (Sweden)

    Mauricio Ahumada

    2009-01-01

    Full Text Available Se describe la pesca artesanal de cangrejo dorado (Chaceon chilensis en las islas Robinson Crusoe y Santa Clara, en el archipiélago de Juan Fernández (Chile, desarrollada entre julio de 2005 y mayo de 2006. Se dan a conocer aspectos biológico-pesqueros relativos a esfuerzo y rendimientos de pesca, proporción sexual, así como los resultados de una evaluación directa de biomasa vulnerable mediante el método de area de influencia de las trampas. La extracción se efectuó fundamentalmente en el cuadrante NE de ambas islas, mediante botes de madera de 9,0 m de eslora. Se monitorearon 157 salidas de pesca y se capturaron 13.903 ejemplares, los cuales mayoritariamente fueron machos (97,5%. La CPUE promedio fue 16,7 ejemplares por trampa y de 13,5 ejemplares comerciales por trampa. A partir del muestreo sistemático, se detectó al recurso entre 300 y 1000 m de profundidad, con mayores rendimientos entre 400 y 500 m de profundidad (19,8 y 15,9 ejemplares por trampa. Se consideran y discuten dos escenarios de evaluación de stock para ejemplares de talla comercial en el area actualmente explotada (45,8 km , el primero estimó un radio efectivo para las trampas de 13,4 m (area de 564,1 m , con una biomasa vulnerable de 1.002 ton, equivalentes a 832.983 ejemplares, mientras que el segundo consideró un radio de 30,0 m con una biomasa vulnerable de 203 ton equivalente a 168.587 ejemplares.This work describes the artisanal golden crab (Chaceon chilensis fishery off Robinson Crusoe and Santa Clara islands in the Juan Fernández archipelago (Chile developed between July 2005 and May 2006. We report biological fishery aspects related to the físhing efforts and yields, the sexual proportion of the catch, and the results of a direct evaluation of the vulnerable biomass done using the trap area of influence method. The extraction was done mainly in the NE quadrant of both islands from wooden boats (9.0 m length. Monitoring was done during 157 f

  4. First Harvestman Record for the Juan Fernández Archipelago, Chile, with Morphological Notes on Acropsopilio chilensis (Opiliones: Caddidae: Acroposopilioninae).

    Science.gov (United States)

    Pérez-González, Abel; Ramírez, Martín J; Soto, Eduardo M; Pizarro-Araya, Jaime

    2014-08-15

    Acropsopilio chilensis Silvestri, 1904 (Eupnoi: Caddidae: Acropsopilioninae), is recorded for Robinson Crusoe Island, Chile. This is the first harvestman species recorded for the Juan Fernández Archipelago and also the first extra-continental record for this species. During the comparison with continental co-specific specimens, some previously unknown, remarkable morphological characteristics were discovered, among them: the absence of ovipositor seminal receptacles and tracheal system, small and probably imperforate spiracles and the presence of a subdistal spiny structure, maybe a stylus, in the major branch of the penis. 

  5. The role of stand composition on pre-dispersal seed predation in Austrocedrus chilensis (Cupressaceae in north west Patagonia El rol de la composición del bosque sobre la depredación predispersiva de semillas en Austrocedrus chilensis (Cupressaceae en el noroeste de la Patagonia

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    JOSÉ M VILLACIDE

    2008-09-01

    Full Text Available We studied the variability of pre-dispersal seed predation by insects on Austrocedrus chilensis (Cupressaceae. This is a dioecious conifer endemic to southern South America (central Chile and the Chilean Argentinean Patagonia that grows naturally in pure and mixed stands, typically in association with broadleaved Nothofagus species. Seeds are attacked while still inside the cones, mainly by larvae of Nanodacna austrocedrella (Lepidoptera: Elachistidae. Our working hypothesis was that observed variations in pre-dispersal seed damage levels were related to forest stand composition, specifically to the relative abundance of A. chilensis versus accompanying Nothofagus species. We compared seed predation levels in six pairs of sites using a block design which included a mixed and a pure stand for each paired site. At each site, we manually collected 50 closed seed cones from each of five neighbouring adult trees of A. chilensis. Pre-dispersal seed damage was highly variable among trees and sites, with values ranging between 16.7 to 73.0 % of seeds damaged. We found significant differences in predation rates among stands differing in canopy composition. In mixed stands, with Nothofagus, the proportion of seeds attacked was always greater than that observed in the paired pure A. chilensis stand. We showed that canopy composition influenced the level of pre-dispersal seed predation by insects, supporting the hypothesis that damage increases in mixed stands. Our study is the first to present data on variations of pre-dispersal seed predation in A. chilensis at a large spatial scale, examining the effects of forest type. This information may be useful in planning for commercial A. chilensis seed harvesting, as well as for the conservation this endemic conifer.Estudiamos la variabilidad en la depredación predispersiva de semillas por insectos en Austrocedrus chilensis (D. Don Pie. Serm. & Bizzarri (Cupressaceae. Esta especie es una conifera dioica end

  6. Identification and Characterization of Microsatellite Loci in Maqui (Aristotelia chilensis [Molina] Stunz) Using Next-Generation Sequencing (NGS).

    Science.gov (United States)

    Bastías, Adriana; Correa, Francisco; Rojas, Pamela; Almada, Rubén; Muñoz, Carlos; Sagredo, Boris

    2016-01-01

    Maqui (Aristotelia chilensis [Molina] Stunz) is a small dioecious tree native to South America with edible fruit characterized by very high antioxidant capacity and anthocyanin content. To preserve maqui as a genetic resource it is essential to study its genetic diversity. However, the complete genome is unknown and only a few gene sequences are available in databases. Simple sequence repeats (SSR) markers, which are neutral, co-dominant, reproducible and highly variable, are desirable to support genetic studies in maqui populations. By means of identification and characterization of microsatellite loci from a maqui genotype, using 454 sequencing technology, we develop a set of SSR for this species. Obtaining a total of 165,043 shotgun genome sequences, with an average read length of 387 bases, we covered 64 Mb of the maqui genome. Reads were assembled into 4,832 contigs, while 98,546 reads remained as singletons, generating a total of 103,378 consensus genomic sequences. A total of 24,494 SSR maqui markers were identified. Of them, 15,950 SSR maqui markers were classified as perfects. The most common SSR motifs were dinucleotide (31%), followed by tetranucleotide (26%) and trinucleotide motifs (24%). The motif AG/CT (28.4%) was the most abundant, while the motif AC (89 bp) was the largest. Eleven polymorphic SSRs were selected and used to analyze a population of 40 maqui genotypes. Polymorphism information content (PIC) ranged from 0.117 to 0.82, with an average of 0.58. Non-significant groups were observed in the maqui population, showing a panmictic genetic structure. In addition, we also predicted 11150 putative genes and 3 microRNAs (miRNAs) in maqui sequences. This results, including partial sequences of genes, some miRNAs and SSR markers from high throughput next generation sequencing (NGS) of maqui genomic DNA, constitute the first platform to undertake genetic and molecular studies of this important species. PMID:27459734

  7. Identification and Characterization of Microsatellite Loci in Maqui (Aristotelia chilensis [Molina] Stunz) Using Next-Generation Sequencing (NGS)

    Science.gov (United States)

    Bastías, Adriana; Correa, Francisco; Rojas, Pamela; Almada, Rubén; Muñoz, Carlos; Sagredo, Boris

    2016-01-01

    Maqui (Aristotelia chilensis [Molina] Stunz) is a small dioecious tree native to South America with edible fruit characterized by very high antioxidant capacity and anthocyanin content. To preserve maqui as a genetic resource it is essential to study its genetic diversity. However, the complete genome is unknown and only a few gene sequences are available in databases. Simple sequence repeats (SSR) markers, which are neutral, co-dominant, reproducible and highly variable, are desirable to support genetic studies in maqui populations. By means of identification and characterization of microsatellite loci from a maqui genotype, using 454 sequencing technology, we develop a set of SSR for this species. Obtaining a total of 165,043 shotgun genome sequences, with an average read length of 387 bases, we covered 64 Mb of the maqui genome. Reads were assembled into 4,832 contigs, while 98,546 reads remained as singletons, generating a total of 103,378 consensus genomic sequences. A total of 24,494 SSR maqui markers were identified. Of them, 15,950 SSR maqui markers were classified as perfects. The most common SSR motifs were dinucleotide (31%), followed by tetranucleotide (26%) and trinucleotide motifs (24%). The motif AG/CT (28.4%) was the most abundant, while the motif AC (89 bp) was the largest. Eleven polymorphic SSRs were selected and used to analyze a population of 40 maqui genotypes. Polymorphism information content (PIC) ranged from 0.117 to 0.82, with an average of 0.58. Non-significant groups were observed in the maqui population, showing a panmictic genetic structure. In addition, we also predicted 11150 putative genes and 3 microRNAs (miRNAs) in maqui sequences. This results, including partial sequences of genes, some miRNAs and SSR markers from high throughput next generation sequencing (NGS) of maqui genomic DNA, constitute the first platform to undertake genetic and molecular studies of this important species. PMID:27459734

  8. 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

    Directory of Open Access Journals (Sweden)

    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

  9. The identity of Isocrassina, Laevastarte and Ashtarotha (Mollusca, Bivalvia, Astartidae) and their representatives from beaches and estuaries in The Netherlands and Pliocene strata in Belgium

    NARCIS (Netherlands)

    Pouwer, R.

    2009-01-01

    The identity of the subgenera Isocrassina Chavan, 1950, Laevastarte Hinsch, 1952, and Ashtarotha Dall, 1903, of the genus Astarte Sowerby, 1816 in the family Astartidae (Mollusca, Bivalvia) is discussed. Isocrassina has been widely used for Pliocene species in the North Sea Basin. Here it is demonst

  10. Health status and bioremediation capacity of wild freshwater mussels (Diplodon chilensis) exposed to sewage water pollution in a glacial Patagonian lake.

    Science.gov (United States)

    Bianchi, Virginia A; Castro, Juan M; Rocchetta, Iara; Bieczynski, Flavia; Luquet, Carlos M

    2014-04-01

    Deleterious effects on health and fitness are expected in mussels chronically exposed to sewage water pollution. Diplodon chilensis inhabiting SMA, an area affected by untreated and treated sewage water, shows increased hemocyte number and phagocytic activity, while bacteriolytic and phenoloxidase activities in plasma and reactive oxygen species production in hemocytes are lower compared to mussels from an unpolluted area (Yuco). There are not differences in cell viability, lysosomal membrane stability, lipid peroxidation and total oxygen scavenging capacity between SMA and Yuco mussels' hemocytes. Energetic reserves and digestive gland mass do not show differences between groups; although the condition factor is higher in SMA than in Yuco mussels. Gills of SMA mussels show an increase in mass and micronuclei frequency compared to those of Yuco. Mussels from both sites reduce bacterial loads in polluted water and sediments, improving their quality with similar feeding performance. These findings suggest that mussels exposed to sewage pollution modulate physiological responses by long-term exposure; although, gills are sensitive to these conditions and suffer chronic damage. Bioremediation potential found in D. chilensis widens the field of work for remediation of sewage bacterial pollution in water and sediments by filtering bivalves. PMID:24589503

  11. Deep Sequencing Reveals the Complete Genome and Evidence for Transcriptional Activity of the First Virus-Like Sequences Identified in Aristotelia chilensis (Maqui Berry

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    Javier Villacreses

    2015-04-01

    Full Text Available Here, we report the genome sequence and evidence for transcriptional activity of a virus-like element in the native Chilean berry tree Aristotelia chilensis. We propose to name the endogenous sequence as Aristotelia chilensis Virus 1 (AcV1. High-throughput sequencing of the genome of this tree uncovered an endogenous viral element, with a size of 7122 bp, corresponding to the complete genome of AcV1. Its sequence contains three open reading frames (ORFs: ORFs 1 and 2 shares 66%–73% amino acid similarity with members of the Caulimoviridae virus family, especially the Petunia vein clearing virus (PVCV, Petuvirus genus. ORF1 encodes a movement protein (MP; ORF2 a Reverse Transcriptase (RT and a Ribonuclease H (RNase H domain; and ORF3 showed no amino acid sequence similarity with any other known virus proteins. Analogous to other known endogenous pararetrovirus sequences (EPRVs, AcV1 is integrated in the genome of Maqui Berry and showed low viral transcriptional activity, which was detected by deep sequencing technology (DNA and RNA-seq. Phylogenetic analysis of AcV1 and other pararetroviruses revealed a closer resemblance with Petuvirus. Overall, our data suggests that AcV1 could be a new member of Caulimoviridae family, genus Petuvirus, and the first evidence of this kind of virus in a fruit plant.

  12. Biología reproductiva de Convolvulus chilensis (Convolvulaceae en una población de Aucó (centro-norte de Chile Reproductive biology of Convolvulus chilensis (Convolvulaceae in a population of Aucó (north-central Chile

    Directory of Open Access Journals (Sweden)

    Lorena H. Suárez

    2004-12-01

    Full Text Available Convolvulus chilensis es una hierba perenne, única representante endémica de la familia Convolvulaceae en Chile. Se estudió el sistema de reproducción, fenología, morfología y longevidad floral de C. chilensis en una población natural ubicada en la localidad de Aucó, dentro de la Reserva Nacional Las Chinchillas, IV Región, Chile. Se montó un experimento de polinización controlada considerando los tratamientos de polinización natural, polinización cruzada, autopolinización manual, autopolinización automática y apomixis, evaluándose su efecto sobre la formación de frutos y el número de semillas producidas por fruto. Adicionalmente, se compararon los siguientes atributos de la progenie según tipo de polinización (autopolinización o polinización cruzada: peso de semilla, germinación, altura y número de hojas de plántulas de ocho semanas en condiciones de invernadero. Se encontró que C. chilensis es una especie autocompatible, parcialmente autógama (capaz de autopolinizarse sin mediador y parcialmente apomíctica (capaz de producir semillas sin participación de gameto masculino. La longevidad floral fue estimada en 5,25 h. Durante este período, aproximadamente en 1,5 h hay disponibilidad de polen en los estambres. El período de floración se extiende por 22 semanas (agosto a enero. El tratamiento de apomixis presentó el menor porcentaje de formación de frutos y la menor cantidad de semillas por flor en comparación a los tratamientos de polinización natural, cruzada manual, autopolinización automática y autopolinización manual, los cuales no mostraron diferencias entre sí en ambos atributos. El tipo de polinización (autopolinización o polinización cruzada no afecta el desempeño de la progenie en los atributos de semilla y plántula evaluadosThe perennial herb Convolvulus chilensis is the only endemic species of the Convolvulaceae in Chile. The breeding system, phenology, morphology and floral longevity of C

  13. Evaluación y comparación de la eficiencia de dos sistemas de incubación de huevos de Genypterus chilensis (Guichenot, 1848 Evaluation and comparison of the efficiency of two incubation systems for Genypterus chilensis (Guichenot, 1848 eggs

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    Rolando Vega

    2012-03-01

    Full Text Available Actualmente la tendencia de la acuicultura mundial está orientada hacia la diversificación de los cultivos, principalmente de especies nativas. El congrio colorado Genypterus chilensis es un pez nativo de alta demanda gastronómica y explotación estacional que lo proyecta como candidato para el desarrollo de su tecnología de cultivo. El objetivo de este trabajo fue evaluar la eficiencia de dos sistemas de incubación de masas de huevos de G. chilensis, uno con circuito cerrado de agua (SICC y el otro con circuito abierto (SICA; su eficiencia fue medida por el porcentaje de eclosión de huevos. Dos ensayos fueron realizados midiendo y comparando los porcentajes de fecundación y eclosión de huevos en cuatro réplicas entre los dos sistemas, encontrándose solo diferencias significativas entre los porcentajes de fecundación del bioensayo 2. El bioensayo 1 tuvo un 81% promedio de fecundación de los huevos y el porcentaje promedio de eclosión para el SICC fue 42,9 ± 34,5% y para el SICA fue 0,0 ± 0,0%. El bioensayo 2 tuvo un porcentaje promedio de fecundación de los huevos de 87,3 ± 2,6% para el SICC y 79,8 ± 3,2% para el SICA y el porcentaje promedio de eclosión para el SICC fue 27,9 ± 33,7% y para el SICA fue 4,8 ± 5,6%. Se discuten los parámetros de incubación para obtener una máxima eclosión y se entrega una proposición para mejorar el sistema SICC. El sistema de incubación con circuito cerrado de agua generó mayores sobrevivencias en los huevos de G. chilensis.The current trend in world aquaculture is towards the diversification of cultures, mainly native species. The red cusk eel Genypterus chilensis is a native Chilean species of high gastronomic demand and seasonal exploitation that is projected as a candidate for the development of farming technology. The objective of this study was to test the efficiency of two incubation systems for G. chilensis egg masses, one with a closed water circuit (SICC and the other with an

  14. 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

    Abstract 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

  15. 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.

  16. Molecular phylogenetics in 2D: ITS2 rRNA evolution and sequence-structure barcode from Veneridae to Bivalvia.

    Science.gov (United States)

    Salvi, Daniele; Mariottini, Paolo

    2012-11-01

    In this study, we analyzed the nuclear ITS2 rRNA primary sequence and secondary structure in Veneridae and comparatively with 20 Bivalvia taxa to test the phylogenetic resolution of this marker and its suitability for molecular diagnosis at different taxonomic levels. Maximum likelihood and Bayesian trees based on primary sequences were congruent with (profile-) neighbor-joining trees based on a combined model of sequence-structure evolution. ITS2 showed higher resolution below the subfamily level, providing a phylogenetic signal comparable to (mitochondrial/nuclear) gene fragments 2-5 times longer. Structural elements of the ITS2 folding, such as specific mismatch pairing and compensatory base changes, provided further support for the monophyly of some groups and for their phylogenetic relationships. Veneridae ITS2 folding is structured in six domains (DI-VI) and shows five striking sequence-structure features. Two of them, the Basal and Apical STEMs, are common to Bivalvia, while the presence of both the Branched STEM and the Y/R stretches occurs in five superfamilies of the two Heterodonta orders Myoida and Veneroida, thus questioning their reciprocal monophyly. Our results validated the ITS2 as a suitable marker for venerids phylogenetics and taxonomy, and underlined the significance of including secondary structure information for both applications at several systematic levels within bivalves.

  17. Paragonimus y paragonimiasis en el norte peruano. Infección natural de Pseudothelphusa chilensis por metacercarias de Paragonimus Braun, 1899

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    César Cuba

    2014-06-01

    Full Text Available Se ha estudiado el índice de infección natural y la intensidad del parasitismo en cangrejos recolectados en tres provincias del Departamento de Cajamarca, Perú, habiéndose encontrado metacercarias de Paragonimus Braun, 1899 en el 43.97% de 539 especímenes de Pseudothelphusa chilensis Milne Edwards, 1843, único cangrejo hallado en la zona. El órgano parasitado fue casi exclusivamente el hepatopancreas, siendo 10.33 el número promedio de metacercarias por cangrejo. Las formas adultos logradas mediante inoculación de las metacercarias, fueron identificadas como Paragonimus peruvianus Miyazaki, Ibáñez y Miranda, 1969, con excepción de tres ejemplares que correspondieron a lo especie Paragonimus caliensis Little, 1968.

  18. Heavy metal concentrations and biomarkers of oxidative stress in native mussels (Mytilus edulis chilensis) from Beagle Channel coast (Tierra del Fuego, Argentina).

    Science.gov (United States)

    Duarte, Claudia A; Giarratano, Erica; Amin, Oscar A; Comoglio, Laura I

    2011-08-01

    The aim of this study was to evaluate the usefulness of oxidative stress biomarkers of pollution in native mussels Mytilus edulis chilensis from the Beagle Channel. Spatial and seasonal variations of catalase, glutathione-S-transferase and lipid peroxidation in gills and digestive gland were analyzed in relation to environmental parameters, heavy metals in sediment and in tissue. Four sites with anthropogenic impact and a control site were selected and monitored during the four seasons of 2007. We found significant differences among sites in concentrations of dissolved nutrients and heavy metals in sediments, with the highest values recorded at sites with anthropogenic pressure. Different patterns were observed between concentrations of metals in tissues and in sediments suggesting differences in bioavailability. There were also significant differences in biomarker responses among sites, despite the strong seasonal variability. Our results showed relatively moderate levels of pollution in the study area as a result of urban influences. PMID:21704346

  19. First evidence of azaspiracids (AZAs): A family of lipophilic polyether marine toxins in scallops (Argopecten purpuratus) and mussels (Mytilus chilensis) collected in two regions of Chile.

    Science.gov (United States)

    López-Rivera, A; O'Callaghan, K; Moriarty, M; O'Driscoll, D; Hamilton, B; Lehane, M; James, K J; Furey, A

    2010-04-01

    Azaspiracids are a family of lipophilic polyether marine biotoxins that have caused a number of human intoxication incidents in Europe since 1995 following the consumption by consumers of intoxicated shellfish (Mytilus edulis). These azaspiracids have now been identified in mussels (Mytilus chilensis) and scallops (Argopecten purpuratus) from two Chilean locations. This is the first report of the occurrence of azaspiracid toxins in these species (Mytilus chilensis and Argopecten purpuratus) from Chile. The areas studied were Bahía Inglesa (III Region, 27 degrees SL) and Chiloé Archipelago, both important scallop and mussels farming areas. Separation of azaspiracid (AZA1), azaspiracid isomer (AZA6) and its analogues, 8-methylazaspiracid (AZA2) and 22-demethylazaspiracid (AZA3), was achieved using reversed-phase LC and toxins were identified using a turbo electrospray ionisation (ESI) source, to a triple quadrupole mass spectrometer. In mussels, AZA1 was the predominant toxin in mussel hepatopancreas with AZA2, AZA3 and AZA6 present in approximate equivalent amounts in the remaining tissues, 20-30% of the AZA1 level. AZA2 predominated in the scallop samples with the toxin almost entirely present in the hepatopancreas (digestive gland). AZA1 was only observed in some of the scallop samples and was present at 12-15% of the AZA2 levels. Whilst the levels of AZAs in Chilean samples are below the EU regulatory limit of 160mug/kg, it is significant that this toxin is present in Pacific Ocean species. Consequently measures should be taken by regulatory authorities to implement regular seafood monitoring to ensure safety of harvested product. PMID:19852974

  20. The occurrence of domoic acid linked to a toxic diatom bloom in a new potential vector: the tunicate Pyura chilensis (piure).

    Science.gov (United States)

    López-Rivera, Américo; Pinto, Maricela; Insinilla, Andrea; Suárez Isla, Benjamín; Uribe, Eduardo; Alvarez, Gonzalo; Lehane, Mary; Furey, Ambrose; James, Kevin J

    2009-11-01

    The tunicate Pyura chilensis (Molina, 1782); Phylum Chordata; Subphylum Urochordata; Class Ascidiacea, common local name "piure" or sea squirt; a filter-feeder (plankton and suspended particles) sessile species; may play an important role in monitoring domoic acid (DA) the principal toxic component of Amnesic Shellfish Poisoning (ASP). Significant DA concentrations have been determined in tunicate samples, collected during a recent ASP outbreak in Bahía Inglesa, an important scallop (Argopecten purpuratus) farming area. Several infaunal species were tested for the presence of DA, in addition to the usual scallop monitoring programme. DA was found at sub-toxic levels in filtering bivalves such as mussels (Mytilus chilensis), large mussels (Aulacomya ater) and clams (Protothaca thaca) (6.4, 5.4 and 4.7 microg DA/g tissue respectively). Of particular interest was the observation of significant accumulations of toxic Pseudo-nitzschia sp. diatoms in the internal siphon and atrium spaces of the tunicate. Toxin distribution within major tunicate organs was heterogeneous with 8.7-15.5 microg DA/g in edible tissues, 14.9-17.9 microg DA/g in the fecal material and 13.6-32.7 microg DA/g in the gut content. DA was determined by HPLC-UV and confirmed by diode-array detection and LC-MS/MS analysis. This is the first report of the presence of DA in a tunicate that is regularly consumed by coastal populations. These results confirm the need to include these organisms in sanitation programs for marine toxins. PMID:19505493

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

    Directory of Open Access Journals (Sweden)

    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.

  2. 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

  3. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Stephen Thomas

    2002-07-01

    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 {gamma}-irradiation survival rates. Experimental stressors for Bivalvia were increased seawater temperature, H{sub 2}O{sub 2} and {sup 60}Co {gamma}-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 H{sub 2}O{sub 2} (<30% v/v) stressors were used, nor with between-site comparisons. Concentrated H{sub 2}O{sub 2} (30% v/v) produced a small difference. {sup 60}Co {gamma}-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

  6. 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)

    OpenAIRE

    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 complexity of coral reef ecosystems. Previously, Fungiacava was regarded as a genus that had descended from Leiosolenus or as belonging to the subfamily Crenellinae, but no phylogenetic support has been ...

  7. The Upper Miocene of the Rostov Dome (Eastern Paratethys: Implication of the chronostratigraphy and bivalvia-based biostratigraphy

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    Ruban Dmitry A.

    2005-01-01

    Full Text Available The Rostov Dome is located in the south of the Russian Platform. In the Late Miocene this area was embraced by the Eastern Paratethys. The implications of a recently developed Neogene chronostratigraphy to the studied area are discussed. The Sarmatian regional stage corresponds to the upper part of the Langhian, the entire Serravalian and the lower part of the Tortonian global stages; the Maeotian regional stage corresponds to the upper part of the Tortonian and the lowermost horizons of the Messinian global stages; the Pontian regional stage corresponds to most of the Messinian and the lowermost Zanclean global stages. A first Bivalvia-based bio-stratigraphic framework is proposed for the territory of the Rostov Dome. Five biozones were established within the Serravalian-Messinian: Tapes vitalianus, Cerastoderma fittoni-Cerastoderma subfittoni, Congeria panticapaea, Congeria amygdaloides navicula and Monodacna pseudocatillus-Prosodacna schirvanica.

  8. Phylogenetic analysis of four nuclear protein-encoding genes largely corroborates the traditional classification of Bivalvia (Mollusca).

    Science.gov (United States)

    Sharma, Prashant P; González, Vanessa L; Kawauchi, Gisele Y; Andrade, Sónia C S; Guzmán, Alejandra; Collins, Timothy M; Glover, Emily A; Harper, Elizabeth M; Healy, John M; Mikkelsen, Paula M; Taylor, John D; Bieler, Rüdiger; Giribet, Gonzalo

    2012-10-01

    Revived interest in molluscan phylogeny has resulted in a torrent of molecular sequence data from phylogenetic, mitogenomic, and phylogenomic studies. Despite recent progress, basal relationships of the class Bivalvia remain contentious, owing to conflicting morphological and molecular hypotheses. Marked incongruity of phylogenetic signal in datasets heavily represented by nuclear ribosomal genes versus mitochondrial genes has also impeded consensus on the type of molecular data best suited for investigating bivalve relationships. To arbitrate conflicting phylogenetic hypotheses, we evaluated the utility of four nuclear protein-encoding genes-ATP synthase β, elongation factor-1α, myosin heavy chain type II, and RNA polymerase II-for resolving the basal relationships of Bivalvia. We sampled all five major lineages of bivalves (Archiheterodonta, Euheterodonta [including Anomalodesmata], Palaeoheterodonta, Protobranchia, and Pteriomorphia) and inferred relationships using maximum likelihood and Bayesian approaches. To investigate the robustness of the phylogenetic signal embedded in the data, we implemented additional datasets wherein length variability and/or third codon positions were eliminated. Results obtained include (a) the clade (Nuculanida+Opponobranchia), i.e., the traditionally defined Protobranchia; (b) the monophyly of Pteriomorphia; (c) the clade (Archiheterodonta+Palaeoheterodonta); (d) the monophyly of the traditionally defined Euheterodonta (including Anomalodesmata); and (e) the monophyly of Heteroconchia, i.e., (Palaeoheterodonta+Archiheterodonta+Euheterodonta). The stability of the basal tree topology to dataset manipulation is indicative of signal robustness in these four genes. The inferred tree topology corresponds closely to those obtained by datasets dominated by nuclear ribosomal genes (18S rRNA and 28S rRNA), controverting recent taxonomic actions based solely upon mitochondrial gene phylogenies.

  9. Molecular phylogeny of Pholadoidea Lamarck, 1809 supports a single origin for xylotrophy (wood feeding) and xylotrophic bacterial endosymbiosis in Bivalvia.

    Science.gov (United States)

    Distel, Daniel L; Amin, Mehwish; Burgoyne, Adam; Linton, Eric; Mamangkey, Gustaf; Morrill, Wendy; Nove, John; Wood, Nicole; Yang, Joyce

    2011-11-01

    The ability to consume wood as food (xylotrophy) is unusual among animals. In terrestrial environments, termites and other xylotrophic insects are the principle wood consumers while in marine environments wood-boring bivalves fulfill this role. However, the evolutionary origin of wood feeding in bivalves has remained largely unexplored. Here we provide data indicating that xylotrophy has arisen just once in Bivalvia in a single wood-feeding bivalve lineage that subsequently diversified into distinct shallow- and deep-water branches, both of which have been broadly successful in colonizing the world's oceans. These data also suggest that the appearance of this remarkable life habit was approximately coincident with the acquisition of bacterial endosymbionts. Here we generate a robust phylogeny for xylotrophic bivalves and related species based on sequences of small and large subunit nuclear rRNA genes. We then trace the distribution among the modern taxa of morphological characters and character states associated with xylotrophy and xylotrepesis (wood-boring) and use a parsimony-based method to infer their ancestral states. Based on these ancestral state reconstructions we propose a set of plausible hypotheses describing the evolution of symbiotic xylotrophy in Bivalvia. Within this context, we reinterpret one of the most remarkable progressions in bivalve evolution, the transformation of the "typical" myoid body plan to create a unique lineage of worm-like, tube-forming, wood-feeding clams. The well-supported phylogeny presented here is inconsistent with most taxonomic treatments for xylotrophic bivalves, indicating that the bivalve family Pholadidae and the subfamilies Teredininae and Bankiinae of the family Teredinidae are non-monophyletic, and that the principle traits used for their taxonomic diagnosis are phylogenetically misleading.

  10. Modulating effects of orally supplied Euglena gracilis on the physiological responses of the freshwater mussel Diplodon chilensis, exposed to sewage water pollution in a Patagonian river (Argentina).

    Science.gov (United States)

    Bianchi, Virginia A; Castro, Juan M; Rocchetta, Iara; Conforti, Visitación; Pascual, Mariano; Luquet, Carlos M

    2016-04-01

    In order to test if orally supplied Euglena sp. cells modulate the physiological status of bivalves during bioremediation procedures, we evaluated the effect of Euglena gracilis diet on the immune response, oxidative balance and metabolic condition of Diplodon chilensis exposed to sewage water pollution. Mussels were fed for 90 days with E. gracilis (EG) or Scenedesmus vacuolatus (SV, control diet), and then exposed for 10 days at three sites along the Pocahullo river basin: 1) an unpolluted site, upstream of the city (control, C); 2) upstream (UpS) and 3) downstream (DoS) from the main tertiary-treated sewage discharge, in the city of San Martín de los Andes, Northwest Patagonia, Argentina. Our results show that the total hemocyte number decreases while pollution load increases along the river course for both, EG and SV mussels. Phagocytic activity is higher in EG mussels than in SV ones under all conditions. Reactive oxygen species (ROS) production in hemocytes increases with the increase in the pollution load, being significantly higher for EG mussels than for SV ones at DoS; no changes are observed for total oxyradical scavenging capacity (TOSC). Hemocytes' viability is increased for E. gracilis diet at C and remains unchanged in this group of mussels when exposed at the polluted sites. Lysosomal membrane stability is higher in EG mussels than in SV ones for all conditions, although it is decreased at polluted sites compared with that at C. Antioxidant (catalase) and detoxifying (gluthatione S-transferase) defenses are generally lower in gills and digestive gland of EG mussels than in SV ones. Lipid peroxidation (TBARS) is evident in gills of EG mussels at C, and in digestive gland of the same group, at all the sites. Gill mass factor (GF) is affected by the E. gracilis diet; it is increased at C and decreased at polluted sites when compared with that of SV ones. Digestive gland mass factor (DGF) is higher in EG mussels than in SV ones. In D. chilensis

  11. Modulating effects of orally supplied Euglena gracilis on the physiological responses of the freshwater mussel Diplodon chilensis, exposed to sewage water pollution in a Patagonian river (Argentina).

    Science.gov (United States)

    Bianchi, Virginia A; Castro, Juan M; Rocchetta, Iara; Conforti, Visitación; Pascual, Mariano; Luquet, Carlos M

    2016-04-01

    In order to test if orally supplied Euglena sp. cells modulate the physiological status of bivalves during bioremediation procedures, we evaluated the effect of Euglena gracilis diet on the immune response, oxidative balance and metabolic condition of Diplodon chilensis exposed to sewage water pollution. Mussels were fed for 90 days with E. gracilis (EG) or Scenedesmus vacuolatus (SV, control diet), and then exposed for 10 days at three sites along the Pocahullo river basin: 1) an unpolluted site, upstream of the city (control, C); 2) upstream (UpS) and 3) downstream (DoS) from the main tertiary-treated sewage discharge, in the city of San Martín de los Andes, Northwest Patagonia, Argentina. Our results show that the total hemocyte number decreases while pollution load increases along the river course for both, EG and SV mussels. Phagocytic activity is higher in EG mussels than in SV ones under all conditions. Reactive oxygen species (ROS) production in hemocytes increases with the increase in the pollution load, being significantly higher for EG mussels than for SV ones at DoS; no changes are observed for total oxyradical scavenging capacity (TOSC). Hemocytes' viability is increased for E. gracilis diet at C and remains unchanged in this group of mussels when exposed at the polluted sites. Lysosomal membrane stability is higher in EG mussels than in SV ones for all conditions, although it is decreased at polluted sites compared with that at C. Antioxidant (catalase) and detoxifying (gluthatione S-transferase) defenses are generally lower in gills and digestive gland of EG mussels than in SV ones. Lipid peroxidation (TBARS) is evident in gills of EG mussels at C, and in digestive gland of the same group, at all the sites. Gill mass factor (GF) is affected by the E. gracilis diet; it is increased at C and decreased at polluted sites when compared with that of SV ones. Digestive gland mass factor (DGF) is higher in EG mussels than in SV ones. In D. chilensis

  12. El uso de moluscos de agua dulce (Diplodon chilensis patagonicus en el sitio Angostura 1 (Departamento de General Conesa, Río Negro The use of freshwater mollusks (Diplodon Chilensis patagonicus at Angostura 1 site (General Conesa District, Río Negro province, Argentina

    Directory of Open Access Journals (Sweden)

    Luciano Prates

    2007-12-01

    Full Text Available En esta nota se presentan los resultados del estudio de las valvas de moluscos de agua dulce (Diplodon chilensis patagonicus recuperadas en el componente inferior del sitio arqueológico Angostura 1 (Departamento de General Conesa, provincia de Río Negro. Los atributos tenidos en cuenta para el análisis de los especímenes fueron: lateralidad de las valvas, tamaño, estado de fragmentación y presencia de periostraco; en forma secundaria se consideraron otras variables tales como evidencias de combustión y relación espacial con el resto de los materiales. A partir de estos datos y de la información contextual se propone la asociación de las valvas con el registro arqueológico del sitio (materiales líticos, cerámicos, óseos y vegetales y se discuten algunos procesos de formación vinculados con la actividad humana.This note presents the results of an analysis of freshwater mollusk shells (Diplodon chilensis patagonicus recovered from the lower cultural component of the Angostura 1 archaeological site (General Conesa District, Rio Negro Province, Argentina. Primarily, morphological features of this assemblage were analyzed, including: laterality, size, state of fracture, and the presence of periostracum. Secondarily, burning evidence and spatial relationships were considered. Site formation processes linked to human activity are discussed in light of these results and the contextual information from the site, i.e., mollusk shells associated with other archaeological remains (lithics, pottery, bones, and organic remains. It is proposed that the presence of freshwater mollusk shells in Angostura 1 site is linked to human activity.

  13. Production and performance of larvae and spat of pure and hybrid species of Mytilus chilensis and M. galloprovincialis from laboratory crosses Producción y comportamiento de larvas de especies puras e híbridas entre Mytilus chilensis y Mytilus galloprovincialis obtenidas en laboratorio

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    Jorge E Toro

    2012-03-01

    Full Text Available Adult specimens of M. galloprovincialis from Concepción Bay and M. chilensis from Yaldad Bay, Chile, were transferred to the laboratory to produce crosses of "pure" and "hybrid" species in order to evaluate early larval development and growth. These variables are important for understanding the dynamics of these two mussel species in this potential hybrid zone where they occur sympatrically. The study showed that fertilization occurred in all crosses and significant differences were not detected between pure lines and hybrids in terms of the percentage of eggs that developed into larvae. Hybrid larvae and spat from both reciprocal crosses grew significantly more than those from pure lines, although valve length values were within the ranges reported in the literature.Ejemplares adultos de M. galloprovincialis de la bahía de Concepción y de M. chilensis de la bahía de Yaldad, Chile, se trasladaron al laboratorio para realizar cruzamientos puros de cada especie e híbridos, para evaluar el desarrollo larval temprano y su crecimiento. Estas variables son importantes para entender la dinámica de estas dos especies de mitílidos en esta potencial zona híbrida donde se encuentran en forma simpátrica. El estudio mostró que la fertilización ocurrió en todos los cruzamientos y no se detectó diferencias significativas entre líneas puras e híbridas en el porcentaje de huevos que se desarrollaron a larvas. Las larvas y juveniles híbridos de ambos cruzamientos recíprocos crecieron significativamente más que las larvas de los cruzamientos de especies puras, aunque los valores de longitud de la valva están dentro de los rangos reportados en la bibliografía.

  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

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    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. Gastropoda-Bivalvia Fauna And Neogene-Quaternary Stratigraphy of the Southwest of Dardanelles (Çanakkale-NWAnatolia)

    Science.gov (United States)

    Kapan, Sevinç; Kabasakal, Sinem

    2016-04-01

    Gastropoda-Bivalvia Fauna And Neogene-Quaternary Stratigraphy of the Southwest of Dardanelles (Çanakkale-NWAnatolia) Sevinç KAPAN, Sinem KABASAKAL, Çanakkale Onsekiz Mart University, Engineering Faculty, Geological Engineering Department sevinckapan_yesilyurt@hotmail.com In this study, paleontology and stratigraphy of Neogene and Quaternary units around south of the Dardanelles have been examined using Gastropoda and Bivalvia fauna. In the investigation area, the base of the sediments that belongs to Neogene, consist of the volcanics which are formed with basalts, andesites and tuff. Neogene begins unconformity with basal conglomerate which are formed with basalt and tuff gravels. The measurable thickness of the Neogene sediments is approximately 200meters in total. First fossiliferius level which consist of Lymnocardium (Euxinicardium) nobile Sabba has showed similarities with the Pontian (Late Miocene) fauna of the Eastern Paratethys. The existence of Melanopsis and Psidium species indicate that the basin has been brackish water feeding by fresh water in the Early Pliocene. Theodoxus fluviatilis (Linne), Theodoxus (Calvertia) aff. imbricata Brusina, Theodoxus (Calvertia) licherdopoli scriptus (Stefanescu), Viviparus mammatus (Stefanescu), Valvata (Valavata) sulekiana Brusina, Valvata (Cincinna) crusitensis Fontannes, Hydrobia cf grandis Cobalcescu, Hydrobia ventrosa Monfort, Melanopsis (Melanopsis) cf. bergeroni Stefanescu, , Melanopsis (Melanopsis) sandbergeri rumana Tournouer, Melanopsis (Canthidomus) hybostoma anili Taner, Melanopsis (Canthidomus) hybostoma amaradica Fontannes, Melanopsis (Canthidomus) lanceolata Neumayr, Amphimelania fossariformis (Tournouer), Melanoides tuberculata monolithica (Bukowski), Radix (Radix) peregra (Müller), Planorbarius thiollierei (Michaud), Potamida (Potamida) craiovensis craiovensis (Tournouer), Potamida (Potamida) berbestiensis (Fontannes), Unio pristinus davilai Porumbaru, Unio subexquisitus Jatzko, Anadonta zmaji

  16. 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.

  17. Recruitment Dynamics of the Relict Palm, Jubaea chilensis: Intricate and Pervasive Effects of Invasive Herbivores and Nurse Shrubs in Central Chile.

    Science.gov (United States)

    Fleury, Marina; Marcelo, Wara; Vásquez, Rodrigo A; González, Luis Alberto; Bustamante, Ramiro O

    2015-01-01

    Shrubs can have a net positive effect on the recruitment of other species, especially relict species in dry-stressful conditions. We tested the effects of nurse shrubs and herbivory defoliation on performance (survival and growth) of nursery-grown seedlings of the largest living palm, the relict wine palm Jubaea chilensis. During an 18-month period, a total of more than 300 seedlings were exposed to of four possible scenarios produced by independently weakening the effects of nurse shrubs and browsers. The experiment followed a two-way fully factorial design. We found consistent differences in survival between protected and unprotected seedlings (27.5% and 0.7%, respectively), and herbivory had a dramatic and overwhelmingly negative effect on seedling survival. The invasive rabbit (Oryctolagus cuniculus) is clearly creating a critical bottleneck in the regeneration process and might, therefore, partially explain the general lack of natural regeneration of wine palms under natural conditions. Apparently biotic filters mediated by ecological interactions are more relevant in the early stages of recruitment than abiotic, at least in invaded sites of central Chile. Our data reveal that plant-plant facilitation relationship may be modulated by plant-animal interactions, specifically by herbivory, a common and widespread ecological interaction in arid and semi-arid environments whose role has been frequently neglected. Treatments that protect young wine palm seedlings are mandatory to enable the seedlings to attain a height at which shoots are no longer vulnerable to browsing. Such protection is an essential first step toward the conservation and reintroduction of this emblematic and threatened species. PMID:26218100

  18. Cruzamientos interpoblacionales en Mytilus chilensis, un bivalvo de importancia comercial y sus efectos sobre el crecimiento en longitud de la valva durante la etapa larval Inter-population breeding in Mytilus chilensis, an economically important bivalve, and its effects on the shell length during the larval stage

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    JE Toro

    2008-01-01

    Full Text Available Dos poblaciones naturales de Mytilus chilensis aisladas geográficamente fueron utilizadas para realizar los cruzamientos experimentales en el presente trabajo. En todos los cruzamientos, utilizando un diseño factorial con réplicas, ocurrió fertilización de las ovas, no detectándose diferencias significativas entre los cruzamientos intra e interpoblacionales en cuanto al porcentaje de ovas que desarrollaron larvas al día 4 (P > 0,05. Sin embargo, el porcentaje de larvas anormales al día 4 fue significativamente mayor en los cruzamientos interpoblacionales (P Two geographically separated natural populations of Mytilus chilensis were utilized to carry out the experimental crosses on the present study. In every crossing, using the factorial design with replication, fertilization of eggs occurred without detection of significant differences among inter and intra-population crosses in relation to percentage of eggs developed into larvae at day 4 (P > 0.05. However, the percentage of abnormal larvae at day 4, was significantly higher among inter-population crosses (P < 0.05. The larvae from each cross were placed into a 200 l fiber-glass tank containing 1 µm filtered and U.V. treated fresh sea water, at a density of 100 larvae per ml. A high cell concentration of the micro algae Isochrysis galbana was used as food. Samples for analyzing larval growth were taken from the larval cultures at 4, 10 and 20 days after fertilization. Larval samples were videotyped from a plankton decantation chamber in an inverted microscope fitted with a Pulnex video camera. Selected images were captured for subsequent processing and measurement of each larva using a Scion Image 3.0b PC Software. Significantly differences (P < 0.05 were found in the size of the larvae among the experimental crosses. The sibs from inter-population crosses showed significantly (P < 0.05 higher sizes than those produced by the intra-population crosses. These higher values in the shell

  19. 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.

  20. The effect of temperature and body size on filtration rates of Limnoperna fortunei (Bivalvia, Mytilidae under laboratory conditions

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    Débora Pestana

    2009-02-01

    Full Text Available The golden mussel (Limnoperna fortunei, Mollusca: Bivalvia is an invasive species that has been causing considerable environmental and economic problems in South America. In the present study, filtration rates of L. fortunei were determined in the laboratory under different temperatures (10, 15, 20, 25, 28, and 30 ºC and two types of food (Algamac-2000® and the chlorophycean alga Scenedesmus sp.. There was a statistically significant relationship between time and filtration rates in the experiment using Scenedesmus sp., regardless of temperature. However, this pattern was absent in the experiment using Algamac, suggesting that the relationship between filtration rates and temperature might depend on the size of the filtered particles. In addition, there was no correlation between filtration rates and either shell size or condition index (the relationship between the weight and the length of a mussel. The filtration rate measured in the present study (724.94 ml/h was one of the highest rates recorded among invasive bivalves to date. Given that the colonies of the golden mussel could reach hundreds of thousands of individuals per square meter, such filtration levels could severely impact the freshwater environments in its introduced range.

  1. Molecular phylogenetic analysis supports a Gondwanan origin of the Hyriidae (Mollusca: Bivalvia: Unionida) and the paraphyly of Australasian taxa.

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    Graf, Daniel L; Jones, Hugh; Geneva, Anthony J; Pfeiffer, John M; Klunzinger, Michael W

    2015-04-01

    The freshwater mussel family Hyriidae (Mollusca: Bivalvia: Unionida) has a disjunct trans-Pacific distribution in Australasia and South America. Previous phylogenetic analyses have estimated the evolutionary relationships of the family and the major infra-familial taxa (Velesunioninae and Hyriinae: Hyridellini in Australia; Hyriinae: Hyriini, Castaliini, and Rhipidodontini in South America), but taxon and character sampling have been too incomplete to support a predictive classification or allow testing of biogeographical hypotheses. We sampled 30 freshwater mussel individuals representing the aforementioned hyriid taxa, as well as outgroup species representing the five other freshwater mussel families and their marine sister group (order Trigoniida). Our ingroup included representatives of all Australian genera. Phylogenetic relationships were estimated from three gene fragments (nuclear 28S, COI and 16S mtDNA) using maximum parsimony, maximum likelihood, and Bayesian inference, and we applied a Bayesian relaxed clock model calibrated with fossil dates to estimate node ages. Our analyses found good support for monophyly of the Hyriidae and the subfamilies and tribes, as well as the paraphyly of the Australasian taxa (Velesunioninae, (Hyridellini, (Rhipidodontini, (Castaliini, Hyriini)))). The Hyriidae was recovered as sister to a clade comprised of all other Recent freshwater mussel families. Our molecular date estimation supported Cretaceous origins of the major hyriid clades, pre-dating the Tertiary isolation of South America from Antarctica/Australia. We hypothesize that early diversification of the Hyriidae was driven by terrestrial barriers on Gondwana rather than marine barriers following disintegration of the super-continent.

  2. Chinese pond mussel Sinanodonta woodiana (Lea, 1834 (Bivalvia: origin of the Polish population and GenBank data

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    Marianna Soroka

    2014-05-01

    Full Text Available DDNA sequences of the mitochondrial cox1 gene were analysed in 4 new local populations of Sinanodonta woodiana (Bivalvia in Poland, in the first reported Polish population, and in a population from Hungary. The gene sequences of Polish specimens were identical to those of specimens from Hungary, Italy and Ukraine, but different from those of Romanian specimens (data from GenBank. According to fish farm documentation, S. woodiana had spread in Poland by 2 routes: i direct import of fish infected by glochidia of S. woodiana from Hungary; and ii indirectly, by the major distributor of thermophilous fish in Poland, Gosławice Fish Farm, which started to import Hungarian fish in the 1960s. The genetic analysis and available documentation unambiguously confirm that Polish populations of S. woodiana derive from a source population in Hungary. In addition, we noticed doubtful identification of this species in GenBank data and further research is needed to resolve this problem. 

  3. 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

  4. 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.

  5. 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.

  6. Polyphenol content and antioxidant activity of maqui (Aristotelia chilensis Molina Stuntz during fruit development and maturation in Central Chile Contenidos de polifenoles y actividad antioxidante de maqui (Aristotelia chilensis Molina Stuntz durante el desarrollo y maduración de frutos en Chile Central

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    Carolina Fredes

    2012-12-01

    Full Text Available Maqui (Aristotelia chilensis Molina Stuntz, Elaeocarpaceae is a Chilean native species which produces small berries that are mainly collected from the wild. The health benefits of maqui fruit are attributed to their high polyphenol content as well as their wide variety of anthocyanins and flavonols. One of the main factors that affect the polyphenol content in fruit is the maturity stage at harvest. The objective of this study was to determine total phenol and total anthocyanin content and antioxidant activity (by ferric reducing ability of plasma FRAP assay of maqui fruits harvested at different fruit maturity stages from two wild populations located in Central Chile. Each maturity stage was determined by days from fruit set, berry size, and soluble solids. Total phenol content declined while total anthocyanin content increased from the green to light red stage. Nevertheless, both total phenol and anthocyanin content increased from the light red to dark purple stage. The highest anthocyanin content and antioxidant activity was found in the late maturity stage (dark purple. The results show that ripening in maqui fruit can be expected with 1100 growing degree-days (91 d after fruit set in Central Chile. At this moment of harvest, fruits with 18-19 °Brix have the highest anthocyanin content and antioxidant activity (FRAP. This study constitutes the first advances in the understanding of maqui fruit ripening and corresponding antioxidant activity.El maqui (Aristotelia chilensis Molina Stuntz, Elaeocarpaceae es una especie nativa de Chile que produce unas bayas pequeñas que se recolectan principalmente de individuos silvestres. Los beneficios para la salud atribuidos a los frutos de maqui se deben a sus altos contenidos de polifenoles, así como a la gran variedad de antocianos y flavonoles. Uno de los principales factores que afectan el contenido de polifenoles en frutos es el estado de madurez a la cosecha. El objetivo de este estudio fue

  7. Factores que afectan la distribución circular del muérdago sin hojas Tristerix aphyllus (Loranthaceae sobre el cacto Echinopsis chilensis Factors affecting the circular distribution of the leafless mistletoe Tristerix aphyllus (Loranthaceae on the cactus Echinopsis chilensis

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    CAREZZA BOTTO-MAHAN

    2000-09-01

    Full Text Available Describimos el patrón de emergencia del muérdago holoparásito Tristerix aphyllus desde su cacto hospedador Echinopsis chilensis en un ecosistema semiárido de Chile. La distribución circular de las inflorescencias del parásito difirió significativamente de una distribución uniforme basada en un proceso aleatorio. Cuantificamos la distribución circular de las semillas defecadas sobre la superficie del cacto por el mímido Mimus thenca, el único ave responsable de la dispersión del muérdago. Nuestros datos no sostuvieron la idea de una deposición de semillas direccional por parte del ave. Para someter a prueba la hipótesis que la distribución circular observada es atribuible a una sobrevivencia diferencial de las semillas debido a variación térmica entre micrositios, infectamos cactos con semillas de T. aphyllus cada 30º y evaluamos la temperatura asociada a cada ángulo. Aun cuando las semillas ubicadas en ángulos con mayor exposición solar presentaron la menor formación de disco haustorial, esta variación en mortalidad no fue suficiente para dar cuenta de la polaridad angular observada. No obstante, las inflorescencias de T. aphyllus que emergieron 17 meses después de la infección experimental, revelaron estadígrafos circulares indistinguibles de aquellos observados en la situación natural. La inspección de la estructura anatómica en dos ángulos opuestos de la cactácea reveló diferencias en la constitución de la epidermis, observándose un espesor en promedio cuatro veces mayor en las muestras orientadas hacia el norte que en las orientadas hacia el sur debido a la formación de corteza altamente lignificada. Sugerimos que la formación de corteza es probablemente el factor más importante en determinar la distribución circular sesgada de T. aphyllusWe describe the pattern of emergence of the holoparasitic mistletoe Tristerix aphyllus from its cactus host Echinopsis chilensis in a semiarid Chilean ecosystem. The

  8. On some Indo-Pacific boring endolithic Bivalvia species introduced into the Mediterranean Sea with their host – spread of Sphenia rueppelli A. Adams, 1850

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    A. ZENETOS

    2012-12-01

    Full Text Available The study of the endolithic molluscs found on/in living alien Spondylusshells collected in the Gulf of Iskenderun (Turkey brought to light three more alien bivalvia species namely Petricola hemprichi, Gastrochaena cymbium and Sphenia rueppelli. The presence of Sphenia rueppellideserves attention as it constitutes the first record of this species as living in the Mediterranean Sea. The definitive establishment and spreading of these bivalves in the basin seems to be also attested by careful analysis of specimens sampled in other southern Turkish localities and previously retained in local private collections. The present records raise some questions on the vector of arrival of the species in the Mediterranean Sea that could be strictly connected with their hosts.

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

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    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. La dieta y la fauna de parásitos metazoos del torito Bovichthys chilensis Regan 1914 (Pisces: Bovichthydae en la costa de Chile centro-sur: variaciones geográficas y ontogenéticas Diet and metazoan parasite fauna of the thornfish Bovichthys chilensis Regan 1914 (Pisces: Bovichthydae on the coast of central-south Chile: geographical and ontogenetic variations

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    GABRIELA MUÑOZ

    2002-12-01

    Full Text Available Conocer qué, cuánto, cuándo y dónde comen y viven los hospedadores permitiría complementar los estudios parasitarios, ya que la transmisión de los endoparásitos está estrechamente ligada a la dieta, y la de los ectoparásitos al uso del hábitat. Por esto, se describen y comparan la composición y características cuantitativas de la dieta y de las infracomunidades de parásitos metazoos del torito Bovichthys chilensis con datos obtenidos de 108 ejemplares juveniles recolectados desde la zona intermareal de cuatro localidades de la costa de Chile (entre 33º y 40º S, y de 14 adultos recolectados desde el submareal somero de una quinta localidad (36º S, y se discute los resultados a la luz de los cambios ontogenéticos en el nicho de este huésped. Cerca del 70 % de los ejemplares tenía contenido alimentario, en el que se distinguieron 25 ítems presa, de los cuales sólo uno era compartido entre juveniles y adultos. La dieta de los toritos juveniles estuvo compuesta principalmente por anfípodos y la de los adultos por crustáceos decápodos. Cerca de un 40 % de los toritos albergaba un total de 624 parásitos en los que se reconocieron 16 taxa, y sólo cuatro eran compartidos entre juveniles y adultos. En los toritos juveniles muestreados en las cuatro localidades había baja y similar intensidad total, riqueza y diversidad parasitarias, y variaciones geográficas significativas en la prevalencia total, composición de la dieta y de las infracomunidades de parásitos. La falta de una relación clara entre la composición de la dieta y del parasitismo en los toritos juveniles puede deberse a que las parasitosis son necesariamente recientes, y a que pueden haber grandes diferencias en el tiempo de residencia de presas y parásitos en el tracto digestivo. En los toritos adultos hubo mayor prevalencia, intensidad y diversidad de parásitos que en los juveniles de una localidad cercana. Se requieren más estudios, en especial en la

  11. Efecto del Compost de Biosólidos en la producción de plantines de Austrocedrus Chilensis (ciprés de la cordillera Effect of Biosolids Compost on seedling production of Austrocedrus Chilensis (ciprés de la cordillera

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    Gustavo Basil

    2009-06-01

    Full Text Available La utilización de compost de residuos urbanos como sustrato en contenedores es una alternativa interesante a nivel económico y ambiental, dado que reduciría el uso de turba y «tierra negra» en la producción de plantines, y la disposición de residuos en vertederos. En el presente trabajo se estudió el efecto de 0, 30 y 50% de compost de biosólidos en el crecimiento inicial (primer año de ciprés de la cordillera, y el efecto durante los dos años siguientes de un tratamiento único con 50% de compost en el crecimiento posterior y el estado nutricional de los plantines. Se determinó diámetro y altura a 18, 25 y 37 meses, biomasa aérea y radicular a 25 y 37 meses, y concentración foliar de C, N, P, K, Ca y Mg a 37 meses. A pesar de que los tres tratamientos iniciales fueron homogeneizados al año en un único tratamiento con 50% de compost, se encontraron diferencias significativas de diámetro, altura y biomasa aérea y radicular entre los tratamientos originales en todas las fechas analizadas, correspondiendo los mayores valores a los tratamientos con compost. Al finalizar el ensayo, las concentraciones foliares de nutrientes fueron muy similares en todos los plantines, excepto Mg que fue mayor en el tratamiento original con 50% de compost. Los resultados muestran la importancia de los primeros meses de crecimiento en el desarrollo posterior de los plantines de ciprés y el valor potencial de los compost de biosólidos como sustrato para la producción de esta especie en contenedores.Using composts of urban waste, including biosolids, as substrates for containerized plant production is a sound economic and environmental alternative, since it could reduce the use of peat- and «black earth»-based media, and the disposal of organic wastes in landfills. The objectives of this work were to study the effect of 0, 30 and 50% biosolids compost on the initial growth (first year of cypress (Austrocedrus chilensis D. Don, and the effect

  12. Acacia senegal and Prosopis chilensis-nodulating rhizobia Sinorhizobium arboris HAMBI 2361 and S. kostiense HAMBI 2362 produce tetra- and pentameric LCOs that are N-methylated, O-6-carbamoylated and partially sulfated.

    Science.gov (United States)

    Nowak, Petri; Soupas, Laura; Thomas-Oates, Jane; Lindström, Kristina

    2004-04-28

    Sinorhizobium arboris and S. kostiense are rhizobia that nodulate the tropical leguminous trees Acacia senegal and Prosopis chilensis. The lipochito-oligosaccharidic signalling molecules (LCOs) of S. arboris HAMBI 2361 and S. kostiense HAMBI 2362 were analyzed by mass spectrometry. The major LCOs produced by the strains were shown to be pentameric, acylated with common fatty acids, N-methylated, O-6-carbamoylated and partially sulfated, as are the LCOs characterized to date for other Acacia-nodulating rhizobia. Besides the major LCOs the two strains produced (i) tetrameric LCOs, (ii) LCOs acylated with fatty acids other than those commonly found, (iii) LCOs with only an acyl substituent and (iv) noncarbamoylated LCOs. Production of LCOs (i) to (iii) are novel among Acacia-nodulating rhizobia. The roles of the different structural characteristics of LCOs in the rhizobium-A. senegal symbiosis are discussed. Specific structural features of the LCOs are proposed to be important in the selection of effective nitrogen-fixing rhizobia by A. senegal.

  13. Community structure of the macroinfauna in the sediments below an intertidal mussel bed (Mytilus chilensis (Hupe of southern Chile Estructura comunitaria de la macroinfauna en los sedimentos bajo un banco intermareal de bivalvos (Mytilus chilensis (Hupe en el sur de Chile

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    CRISTIAN DUARTE

    2006-09-01

    Full Text Available The mytilid mussel Mytilus chilensis (Hupe can form dense beds in sedimentary areas of the inland coast of the Nord-Patagonic archipelagos of the Chilean coast (ca. 40-43° S. During the autumn of 2002, we collected replicated samples at five intertidal stations in Panitao (Golfo de Reloncaví ordered along a transect parallel to the low tide level and extended from the center of the bank (stations one and two with 100 and ca. 25 % of mussel cover, respectively to the bare sediments of the intertidal (stations 3, 4 and 5, without mussels. The macroinfauna was numerically dominated by Polychaeta, Oligochaeta and Crustacea Peracarida. The total number of species collected was 14, being the most abundant the polychaete Perinereis vallata, oligochaetes from the family Tubificidae and the crustacean amphipod Corophium insidiosum. The number of species, Shannon-Wiener diversity and total abundance of the macroinfauna did not differ significantly among stations. However, the percent contribution of polychaetes was significantly higher at the sediments sampled outside the mussel bed (stations three, four and five, while the percentual contribution of oligochaetes was significantly higher at the sediments sampled in the mussel bed (stations one and two. No significant differences were found between the percentual contribution of peracarid crustaceans between stations sampled in the mussel bed versus that sampled on the bare intertidal. The graphic results of NMMDS show that the macroinfaunal assemblage of the stations located inside the mussel bed differed from that of stations located outside the bed. Results of SIMPER and ANOSIM showed that the macroinfaunal composition of stations one and two was significantly dissimilar (61-54 % to that of the stations located outside the mussel bed, which had similar composition. The graphic results of a NMMDS based upon sedimentological characteristics show that most replicates of station one and some of station

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

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    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)

  15. Complete mitochondrial genome of Coelomactra antiquata (Mollusca: Bivalvia): The first representative from the family Mactridae with novel gene order and unusual tandem repeats.

    Science.gov (United States)

    Meng, Xueping; Zhao, Nana; Shen, Xin; Hao, Jue; Liang, Meng; Zhu, Xiaolin; Cheng, Hanliang; Yan, Binlun; Liu, Zhaopu

    2012-06-01

    The complete mitochondrial genome plays an important role in the accurate inference of phylogenetic relationships among metazoans. Mactridae, also known as trough shells or duck clams, is an important family of marine bivalve clams in the order Veneroida. Here we present the complete mitochondrial genome sequence of the Xishishe Coelomactra antiquata (Mollusca: Bivalvia), which is the first representative from the family Mactridae. The mitochondrial genome of C. antiquata is of 17,384bp in length, and encodes 35 genes, including 12 protein-coding, 21 transfer RNA, and 2 ribosomal RNA genes. Compared with the typical gene content of animal mitochondrial genomes, atp8 and tRNAS(2) are missing. Gene order of the mitochondrial genome of C. antiquata is unique compared with others from Veneroida. In the mitochondrial genome of the C. antiquata, a total of 2189bp of non-coding nucleotides are scattered among 26 non-coding regions. The largest non-coding region contains one section of tandem repeats (99 bp×11), which is the second largest tandem repeats found in the mitochondrial genomes from Veneroida. The phylogenetic trees based on mitochondrial genomes support the monophyly of Veneridae and Lucinidae, and the relationship at the family level: ((Veneridae+Mactridae)+(Cardiidae+Solecurtidae))+Lucinidae. The phylogenetic result is consistent with the morphological classification. Meanwhile, bootstrap values are very high (BP=94-100), suggesting that the evolutionary relationship based on mitochondrial genomes is very reliable.

  16. 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

  17. Scorched mussels (BIVALVIA: MYTILIDAE: BRACHIDONTINAE) from the temperate coasts of South America: phylogenetic relationships, trans-Pacific connections and the footprints of Quaternary glaciations.

    Science.gov (United States)

    Trovant, Berenice; Orensanz, J M Lobo; Ruzzante, Daniel E; Stotz, Wolfgang; Basso, Néstor G

    2015-01-01

    This study addresses aspects of the phylogeny and phylogeography of scorched mussels (BIVALVIA: MYTILIDAE: BRACHIDONTINAE) from southern South America (Argentina and Chile), as well as their ecophylogenetic implications. Relationships were inferred from sequences of two nuclear (28S and 18S) and one mitochondrial (COI) genes, using Bayesian and maximum likelihood analyses. Our results indicate that the monophyletic BRACHIDONTINAE include three well supported clades: [i] Brachidontes Swainson (=Hormomya Mörch), [ii] Ischadium Jukes-Browne+Geukensia van de Poel, and [iii] Austromytilus Laseron+Mytilisepta Habe (usually considered a member of the SEPTIFERINAE)+Perumytilus Olsson. Species of clade [iii] are distributed along the temperate coasts of the Pacific Ocean. Available evidence supports divergence between Austromytilus (Australia) and Perumytilus (South American) following the breakup of Australian, Antarctic and South American shelves. Four brachidontins occur in southern South America: Brachidontes rodriguezii (d'Orbigny), B. granulatus (Hanley), and two genetically distinct clades of Perumytilus. The latter are confined to the Chile-Peru (North Clade) and Magellanic (South Clade) Biogeographic Provinces, respectively warm- and cold-temperate. The South Clade is the only brachidontin restricted to cold-temperate waters. Biogeographic considerations and the fossil record prompted the hypothesis that the South Clade originated from the North Clade by incipient peripatric differentiation, followed by isolation during the Quaternary glaciations, genetic differentiation in the non-glaciated coasts of eastern Patagonia, back-expansion over southern Chile following post-LGM de-glaciation, and development of a secondary contact zone between the two clades in south-central Chile. Evidence of upper Pleistocene expansion of the South Clade parallels similar results on other organisms that have colonized coastal ecosystems from eastern Patagonia since the LGM

  18. Seasonal variation in larval density of Limnoperna fortunei (Bivalvia, Mytilidae in the Iguaçu and Paraná rivers, in the region of Foz do Iguaçu, Paraná, Southern Brazil

    Directory of Open Access Journals (Sweden)

    Débora Pestana

    2008-06-01

    Full Text Available The larval density of the invasive mussel Limnoperna fortunei (Bivalvia, Mytilidae was monitored from January 2005 to February 2006 at two points along the Paraná and the Iguaçu Rivers, near Foz do Iguaçu, PR, Brazil. The results indicated two density peaks in the Paraná River: a lower peak between March and June and a higher peak in October. In the Iguaçu River, the values were much lower, yet they also showed a peak between September and October. A reduction in the reproductive activity was observed in both the rivers between July and August. The average larval density at the collection point in the Paraná reached 948.5 larvae/m³, with a peak of 2,999.5 larvae/m³ in October. The present study represented the first quantification of the larval density of L. fortunei in the lower reaches of the Iguaçu River, downstream of the Iguaçu falls.A densidade larval do molusco invasor Limnoperna fortunei (Bivalvia, Mytilidae foi monitorada entre janeiro de 2005 e fevereiro de 2006 em dois pontos dos rios Paraná e Iguaçu, na região de Foz do Iguaçu, PR. Os resultados registraram dois picos de densidade no rio Paraná: entre março e junho e um maior em outubro. No rio Iguaçu, os valores foram muito inferiores, mas também com um pico entre setembro-outubro. Em ambos os rios foi verificada uma pausa reprodutiva entre os meses de julho-agosto. A densidade média de larvas de L. fortunei no ponto amostrado no rio Paraná chegou a 948.5 larvas/m³, com pico de 2.999,5 larvas/m³ em outubro. O presente estudo representa a primeira quantificação da densidade larval de L. fortunei no rio Iguaçu, a jusante das Cataratas do Iguaçu.

  19. 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

  20. Fauna Europaea: Mollusca – Bivalvia

    Directory of Open Access Journals (Sweden)

    Rafael Araujo

    2015-07-01

    European freshwater bivalves belong to the Orders Unionoida and Cardiida. All the European unionoids are included in the superfamily Unionoidea, the freshwater mussels or naiads. The European cardiids belong to the following three superfamilies: Cardioidea, Cyrenoidea and Dreissenoidea. Among the Unionoidea there are the most imperilled animal groups on the planet while the Cardioidea includes the cosmopolitan genus Pisidium, the Cyrenoidea the Asiatic clam (Corbicula fluminea and the Dreissenoidea the famous invasive zebra mussel (Dreissena polymorpha. Basic information is summarized on their taxonomy and biology. Tabulations include a complete list of the current estimated families, genera and species.

  1. [Biomechanics of the jaw apparatus in the horn-shark (Heterodontus portusjacksoni = Heterodontus philippi)].

    Science.gov (United States)

    Nobiling, G

    1977-01-01

    The constructional morphology of the jaw apparatus in the horn-shark Heterodontus has been investigated. The origines and insertions of the jaw muscles have been delimited and the lines of action were determined. The individual muscles have been weighed, in order to get on the basis of their masses an estimate of the forces which are exerted by the components of the jaw musculature. The mandibular joints, the occlusion of the jaws, morphological details of the upper and lower jaws as well as the "subodontium" have been subject to macroscopic and microscopic study. The joint between palatoquadrate and mandibular consists of a medial and a lateral compartment. Only hinge movements are possible. If the jaws are closed, the contacts between upper and lower jaws are confined to the large crushing teeth of only one or two tooth families. The teeth are fixed to the jaw cartilage by ligamentous structures. Three layers can be discerned histologically: The uppermost layer, beneath the bases of the teeth, is composed of the fibrae interdentales and of the fibrae subbasales. By these, the individual teeth are firmly connected to form a continuous pavement. - The middle layer is characterised by the great number of cell nuclei. - The fibre system which constitutes the lowermost layer is arranged according to its function. The subdental layer of fibrous tissue grows faster than the one adjacent to the jaws. Thus a particular growth structure is formed. - Two constructive principles are realised: 1. The biting forces or "loads", applied to one or two teeth, are split and distributed on all teeth of the same family which are lingual of the loaded one. 2. As in the thecodont mammals, the compressive biting (= occlusal) force is transformed into a tensile force by the tooth-fixing apparatus and by the shapes of the jaws and this is sustained by fibrous structures. Magnitude and directions of the stresses which appear in the upper and lower jaw during biting are compared with stress patterns evoked in consoles and in beams of technical constructions. The moments of resistence have been calculated for 9 or 8 cross sections, respectively, through the upper and the lower jaw. The forms of both jaws are comparable to a beam of equal strength on two supports, namely, bitten object and joints; while the load is represented by the muscular force. Where the bending moments are at a maximum, opposite to the muscle insertions, a strong ligamentous reinforcement of the perichondrium extends parallel to the tooth rows and fades out towards the joint and towards the symphysis. The strength properties of cartilage and of collagenous fibres in the species under consideration have been measured. The lines of action of the jaw muscles intersect in the area where the moments of resistence reach their maximum. The largest crushing teeth are located in this same section, so that the muscles exert most force on the teeth, while the joint is exposed to only moderate compression.

  2. Daily food intake of Kajikia audax (Philippi, 1887) off Cabo San Lucas, Gulf of California, Mexico

    OpenAIRE

    Leonardo A. Abitia-Cárdenas; Felipe Galván-Magaña; Víctor H Cruz-Escalona; Peterson, Mark S.; Jesús Rodríguez-Romero

    2011-01-01

    The daily food intake rates of the striped marlin, Kajikia audax (Perciformes: Istiophoridae), were estimated using qualitative and quantitative analyses of their trophic spectrum. We analyzed the stomach contents of 505 striped marlin caught by the sport fishing fleet off Cabo San Lucas, Baja California Sur, Mexico, sampled from October 1987 through December 1989. The most important preys were chub mackerel (Scomber japonicus), California pilchard (Sardinops caeruleus), and jumbo squid (Dosi...

  3. Daily food intake of Kajikia audax (Philippi, 1887) off Cabo San Lucas, Gulf of California, Mexico

    OpenAIRE

    Abitia Cárdenas, Leonardo Andrés; Galván Magaña, Felipe; Cruz Escalona, Víctor Hugo; Peterson, Mark S.; Rodriguez Romero, Jesús

    2011-01-01

    The daily food intake rates of the striped marlin, Kajikia audax (Perciformes: Istiophoridae), were estimated using qualitative and quantitative analyses of their trophic spectrum. We analyzed the stomach contents of 505 striped marlin caught by the sport fishing fleet off Cabo San Lucas, Baja California Sur, Mexico, sampled from October 1987 through December 1989. The most important preys were chub Mackerel (Scomber japonicus), California pilchard (Sardinops caeruleus), and jumbo squid (Dosi...

  4. 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

  5. 西藏札达地区早侏罗世双壳类Lithiotis生物岩礁的发现及其地质意义%Discovery of the early Juassic Lithiotis(Bivalvia) bioherm in Zhada area in Tibet and its geological implications

    Institute of Scientific and Technical Information of China (English)

    李金和; 孙苑迪; 夏祥

    2013-01-01

    西藏札达地区首次发现了早侏罗世Lithiotis生物岩礁,赋存于聂聂雄拉组的下部,属进积礁类型。 Lithiotis和相邻层位化石的发现,证明聂聂雄拉组的时代下限可以延伸到早侏罗世土阿辛期,此时札达地区的古地理条件处于能够适应Lithiotis大量繁衍的低纬度碳酸盐岩台地环境。%The discovery of the early Jurassic Lithiotis(Bivalvia) bioherm, for the first time in Zhada area in Tibet, is saved in the Nieniexiongla Formation's lower part and belong to the type of prograded reef. The discovery of the Lithiotis bioherm and the close horizon fossils proof the age of Nieniexiongla Formation's lower part extend to the Toarcian of the Early Jurassic time. The term of palaeogeograph of the this time Zhada area be placed in and can adapt to the low degree of latitude carbonate platform environment that Lithiotis multiply greatly.

  6. 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.

  7. Daily food intake of Kajikia audax (Philippi, 1887) off Cabo San Lucas, Gulf of California, Mexico Tasa de consumo diario de alimento de Kajikia audax (Philippi, 1887) frente a Cabo San Lucas, golfo de California, México

    OpenAIRE

    Leonardo A. Abitia-Cárdenas; Felipe Galván-Magaña; Víctor H Cruz-Escalona; Peterson, Mark S.; Jesús Rodríguez-Romero

    2011-01-01

    The daily food intake rates of the striped marlin, Kajikia audax (Perciformes: Istiophoridae), were estimated using qualitative and quantitative analyses of their trophic spectrum. We analyzed the stomach contents of 505 striped marlin caught by the sport fishing fleet off Cabo San Lucas, Baja California Sur, Mexico, sampled from October 1987 through December 1989. The most important preys were chub mackerel (Scomber japonicus), California pilchard (Sardinops caeruleus), and jumbo squid (Dosi...

  8. Daily food intake of Kajikia audax (Philippi, 1887 off Cabo San Lucas, Gulf of California, Mexico Tasa de consumo diario de alimento de Kajikia audax (Philippi, 1887 frente a Cabo San Lucas, golfo de California, México

    Directory of Open Access Journals (Sweden)

    Leonardo A Abitia-Cárdenas

    2011-11-01

    Full Text Available The daily food intake rates of the striped marlin, Kajikia audax (Perciformes: Istiophoridae, were estimated using qualitative and quantitative analyses of their trophic spectrum. We analyzed the stomach contents of 505 striped marlin caught by the sport fishing fleet off Cabo San Lucas, Baja California Sur, Mexico, sampled from October 1987 through December 1989. The most important preys were chub mackerel (Scomber japonicus, California pilchard (Sardinops caeruleus, and jumbo squid (Dosidicus gigas; together these represented ~55% of the striped marlin diet. The daily food consumption was estimated to be 2 kg per day, or ~3.6% of the mean body weight of K. audax. The total biomass of the prey consumed by the striped marlin during the 27 months of sampling around Los Cabos was estimated at 24.8 ton, of which the chub mackerel represented ~29% (7.2 ton, California pilchard just under 16% (3.9 ton, and jumbo squid ~10% (2.5 ton. The feeding habits of K. audax are discussed in terms of the distribution of the epipelagic (neritic and oceanic zones, demersal, and benthic prey, confirming that striped marlin migrate vertically and horizontally in search of their food.Se estimó la tasa de consumo diario de alimento del marlín rayado Kajikia audax (Perciformes: Istiophoridae, sobre la base de análisis cualitativos y cuantitativos de su espectro trófico. Se analizó el contenido estomacal de 505 ejemplares capturados por la flota deportiva frente a Cabo San Lucas, Baja California Sur, México muestreados de octubre 1987 a diciembre 1989. Las presas más importantes fueron la macarela del Pacífico (Scomber japonicus, sardina monterrey (Sardinops caeruleus y calamar gigante (Dosidicus gigas, que en conjunto representaron aproximadamente el 55% de la dieta. La tasa de consumo de alimento fue estimado en 2 kg diarios, lo cual representó aproximadamente el 3,6% del peso corporal de K. audax. La biomasa total de presas consumidas por el marlín rayado durante los 27 meses muestreados en la zona de Los Cabos fue estimada en 24,8 ton, de las cuales la macarela del Pacífico representó alrededor del 29% (7,2 ton, la sardina monterrey poco menos del 16% (3,9 ton y el calamar gigante aproximadamente el 10% (2,5 ton. Los hábitos alimentarios de K. audax se discutieron según la distribución de las presas epipelágicas (neríticas y oceánicas, demersales y bentónicas; lo cual confirmó la conducta migratoria (movimientos verticales y horizontales del marlín rayado en busca de su alimento.

  9. Revision of Plumarius Philippi 1873 (Hymenoptera: Chrysidoidea, Plumariidae) from Argentina north of Patagonia, with description of eighteen new species.

    Science.gov (United States)

    Diez, Patricia A; Roig-Alsina, Arturo

    2016-01-01

    Twenty six species of Plumarius from Argentina north of Patagonia are revised. Eighteen new species: Plumarius politus sp. nov., P. sarophorus sp. nov., P. globulosus sp. nov., P. angulatus sp. nov., P. noa sp. nov., P. divergens sp. nov., P. malaris sp. nov., P. gracilior sp. nov., P. riojanus sp. nov., P. exophthalmus sp. nov., P. planatus sp. nov., P. albinervis sp. nov., P. truncatus sp. nov., P. mikrommatus sp. nov., P. obscurus sp. nov., P. gracilis sp. nov., P. fidalgoi sp. nov., and P. ocellulatus sp. nov. are described and illustrated. A new record for known species as well as a key to 26 known species in the region is given. A redescription of P. tumidulus Papp, 2000, which is the first record of the family Plumariidae from Uruguay, is done. PMID:27394595

  10. 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.

  11. 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.

  12. Mollusca (terrestrial and marine Gastropods et Bivalvia from Morocco

    Directory of Open Access Journals (Sweden)

    Atanas Irikov

    2013-12-01

    Full Text Available Fifteen samples with molluscs are collected from various habitats and regions of Morocco, located in the seashore zone, as well as the central and the eastern parts of the country. We recorded 21 terrestrial and 15 marine species of molluscs. New localities and new species for the fauna of Morocco and the African continent are reported for the first time.

  13. An infection of Ruditapes decussatus (Bivalvia) by Rickettsia

    OpenAIRE

    Mialhe, Eric; Chagot, Dominique; Boulo, Viviane; Comps, Michel; Ruano, Francisco; Grizel, Henri

    1987-01-01

    The authors report the presence of a Rickettsia in Ruditapes decussatus from natural populations of the Algarve (Portugal). Light microscopic shows infections of varying importance in gill tissues. Some enclose small procaryotic colonies (cp) scattered in all lamellae; in others, the colonies are scarce and hypertrophic (100 mu m). These different pictures suggest an amplification process. Digestive diverticulae may also be infected, but to a lesser extent. The ultrastructural features of thi...

  14. Early Cretaceous Aucellina (bivalvia) from the Dajiashan area, northeastern China

    Science.gov (United States)

    Jiang, B. Y.; Huawei, Cai; Jingeng, Sha

    2004-07-01

    Aucellina is described systematically for the first time from the Dajiashan Formation of the Dajiashan area. Earlier, it had been identified as Otapiria. Based on the occurrence of Aucellina caucasica-Aucellina aptiensis-Aucellina acuminata assemblage, the age of the Dajiashan Formation is revised from Early Jurassic to Early Cretaceous and probably ranges from Late Barremian to Early Albian. In addition, the distribution of Aucellina, as well as the differentiation between Aucellina and Buchia, are discussed briefly in this paper.

  15. 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.

  16. A phylogenetic backbone for Bivalvia: an RNA-seq approach

    OpenAIRE

    González, Vanessa L.; Andrade, Sónia C. S.; Bieler, Rüdiger; Collins, Timothy M.; Dunn, Casey W.; Mikkelsen, Paula M.; Taylor, John D.; Giribet, Gonzalo

    2015-01-01

    Bivalves are an ancient and ubiquitous group of aquatic invertebrates with an estimated 10 000–20 000 living species. They are economically significant as a human food source, and ecologically important given their biomass and effects on communities. Their phylogenetic relationships have been studied for decades, and their unparalleled fossil record extends from the Cambrian to the Recent. Nevertheless, a robustly supported phylogeny of the deepest nodes, needed to fully exploit the bivalves ...

  17. Morphological and molecular diversity of Unionidae (Mollusca, Bivalvia from Portugal

    Directory of Open Access Journals (Sweden)

    Reis, J.

    2013-06-01

    Full Text Available Freshwater mussels from the family Unionidae are known to exhibit a high level of ecological phenotypic plasticity that is reflected in their shell shape. This variation has caused uncertainty on systematics and taxonomy of the group. Several naiad populations from nine river basins from Portugal were analyzed genetically, using two mitochondrial gene fragments (16SrRNA and Cytochrome Oxidase I and morphologically, using ANOVA analyses of shell dimmensions. Molecular phylogenetic analyses were used to revise the systematics and to infer an evolutionary hypothesis for the family at the western-most Atlantic Iberian Peninsula. Genetic and morphological data were in agreement and supported the occurrence of 5 species in the region: Anodonta anatina, Anodonta cygnea, Potomida littoralis, Unio tumidiformis and Unio delphinus. The differentiation of all these species, except A. cygnea, is thought to have taken place during the isolation of the Iberian Peninsula and formation of the current river basins in the Tertiary. The possibility of A. cygnea being a relatively recent introduction is discussed. Basic morphometric measures of the shell proved to be useful to separate Unio species, but also seem to be strongly affected by environmental conditions. The high intra-specific morphologic variation was partially related to the species’ high level of phenotypic plasticity, but seems to have an important role in evolutionary processes.Las náyades de la familia Unionidae tienen gran plasticidad fenotípica, lo que se refleja en la forma de su concha. Esta variabilidad morfológica ha sido causa de gran confusión en la taxonomía y sistemática del grupo. Se han estudiado, genética y morfológicamente, numerosas poblaciones de náyades provenientes de nueve cuencas hidrográficas portuguesas. Para ello se han analizando dos fragmentos de genes mitocondriales (ARNr 16S y Citocromo Oxidasa I así como diferentes variables morfológicas de la concha. Se han realizado además análisis filogenéticos para conocer la sistemática de la familia e inferir una hipótesis evolutiva de su distribución en el oeste de la península Ibérica. Los datos genéticos y morfológicos sugieren la existencia de cinco especies: Anodonta anatina, Anodonta cygnea, Potomida littoralis, Unio tumidiformis y Unio delphinus. La diferenciación de estas especies, con la excepción de A. cygnea, ha ocurrido durante el aislamiento de la península Ibérica y posterior formación de las actuales cuencas hidrográficas en el Terciario. Se discute la posibilidad de que la presencia de A. cygnea se deba a una introducción reciente. Los datos morfométricos analizados pueden ser útiles para separar las especies del género Unio, pero son también dependientes de las condiciones ambientales. La elevada variabilidad morfológica dentro de cada especie está relacionada con su plasticidad fenotípica, pero tiene a su vez un importante papel en el proceso evolutivo.

  18. Type specimens of Pectinidae (Bivalvia) described by Ignaz von Born

    NARCIS (Netherlands)

    Dijkstra, H.H.

    2009-01-01

    Born described in two publications (1778, 1780) the molluscs in the collection of Empress Maria Theresa (1717-1780), now in the Natural History Museum at Vienna. In this paper the Pectinidae type material is described. Ten new species were introduced of which Argopecten nucleus (Born, 1778) and Minn

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

    DEFF Research Database (Denmark)

    Jespersen, Åse; Lützen, Jørgen

    2006-01-01

    Reproduction and/or sperm structure was studied in 18 species belonging to five genera of Galeommatidae from Phuket Island, Andaman Sea, Thailand, and Hong Kong. Incubation of the ova occurs in the inner and outer demibranchs of both gills, and sperm is most probably transferred to the ctenidial ...

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

    DEFF Research Database (Denmark)

    Jespersen, Åse

    2009-01-01

    Males and females of the commensal protandric bivalve Pseudopythina subsinuata have paired seminal receptacles, the interior of which contains many slender elongate cells. The testis produces small euspermatozoa and comparatively few and much larger paraspermatozoa. The 16-µm-long and 3-5-µm-thic...

  1. 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.

  2. Variación ontogenética en la palatibilidad de los renacuajos de Bufo spinulosus papillosus Philippi, 1902 (Anura: Bufonidae

    Directory of Open Access Journals (Sweden)

    Jara, Fabián Gastón

    2006-03-01

    Full Text Available Se evaluó la variación ontogenética de la palatabilidad en Bufo spinulosus papillosus expuestos a larvas del odonato Rhionaeshna variegata (Odonata, Aeshnidae. Los renacuajos fueron agrupados en cuatro categorías de desarrollo y fueron expuestos a la depredación directa determinándose el número de renacuajos consumidos al finalizar los experimentos. Bufo spinulosus papillosus no fue palatable en los primeros estadios del desarrollo (categorías I, estadios 24-26 y categoría II, estadios 32-34, mientras que los estadios de las categoría III (estadios 38-40 y categoría IV (estadios 42-45 fueron progresivamente palatables. Se observó un comportamiento de rechazo por parte de los depredadores luego de la captura de renacuajos de las categorías I y II. El patrón de palatabilidad encontrado en Bufo spinulosus papillosus difiere del observado en otras especies relacionadas del género Bufo (Brodie y Formanowicz, 1987; Kehr y Schnack, 1991; Lawler y Hero, 1997. We evaluated the ontogenetic variation in the palatability of Bufo spinulosus papillosus tadpoles exposed to odonate larvae of Rhionaeshna variegata (Odonata, Aeshnidae. We exposed tadpoles to direct predation and determined the number of consumed tadpoles in four developmental categories. Bufo spinulosus papillosus tadpoles of categories I (stages 24-26 and II (stages 32-34 were unpalatable, while categories III (stages 38-40 and IV (stages 42-45 were progressively palatable. We observed a post-capture rejection behavior when they caught unpalatable tadpoles in categories I and II. The palatability pattern observed in Bufo spinulosus papillosus was different from related Bufo species (Brodie and Formanowicz, 1987; Kehr and Schnack, 1991; Lawler and Hero, 1997.

  3. Accumulation of toxic metals (Pb and Cd) in the sea urchin Diadema aff. antillarum Philippi, 1845, in an oceanic island (Tenerife, Canary Islands).

    Science.gov (United States)

    Hernández, Ofelia Dolores; Gutiérrez, Angel José; González-Weller, Dailos; Lozano, Gonzalo; Melón, Enrique García; Rubio, Carmen; Hardisson, Arturo

    2010-06-01

    This document shows the results obtained from a study on the concentration of toxic heavy metals in the internal tissue and exoskeleton of sea urchins, collected from their natural habitat. The levels of lead and cadmium were measured by Graphite Furnace Atomic Absorption Spectrometry. The mean concentrations of lead and cadmium in the internal tissue were 304.04 and 260.54 microg/kg respectively, whereas in the shell they were 185.02 and 142.48 microg/kg. We also performed a statistical analysis of the differences in the distribution of metals between their exoskeleton and their internal content, a correlation study of the metal content in internal tissue and shell and sampling areas, and a correlation study between the metal content and sample size. Since the sea urchin Diadema antillarum presents a wide range of variation in metal content, this study suggests that this species is an excellent bioindicator of heavy metal contamination.

  4. The glance of travellers and scientists of the 19th century about the moving "gea chilensis"

    Directory of Open Access Journals (Sweden)

    M Zenobio Saldivia

    2014-01-01

    Full Text Available This paper analyses the vision of Chilean nature and the impact of earthquakes on the physical body of Chile and in the national collective imagination, that were forged Chilean and foreign nineteenth-century scientists and travelers with some natural history studies as Mary Graham. And from such perceptions reflect on whether to take in to account this reality in the fields of public policy and education.

  5. [Storage of cereal bars with mesquite cotyledon (Prosopis chilensis (Mol) Stuntz)].

    Science.gov (United States)

    Escobar, B; Estévez, A M; Guiñez, M A

    2000-06-01

    The use of walnut or peanut in the elaboration of cereal bars represents a possible risk of undesirable changes during their storage due to their high content of unsaturated fatty acids in the oil; oxidizing of the fatty acids is one of the main causes of deterioration. Development of new snack products implies the use of packages that should protect the food against the damage caused by light and reduce the oxygen concentration of in their interior. The objective of this investigation was to evaluate the physical, chemical and sensory changes in the storage of cereal bars with peanut or walnut and mezquite cotyledon subjected to two thermal treatments, packed in cellophane or milky polypropilene. Four types of bars were elaborated with 6% of mezquite cotyledon, treated by microwaves or toasted, and with 18% of peanut or walnut. The bars were stored for 90 days at room temperature; and each 30 days it was measured moisture content, peroxides index, water activity, sensory quality and acceptability. The peroxides values (4.9-13.8 meq/kg of oil) indicates that the shelf life of the bars in all the studied treatments was 90 days. The packaging materials used allows to maintain in good conditions, for 3 months, the cereals bars of moisture (7.4-11.2%), water activity (0.50-0.65) and sensory acceptability.

  6. The glance of travellers and scientists of the 19th century about the moving "gea chilensis"

    OpenAIRE

    M Zenobio Saldivia

    2014-01-01

    This paper analyses the vision of Chilean nature and the impact of earthquakes on the physical body of Chile and in the national collective imagination, that were forged Chilean and foreign nineteenth-century scientists and travelers with some natural history studies as Mary Graham. And from such perceptions reflect on whether to take in to account this reality in the fields of public policy and education.

  7. Caracterización del aceite de coquito de palma chilena (Jubaea chilensis

    Directory of Open Access Journals (Sweden)

    Torija, M. Esperanza

    2008-03-01

    Full Text Available The characteristics of the seeds from Chilean palm and the detailed composition of its fat are studied starting from 4 lots of seeds from the two regions being the major producers of Chilean palm seeds. From the proximate composition of the seeds a high content of fats is deduced with a mean value of 67.3%. The contents of proteins, carbohydrates and fibre were in the range of 7-11%. A detailed analysis of the fat indicates a high content of saturated fatty acids being capric, caprilic, lauric and miristic acids the major fatty acids. For this reason the presence of a high percentage of medium-chain triglycerides are detected in the triglyceride analysis. As for tocopherols, the fat contains low amounts of α-, γ- y δ-tocopherol with a total average of 84 mg/kg. Concerning phytosterols, the total content was around 1000 mg/kg being β-sitosterol and Δ7-estigmastenol the two major sterolsSe analizan las características generales del coquito de palma chilena y se estudia con detalle la composición de su aceite. Con este objetivo, se analizan 4 lotes de coquitos procedentes de las dos regiones de Chile donde existe mayor producción. La composición proximal del coquito indica un contenido muy mayoritario de grasa, con un promedio de 67,3% mientras los contenidos de proteínas, hidratos de carbono y fibra se encuentran entre el 7 y el 11%. Un análisis detallado de la grasa muestra un contenido elevado de ácidos grasos saturados (alrededor del 85% siendo los ácidos cáprico, caprílico, láurico y mirístico los que se encuentran en mayor concentración, lo que origina un elevado porcentaje de triglicéridos de cadena media. Respecto a los tocoferoles, el aceite contiene cantidades limitadas de α-, γ- y δ-tocoferol con un valor promedio total de 84 mg/kg, no detectándose la presencia de tocotrienoles. Respecto a los fitoesteroles, el contenido total es del orden de 1000 mg/kg siendo los esteroles mayoritarios el β-sitosterol y el Δ7-estigmastenol.

  8. Digital Native Chilensis: The Young people, of South of the Internet

    Directory of Open Access Journals (Sweden)

    Lic. Felipe Andres Nesbet Montecinos

    2008-01-01

    Full Text Available It is undeniable that the Internet has a capital importance in the contemporary society. In the new technological paradigm, known as the Information Age, the relevance of the network is equivalent to that of oil in the Industrial Age. Although we can dissent of the prediction done by Nicholas Negroponte in 1995, in its famous book “Being Digital”, with respect to which the digital divide would be translated in a subject, net, generational, expressed in the dichotomy: young person-rich versus old-poor men. However, this author (1995 guessed right in his theory of the greater facility of the young people towards the new technologies. For that reason, the Internet is dominated by young people. The appearance of Wena Naty, a video uploaded to the network (with the explicit consent of their protagonists in which a 14 year old girl practiced oral sex to a partner in a public square, is the most dramatic demonstration of the use and abuse that young Chileans make new technologies.The present article reviews data collected on the use of technologies in Chile (INJUV 2002, Godoy 2006 y PNUD 2006. As well as it analyzes collected own data from the investigations of Carcamo “Percepción del tiempo y de la motivación ante tareas de búsqueda de información y conferencias de texto (Chat mediadas por computador en estudiantes secundarios de Chile” and Nesbet (2007, “Usos de la mensajería instantánea en estudiantes secundarios de Valdivia.”

  9. [Storage of cereal bars with mesquite cotyledon (Prosopis chilensis (Mol) Stuntz)].

    Science.gov (United States)

    Escobar, B; Estévez, A M; Guiñez, M A

    2000-06-01

    The use of walnut or peanut in the elaboration of cereal bars represents a possible risk of undesirable changes during their storage due to their high content of unsaturated fatty acids in the oil; oxidizing of the fatty acids is one of the main causes of deterioration. Development of new snack products implies the use of packages that should protect the food against the damage caused by light and reduce the oxygen concentration of in their interior. The objective of this investigation was to evaluate the physical, chemical and sensory changes in the storage of cereal bars with peanut or walnut and mezquite cotyledon subjected to two thermal treatments, packed in cellophane or milky polypropilene. Four types of bars were elaborated with 6% of mezquite cotyledon, treated by microwaves or toasted, and with 18% of peanut or walnut. The bars were stored for 90 days at room temperature; and each 30 days it was measured moisture content, peroxides index, water activity, sensory quality and acceptability. The peroxides values (4.9-13.8 meq/kg of oil) indicates that the shelf life of the bars in all the studied treatments was 90 days. The packaging materials used allows to maintain in good conditions, for 3 months, the cereals bars of moisture (7.4-11.2%), water activity (0.50-0.65) and sensory acceptability. PMID:11048587

  10. High population density survival of the sea urchin Diadema antillarum (Philippi 1845 to a category 5 hurricane in southern Mexican Caribbean Supervivencia de una alta densidad poblacional del erizo de mar Diadema antillarum (Philippi 1845 a un huracán categoría 5 en el sur del Caribe mexicano

    Directory of Open Access Journals (Sweden)

    Pablo Jorgensen

    2008-12-01

    Full Text Available The vulnerability of the sea urchin Diadema antillarum to the impact of the category 5 hurricane "Dean" was assessed at a back-reef area of Mahahual (Southern Mexican Caribbean. Seventy days after Dean, there was a high mean Diadema population density of 12.6 ± 4.3 (SD; from here forward ind m-2, with a large mean individual test diameter of 59.2 ±9.8 mm. This population was comparable to a previous report for the same area, just before the landfall of Dean on 21 August 2007. Immigration of adults from deeper fore-reef sites after Dean across the reef-crest was unlikely, considering the homing behavior displayed by tagged urchins. The degree of physical alteration of the habitat indicated that Diadema may survive higher hurricane-generated disturbances than those reported in previous works. These results have strong implications on the conservation of the Mexican Caribbean coral reefs since the Diadema populations surveyed have a high grazing activity and are persistent against hurricanes impact.La vulnerabilidad del erizo de mar Diadema antillarum al impacto del huracán categoría 5 "Dean" fue evaluada en el arrecife posterior de Mahahual, México. Setenta días después de la recalada de Dean fue estimada una alta densidad media poblacional de Diadema de 12.6 ind m-2 (DE = 4.3, con un elevado tamaño individual promedio de 59.2 mm de diámetro (DE = 9.8. Esta densidad fue comparable a la de un reporte previo para la misma zona, días antes del paso de Dean el 21 de agosto de 2007. Considerando la fidelidad al refugio mostrado por erizos marcados, la inmigración de adultos desde el arrecife anterior después del paso de Dean fue poco factible. El nivel de destrucción del hábitat indica que Diadema sería más persistente al impacto directo de huracanes que lo sugerido por estudios anteriores. Debido al elevado potencial de pastoreo de las poblaciones locales de Diadema, y a su persistencia al impacto de huracanes, los resultados de este estudio tienen fuertes implicaciones para la conservación de los arrecifes coralinos del Caribe mexicano.

  11. Development of dye-sensitized solar cells based on naturally extracted dye from the maqui berry (Aristotelia chilensis)

    Science.gov (United States)

    Leyrer, Julio; Hunter, Renato; Rubilar, Monica; Pavez, Boris; Morales, Eduardo; Torres, Simont

    2016-10-01

    The mini modules of dye-sensitized solar cells (DSSCs) were investigated for their conversion efficiency using anthocyanin-enriched extracts from maqui berry, which to date has never been tested in a DSSC. Anthocyanins are a group of red, purple, violet and blue water-soluble polyphenolic pigments widely found in berry fruits. Maqui berries are a particularly rich source. The aqueous extract concentrations of maqui fruit were tested at 750 and 1500 mg of anthocyanin/L. The immersion time to produce sensitized TiO2 film was 8 h. According to the experimental results, the conversion efficiency of the DSSC prepared with 750 mg of anthocyanin/L was 0.14%, with an open-circuit voltage (VOC) of 0.43 V, a short-circuit current density (JSC) of 0.38 mA/cm2, and a fill factor (FF) of 0.450. The conversion efficiency attained with 1500 mg of anthocyanin/L was 0.19%, with (VOC) of 0.45 V, (JSC) of 0.44 mA/cm2 and FF of 0.55. Therefore, a higher concentration brought about a higher photosensitized performance. The maqui extracts were successfully dye sensitized over a layer of TiO2 nanoparticles, providing useful information for further studies related to the use of natural pigments as sensitizers for solar cells.

  12. 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.

  13. 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.

  14. Introduction of the alien Xenostrobus securis (Bivalvia: Mytilidae) into Hong Kong, China: interactions with and impacts upon native species and the earlier introduced Mytilopsis sallei (Bivalvia: Dreissenidae).

    Science.gov (United States)

    Morton, Brian; Leung, K F

    2015-03-15

    This constitutes the first record of the Australian alien mytilid Xenostrobus securis in China. The introduction occurred prior to 2010 probably via shipping arriving at Yantian in Mirs Bay, China, close to Hong Kong. Point sources of infection could be Australia or Korea or Japan where it has similarly been introduced. Analysis of X. securis in Hong Kong shows that it tolerates a wide range of salinities from 5.4‰ to 28.7‰. Water temperatures in Hong Kong match those in its native range. In Hong Kong, X. securis co-occurs with the similarly introduced Mytilopsis sallei and a native bivalve community. The population structure of X. securis suggests a lifespan of >2 years with new generations produced by conspecifics. Such a life history strategy is also exhibited by M. sallei. Now established in China, northern Asia, the Mediterranean and, most recently, the Iberian Atlantic, the invasion of other locations by X. securis seems probable. PMID:25599632

  15. 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...

  16. Desarrollo embrionario y larval temprano de Gari solida (Gray, 1828 (Bivalvia: Psammobiidae

    Directory of Open Access Journals (Sweden)

    Ramiro Contreras

    2014-03-01

    Full Text Available Se describe el desarrollo temprano del culengue (Gari solida (Gray, 1828 hasta el estado inicial de larva velígera, a partir de dos desoves efectuados en el verano de 2009. El desove se indujo a 80 ejemplares maduros, entre 50-60 mm de longitud valvar, mediante desecación a temperatura ambiente por aproximadamente media hora y posterior choque térmico (12-14°C y 23-25°C. Los reproductores fueron previamente acondicionados durante 90 días a 14°C en promedio, alimentados con Isochrysis aff galbana (T-Iso, Chaetoceros calcitrans y Tetraselmis suecica en proporción 1:1:1, a una concentración de 300.000 cel mL-1. Los ovocitos se fertilizaron en proporción de 10:1 espermatozoide/ovocito y se incubaron en estanques de 50 L, a 15 ± 0,8°C, sin aireación, con agua de mar filtrada a 1 μm e irradiada con luz ultravioleta. Se efectuaron observaciones y mediciones de los estados de embriogénesis y larva velígera tipo D, registrándose el tiempo de duración de cada fase. La embriogénesis se completó entre 23-24 h post- fecundación (pf y el estado de larva velígera tipo D se alcanzó en 36-37 h pf, midiendo 78 ± 4,7 μm de longitud. Una cubierta gelatinosa rodea al ovocito y se mantiene hasta que se desarrolla completamente la larva D libre nadadora, en 50-52 h pf. Este trabajo constituye un primer reporte sobre el desarrollo temprano de G. solida. Para profundizar en este conocimiento sería deseable incluir técnicas de microscopía electrónica en futuros estudios.

  17. 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.

  18. 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.

  19. [Population dynamic of Donax denticulatus (Bivalvia: Donacidae) at Carenero Beach, Southeastern Cuba].

    Science.gov (United States)

    Ocaña, Frank A; Apín, Yanet C; Cala, Yuself R

    2013-12-01

    Bivalve molluscs of Donax genus are a very important component of macro-invertebrate assemblages of sandy beaches, and some species are of commercial value in different countries. Although in Cuba Donax denticulatus is not a currently exploited species, the information concerning a stock assessment is a basic step for future use of this resource. With the aim to generate new data on this species structure, growth and secondary production, monthly samples of D. denticulatus were taken from a beach of the Southeastern coast of Cuba, from February to December 2008. Samples were taken from four stations located along the beach; three strata were marked (P1, P2 and P3) per station across the intertidal zone. Three replicated samples of sediments were taken from each stratum with a 0.025 m2 PVC core and were posteriorly sieved with a 1 mm mesh. Histograms of shell length were constructed based on 1 mm intervals and growth parameters were estimated using ELEFAN I routine of FISAT. Mean density ranged from 146.67-855.55 ind./m2 and no differences were found among months (ANOVA, p > 0.05) but among strata (Scheffé, p < 0.05). An association of recruits, young and adults abundances with the strata (chi2, p < 0.01) was found. Most of the recruits were found in the upper strata while young and adult individuals were abundant in the mid-lower strata. Size frequency histograms of this population showed recruitment between March-June. Growth parameters estimated by Von Bertalanffy were Linfinity = 27.5 mm and K = 1.5/year; and the life spam was estimated in 1.5 years. Using the length-converted catch curve, the mortality rate (Z) was estimated in 4.97/year. Based in terms of Ash free dry mass (AFDM), mean biomass was estimated in 0.47 g/m2.year and the somatic production in 12.4 g/m2.year. The renewal rate (P/B) estimated for this population was 26.38, the highest among other Donax populations. High densities, fast growth and high somatic production indicate that this population can be exploited for fishing purposes for which some management measures are proposed.

  20. Changes of shell microstructural characteristics of Cerastoderma edule (Bivalvia) — A novel proxy for water temperature

    NARCIS (Netherlands)

    Milano, S.; Schöne, B.R.; Witbaard, R.

    2016-01-01

    Shells of bivalves potentially provide an excellent archive for high-resolution paleoclimate studies. However,quantification of environmental variables, specifically water temperature remains a very challenging task.Here, we explore the possibility to infer water temperature from changes of microstr

  1. Lifespan, growth rate, and body size across latitude in marine Bivalvia, with implications for Phanerozoic evolution.

    Science.gov (United States)

    Moss, David K; Ivany, Linda C; Judd, Emily J; Cummings, Patrick W; Bearden, Claire E; Kim, Woo-Jun; Artruc, Emily G; Driscoll, Jeremy R

    2016-08-17

    Mean body size in marine animals has increased more than 100-fold since the Cambrian, a discovery that brings to attention the key life-history parameters of lifespan and growth rate that ultimately determine size. Variation in these parameters is not well understood on the planet today, much less in deep time. Here, we present a new global database of maximum reported lifespan and shell growth coupled with body size data for 1 148 populations of marine bivalves and show that (i) lifespan increases, and growth rate decreases, with latitude, both across the group as a whole and within well-sampled species, (ii) growth rate, and hence metabolic rate, correlates inversely with lifespan, and (iii) opposing trends in lifespan and growth combined with high variance obviate any demonstrable pattern in body size with latitude. Our observations suggest that the proposed increase in metabolic activity and demonstrated increase in body size of organisms over the Phanerozoic should be accompanied by a concomitant shift towards faster growth and/or shorter lifespan in marine bivalves. This prediction, testable from the fossil record, may help to explain one of the more fundamental patterns in the evolutionary and ecological history of animal life on this planet. PMID:27488653

  2. 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

  3. Isolation by distance and low connectivity in the peppery furrow shell Scrobicularia plana (Bivalvia)

    NARCIS (Netherlands)

    Santos, Silvia; Cruzeiro, Catarina; Olsen, Jeanine L.; van der Veer, Henk W.; Luttikhuizen, Pieternella C.

    2012-01-01

    Scrobicularia plana da Costa, 1778, a commercially important bivalve species in southern Europe, is commonly found along the NE Atlantic and Mediterranean coasts. Like other intertidal mollusk species, it has a wide distributional range and high potential for larval dispersal. However, S. plana has

  4. 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

  5. Intraspecific phylogeography of Lasmigona subviridis (Bivalvia: Unionidae): Conservation implications of range discontinuity

    Science.gov (United States)

    King, T.L.; Eackles, M.S.; Gjetvaj, B.; Hoeh, W.R.

    1999-01-01

    A nucleotide sequence analysis of the first internal transcribed spacer region (ITS-1) between the 5.8S and 18S ribosomal DNA genes (640 bp) and cytochrome c oxidase subunit I (COI) of mitochondrial DNA (mtDNA) (576 bp) was conducted for the freshwater bivalve Lasmigona subviridis and three congeners to determine the utility of these regions in identifying phylogeographic and phylogenetic structure. Sequence analysis of the ITS-1 region indicated a zone of discontinuity in the genetic population structure between a group of L. subviridis populations inhabiting the Susquehanna and Potomac Rivers and more southern populations. Moreover, haplotype patterns resulting from variation in the COI region suggested an absence of gene exchange between tributaries within two different river drainages, as well as between adjacent rivers systems. The authors recommend that the northern and southern populations, which are reproductively isolated and constitute evolutionarily significant lineages, be managed as separate conservation units. Results from the COI region suggest that, in some cases, unionid relocations should be avoided between tributaries of the same drainage because these populations may have been reproductively isolated for thousands of generations. Therefore, unionid bivalves distributed among discontinuous habitats (e.g. Atlantic slope drainages) potentially should be considered evolutionarily distinct. The DNA sequence divergences observed in the nuclear and mtDNA regions among the Lasmigona species were congruent, although the level of divergence in the COI region was up to three times greater. The genus Lasmigona, as represented by the four species surveyed in this study, may not be monophyletic.

  6. 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 ...

  7. 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.

  8. 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.

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

    Directory of Open Access Journals (Sweden)

    Daniel García-Souto

    2016-08-01

    Full Text Available 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.

  10. 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...

  11. Diversity of Edible Mollusc (Gastropoda and Bivalvia at Selected Divison of Sarawak, Malaysia

    Directory of Open Access Journals (Sweden)

    Hadi Hamli

    2012-01-01

    Full Text Available Diversity of edible mollusc was studied at eight divisions of Sarawak from August 2010 to May 2011. At each division, diversity and number of species were collected from road site selling out lets and local wet markets. Total number of mollusc was comprised of 29 species namely  Solen regularies, S. lamarckii,  Pharella acutidens, Anadara granosa, Pholas orientalis, Gluconome virens, Circe scripta, Anodonta woodina, Paphia undulata, Amusium pleuronectes, Meretrix meretrix, M. lyrata, Polymesoda bengalensis, P. erosa and P. expansa  for bivalve and  Cerithidea rizophorarum, C. obtusa, Telescopium telescopium, Clithon retropictus, Nerita articulate, N. chamaeleon, N. albicilla, Ellobium aurisjuda, Trochus radiates, Planaxis sulcatus, Monodonta labio, Turbo crasus, Thais aculate  and Melo melo  for gastropod. The species number of bivalve was recorded highest (15 species in mollusc group from Sarawak. Mollusc diversity was found highest (14 species in Bintulu and lowest (1 species in the division of Sarikei. From this study, there is a wide chance of research to further explore both on the possibility of commercial value and ecosystem conservation.

  12. 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

  13. 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.

  14. 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.

  15. [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

  16. 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.

  17. 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...

  18. 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.)

  19. NUCINELLA ALIBRANDI (CONTI, 1864 AND N. SEGUENZAE (DALL, 1898,THE LAST EUROPEAN NUCINELLIDS (BIVALVIA, PROTOBRANCHIA

    Directory of Open Access Journals (Sweden)

    RAFAEL LA PERNA

    2004-07-01

    Full Text Available The revision of the genus Nucinella Wood, 1851 from the Italian Pleistocene led to the identification of two species, Nucinella alibrandi (Conti, 1864 and N. seguenzae (Dall, 1898. The former is from the continental shelf deposit of Monte Mario (Rome, the latter from upper slope deposits in Southern Italy (Calabria and Messina. The two species are very similar to each other and differ mainly in the anterior features of hinge. The peculiar hinge of Nucinella is examined in detail and its ontogenetic changes are reported. The Tertiary to Quaternary palaeobiogeographic history of Nucinella in the European area proves the Tethyan origins of this genus. Since the closure of the seaway to the Indo-Pacific in the Early Miocene, Nucinella survived in the European waters as a Tethyan relict until the Plio-Pleistocene, when cooling caused its definitive disappearance. N. alibrandi and N. seguenzae are the last representatives of the genus in the European waters.

  20. The Chamidae family (Bivalvia: Venerida in Peru, with the addition of five new records

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    Franz Cardoso

    2016-05-01

    Full Text Available The family Chamidae in Peru is revised, which includes eleven species, distributed in the genus Arcinella Schumacker, 1817 and Chama Linnaeus, 1758. Chama frondosa Broderip, 1835, Chama granti (Strong, 1934, Chama hicksi Valentich-Scott & Coan, 2010, Chama janus Reeve, 1847 and Chama producta Broderip, 1835 are recorded for the first time. Descriptions and data about distribution, ecology and other remarks are given for all species.

  1. The Recent Pectinoidea of the New Zealand region (Mollusca: Bivalvia: Propeamussiidae, Pectinidae and Spondylidae)

    NARCIS (Netherlands)

    H.H. Dijkstra; B.A. Marshall

    2008-01-01

    The Recent Pectinoidea of the New Zealand region are reviewed. Eight new species are described from the New Zealand Exclusive Economic Zone: Parvamussium cancellorum, Cyclochlamys austrina, Cc. delli, Cc. irregularis, Cc. munida, Cc. pileolus, Cyclopecten fluctuosus, and Catillopecten tasmani. Nine

  2. 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

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

    OpenAIRE

    Sonia Maria Lima Santos; Claudia Helena Tagliaro; Colin Robert Beasley; Horacio Schneider; Iracilda Sampaio; Carlos Santos Filho; Ana Cláudia de Paula Müller

    2005-01-01

    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 w...

  4. Analysis of the shapes of hemocytes of Callista brevisiphonata in vitro (Bivalvia, Veneridae).

    Science.gov (United States)

    Karetin, Yu A; Pushchin, I I

    2015-08-01

    Fractal formalism in conjunction with linear methods of image analysis is suitable for the comparative analysis of such "irregular" shapes (from the point of view of classical Euclidean geometry) as flattened amoeboid cells of invertebrates in vitro. Cell morphology of in vitro spreading hemocytes from the bivalve mollusc Callista brevisiphonata was analyzed using correlation, factor and cluster analysis. Four significantly different cell types were identified on the basis of 36 linear and nonlinear parameters. The analysis confirmed the adequacy of the selected methodology for numerical description of the shape and the adequacy of classification of nonlinear shapes of spread hemocytes belonging to the same species. Investigation has practical significance for the description of the morphology of cultured cells, since cell shape is a result of summation of a number of extracellular and intracellular factors.

  5. The contrasted evolutionary fates of deep-sea chemosynthetic mussels (Bivalvia, Bathymodiolinae)

    OpenAIRE

    Thubaut, Justine; Puillandre, Nicolas; Faure, Baptiste; Cruaud, Corinne; Samadi, Sarah

    2013-01-01

    International audience; Bathymodiolinae are giant mussels that were discovered at hydrothermal vents and harboring chemosynthetic symbionts. Due to their close phylogenetic relationship with seep species and tiny mussels from organic substrates, it was hypothesized that they gradually evolved from shallow to deeper environments, and specialized in decaying organic remains, then in seeps, and finally colonized deep-sea vents. Here, we present a multigene phylogeny that reveals that most of the...

  6. 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.

  7. 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.

  8. Comparative Large-Scale Mitogenomics Evidences Clade-Specific Evolutionary Trends in Mitochondrial DNAs of Bivalvia.

    Science.gov (United States)

    Plazzi, Federico; Puccio, Guglielmo; Passamonti, Marco

    2016-01-01

    Despite the figure of complete bivalve mitochondrial genomes keeps growing, an assessment of the general features of these genomes in a phylogenetic framework is still lacking, despite the fact that bivalve mitochondrial genomes are unusual under different aspects. In this work, we constructed a dataset of one hundred mitochondrial genomes of bivalves to perform the first systematic comparative mitogenomic analysis, developing a phylogenetic background to scaffold the evolutionary history of the class' mitochondrial genomes. Highly conserved domains were identified in all protein coding genes; however, four genes (namely, atp6, nad2, nad4L, and nad6) were found to be very divergent for many respects, notwithstanding the overall purifying selection working on those genomes. Moreover, the atp8 gene was newly annotated in 20 mitochondrial genomes, where it was previously declared as lacking or only signaled. Supernumerary mitochondrial proteins were compared, but it was possible to find homologies only among strictly related species. The rearrangement rate on the molecule is too high to be used as a phylogenetic marker, but here we demonstrate for the first time in mollusks that there is correlation between rearrangement rates and evolutionary rates. We also developed a new index (HERMES) to estimate the amount of mitochondrial evolution. Many genomic features are phylogenetically congruent and this allowed us to highlight three main phases in bivalve history: the origin, the branching of palaeoheterodonts, and the second radiation leading to the present-day biodiversity.

  9. The Marine Mollusca of Suriname (Dutch Guiana) Holocene and recent Part II. Bivalvia and Scaphopoda

    NARCIS (Netherlands)

    Regteren Altena, van C.O.

    1971-01-01

    "The student must know something of systematic work. This is populary supposed to be a dry-as-dust branch of zoology. In fact, the systematist may be called the dustman of biology, for he performs a laborious and frequently thankless task for his fellows, and yet it is one which is essential for the

  10. Uncovering a gene duplication of the photoreceptive protein, opsin, in scallops (Bivalvia: Pectinidae).

    Science.gov (United States)

    Serb, Jeanne M; Porath-Krause, Anita J; Pairett, Autum N

    2013-07-01

    Evolutionary biologists have long been interested in how expansions of the photosensory system might contribute to morphological differentiation of animals. Comparative studies in vertebrate and arthropod lineages have provided considerable insight into how the duplication of opsin, the first gene of the phototransduction pathway, have led to functional differentiation and new ecological opportunities; however, this relationship cannot be examined in many invertebrate groups as we have yet to characterize their opsin content. Scallops (Pectinidae) are a promising molluscan model to study the evolution of opsin and its potential role in speciation. Recently, we discovered a second Gq-coupled, or r-, opsin gene expressed in the eyes of two scallop species. To investigate the evolutionary origin of this opsin, we screened 12 bivalve species from 4 families, representing both mobile and sessile species, with and without eyes. Although only one ortholog was recovered from the genome of the eyeless, immobile oyster, we found both genes to have been retained in 3 families comprising the order Pectinoida. Within this clade, non-mobile species of scallops appear to have lost one gene. Phylogeny-based tests of selection indicate different degrees of purifying selection following duplication. These data, in conjunction with highly divergent gene sequences and ortholog-specific retention, suggest functional differences. Our results are congruent with a Gq-opsin gene duplication in an oyster-Pectinoida ancestor, approximately 470 Mya, and suggest the likelihood of retaining both genes is associated with either the presence of eyes and/or degree of mobility. The identification of two highly divergent Gq-opsin genes in scallops is valuable for future functional investigations and provides a foundation for further study of a morphologically and ecologically diverse clade of bivalves that has been understudied with respect to visual ecology and diversification of opsin.

  11. Phylogeny and androgenesis in the invasive Corbicula clams (Bivalvia, Corbiculidae in Western Europe

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    Descy Jean-Pierre

    2011-05-01

    Full Text Available Abstract Background The genus Corbicula is one of the most invasive groups of molluscs. It includes both sexual and androgenetic lineages. The present study re-assessed the different morphotypes and haplotypes of West European Corbicula in order to clarify their taxonomic identification and phylogenetic relationships with American and Asian Corbicula clams. We studied several populations from West European river basins (Meuse, Seine, Rhine and Rhône through an "integrative taxonomy" approach. We combined morphology, partial mitochondrial COI and cyt b sequences and eleven microsatellite loci. Furthermore, we looked for discrepancies between mtDNA and nrDNA/morphology, indicative of androgenesis between lineages. Results There are three Corbicula morphotypes in Western Europe associated to three mitochondrial lineages and three genotypes. Form R shares the same COI haplotype as the American form A and the Japanese C. leana. Form S and the American form C have the same haplotype, although their morphologies seem divergent. The European form Rlc belongs to the same mitochondrial lineage as both the American form B and the Asian C. fluminea. Interestingly, within each haplotype/genotype or lineage, no genetic diversity was found although their invasive success is high. Moreover, we detected rare mismatches between mtDNA and nrDNA/morphology, indicative of androgenesis and mitochondrial capture between form R and form S and therefore challenging the phylogenetic relatedness and the species status within this genus. The global phylogenetic analysis revealed that the sexual Corbicula lineages seem restricted to the native areas while their androgenetic relatives are widespread and highly invasive. Conclusions We clarified the discrepancies and incongruent results found in the literature about the European morphotypes of Corbicula and associated mitochondrial lineages. The three West European morphotypes belong to three distinct nuclear and mitochondrial lineages. However mitochondrial capture occurs in sympatric populations of forms R and S. The species status of the morphotypes therefore remains doubtful. Moreover the androgenetic lineages seem widely distributed compared to their sexual relatives, suggesting that androgenesis and invasive success may be linked in the genus Corbicula.

  12. 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.

  13. Identifying the true oysters (Bivalvia: Ostreidae) with mitochondrial phylogeny and distance-based DNA barcoding.

    Science.gov (United States)

    Liu, Jun; Li, Qi; Kong, Lingfeng; Yu, Hong; Zheng, Xiaodong

    2011-09-01

    Oysters (family Ostreidae), with high levels of phenotypic plasticity and wide geographic distribution, are a challenging group for taxonomists and phylogenetics. As a useful tool for molecular species identification, DNA barcoding might offer significant potential for oyster identification and taxonomy. This study used two mitochondrial fragments, cytochrome c oxidase I (COI) and the large ribosomal subunit (16S rDNA), to assess whether oyster species could be identified by phylogeny and distance-based DNA barcoding techniques. Relationships among species were estimated by the phylogenetic analyses of both genes, and then pairwise inter- and intraspecific genetic divergences were assessed. Species forming well-differentiated clades in the molecular phylogenies were identical for both genes even when the closely related species were included. Intraspecific variability of 16S rDNA overlapped with interspecific divergence. However, average intra- and interspecific genetic divergences for COI were 0-1.4% (maximum 2.2%) and 2.6-32.2% (minimum 2.2%), respectively, indicating the existence of a barcoding gap. These results confirm the efficacy of species identification in oysters via DNA barcodes and phylogenetic analysis.

  14. Convergent and parallel evolution in life habit of the scallops (Bivalvia: Pectinidae)

    OpenAIRE

    Puslednik Louise; Alejandrino Alvin; Serb Jeanne M

    2011-01-01

    Abstract Background We employed a phylogenetic framework to identify patterns of life habit evolution in the marine bivalve family Pectinidae. Specifically, we examined the number of independent origins of each life habit and distinguished between convergent and parallel trajectories of life habit evolution using ancestral state estimation. We also investigated whether ancestral character states influence the frequency or type of evolutionary trajectories. Results We determined that temporary...

  15. Convergent and parallel evolution in life habit of the scallops (Bivalvia: Pectinidae

    Directory of Open Access Journals (Sweden)

    Puslednik Louise

    2011-06-01

    Full Text Available Abstract Background We employed a phylogenetic framework to identify patterns of life habit evolution in the marine bivalve family Pectinidae. Specifically, we examined the number of independent origins of each life habit and distinguished between convergent and parallel trajectories of life habit evolution using ancestral state estimation. We also investigated whether ancestral character states influence the frequency or type of evolutionary trajectories. Results We determined that temporary attachment to substrata by byssal threads is the most likely ancestral condition for the Pectinidae, with subsequent transitions to the five remaining habit types. Nearly all transitions between life habit classes were repeated in our phylogeny and the majority of these transitions were the result of parallel evolution from byssate ancestors. Convergent evolution also occurred within the Pectinidae and produced two additional gliding clades and two recessing lineages. Furthermore, our analysis indicates that byssal attaching gave rise to significantly more of the transitions than any other life habit and that the cementing and nestling classes are only represented as evolutionary outcomes in our phylogeny, never as progenitor states. Conclusions Collectively, our results illustrate that both convergence and parallelism generated repeated life habit states in the scallops. Bias in the types of habit transitions observed may indicate constraints due to physical or ontogenetic limitations of particular phenotypes.

  16. The smaller vesicomyid bivalves in the genus Isorropodon (Bivalvia, Vesicomyidae, Pliocardiinae) also harbour chemoautotrophic symbionts

    OpenAIRE

    Rodrigues, Clara F.; Cunha, Marina R.; Olu, Karine; Duperron, Sébastien

    2012-01-01

    Species of Isorropodon are vesicomyid bivalves for which little information is available regarding host phylogeny and bacterial symbioses. In this study we investigated the symbioses in three Isorropodon species from three cold seep areas: Isorropodon bigoti (Gulf of Guinea), Isorropodon megadesmus (Gulf of Cadiz) and Isorropodon perplexum (Eastern Mediterranean). Analysis of bacterial 16S ribosomal RNA gene sequences demonstrated that each vesicomyid species harbours a single symbiont phylot...

  17. 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.

  18. 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.

  19. Genetic diversity of European populations of the invasive soft-shell clam Mya arenaria (Bivalvia)

    NARCIS (Netherlands)

    Lasota, R.; Hummel, H.; Wolowicz, M.

    2004-01-01

    The genetic diversity of the soft-shell clam Mya arenaria from seven locations in Europe (two stations in the southern Baltic Sea (the Gulf of Gdansk) and two in the North Sea (Veerse Meer and Oosterschelde), and three additional stations in the Denmark Straits and Bay of Biscay) was determined usin

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

    NARCIS (Netherlands)

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

  1. 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 (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.

  2. New bathyal species and records of Pectinoidea (Bivalvia: Propeamussiidae and Pectinidae) from Taiwan

    NARCIS (Netherlands)

    Dijkstra, H.H.; Maestrati, P.

    2009-01-01

    New species: Parvamussium liaoi n. sp., Scaeochlamys squamea n. sp. New records for Taiwan: Propeamussium siratama, Parvamussium aldeynzeri, Parvamussium cristatellum, Parvamussium undisonum, Parvamussium vesiculatum, Cic/opecten fluctuatus, Delectopecten musorstomi

  3. Thyasira ockelmanni (Mollusca: Bivalvia: Veneroidea, A new species of Thyasiridae from the Norwegian Sea

    Directory of Open Access Journals (Sweden)

    Rozemarijn Keuning

    2010-12-01

    Full Text Available 800x600 Normal 0 21 false false false NO-BOK X-NONE X-NONE MicrosoftInternetExplorer4 A new species of Thyasiridae, Thyasira ockelmanni n.sp. is described from the abyssal depths of the Norwegian Sea. The generic assignment is tentative and possible alternatives are discussed. The new species has some resemblance to Thyasira subovata (Jeffreys, 1881 and Adontorhina similis Barry & McCormack, 2007, but the posterior outline is rounded and not angulate or truncate as in these species.

  4. 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.

  5. Sinanodonta woodiana (Mollusca: Bivalvia: Unionidae: Isolation and Characterization of the First Microsatellite Markers

    Directory of Open Access Journals (Sweden)

    Elena Iulia Iorgu

    2011-08-01

    Full Text Available Sinanodonta woodiana (Lea, 1834 is a large Unionid species with a real invasion success. It colonized Europe, Central America, the Indonesian Islands and recently North America. The species life cycle involves a larval parasitic stage on freshwater fish species which contributes to the spread of the mussel. In this paper we describe, for the first time, eight polymorphic microsatellite loci for the species Sinanodonta woodiana. The genetic screening of individuals confirmed that all loci were highly polymorphic. The number of alleles per locus ranged from 7 to 14 and the observed heterozygosity ranged from 0.650 to 0.950. These loci should prove useful to study the species population genetics which could help to infer important aspects of the invasion process.

  6. REVIEW: Symbiosis between the Giant Clams (Bivalvia: Cardiidae and Zooxanthellae (Dinophyceae

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    UDHI EKO HERNAWAN

    2008-01-01

    Full Text Available Giant clams are the largest bivalves in the world that maintain a mutual relationship with zooxanthellae. Individual giant clam can harbor heterogeneous zooxanthellae, at least four taxa in genus Symbiodinium. The Symbiodinium lives in the zooxanthellal tubular system, a tube structure arising from one of the diverticular duct of the clam’s stomach. Since the numbers of zooxanthellae is the one of some significant factors contributing to the clams growth and survival, the giant clams need to adjust the number of zooxanthellae for physiological reason with unclear mechanism. The important role of the symbiotic relationship to the clams can be seen on the survival, growth and nutrition of the clams. There are at least two significant factors determining the symbiosis, i.e. water temperature in related with level of light intensities and ammonium-phosphate rate. Some topic is still unclear, i.e. the determination of species in genus Symbiodinium, the mechanism for adjusting the population numbers of the algae and what kind of environmental factors determining the symbiosis. Thereby further research is still needed to clarify those missing.

  7. A review of North American Recent Radiolucina (Bivalvia, Lucinidae with the description of a new species

    Directory of Open Access Journals (Sweden)

    Elizabeth Garfinkle

    2012-07-01

    Full Text Available North American members in the genus Radiolucina are reviewed. A lectotype for the type species, Radiolucina amianta, is designated and descriptions and illustrations are provided. A description of a new species, Radiolucina jessicae, from the west coast of Mexico is presented. Key diagnostic species characteristics are outlined and compared among members of the genus.

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

    Energy Technology Data Exchange (ETDEWEB)

    Fishelson, L.; Manelis, R. [Department of Zoology, Faculty of Life Sciences, Tel Aviv University, Tel Aviv (Israel); Bresler, V.; Zuk-Rimon, Z.; Dotan, A.; Yawetz, A. [Institute for Nature Conservation Research, Faculty of Life Sciences, Tel Aviv University, Tel Aviv (Israel); Hornung, H. [Israel Oceanographic and Limnological Research, National Institute of Oceanography, Haifa (Israel)

    1999-02-09

    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 m{sup 2}. 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.)

  9. The aquatic molluscs (Mollusca: Gastropoda and Bivalvia of Vrachanski Balkan Nature Park

    Directory of Open Access Journals (Sweden)

    DILIAN GEORGIEV

    2016-05-01

    Full Text Available Till now 13 species of aquatic molluscs are known to inhabit the park area: 11 species of snails and 2 species of clams. Even included in the list the species of Grossuana and Radix balthica has to be studied anatomically for sure identification. Nine species are of conservation statute classified as "Least Concern" or "Vulnerable", and four does not have any statute. Three stygobiotic snail species are local endemics.

  10. 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

    The option of storing CO(2) in subsea rock formations to mitigate future increases in atmospheric CO(2) may induce problems for animals in the deep sea. In the present study the deep-sea bivalve Acesta excavata was subjected to environmental hypercapnia (pHSW 6.35, P(CO2), =33,000 mu atm) corresp...

  11. 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.

  12. Low Genetic Diversity and High Invasion Success of Corbicula fluminea (Bivalvia, Corbiculidae (Muller, 1774 in Portugal.

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    Cidália Gomes

    Full Text Available The Asian clam, Corbicula fluminea, is an invasive alien species (IAS originally from Asia that has spread worldwide causing major ecological and economic impacts in aquatic ecosystems. Here, we evaluated C. fluminea genetic (using COI mtDNA, CYTb mtDNA and 18S rDNA gene markers, morphometric and sperm morphology variation in Portuguese freshwater ecosystems. The COI marker revealed a single haplotype, which belongs to the Asian FW5 invasive lineage, suggesting a common origin for all the 13 Portuguese C. fluminea populations analysed. Morphometric analyses showed differences between the populations colonizing the North (with the exception of the Lima River and the Centre/South ecosystems. The sperm morphology examination revealed the presence of biflagellate sperm, a distinctive character of the invasive androgenetic lineages. The low genetic variability of the Portuguese C. fluminea populations and the pattern of sperm morphology have been illuminating for understanding the demographic history of this invasive species. We hypothesize that these populations were derived from a unique introductory event of a Corbicula fluminea FW5 invasive androgenic lineage in the Tejo River, which subsequently dispersed to other Portuguese freshwater ecosystems. The C. fluminea asexual reproductive mode may have assisted these populations to become highly invasive despite the low genetic diversity.

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

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    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.

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

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    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.

  15. Novel Microsatellite Markers of Meretrix petechialis and Cross-species Amplification in Related Taxa (Bivalvia: Veneroida

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    Hyun-Sook Ko

    2012-11-01

    Full Text Available The Asian hard clam, Meretrix petechialis, is an economically important bivalve, but its catch and population sizes are decreasing rapidly, owing to many factors, including large-scale reclamation of its natural habitat on the western coast of the Korean peninsula. Attempts to restore the resources and production of this species require genetic structure and diversity information. In this study, we developed 15 microsatellite markers from a partial genomic library enriched in GT repeats. Nine of these markers were polymorphic, with an average allele number of six, and six were monomorphic in 95 tested individuals. No linkage disequilibrium was found between any pair of loci (p > 0.05, and deviations from the Hardy–Weinberg equilibrium (HWE test showing excess of heterozygotes was observed in only one of nine loci. In addition, no null alleles or genetic differentiation between two tested populations were detected. A cross-species amplification in 12 species of four families resulted in two M. petechialis-specific loci and three possible universal markers. This information will be useful in the future development of high-quality artificial seedlings and sustainable resource management.

  16. Results of the Rumphius Biohistorical Expedition to Ambon : Part 6. Mollusca, Bivalvia, Pectinidae

    NARCIS (Netherlands)

    Dijkstra, H.H.

    1997-01-01

    During the Rumphius Biohistorical Expedition (1990) to Ambon 17 Pectinidae species were collected, nine of which were described by Rumphius (1705) and five illustrated by Rumphius. One species, viz. Decatopecten plica (Linnaeus, 1758), illustrated in Rumphius (1705: pl. 44, fig. O), has not been ref

  17. The sensorial structures of Spondylus americanus Hermann,1781 (Mollusca: Bivalvia, Spondylidae

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    Marina Gomes Viana

    2007-09-01

    Full Text Available Adult animals of Spondylus americanus were analyzed and specialized sensorial structures, the sensorial papillae and the eyes, were characterized. The sensorial papillae were projections on the edge of the mantle in form of light brown fingers which had function of percepting stimulus coming from the medium. They were constituted by loose conjunctive tissues with longitudinal muscular fibers and externally covered by ciliated cubic epithelium, which presented high amount of melanocytes that gave the coloration of the papillae. The eyes were more complex, being on small stalks histologically similar to the papillae. They exhibited a circular formate and had a metallic blue color. Theses structures were constituted by a corneo epithelium, cornea, lens, retina, basal stalk, periocular band and optical nerve. The eyes were distributed asymmetrically to both valves related with the sedentarism of the species. Right valve presented a smaller number of eyes when compared to left one.Foram examinados exemplares adultos de Spondylus. americanus Hermann, 1781 e estruturas especializadas na percepção de estímulos foram caracterizadas: as papilas sensoriais e os ocelos. As papilas sensoriais são projeções do bordo manto em forma de dedos de cor castanha e com a função de perceber estímulos vindo do meio, são constituídas por tecido conjuntivo frouxo contendo fibras musculares longitudinais e revestidas externamente por epitélio cúbico ciliado, o qual apresenta grande quantidade de melanócitos, que dão a coloração das papilas. Os ocelos são mais complexos, estando sobre pequenos pedúnculos histologicamente semelhante às papilas, têm formato circular e possui cor azul metálica. Constituí-se por um epitélio córneo, córnea, lente, retina, pedúnculo basal, banda periocular e nervo óptico. Os ocelos distribuem-se assimetricamente por ambas as valvas, o que está relacionado com o sedentarismo da espécie. A valva direita apresenta menor número de ocelos quando comparada a esquerda.

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

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    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.

  19. Cytogenetic analysis in two scallops (Bivalvia: Pectinidae) by PRINS and PI banding

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Cytogenetic analysis was performed for the bay scallop (Argopecten irradians Lamarck 1819) and the Japanese scallop (Patinopecten yessoensis Jay 1857) by primed in situ labeling (PRINS) and propidium iodide (PI) banding techniques. The PRINS analysis revealed that major rRNA genes were clustered in two loci on the telomeric regions of the short arms on two acrocentric chromosome pairs in A. irradians and on two submetacentric pairs in P. yessoensis. The histone H3 gene sites differed in number and location between these two species. The C-band-like patterns revealed by PI staining varied considerably between these two species. A. irradians displayed terminal bands at long arms on all chromosomes, centromeric bands on some pairs and interstitial bands on five pairs. P. yessoensis exhibited only centromeric bands on all chromosomes. These results would contribute to the better understanding of karyotype evolution in A. irradians and P. yessoensis.

  20. 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...

  1. 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...... to its shell development, alimentary system, gill anatomy and life habits provide important clues to the evolution of the Bathymodiolinae....

  2. 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

  3. Lifespan, growth rate, and body size across latitude in marine Bivalvia, with implications for Phanerozoic evolution.

    Science.gov (United States)

    Moss, David K; Ivany, Linda C; Judd, Emily J; Cummings, Patrick W; Bearden, Claire E; Kim, Woo-Jun; Artruc, Emily G; Driscoll, Jeremy R

    2016-08-17

    Mean body size in marine animals has increased more than 100-fold since the Cambrian, a discovery that brings to attention the key life-history parameters of lifespan and growth rate that ultimately determine size. Variation in these parameters is not well understood on the planet today, much less in deep time. Here, we present a new global database of maximum reported lifespan and shell growth coupled with body size data for 1 148 populations of marine bivalves and show that (i) lifespan increases, and growth rate decreases, with latitude, both across the group as a whole and within well-sampled species, (ii) growth rate, and hence metabolic rate, correlates inversely with lifespan, and (iii) opposing trends in lifespan and growth combined with high variance obviate any demonstrable pattern in body size with latitude. Our observations suggest that the proposed increase in metabolic activity and demonstrated increase in body size of organisms over the Phanerozoic should be accompanied by a concomitant shift towards faster growth and/or shorter lifespan in marine bivalves. This prediction, testable from the fossil record, may help to explain one of the more fundamental patterns in the evolutionary and ecological history of animal life on this planet.

  4. 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...

  5. 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

  6. 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.

  7. Redescription of Hiatella meridionalis d'Orbigny, 1846 (Mollusca, Bivalvia, Hiatellidae from Argentina

    Directory of Open Access Journals (Sweden)

    Luiz Ricardo L. Simone

    2008-01-01

    Full Text Available The redescription of Hiatella meridionalis (d’Orbigny, 1846 is provided as first attempt to improve the systematics of the genus in the regions of Atlantic and western Pacific. This reanalysis is based on specimens collected in the vicinity of the type localities and is based on detailed morphology of samples that some researches consider a single, wide ranging species. From the morphological characters, the more interesting are: a high quantity of papillae at incurrent siphon; the retractor muscles of siphon divided in two bundles; the small size of the palps; the muscular ring in the stomach; and the zigzag fashion of the short intestinal loops. These characters distinguish the species from the other hiatellids so far examined. Type material of the species was examined, by first time illustrated, and the lectotype is designated.A redescrição de Hiatella meridionalis (d’Orbigny, 1846 é realizada como primeiro passo na melhoria da sistemática do gênero das regiões atlântica e pacífica oeste. Esta re-análise é baseada em espécimes coletados nas vizinhanças da localidade tipo e em morfologia detalhada de amostras que alguns pesquisadores consideram pertencer a uma única espécie de ampla distribuição. Dos caracteres anatômicos, os mais interessantes são: uma grande quantidade de papilas no sifão inalante; o músculo retrator dos sifões dividido em duas porções; o tamanho pequeno dos palpos; um anel muscular transversal no estomago; e um padrão em zigzag no curto intestino. Estes caracteres distinguem a espécie dos demais hiatelídeos até então examinados. Os sintipos da espécie foram também examinados e pela primeira vez ilustrados; o lectótipo é designado.

  8. 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.

  9. Determination of the variability of both hydrophilic and lipophilic toxins in endemic wild bivalves and carnivorous gastropods from the southern part of Chile.

    Science.gov (United States)

    Zamorano, Ruben; Marín, Michelle; Cabrera, Fabiola; Figueroa, Diego; Contreras, Cristóbal; Barriga, Andrés; Lagos, Néstor; García, Carlos

    2013-01-01

    The aim of this study was to analyse and determine the composition of paralytic shellfish poisoning (PSP) toxins and lipophilic toxins in the Region of Aysén, Chile, in wild endemic mussels (Mytilus chilensis, Venus antiqua, Aulacomya ater, Choromytilus chorus, Tagelus dombeii and Gari solida) and in two endemic carnivorous molluscs species (Concholepas concholepas and Argobuccinum ranelliforme). PSP-toxin contents were determined by using HPLC with fluorescence detection, while lipophilic toxins were determined by using LC-MS/MS. Mean concentrations for the total of PSP toxins were in the range 55-2505 μg saxitoxin-equivalent/100 g. The two most contaminated samples for PSP toxicity were bivalve Gari solida and carnivorous Argobuccinum ranelliforme with 2505 ± 101 and 1850 ± 137 μg saxitoxin-equivalent/100 g, respectively (p shellfish together with YTX at levels ranging from 1.0 ± 0.1 to 18 ± 0.9 μg of YTX-equivalent/kg shellfish and AZA at levels ranging from 3.6 ± 0.2 to 31 ± 2.1 μg of AZA-equivalent/kg shellfish. Furthermore, different bivalves and gastropods differ in their capacity of retention of lipophilic toxins, as shown by the determination of their respective lipophilic toxins levels. In all the evaluated species, the presence of lipophilic toxins associated with biotransformation in molluscs and carnivorous gastropods was not identified, in contrast to the identification of PSP toxins, where the profiles identified in the different species are directly related to biotransformation processes. Thus, this study provides evidence that the concentration of toxins in the food intake of the evaluated species (Bivalvia and Gastropoda class) determines the degree of bioaccumulation and biotransformation they will thereafter exhibit. PMID:23822152

  10. High amount of dinophysistoxin-3 in Mytilus chilensis collected in Seno de Reloncaví, chile, during massive human intoxication associated with outbreak of Vibrio parahaemolyticus.

    Science.gov (United States)

    García, Carlos; Schonstedt, Valeria; Santelices, Juan Palbo; Lagos, Néstor

    2006-10-01

    This study describes the detection of high amount of 7-O-acyl-derivative dinophysistoxin-1 (Dinophysistoxin-3) in filter bivalves collected on February 2005 in the Seno de Reloncaví, Puerto Montt City, Southern Chile, in the same period of time where an intoxication episode was associated with the presence of Vibrio parahaemolyticus in shellfish. The Diarrhetic Shellfish Poisoning (DSP) mouse bioassay of mussel extract samples, performed as described for regulatory testing, were negative to DSP toxins. Therefore, the same mussel samples collected from 8 places of Seno de Reloncaví were then analyzed by the HPLC-FLD method with pre-column derivatization procedure for DSP toxins. The samples showed mainly 7-O-acyl-derivative dinophysistoxin-1 (Dinophysistoxin-3) in concentrations ranging from 190.3 +/- 6.8 to 311.1 +/- 4.8 ng of DSP toxin/g hepatopancreas and less amounts of Dinophysistoxin-1 ranging from 1.9 +/- 1.5 to 11.7 +/- 4.6 ng of DSP toxin/g hepatopancreas. After alkaline hydrolysis of the mussel extracts, 279.4 +/- 7.2 ng of Dinophysistoxin-1 /g hepatopancreas (mean +/- SEM, N=6) were found in mussel extracts (Zone 8). These data showed that these shellfish samples are contaminated with the ester form 7-O-acyl-derivatives of Dinophysisyoxin-1, far beyond the safe regulatory limit. This paper also shows a direct relation between lipid content in the mussel tissue extracts and the levels of Dinophysistoxin-3. The 7-O-acyl-derivative dinophysistoxin-1 ester was the only compound associated with DSP toxins detected in the shellfish samples, and in view of the fact that metabolic transformation of Dinophysistoxin-3 into Dinophysistoxin-1 in humans has recently been described in the literature, the consumption of shellfish contaminated with 7-O-acyl-derivatives dinophysistoxin-1 could be a major reason that explains the diarrhetic symptoms shown by the intoxicated patients. PMID:17077585

  11. Sporothrix chilensis sp. nov. (Ascomycota : Ophiostomatales), a soil-borne agent of human sporotrichosis with mild-pathogenic potential to mammals

    NARCIS (Netherlands)

    Rodrigues, Anderson Messias; Cruz Choappa, Rodrigo; Fernandes, Geisa Ferreira; de Hoog, G Sybren; de Camargo, Zoilo Pires

    2016-01-01

    A combination of phylogeny, evolution, morphologies and ecologies has enabled major advances in understanding the taxonomy of Sporothrix species, including members exhibiting distinct lifestyles such as saprobes, human/animal pathogens, and insect symbionts. Phylogenetic analyses of ITS1/2 + 5.8s se

  12. 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 ...

  13. The interference of methods in the collection of teredinids (Mollusca, Bivalvia in mangrove habitats Interferência de métodos na coleta de teredinídios (Mollusca, Bivalvia em habitats de manguezais

    Directory of Open Access Journals (Sweden)

    Rosa M. V. Leonel

    2006-03-01

    Full Text Available In the estuary of the Mamanguape River (Paraíba, Brazil, a new collection technique was developed and applied with virgin poles of mangrove trees Avicennia schaueriana (Verbenaceae, Rhizophora mangle (Rhizophoraceae, and Laguncularia racemosa (Combretaceae, taking into account wood preference, water salinity and depth influence during teredinid larval settlement. Sets of poles were vertically fixed in the riverbed at three sites along a decreasing salinity gradient, where they stayed for four months. The poles were collected and divided into upper, median, and lower segments, in agreement with different immersion regimes. An increase of 239% was obtained in the number of individuals when compared to a previous study in the same area using a different methodology. The species Teredo bartschi (Clapp, 1923, Nausitora fusticula (Jeffreys, 1860 and Bankia fimbriatula Moll & Roch, 1931 were registered in both studies, and the species Psiloteredo healdi (Bartsch, 1931 is here registered for the first time as occurring in that estuary. The species Neoteredo reynei (Bartsch, 1920, previously registered on tree branches of the mangrove habitat, was not found in the present work. Bankia fimbriatula, the most abundant species, did not show preference for any substratum but occurred significantly on the lower segment of the poles. N. fusticula, second in abundance, preferred to settle on poles of A. schaueriana and on any of the three segments. Aiming to assess the habitat variations, a more accurate study on teredinids diversity in mangrove ecosystems should be performed through a concomitant analysis from tree branches of the mangrove habitat, as well as from poles of mangrove trees or panels made of pine wood or mangrove trees wood. These collection devices should be maintained along a decreasing salinity gradient exposed to different tide levels.Contemplando a preferência pelo tipo de madeira, a influência da profundidade e da salinidade durante assentamento larval de teredinídeos, uma nova técnica de coleta foi aplicada e desenvolvida no estuário do rio Mamanguape (Paraíba, Brasil, utilizando varas virgens de três espécies de árvores do manguezal: Avicennia schaueriana (Verbenaceae, Rhizophora mangle (Rhizophoraceae e Laguncularia racemosa (Combretaceae. Em três estações demarcadas ao longo do gradiente decrescente de salinidade, conjuntos de varas foram verticalmente fixados nas margens do rio. Após quatro meses, as varas eram coletadas e divididas em três segmentos (superior, médio e inferior, de acordo com os regimes de imersão a que foram submetidas. Comparativamente aos dados obtidos por um estudo anterior na mesma área, com outras metodologias de coleta, foi obtido um aumento de 239% no número de indivíduos coletados com a nova técnica. Embora as espécies Teredo bartschi (Clapp, 1923, Nausitora fusticula (Jeffreys, 1860 e Bankia fimbriatula Moll & Roch, 1931 tenham ocorrido nos dois estudos, o teredinídeo Psiloteredo healdi (Bartsch, 1931 tem sua presença registrada pela primeira vez neste estuário. Tendo sido previamente registrada em ramos de árvores do manguezal, Neoteredo reynei (Bartsch, 1920 não foi coletada no presente trabalho. Sendo a espécie mais abundante, B. fimbriatula não mostrou preferência de assentamento em nenhum dos substratos, ocorrendo significativamente associada ao segmento inferior das varas. Como segunda espécie mais abundante, N. fusticula mostrou preferência significativa de assentamento em A. schaueriana, ocorrendo indistintamente nos três segmentos das varas. Visando contemplar as variações do habitat e obter maior precisão de resultados, é recomendável que em estudos sobre a diversidade de teredinídeos, sejam incluídas análises concomitantes de troncos e ramos das árvores, com o uso de varas de árvores do manguezal ou de coletores artificiais feitos com pinho ou madeira de árvores do manguezal. Os coletores devem ser mantidos ao longo do gradiente de salinidade e expostos aos diferentes níveis das marés.

  14. 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.

  15. 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.

  16. Características histológicas del ciclo reproductivo de Euvola ziczac (Linnaeu (Pectinidae, Bivalvia del litoral sur-sudeste del Brasil Histological characteristics of the reproductive cycle of Euvola ziczac (Pectinidae, Bivalvia from south-southern Brazil

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Borzone

    2003-12-01

    Full Text Available Scallops were collected from beds at 30 to 40 m depth on the south-southern inner continental shelf of Brazil for histological gonadal characterization of the reproductive cycle. This hermaphroditic scallop was an important shellfish resource during 70-80 decade, with maximal annual landings of 8,845 tons, but now is depleted. Results shows that reproduction is continuous, with two major spawning periods, the first during end of summer and throughout autumn, and the second during winter and beginning of spring. A characteristic phenomenon of oocyte atresia, with maximal incidences in September is described. This phenomenon, followed by the mature oocyte resorption and new oocyte proliferation and maturation, was related to the lack of spawning stimulation. A semi-annual thermal cycle on the bottom water due to the South Atlantic Central Water intrusion seems to be the principal reproductive cycle controller. Fluctuations in landings registered since the beginning of the fishery may be partly related to oceanographic variations.

  17. 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.

  18. 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

  19. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  1. Strict sex-specific mtDNA segregation in the germ line of the DUI species Venerupis philippinarum (Bivalvia: Veneridae).

    Science.gov (United States)

    Ghiselli, Fabrizio; Milani, Liliana; Passamonti, Marco

    2011-02-01

    Doubly Uniparental Inheritance (DUI) is one of the most striking exceptions to the common rule of standard maternal inheritance of metazoan mitochondria. In DUI, two mitochondrial genomes are present, showing different transmission routes, one through eggs (F-type) and the other through sperm (M-type). In this paper, we report results from a multiplex real-time quantitative polymerase chain reaction analysis on the Manila clam Venerupis philippinarum (formerly Tapes philippinarum). We quantified M- and F-types in somatic tissues, gonads, and gametes. Nuclear and external reference sequences were used, and the whole experimental process was designed to avoid any possible cross-contamination. In most male somatic tissues, the M-type is largely predominant: This suggests that the processes separating sex-linked mitochondrial DNAs (mtDNAs) in somatic tissues are less precise than in other DUI species. In the germ line, we evidenced a strict sex-specific mtDNA segregation because both sperm and eggs do carry exclusively M- and F-types, respectively, an observation that is in contrast with a previous analysis on Mytilus galloprovincialis. More precisely, whereas two mtDNAs are present in the whole gonad, only the sex-specific one is detected in gametes. Because of this, we propose that the mtDNA transmission is achieved through a three-checkpoint process in V. philippinarum. The cytological mechanisms of male mitochondria segregation in males and degradation in females during the embryo development (here named Checkpoint #1 and Checkpoint #2) are already well known for DUI species; a Checkpoint #3 would act when primordial germ cells (PGCs) are first formed and would work in both males and females. We believe that Checkpoint #3 is a mere variation of the "mitochondrial bottleneck" in species with standard maternal inheritance, established when their PGCs separate during embryo cleavage.

  2. 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.

    2015-01-01

    tubes accommodating the inhalant and exhalant streams. There is reduction in musculature and, most importantly, anterior foreshortening of the outer ctenidial demibranchs and loss of the labial palps. This creates an anterior space in the mantle for the initial brooding of fertilized ova by females...

  3. Anatomy and systematics of Anodontites Elongatus (Swainson from Amazon and Parana Basins, Brazil (Mollusca, Bivalvia, Unionoida, Mycetopodidae

    Directory of Open Access Journals (Sweden)

    Luiz Ricardo L Simone

    1997-12-01

    Full Text Available The anatomy of Anodontiies elongatus (Swainson, 1823, a rare species restricted to the Amazon and Parana Basins, is described by first time, showing a group of conchological and anatomical characters exclusive of this species that may be analyzed to identify it. Diagnosis of A. elongatus: shell long antero-posteriorly, umbones prominent, periostracum opaque and smooth, two posterior radial striae; middle fold of mantle edge veiy tall; gill long antero-posteriorly and short dorso-ventrally, extending about a half of it total length beyond visceral mass; palps proportionally small, several furrows in its outer surface; stomach without esophageal transversal ridjp, dorsal hood and gastric shield poorly developed, major typhlosole entering in ddd , posterior pouch of sa³ very-long; style sac reduced, without crystalline style; distal region of intestine and rectum with a well developed typhlosole, "T" in section, other intestinal regions without folds; gonad gonochoristic.

  4. 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.

  5. Evolutionary ecology of the Pachydontinae (Bivalvia, Corbulidae) in the Pebas lake/wetland system (Miocene, western Amazonia)

    NARCIS (Netherlands)

    Wesselingh, F.P.

    2006-01-01

    Miocene deposits in western Amazonia and adjacent areas of South America harbour a diverse suite of endemic corbulid bivalves, commonly referred to as Pachydontinae, that show a wide variety of morphologies. Especially in the Miocene Pebas Formation (Peru, Colombia and Brazil), this group diversifie

  6. 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

  7. 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.

  8. 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

  9. SEM observation of structural (non-mineralogical) alteration inside the previously crystallized nacreous layer of Crenomytilus grayanus (Bivalvia: Mytilidae).

    Science.gov (United States)

    Zuykov, Michael; Pelletier, Emilien; Kolyuchkina, Galina

    2013-01-01

    A microstructural and mineralogical study shows the transition of aragonitic nacreous tablets to aragonitic prisms inside previously secreted nacre, i.e. without contact with the mantle or extrapallial fluid, in a field-collected mytilid bivalve Crenomytilus grayanus (D.). The intermediate zone between nacre and new prisms is represented by nacre tablets "stuck together" or by disordered calcium carbonate material. The modified nacre forms aragonitic lenses of prisms (ALPs). These lenses may reach 500 μm in thickness below the tunnels excavated by the shell borers. ALPs are similar to myostracal prisms in mineralogy, morphology, and orientation, but differ from those in the outer shell layer. The process of ALPs formation is different to that of normal shell formation (e.g. nacre-prisms transition between prismatic and nacreous layers), remote biomineralization, extra shell thickening, as well as, shell repair, erosion, deformation or disease. Response to shell excavation by boring organisms is discussed as the reason for the appearance of ALPs.

  10. 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

  11. New species and new records of deep-water Pectinoidea (Bivalvia: Propeamussiidae, Entoliidae and Pectinidae) from the South Pacific

    NARCIS (Netherlands)

    Dijkstra, H.H.; Maestrati, P.

    2008-01-01

    Fifty-two deep-water species of Pectinoidea (37 Propeamussiidae, 1 Entoliidae, 14 Pectinidae) are listed from Norfolk Ridge (11 species), Loyalty Islands (4 species), Fiji Islands (30 species), Tonga (26 species), Solomon Islands (26 species) and the Marquesas archipelago (8 species). All species fr

  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.

  13. 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

  14. 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 ...

  15. 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.

  16. Search effort and imperfect detection: Influence on timed-search mussel (Bivalvia: Unionidae surveys in Canadian rivers

    Directory of Open Access Journals (Sweden)

    Reid S. M.

    2016-01-01

    Full Text Available Inventories and population monitoring are essential activities supporting the conservation of freshwater mussel diversity in Canadian rivers. Despite widespread use of timed-search methods to survey river mussels, the relationship between species detection and search effort has received limited study. In this study, repeat-sampling data from 54 Ontario river sites were used to estimate: (1 species detection probabilities; (2 the number of sampling events required to confidently detect species; and, (3 the power of timed-search surveys to detect future distribution declines. Mussels were collected using visual and tactile methods, and collection data were recorded separately for each 1.5 h of search time (up to 4.5 h. Thirteen species were collected; including two endangered species (Rainbow Villosa iris and Eastern Pondmussel Ligumia nasuta. In all cases, species detection was imperfect. However, detection probabilities (p for most species were high (>0.69. Two repeat 4.5 h surveys are required to confidently assess whether most (83% species are present at a site. Search effort had a positive effect on estimates of species richness, detection probability and site occupancy, and the power to detect future distribution declines. At all levels of sampling effort, detection probability and site occupancy estimates were positively correlated to mussel abundance.

  17. 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.

  18. First Indonesian record of Fungiacava eilatensis Goreau et al., 1968 (Bivalvia: Mytilidae), endosymbiont of Fungia spp. (Scleractinia: Fungiidae)

    NARCIS (Netherlands)

    Hoeksema, B.W.; Achituv, Y.

    1993-01-01

    The mytilid bivalve Fungiacava eilatensis Goreau, Goreau, Neumann & Yonge, 1968, previously mistakenly referred to as F. eilatensis Soot-Ryen, 1969, is reported for the first time from Indonesia. It lives as an obligate endosymbiont of mushroom corals, particulary Fungia spp., reef-dwelling corals r

  19. 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)

  20. Cretaceous trigonioidid (non-marine Bivalvia) assemblages and biostratigraphy in Asia with special remarks on the classification of Trigonioidacea

    Science.gov (United States)

    Sha, Jingeng

    2007-01-01

    Non-marine Cretaceous bivalve Trigonioidacea, having an anterior pedal retractor scar distinctly separated from the anterior adductor scar, are subdivided herein into seven families and subfamilies, and 26 genera and subgenera. The general ornament pattern at the family and subfamily level, and features of the radial ribs, including the VA (angle of V-shaped ribs) and hinge teeth at the generic and subgeneric level serve as the basis for classification. They have a wide distribution in Asia, particularly in Middle and East Asia. Seven trigonioidid assemblages are recognized and dated on the basis of morphological features and stratigraphical occurrence of the fossils as well as associated intercalated marine deposits. The seven assemblages are as follows: (1) Hauterivian-Barremian and ?Valanginian Nippononaia ( Eonippononaia) tetoriensis- Koreanaia ( Eokoreanaia) cheongi- Danlengiconcha elongata assemblage; (2) Late Barremian-Early Albian, but mainly Aptian, Nippononaia ( Nippononaia) ryosekiana- Koreanaia ( Koreanaia) bongkyuni- Trigonioides ( Wakinoa) wakinoensis- Trigonioides ( Trigonioides) kodairai- Trigonioides ( Trigonioides) quadratus- Plicatounio ( Plicatounio) naktongensis- Pseudohyria ( Matsumotoina) matsumotoi assemblage; (3) Aptian-Early Albian, but mainly Aptian, Trigonioides ( Trigonioides)- Plicatounio ( Guangxiconcha) suzukii assemblage; (4) Late Aptian-Early Cenomanian, but mainly Albian, Trigonioides ( Diversitrigonioides) diversicostatus- Pseudohyria ( Pseudohyria) subovalis assemblage; (5) Albian, probably extending down into Aptian, Trigonioides ( Trigonioides) heilongjiangensis bed; (6) Cenomanian, but possibly going up into Turonian, Trigonioides ( Trigonioides) paucisulcatus- Trigonioides ( Trigonioides) matsumotoi- Trigonioides ( Trigonioides) mifunensis- Plicatounio ( Guangxiconcha) tamurai assemblage; and (7) Turonian—Early Maastrichtian, but mainly Santonian—Early Maastrichtian, Plicatounio ( Plicatounio) hunanensis- Pseudohyria ( Pseudohyria) turberculata- Pseudohyria ( Pseudohyria) cardiiformis- Pseudohyria ( Pseudohyria) aralica assemblage. This biostratigraphy permits correlation and age determination of trigonioidid-bearing formations throughout Asia.

  1. Karyotypic diversification in Mytilus mussels (Bivalvia: Mytilidae) inferred from chromosomal mapping of rRNA and histone gene clusters

    OpenAIRE

    Pérez-García, Concepción; Morán, Paloma; Pasantes, Juan J

    2014-01-01

    Background: Mussels of the genus Mytilus present morphologically similar karyotypes that are presumably conserved. The absence of chromosome painting probes in bivalves makes difficult verifying this hypothesis. In this context, we comparatively mapped ribosomal RNA and histone gene families on the chromosomes of Mytilus edulis, M. galloprovincialis, M. trossulus and M. californianus by fluorescent in situ hybridization (FISH). Results: Major rRNA, core and linker histone gene clusters mapped...

  2. Prodigious polyphyly in imperilled freshwater pearly-mussels (Bivalvia: Unionidae): a phylogenetic test of species and generic designations

    Science.gov (United States)

    2000-01-01

    Unionid bivalves or freshwater pearly-mussels (Unionoidea: Unionidae) serve as an exemplary system for examining many of the problems facing systematists and conservation biologists today. Most of the species and genera were described in the late 1800s and early 1900s, but few phylogenetic studies have been conducted to test conventional views of species and classification. Pearly-mussels of Gulf Coastal drainages of the southeastern United States from the Escambia (southern Alabama to Florida) to the Suwannee Rivers (Florida) are a unique fauna comprised of approximately 100 species, with about 30 endemic to the region. In this study, mitochondrial cytochrome c oxidase subunit I and 16S rRNA gene sequences were used to test the monophyly and to estimate evolutionary relationships of five unionid species representing three different genera. The molecular phylogenies depict all three genera as polyphyletic. The prodigious polyphyly exhibited within unionids is due to incorrect notions of homology and false assumptions about missing anatomical data. In contrast, the molecular phylogeny provides evidence to support the recognition of all five unionid species as distinct evolutionary entities. Furthermore, molecular genealogical evidence supports the elevation of Quincuncina infucata (Conrad) of the Suwannee River to species level, for which Q. kleiniana (Lea) is available.

  3. A preliminary study for establishing Perna viridis (Mollusca:Bivalvia) as a biological monitor for pollution in Karachi coastal water

    OpenAIRE

    Zehra, Itrat; Naz, Huma; Naqvi, Iftikhar Imam

    1996-01-01

    Adverse effects of toxic substances on the environmental quality have become a subject of concern in recent years. Toxicity of heavy metals has never been in dispute and therefore their presence in our natural environment is undesirable. This study was undertaken to establish the capability of Perna viridis as a monitor for pollution in the Manora channel. Accumulation of Zinc, Copper, Iron and Manganese by marine mussels, sampled from Manora channel, was determined. Metal load varied markedl...

  4. Shell microstructures of mussels (Bivalvia: Mytilidae: Bathymodiolinae) from deep-sea chemosynthetic sites: Do they have a phylogenetic significance?

    Science.gov (United States)

    Génio, Luciana; Kiel, Steffen; Cunha, Marina R.; Grahame, John; Little, Crispin T. S.

    2012-06-01

    The increasing number of bathymodiolin mussel species being described from deep-sea chemosynthetic environments worldwide has raised many questions about their evolutionary history, and their systematics is still being debated. Mussels are also abundant in fossil chemosynthetic assemblages, but their identification is problematic due to conservative shell morphology within the group and preservation issues. Potential resolution of bathymodiolin taxonomy requires new character sets, including morphological features that are likely to be preserved in fossil specimens. To investigate the phylogenetic significance of shell microstructural features, we studied the shell microstructure and mineralogy of 10 mussel species from hydrothermal vents and hydrocarbon seeps, and 15 taxa from sunken wood and bone habitats, and compared these observations with current molecular phylogenies of the sub-family Bathymodiolinae. In addition, we analyzed the shell microstructure in Adipicola chickubetsuensis from fossil whale carcasses, and in Bathymodiolus cf. willapaensis and “Modiola exbrocchii” from fossil cold seeps, and discussed the usefulness of these characters for identification of fossil chemosymbiotic mussels. Microstructural shell features are quite uniform among vent, seep, wood and bone mussel taxa, and therefore established bathymodiolin lineages cannot be discriminated, nor can the relations between fossil and modern species be determined with these characters. Nevertheless, the uniformity of shell microstructures observed among chemosymbiotic mussels and the similarity with its closest relative, Modiolus modiolus, does not challenge the monophyly of the group. Slight differences are found between the large vent and seep mussels and the small mytilids commonly found in habitats enriched in organic matter. Together with previous data, these results indicate that a repeated pattern of paedomorphism characterizes the evolutionary history of deep-sea mussels, and the occurrence of neotenous features should be considered in the taxonomic revision of this group.

  5. Bad taxonomy can kill : molecular reevaluation of Unio mancus Lamarck, 1819 (Bivalvia : Unionidae) and its accepted subspecies

    OpenAIRE

    Prie V.; Puillandre N.; Bouchet P.

    2012-01-01

    The conservation status of European unionid species rests on the scientific knowledge of the 1980s, before the current revival of taxonomic reappraisals based on molecular characters. The taxonomic status of Unio mancus Lamarck, 1819, superficially similar to Unio pictorum (Linnaeus, 1758) and often synonymized with it, is re-evaluated based on a random sample of major French drainages and a systematic sample of historical type localities. We confirm the validity of U. mancus as a distinct sp...

  6. Les Bivalvia du Ledien de la Belgique (Eocène moyen supérieur) II Heterodonta et Anomalodesmata

    OpenAIRE

    Glibert, M.

    1980-01-01

    The first part of this systematic revision concerned the Palaeotaxodonta, Cryptodonta and Pteriomorphia from the Ledian of Belgium representedby forty-seven taxa, three of which were new : Nucula smithsoni, Vulsella(?) lediensis and Lyropecten (Aequipecten) walleri. This second and last part concerns the Heterodonta and Anomalodesmata of the samestrata, with descriptions or discussions of sixty-four taxa, four of which are new: Divalinga (Stchepinskya) lediana, Vepricardium asperulumledianum,...

  7. Mytilus antiquorum J. Sowerby, 1821 and other Pliocene mussels (Mollusca, Bivalvia) from the Southern North Sea Basin

    NARCIS (Netherlands)

    Vervoenen, M.; Wesselingh, F.P.; Nieulande, van F.A.D.

    2000-01-01

    Mytilus antiquorum J. Sowerby, 1821, is recorded from the Coralline Crag Formation of East Anglia (UK) and the Lillo Formation (Oorderen, Kruisschans and Merksem members) of the Antwerp area (Belgium). The species is diagnosed on the basis of newly collected material and differentiated from modern E

  8. Cryptic species of deep-sea clams (Mollusca: Bivalvia: Vesicomyidae) from hydrothermal vent and cold-water seep environments

    Science.gov (United States)

    Vrijenhoek, Robert C.; Schutz, Steven J.; Gustafson, Richard G.; Lutz, Richard A.

    1994-08-01

    A protein-electrophoretic analysis of six putative morphospecies in the bivalve family Vesicomyidae from eight deep-sea hydrothermal vent sites in the eastern Pacific, three cold-water seep sites in the eastern Pacific and the Gulf of Mexico, and one whale-carcass site off Southern California revealed electromorph patterns diagnostic of 10 vesicomyid species. Electrophoretic patterns for 14 enzymes encoded by 17 presumptive gene loci were scored in all 10 species. The pairwise genetic distances (Nei's D) for these 10 species ranged from 0.857 to 2.792, values within the range expected for distinct species and genera. However, the degree of genetic divergence among these taxa could not be used for phylogenetic inferences because allozyme differences had in many cases reached evolutionary saturation. Notwithstanding, the present results revealed a significant problem with current morphospecies identifications of these clams and with applications of the current generic names Calyptogena and Vesicomya. Given the cryptic nature of these taxa, we suggest that subsequent studies simply refer to these clams as "vesicomyids" until careful morphological analyses and molecular studies are completed and systematic relationships are clarified.

  9. Mytilus antiquorum J. Sowerby, 1821 and other Pliocene mussels (Mollusca, Bivalvia) from the Southern North Sea Basin

    OpenAIRE

    Vervoenen, M.; Wesselingh, F.P.; Nieulande, van, F.A.D.

    2000-01-01

    Mytilus antiquorum J. Sowerby, 1821, is recorded from the Coralline Crag Formation of East Anglia (UK) and the Lillo Formation (Oorderen, Kruisschans and Merksem members) of the Antwerp area (Belgium). The species is diagnosed on the basis of newly collected material and differentiated from modern European mussel species. The presence of M. antiquorum in the southern North Sea Basin is restricted to the Middle (Piacenzian) and early Late Pliocene (Gelasian). A possible occurrence of the speci...

  10. New insight into the phylogeny of Sinonovacula (Bivalvia: Solecurtidae) revealed by comprehensive DNA barcoding analyses of two mitochondrial genes.

    Science.gov (United States)

    Yu, Zhenzhen; Li, Qi; Kong, Lingfeng

    2016-01-01

    The present study was undertaken to clarify the genetic relationships of Sinonovacula through comprehensive DNA barcoding analyses of COI and 16S rRNA genes. For both genes, the K2P distances between individuals of Sinonovacula and individuals of other genera belonging to Tellinoidea were much bigger than those between Sinonovacula and genera of Solenoidea. On the Bayesian tree of combined data, Sinonovacula and Cultellus formed a well supports monophylic clade. An extremely high matching rate of CAs between Sinonovacula and the reference family Cultellidae was found. Thus, we suggest transferring Sinonovacula from Solecurtidae to Cultellidae, as a sister group of Cultellus.

  11. First molecular phylogeny of the circumtropical bivalve family Pinnidae (Mollusca, Bivalvia): evidence for high levels of cryptic species diversity.

    Science.gov (United States)

    Lemer, Sarah; Buge, Barbara; Bemis, Amanda; Giribet, Gonzalo

    2014-06-01

    The family Pinnidae Leach, 1819, includes approximately 50 species of large subtidal and coastal marine bivalves. These commercially important species occur in tropical and temperate waters around the world and are most frequently found in seagrass meadows. The taxonomy of the family has been revised a number of times since the early 20th Century, the most recent revision recognizing 55 species distributed in three genera: Pinna, Atrina and Streptopinna, the latter being monotypic. However, to date no phylogenetic analysis of the family has been conducted using morphological or molecular data. The present study analyzed 306 pinnid specimens from around the world, comprising the three described genera and ca. 25 morphospecies. We sequenced the mitochondrial genes 16S rRNA and cytochrome c oxidase subunit I, and the nuclear ribosomal genes 18S rRNA and 28S rRNA. Phylogenetic analysis of the data revealed monophyly of the genus Atrina but also that the genus Streptopinna is nested within Pinna. Based on the strong support for this relationship we propose a new status for Streptopinna Martens, 1880 and treat it as a subgenus (status nov.) of Pinna Linnaeus, 1758. The phylogeny and the species delimitation analyses suggest the presence of cryptic species in many morphospecies displaying a wide Indo-Pacific distribution, including Pinna muricata, Atrina assimilis, A. exusta and P. (Streptopinna) saccata but also in the Atlantic species A. rigida. Altogether our results highlight the challenges associated with morphological identifications in Pinnidae due to the presence of both phenotypic plasticity and morphological stasis and reveal that many pinnid species are not as widely distributed as previously thought.

  12. Multi-locus fossil-calibrated phylogeny, biogeography and a subgeneric revision of the Margaritiferidae (Mollusca: Bivalvia: Unionoida).

    Science.gov (United States)

    Bolotov, Ivan N; Vikhrev, Ilya V; Bespalaya, Yulia V; Gofarov, Mikhail Y; Kondakov, Alexander V; Konopleva, Ekaterina S; Bolotov, Nikita N; Lyubas, Artyom A

    2016-10-01

    The taxonomy and biogeographic history of the bivalve family Margaritiferidae are controversial because previous molecular studies did not provide a well-resolved phylogenetic framework for these enigmatic freshwater mussels that have extensive but disjunct distribution in North America, Eurasia and North Africa. In this study, we present a new, fossil-calibrated phylogenetic hypothesis based on five molecular markers (∼4kb of total length) for ten species. Our results indicate that all recent margaritiferids are in the single genus, Margaritifera Schumacher, 1816. Additionally, we identified three relatively well-supported phylogenetic clades that are valid subgenera, i.e., Margaritifera s. str. (Holarctic), Margaritanopsis (=Cumberlandia) (southeast North America-southeast Asia disjunct) and Pseudunio (Mediterranean). We suggest that the crown lineage of the Margaritiferidae most likely originated in the Cretaceous (mean age 93Ma, 95% CI 66-126Ma). The combined results of ancestral area reconstructions based on the three different approaches (S-DIVA, DEC and S-DEC) showed that ancient vicariance events could have played an important role in speciation within the family. The rates of mitochondrial evolution of margaritiferids are notably slow, which may be associated with their longevity, long generation time and low metabolic rates. Our findings highlight the complex biogeographic history of the Margaritiferidae as an intermixing of ancient vicariance and dispersal events, which were most likely associated with some inland barriers, continental movements and a sea level dynamic.

  13. Where’s Waldo? A new commensal species, Waldo arthuri (Mollusca, Bivalvia, Galeommatidae), from the Northeastern Pacific Ocean

    OpenAIRE

    Paul Valentich-Scott; Diarmaid O'Foighil; Jingchun Li

    2013-01-01

    Abstract A galeommatid bivalve mollusk, representing a new species, is described from off the coasts of California and Vancouver Island, British Columbia. The new bivalve has a commensal relationship with the heart urchin, Brisaster latifrons . It has been observed crawling between the oral spines of this urchin, frequently near the peristome. The bivalve has been recorded from 80 (Vancouver Island) to 444 (southern California) meters depth, in muddy sediments. In common with other galeommato...

  14. Low Genetic Diversity and High Invasion Success of Corbicula fluminea (Bivalvia, Corbiculidae) (Müller, 1774) in Portugal

    Science.gov (United States)

    Gomes, Cidália; Sousa, Ronaldo; Mendes, Tito; Borges, Rui; Vilares, Pedro; Vasconcelos, Vitor; Guilhermino, Lúcia; Antunes, Agostinho

    2016-01-01

    The Asian clam, Corbicula fluminea, is an invasive alien species (IAS) originally from Asia that has spread worldwide causing major ecological and economic impacts in aquatic ecosystems. Here, we evaluated C. fluminea genetic (using COI mtDNA, CYTb mtDNA and 18S rDNA gene markers), morphometric and sperm morphology variation in Portuguese freshwater ecosystems. The COI marker revealed a single haplotype, which belongs to the Asian FW5 invasive lineage, suggesting a common origin for all the 13 Portuguese C. fluminea populations analysed. Morphometric analyses showed differences between the populations colonizing the North (with the exception of the Lima River) and the Centre/South ecosystems. The sperm morphology examination revealed the presence of biflagellate sperm, a distinctive character of the invasive androgenetic lineages. The low genetic variability of the Portuguese C. fluminea populations and the pattern of sperm morphology have been illuminating for understanding the demographic history of this invasive species. We hypothesize that these populations were derived from a unique introductory event of a Corbicula fluminea FW5 invasive androgenic lineage in the Tejo River, which subsequently dispersed to other Portuguese freshwater ecosystems. The C. fluminea asexual reproductive mode may have assisted these populations to become highly invasive despite the low genetic diversity. PMID:27391333

  15. Assessment of heavy metal accumulation in Mytilus galloprovincialis and Tapes decussatus (Bivalvia distributed in the Homa Lagoon (Izmir Bay.

    Directory of Open Access Journals (Sweden)

    Mustafa Bilgin

    2015-03-01

    Full Text Available Bu çalışma kapsamında Gediz Deltasında yer alan Kırdeniz, Homa ve Çilazmak Dalyanları ile Çamaltı Tuzlası kıyılarından alınan yüzey sedimentlerinde ağır metal konsantrasyonları saptanmıştır. Zenginleşme faktörleri(EF hesap edilerek, metal kirliliğinin muhtemel kaynakları belirlenmiş ve sediment kalite kriterlerine (SQG göre sediment kalitesi ve kirlilik düzeyleri tespit edilmiştir. En yüksek metal konsantrasyonları, Çamlatı Tuzlası, Kırdeniz ve Çilazmak Dalyanlarında saptanmıştır. Tüm çalışma bölgesi için Pb, Cr, Ni’ nin yansıra özellikle Çilazmak ve Çamaltı Tuzlası alanlarında Hg kirlilikleri antropojenik kaynaklıdır. Çalışma alanının tümünde Ni konsantrasyonları PEL değerinin, Pb ve Cr seviyeleri ise TEL değerinin üstündedir. SOQ kriterlerine göre tüm istasyonlar Ni ve Cr açısından aşırı kirli; Pb için ise kısmen kirli olarak sınıflandırılmıştır. En yüksek kirlilik dereceleri Kırdeniz ve Çilazmak Dalyanlarında tespit edilmiştir.

  16. 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

  17. 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.

  18. A new species of living glass-scallop, genus Similipecten (Bivalvia, Propeamussiidae), from the Bahama Islands (West Indies)

    NARCIS (Netherlands)

    Dijkstra, H.H.

    2002-01-01

    Introduction Redfern described and figured a propeamussiid species (as Cyclopecten sp.) from the Bahama Islands, which he compared with Cyclopecten nanus Verril & Bush in Verrill, 1897,known from the sub-tropical and tropical western Atlantic. In fact, both species are more morphologically related t

  19. 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.

  20. Population biology and secondary production of the stout razor clam Tagelus plebeius (Bivalvia, Solecurtidae on a sandflat in southeastern Brazil

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    Jolnnye R. Abrahão

    2010-02-01

    Full Text Available The population biology and production of the stout razor clam Tagelus plebeius Lightfoot, 1786 were investigated on an intertidal sandflat on the southeast coast of Brazil (Enseada Beach, São Sebastião, state of São Paulo between April 1997 and April 1998. Two rectangular sites of 50 X 10 m parallel to the waterline were established, site A (upper intertidal level and site B (middle intertidal level, where the samples were taken in an 0.5 x 0.5 m quadrat. High abundances were recorded in winter and spring, with no significant differences between the sites. The high bivalve abundances were related to the presence of very fine homogeneous sediment with low salinities. Tagelus plebeius had negative allometric growth, characteristic of deep burrowers for the relationships DM/SL and AFDM/SL. Parameters of the modified von Bertalanffy growth function were: L∞ = 67.01 mm, K = 1.73 year-1, t0 = -0.11 year, C = 0.43, WP = 0.96. The instantaneous mortality (Z was 3.12 year-1, relatively high in comparison to other tropical bivalve populations. Secondary production was 1.53 g AFDM m-2 year-1, with a P/B ratio reaching 1.37 year-1. This high turnover ratio (P/B was related to a rapid population replacement, connected with the short life span and high mortality of the species.

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

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    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Blasco, J.; Puppo, J. [Instituto de Ciencias Marinas de Andalucia, Campus Univ. Rio S. Pedro, 11510 Puerto Real, Cadiz (Spain)

    1999-02-01

    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 {mu}g{center_dot}l{sup -1}), Pb (350-700 {mu}g{center_dot}l{sup -1}) and Cu (10-20 {mu}g{center_dot}l{sup -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 {mu}g{center_dot}l{sup -1}, 7 days) and copper (20 {mu}g{center_dot}l{sup -1}, 5 days) were observed significant differences (P<0.05) in foot and gills, respectively, with respect to control. In the case of alanine aminotransferase activity (ALT), significant differences were observed for cadmium and lead in treated animals with respect to control. With regard to copper, a decrease in ALT was observed in gills and foot exposed to 20 {mu}g{center_dot}l{sup -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.)

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

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    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.

  4. New records of Fungiacava eilatensis Goreau et al., 1968 (Bivalvia, Mytilidae) boring into Indonesian mushroom corals (Scleractinia, Fungiidae)

    NARCIS (Netherlands)

    Hoeksema, B.W.; Kleemann, K.

    2002-01-01

    New observations on endoparasites in mushroom corals at South Sulawesi and Bali resulted in eight coral host records of the mytilid bivalve Fungiacava eilatensis Goreau et al., 1968, bringing the total to 14. The host corals were observed in various habitats, most frequently on sandy substrates. The

  5. Comparative efficiency in the culture of the scallop Nodipecten nodosus (Linnaeus, 1758 (Bivalvia: Pectinidae at different densities and depths

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    Jaime Fernando Ferreira

    2006-06-01

    Full Text Available Different methods of growth of scallops are used which employ different densities and depths in several parts of the globe. These methods present different efficiencies depending on the location, the species, and the stage of cultivation. In order to establish a recommended growth system for Nodipecten nodosus, survival and growth rates were compared for two densities (50 and 100 seeds per lanternet floor and three depths (4, 9 and 14 m, evaluating the physico-chemical and environmental parameters of the growing-out area. The seeds had an initial length of 23.93mm ± 2.39, and at the end of the experiment, the highest average was approximately 47.97mm ± 4.54 at a depth of 4m, in low density. After 4 month’s experimentation, it was observed that the survival did not differ according to the tested densities and depths (P>0.05. However, the final growth was significantly greater at 4m in low density, when compared to the final growth at a depth of 14m in high density. It was concluded that the most viable culture method for N. nodosus was the one close to the surface (4m, where organic matter presented the lowest rate, and chlorophyll a and final growth rates were found to be the highest, consequently classifying this depth as the most viable during the intermediate culture.

  6. Bad taxonomy can kill : molecular reevaluation of Unio mancus Lamarck, 1819 (Bivalvia : Unionidae and its accepted subspecies

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    Prie V.

    2012-07-01

    Full Text Available The conservation status of European unionid species rests on the scientific knowledge of the 1980s, before the current revival of taxonomic reappraisals based on molecular characters. The taxonomic status of Unio mancus Lamarck, 1819, superficially similar to Unio pictorum (Linnaeus, 1758 and often synonymized with it, is re-evaluated based on a random sample of major French drainages and a systematic sample of historical type localities. We confirm the validity of U. mancus as a distinct species occurring in France and Spain, where it is structured into three geographical units here ranked as subspecies: U. m. mancus [Atlantic drainages, eastern Pyrenees, Spanish Mediterranean drainages], U. m. turtonii Payraudeau, 1826 [coastal drainages East of the Rhône and Corsica] and U. m. requienii Michaud, 1831 [Seine, Saône-Rhône, and coastal drainages West of the Rhône]. Many populations of Unio mancus have been extirpated during the 20th century and the remaining populations continue to be under pressure; U. mancus satisfies the criteria to be listed as «Endangered» in the IUCN Red List.

  7. Bivalvia (Mollusca) of Nansha Islands, China%中国南沙群岛的双壳纲贝类

    Institute of Scientific and Technical Information of China (English)

    蔡英亚; 刘桂茂

    2004-01-01

    报道了中国南沙群岛的双壳纲贝类141种,分隶于5亚纲8目36科77属.从种类的组成中,帘蛤科有18种,蚶科15种,扇贝科11种,鸟蛤科10种,锉蛤科8种,贻贝科、海菊蛤科和樱蛤科各7种,砗磲科6种,其他各科的种类均在5种以内.按种的性质而论,大多数属于和珊瑚礁有密切联系的热带种或亚热带种,区系性质为印度-西太平洋区的印尼-马来亚区.

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

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    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.

  9. 栉江珧生殖细胞的发生%Gametogenesis in Atria pectinata Linnaeus (Mollusca, Bivalvia)

    Institute of Scientific and Technical Information of China (English)

    王梅芳; 余祥勇; 王如才

    2000-01-01

    通过观察栉江珧(Atrina pectinata linnaeus)的未分化生殖细胞,精原细胞和卵原细胞,精母细胞和卵母细胞,精子和卵子的形态结构与分布状况及核仁在卵成熟过程中的变化,对栉江珧生殖细胞发生及成熟过程的有关问题进行了探讨.

  10. 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.

  11. Lithophaga (Bivalvia, Mytilidae), including a new species, boring into mushroom corals (Scleractinia, Fungiidae) of South Sulawesi, Indonesia

    NARCIS (Netherlands)

    Kleemann, K.; Hoeksema, B.W.

    2002-01-01

    Bivalve species of the mytilid genus Lithophaga, including a new one, are recorded from Indonesian mushroom corals (Scleractinia, Fungiidae). True associations with live hosts including L. laevigata, L. lessepsiana, L. lima, L. punctata spec. nov., and L. simplex, while specimens of L. malaccana and

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

    Energy Technology Data Exchange (ETDEWEB)

    Sokolova, I.M. [Biology Department, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, NC 28223 (United States)]. E-mail: insokolo@uncc.edu; Ringwood, A.H. [Biology Department, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, NC 28223 (United States); Johnson, C. [Johnson C. Smith University, 100 Beatties Ford Road, Charlotte, NC 28216 (United States)

    2005-09-10

    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 {mu}g L{sup -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{sup -1} protein. Among organelles, mitochondria were the main target for Cd bioaccumulation in gills (250-300 ng mg{sup -1} protein), whereas in hepatopancreas tissues, the highest cadmium accumulation occurred in lysosomes (90-94 ng mg{sup -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.

  13. A new species of the genus Policordia (Bivalvia, Verticordioidea, Lyonsiellidae from off the coast of southern California

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    Lyudmila A. Safonova

    2016-10-01

    Full Text Available A new species, Policordia hispida, is described and compared with three similar species: P. densicostata (Locard, 1898; P. pilula (Pelseneer, 1911 and a yet un-described species, Policordia sp. (= P. pilula sensu Ivanova, 1977 not Pelseneer, 1911. This is a first record for the genus in the Californian province.

  14. Isolation and Characterization of the First Microsatellite Markers for the Endangered Relict Mussel Hypanis colorata (Mollusca: Bivalvia: Cardiidae

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    Luis Ovidiu Popa

    2011-01-01

    Full Text Available Hypanis colorata (Eichwald, 1829 (Cardiidae: Lymnocardiinae is a bivalve relict species with a Ponto-Caspian distribution and is under strict protection in Romania, according to national regulations. While the species is depressed in the western Black Sea lagoons from Romania and Ukraine, it is also a successful invader in the middle Dniepr and Volga regions. Establishing a conservation strategy for this species or studying its invasion process requires knowledge about the genetic structure of the species populations. We have isolated and characterized nine polymorphic microsatellite markers in H. colorata. The number of alleles per locus ranged from 4 to 28 and the observed heterozygosity ranged from 0.613 to 1.000. The microsatellites developed in the present study are highly polymorphic and they should be useful for the assessment of genetic variation within this species.

  15. The Pacific clam Nutricola tantilla (Bivalvia:Veneridae) has separate sexes and makes use of brood protection and sperm storage

    DEFF Research Database (Denmark)

    Lützen, Jørgen; Jespersen, Åse; Russell, Michael P.

    2015-01-01

    Et morfologisk studie af en NW Amerikansk blødbunds-musling Nutricola tantilla viste at den er særkønnet og ikke, som tidligere rapporteret, protandrisk hermafrodit. Vi baserer denne konklusion på at små hanner har højt specialiserede kirtelholdige spermiodukter, mens større hunner har simple ovi...

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

    Energy Technology Data Exchange (ETDEWEB)

    Gregory, M.A.; George, R.C.; Marshall, D.J.; Anandraj, A.; McClurg, T.P

    1999-01-01

    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 {mu}g/l{sup -1} over 24 days. Uncontaminated seawater was circulated over the mussels in tank 2 (control) for the same period. A 25 mm{sup 2} 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 {mu}g/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.

  17. Relationship between element concentrations and body size in the Lake Maggiore population of Unio pictorum mancus (Mollusca, Bivalvia

    Directory of Open Access Journals (Sweden)

    Ilenia CATTANI

    2011-08-01

    Full Text Available The study focused on using a fresh-water mussel (Unio pictorum mancus as a bioindicator of various pollutants, and particularly metals. The elements considered were: Al, As, Ca, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, V and Zn. This research was carried out at a site where various other studies have been conducted on important characteristics of the same population of Unio. This site is a small bay called "Sabbie d’Oro" located on the south-east coast of Lake Maggiore. Our study involved quantifying the capacity of this mollusc to concentrate large amounts of metal in its body without evident consequences by using detoxification mechanisms. We analysed not only element concentrations, but also their variability (expressed as CV% in the soft tissues and in the shell, for two main reasons: i the sampling design should include a preliminary analysis to determine how many specimens is necessary collect to ensure a specified level of precision; ii the sample variability value may be combined with the value of analytical precision (BCR to obtain an estimate of the "experimental" precision. In soft tissue, Ca accumulation tended to increase with size, and Al accumulation decreased with size. In shell, Ca and Ni were stored more than in soft tissue, but not proportionally to size. V, Cr and Mo tended to accumulate in the shell progressively over the years, whereas Co and Al are "diluted" during growth, or are absorbed mainly during the juvenile stage. Partition between shell and soft tissue resulted roughly the same in the juvenile and adult stages for the following elements: Fe, Al, Co, As, Pb. The relationships among the various elements were schematized in a hierarchical tree plot.

  18. Pectinoidea (Bivalvia: Propeamussiidae, Entoliidae and Pectinidae) from the Tarava Seamounts, Society Islands and the Tuamotu Archipelago (French Polynesia)

    NARCIS (Netherlands)

    Dijkstra, H.H.; Maestrati, P.

    2013-01-01

    Eighteen species of Pectinoidea (six Propeamussiidae Abbott, 1954, one Entoliidae Teppner, 1922, eleven Pectinidae Rafinesque, 1815) are listed from the Tarava Seamounts, Society Islands and Tuamotu Archipelago, French Polynesia. Four Propeamussiidae species (Parvamussium lamellatum n. sp., Parvamus

  19. Systematic notes on the Mesodesmatidae (Mollusca, Bivalvia), and descriptions of a new species and a new subspecies

    NARCIS (Netherlands)

    Rooij-Schuiling, de L.A.

    1972-01-01

    In 1959, Mr. A. Hoogerwerf obtained a number of small Mollusca from the gizzard of a godwit (Limosa spec.) shot near Koerik, West Irian, New Guinea, that eventually came into my hands for identification. Though the specimens clearly belonged to a species of the genus Mesodesma (Mactracea, fam. Mesod

  20. Comparative studies on the histology and ultrastructure of the siphons of two species of Tellinidae (Mollusca: Bivalvia from Brazil

    Directory of Open Access Journals (Sweden)

    João E.V.V. Vitonis

    2012-06-01

    Full Text Available Despite the great importance of the siphons for infaunal bivalves, only a few studies have examined their tissues using histology techniques or scanning electron microscopy. In the present study, the siphons of Tellina lineata Turton, 1819 and Macoma biota Arruda & Domaneschi, 2005 were investigated. The siphon walls are composed by a series of muscle sheets of longitudinal ("L", circular ("C" and radial ("R" fibers, with a clear pattern common to both species: there is a main median longitudinal layer (Lm, and two peripheral circular layers, one inner (Ci and one outer (Co, near the epithelia. A median circular layer (Cm separates an internal (Lmi from an outer (Lmo median longitudinal layer. Further, the Co is split by a thin outer longitudinal layer (Lo, forming Coi and Coo layers, the former being obliquely oriented. Thin radial fibers (R delimit clear packages of Lmi and Lmo fibers. In each siphon, there are six longitudinal nerve cords, running within the Lmi layer, adjacent to the Cm. The inhalant and exhalant siphons of M. biota are very similar in structure, but the Lmo of the exhalant siphon is almost twice as thick as its Lmi, while in the inhalant siphon these layers have similar thicknesses; the Coi is very thick, especially in the exhalant siphon. The inhalant siphon of T. lineata is very similar to that of M. biota, differing only with respect to the thickness of the Coi, which in the former species is not as well developed as in the latter. The Lmo of the exhalant siphon of T. lineata is by far the most developed layer, with the Lmi represented only by uniseriate small cells; in the vicinities of the nerve cords, the Cm is split in two layers. The epithelia of both siphons of M. biota and T. lineata bear ciliated receptors, which were difficult to observe as they were frequently covered with mucus. It was possible to observe that cilia are present in both species, differing in length and in the number per receptor between the inhalant and exhalant siphons, and between the species. Detailed comparisons among the siphons of M. biota and T. lineata and other bivalve species are very difficult, because of at least two reasons. First, each investigator has used different methods to prepare and observe the siphons through histological sections; and second, different nomenclatural schemes are used to describe the musculature of the siphons, causing confusion when the same layers are compared among different species. In order to unify the nomenclature of tissue layers of the bivalve siphons, we now propose a scheme to name these layers based on topological homology.

  1. 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

  2. New records and a new species of bivalve (Mollusca: Bivalvia) from Miocene hydrocarbon seep deposits, North Island, New Zealand.

    Science.gov (United States)

    Saether, Kristian P; Jingeng, Sha; Little, Crispin T S; Campbell, Kathleen A

    2016-01-01

    Fourteen bivalve taxa belonging to 11 families are present in at least 13 early to middle Miocene hydrocarbon seep deposits in the East Coast Basin, North Island, New Zealand. Among these are at least three new species, one of which, Semeloidea (s. l.) bexhavenensis sp. nov. (Lasaeidae), is described here. New distribution data are recorded for bivalve species in the families Limidae, Propeamussiidae, Malleidae and Solemyidae. Additional morphological details of Gigantidas coseli (Mytilidae) and Pratulum quinarium (Cardiidae) are provided based upon previously unrecorded internal shell features. Palaeoecological analysis indicates that bivalves utilized a broad range of modes of life and niches within the New Zealand Miocene seep environment, and no more than ca. 30% of these bivalve species were likely to have been obligate to seeps. PMID:27615822

  3. A new genus and species of Thyasiridae (Mollusca, Bivalvia from deep-water, Beaufort Sea, northern Alaska

    Directory of Open Access Journals (Sweden)

    Paul Valentich-Scott

    2014-12-01

    Full Text Available Bivalve mollusk shells were collected in 2350 m depth in the Beaufort Sea, Arctic Ocean off northern Alaska. Initial identification suggested the specimens were a member of the bivalve family Thyasiridae, but no known eastern Pacific or Arctic living or fossil thyasirid resembled these deep-water specimens. Comparisons were made with the type of the genera Maorithyas Fleming, 1950, Spinaxinus Oliver & Holmes, 2006, Axinus Sowerby, 1821, and Parathyasira Iredale, 1930. We determined the Beaufort Sea species represents a new genus, herein described as Wallerconcha. These specimens also represent a new species, herein named Wallerconcha sarae. These new taxa are compared with known modern and fossil genera and species of thyasirds.

  4. 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...

  5. 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.

  6. 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...

  7. 7 CFR 360.200 - Designation of noxious weeds.

    Science.gov (United States)

    2010-01-01

    ... (Linnaeus) Schultes (missiongrass, thin napiergrass) Prosopis alpataco R. A. Philippi Prosopis argentina Burkart Prosopis articulata S. Watson Prosopis burkartii Munoz Prosopis caldenia Burkart Prosopis calingastana Burkart Prosopis campestris Griseback Prosopis castellanosii Burkart Prosopis denudans...

  8. 7 CFR 361.6 - Noxious weed seeds.

    Science.gov (United States)

    2010-01-01

    ... Pennisetum polystachion (L.) Schultes Prosopis alapataco R. A. Philippi Prosopis argentina Burkart Prosopis articulata S. Watson Prosopis burkartii Munoz Prosopis caldenia Burkart Prosopis calingastana Burkart Prosopis campestris Grisebach Prosopis castellanosii Burkart Prosopis denudans Bentham Prosopis...

  9. 7 CFR 201.16 - Noxious-weed seeds.

    Science.gov (United States)

    2010-01-01

    .... Pennisetum pedicellatum Trin. Pennisetum polystachion (L.) Schult. Prosopis alapataco R.A. Philippi Prosopis argentina Burkart Prosopis articulata S. Watson Prosopis burkartii Munoz Prosopis caldenia Burkart Prosopis calingastana Burkart Prosopis campestris Griseb. Prosopis castellanosii Burkart Prosopis denudans...

  10. 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).

  11. Diplodon shells from Northwest Patagonia as continental proxy archives: Oxygen isotopic results and sclerochronological analyses

    Science.gov (United States)

    Soldati, A. L.; Beierlein, L.; Jacob, D. E.

    2009-04-01

    Freshwater mussels of the genus Diplodon (Bivalvia, Hyriidae) are the most abundant bivalve (today and in the past) in freshwater bodies at both sides of the South-Andean Cordillera. There are about 25 different Diplodon genera in Argentina and Chile that could be assigned almost completely to the species Diplodon chilensis (Gray, 1828) and two subspecies: D. ch. chilensis and D. ch. patagonicus; this latter species is found in Argentina between Mendoza (32˚ 52' S; 68˚ 51' W) and Chubut (45˚ 51' S; 67˚ 28' W), including the lakes and rivers of the target area, the Nahuel Huapi National Park (Castellanos, 1960). Despite their wide geographic distribution, Diplodon species have only rarely been used as climate archives in the southern hemisphere. Kaandorp et al. (2005) demonstrated for Diplodon longulus (Conrad 1874) collected from the Peruvian Amazonas that oxygen isotopic patterns in the shells could be used in order to reconstruct the precipitation regime and dry/wet seasonal of the monsoonal system in Amazonia. Although this study demonstrated the potential of Diplodon in climatological and ecological reconstructions in the southern hemisphere, as of yet, no systematic study of Diplodon as a multi-proxy archive has been undertaken for the Patagonian region. In this work we present sclerochronological analyses supported by ^18Oshell in recent mussel of Diplodon chilensis patagonicus (D'Orbigny, 1835) collected at Laguna El Trébol (42°S-71°W, Patagonia Argentina), one of the best studied water bodies in the region for paleoclimate analysis. Water temperature was measured every six hours for one year using a temperature sensor (Starmon mini®) placed at 5m depth in the lake, close to a mussel bank. Additionally, ^18Owater was measured monthly for the same time range.g^18Oshell values obtained by micro-milling at high spatial resolution in the growth increments of three Diplodon shells were compared to these records, and to air temperature and

  12. Preliminary Study on Seedling-raising Techniques for Prosopis chilensis L. and Pithecellobium dulce%智利牧豆·牛蹄豆育苗技术初探

    Institute of Scientific and Technical Information of China (English)

    郭尚磊; 陈文德; 彭培好; 史作民

    2008-01-01

    [目的]为智利牧豆和牛蹄豆的引种栽培提供理论依据.[方法]以智利牧豆和牛蹄豆为材料,通过引种栽培试验研究2个物种的苗木生长状况和育苗、移苗技术.[结果]温水浸泡处理可提高牛蹄豆的种子发芽率;智利牧豆较牛蹄豆出苗快,从播种到真叶出现仅需6~10 d,而牛蹄豆需9~12 d;播种3个月后,智利牧豆和牛蹄豆平均苗高生长量分别为 2.56、5.91 cm,平均基径生长量分别为0.030、0.060 cm.智利牧豆和牛蹄豆的生长旺盛期分别在7~8月和8~9月;切根并喷洒生根剂处理的智利牧豆成活率最高,为96.7%.[结论]该试验为智利牧豆和牛蹄豆的引种栽培及大田推广提供了参考.

  13. "In Comitiis Generalibus seu. Hueupin": composición poética en mapudungun para un Parlamento General (B. de Havestadt, Chilidugu sive tractatus linguae chilensis, vol. II, Ed. J. Platzmann, 1883, pp. 598-599.

    Directory of Open Access Journals (Sweden)

    Gertrudis Payas

    2014-07-01

    Full Text Available El jesuita B. de Havestadt (1714-1781 incluyó varias composiciones poéticas y musicales en mapudungun en su Chilidugu, alguna bilingüe mapudungun-latín y, en cuanto a género, casi todas de carácter religioso. La que aquí presentamos es una excepción. Lleva por título In Comitiis Generalibus Seu. Hueupin, y es una composición inspirada en un modelo autóctono, el weupin, pieza de oratoria tradicional mapuche. Según lo indica el título, Havestadt la concibió para ser recitada en un Parlamento General, es decir, durante una asamblea, o coyag, hispanomapuche del máximo nivel de asistencia y representatividad.

  14. 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

  15. First record of a pontoniine shrimp (Caridea, Palaemonidae) in association with a boring bivalve of the genus Spengleria (Bivalvia, Euheterodonta, Gastrochaenidae)

    NARCIS (Netherlands)

    Fransen, C.H.J.M.; Meij, van der S.E.T.

    2010-01-01

    During fieldwork in Raja Ampat, West Papua, Indonesia, in 2007, a pontoniine shrimp, most likely belonging to the genus Anchistus, was collected from a coral boring bivalve of the genus Spengleria. This is the first record of a pontoniine shrimp living in association with a boring bivalve. As it pro

  16. 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.

  17. Extirpation of freshwater mussels (Bivalvia: Unionidae) following the invasion of dreissenid mussels in an interconnecting river of the Laurentian Great Lakes

    Science.gov (United States)

    Schloesser, Don W.; Metcalfe-Smith, Janice L.; Kovalak, William P.; Longton, Gary D.; Smithee, Rick D.

    2006-01-01

    Previous (1992-1994) surveys for native freshwater mussels (Unionidae) along main channels of the Detroit River showed that unionids had been extirpated from all but four sites in the upper reaches of the river due to impacts of dreissenid mussels (Dreissena polymorpha and D. bugensis). These four sites were surveyed again in 1998 using the same sampling method (timed-random searches) to determine if they may serve as ''refugia'' where unionids and dreissenids co-exist. Two additional sites were sampled using additional methods (excavated-quadrat and line-transect searches) for comparison with unpublished data collected in 1987 and 1990. A total of four individuals of four species (Actinonaias ligamentina, Cyclonaias tuberculata, Lasmigona complanata and Pleurobema sintoxia) were found by timed-random searches at four sites in 1998 compared to 720 individuals of 24 species in 1992 and 39 individuals of 13 species in 1994. Excavated-quadrat and line-transect searches at the two additional sites yielded only one live specimen of Ptychobranchus fasciolaris compared to 288 individuals of 18 species in 1987 and 1990. Results of this study suggest that remaining densities of unionids in channels of the Detroit River are too low to support viable reproducing populations of any species. Therefore, we conclude that unionids have been extirpated from main channels of the Detroit River due to dreissenid infestation. As the Detroit River was one of the first water bodies in North America to be invaded by dreissenids, it is likely that unionids will also be extirpated from many other rivers and lakes across eastern North America over the next few decades. Resource agencies should be encouraged to implement active management programs to protect remaining unionid populations from zebra mussels.

  18. 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)

  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

    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....... the Yangtse River in China. Limnoperna fortunei is a highly opportunistic species that has been introduced into many locations outside its mainland Chinese borders, for example, Japan, Taiwan and South America. We suggest the possibility that L. fortunei has also been introduced into tropical Indochina from...

  20. 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...

  1. 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)

  2. 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...

  3. 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

    and locality. With age (≥ 20–45 years), shells often become deformed, particularly posteriorly and around the byssal gape, thereby increasing reproductive capacity (gonadal volume) without increasing somatic growth. Information on the biology, reproductive strategy and life history traits of M. modiolus...... and overall biology. Modiolus modiolus is a typical epibenthic, suspension-feeding mytilid, albeit with anatomical modifications adapting it to a partially buried, gregarious lifestyle in a stable environment experiencing medium–high energy levels. The juvenile shell is covered partly in byssal setae secreted...

  4. 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.

  5. [Lipid and fatty acid profile of Perna viridis, green mussel (Mollusca: Bivalvia) in different areas of the Eastern Venezuela and the West Coast of Trinidad].

    Science.gov (United States)

    Koftayan, Tamar; Milano, Jahiro; D'Armas, Haydelba; Salazar, Gabriel

    2011-03-01

    The species Perna viridis is a highly consumed species, which fast growth makes it an interesting aquaculture alternative for Venezuelan and Trinidad coasts. With the aim to contribute with its nutritional value information, this study analyzed lipid and fatty acid contents from samples taken in five locations from Eastern Venezuela and three from Trinidad West Coast. Total lipids were extracted and quantified, from a pooled sample of 100 organisms per location, by standard gravimetric methods, and their identification and quantification was done by TLC/FID (Iatroscan system). Furthermore, the esterified fatty acids of total lipid, phospholipids and triacylglycerols were identified and quantified by gas chromatography. Eastern Venezuela samples from Los Cedros, La Brea and Chaguaramas showed the highest total lipid values of 7.92, 7.74 and 7.53, respectively, and the minimum values were obtained for La Restinga (6.08%). Among lipid composition, Chacopata samples showed the lowest phospholipid concentration (48.86%) and the maximum values for cholesterol (38.87%) and triacylglycerols (12.26%); besides, La Esmeralda and Rio Caribe samples exhibited maximum phospholipids (88.71 and 84.93 respectively) and minimum cholesterol (6.50 and 4.42%) concentrations. Saturated fatty acids represented between 15.04% and 65.55% within total lipid extracts, with maximum and minimum values for La Esmeralda and Chacopata, respectively. Polyunsaturated results resulted between 7.80 and 37.18%, with higher values in La Brea and lower values in La Esmeralda. For phospholipids, saturated fatty acids concentrations varied between 38.81 and 48.68% for Chaguaramas and Chacopata samples, respectively. In the case of polyunsaturated fatty acids, these varied between non detected and 34.51%, with high concentrations in Los Cedros (27.97%) and Chaguaramas (34.51%) samples. For the triacylglycerols, the saturated fatty acids composition oscillated between 14.27 and 53.80% with low concentrations for Chacopata and high concentration for La Restinga; the polyunsaturated fatty acids were between 4.66 and 35.55% with lower values for Chacopata and higher values for Chaguaramas samples. P. viridis is recommended for human being consumption, according to the high content of unsaturated fatty acids found for this species.

  6. 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...

  7. 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.

  8. 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.

  9. Identification, cloning and environmental factors modulation of a αβ defensin from the Lessepsian invasive mussel Brachidontes pharaonis (Bivalvia: Mytilidae

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    MG Parisi

    2015-10-01

    Full Text Available Immunological effectors of invasive species playing a role in addressing new colonization are still poorly studied. In the present study the cDNA sequence of the defensin from a Lessepsian invasive species, the Red Sea mussel Brachidontes pharaonis, was cloned using RACE method. Defensins are a class of widely known antimicrobial peptides (AMPs, oligopeptides with a broad spectrum of targeted organisms ranging from viruses to parasites. Analysis of BpDef sequence (262 bp revealed the presence of an ORF coding for 81 amino acids. The full-length amino acid sequence showed the highest similarity to antimicrobial peptides MGD1 and MGD2 sequence from Mytilus galloprovincialis. Phylogenetic analysis suggested that BpDef belongs to the αβ defensin AMPs with a typical domain structurally characterized by a α helix and two β sheets. BpDef mRNA is located in circulating hemocytes with small intra-cytoplasmic granules and with large granules. The transcription of defensin gene was modulated by the stress from temperatures and oxygenation condition. Temperatures of 20 °C did not stimulate a BpDef transcription over a short time. At 30 °C the kinetics of BpDef gene transcription showed up regulation after one day, while it was down regulated after six days, both under normoxia and hypoxia conditions.

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

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    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.

  11. Othonella araguaiana (Bivalvia, Megadesmidae from the Corumbataí Formation (Midlle Permian, Eastern Margin of the Paraná Basin: Systematic, Evolutionary and Biostratigraphic Significances

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    Marcello Guimarães Simões

    2010-07-01

    Full Text Available In this study, the occurrence of Othonella araguaiana Mendes, a rare bivalve species is reported for the first time in thePinzonella illusa biozone, Middle Permian Corumbataí Formation, in the State of São Paulo. This species was originallydescribed in coeval rocks of the Estrada Nova Formation (= Corumbataí from the Alto Araguaia and Alto Garças regions,State of Mato Grosso. The specimens of O. araguaiana were found in the base of a bioclastic sandstone bed, a proximaltempestite, in the middle of the Corumbataí Formation, in the city of Rio Claro, São Paulo State. The silicified shells andinternal molds are well preserved, showing impressions of muscle scars and other internal anatomic characters (e.g., hinge,never illustrated by previous authors. In his original description, Mendes (1963 called attention to the similarity betweenO. araguaiana and Terraia aequilateralis, a common veneroid of the Corumbataí Formation. Conversely, Runnegar andNewell (1971 suggested that O. araguaiana belongs to Megadesmidae, being a junior synonym of Plesiocyprinella carinata(the commonest megadesmid of the Passa Dois Group. Our study indicates that O. araguaiana is indeed a megadesmid,but is distinct from the P. carinata. The new occurrence of O. araguaiana demonstrates that a the paleobiogeographicdistribution of this species is wider than previously thought (that it was restricted to the northern part of Paraná Basin,Mato Grosso State; b the molluscan fauna of the Corumbataí Formation (P. illusa biozone in the State of São Paulo ismore diverse and dominated by megadesmids; and c the composition of the molluscan fauna of the Corumbataí Formationin Alto Garças, State of Mato Grosso, is essentially the same as that of the P. illusa biozone of the eastern margin of theParaná Basin.

  12. 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

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    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.

  13. Morphological and genetic diversity of the wood-boring Xylophaga (Mollusca, Bivalvia: new species and records from deep-sea Iberian canyons.

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    Chiara Romano

    Full Text Available Deep-sea bivalves of the Xylophagaidae, a poorly known group, are obligate wood-borers. Deployment of wood in three submarine canyons off the Iberian coast, the Blanes and La Fonera Canyons (Mediterranean Sea and the Avilés Canyon (Cantabric Sea, Bay of Biscay, lead to the discovery of four xylophagaid species in our samples. Xylophaga dorsalis (the dominant species, X. atlantica, X. cf. anselli and the new species X. brava, were identified on the basis of morphological data, and supported by a phylogenetic reconstruction based on the nuclear genes 18S rDNA and 28S rDNA and including several genus of Xylophagaidae. Genetic divergence between species of Xylophaga varied between genes, ranging from 0.5 to 4.0% for the 18SrDNA and from 4.1 to 16.6% for the 28SrDNA. Xylophaga brava sp. nov. appeared to be restricted to the Mediterranean and morphologically resembled the closely related X. cf. anselli from the Cantabrian Sea. However, they clearly diverged in two well-supported clades. Low levels of intraspecific variability and higher interspecific divergence between species also supported the existence of these two different species. Morphologically they differ in the number of cirri at the siphon openings, in the shape of the posterior shell and in the size of prodissoconch II. The new species is characterized by having weak, poorly mineralized mesoplax and siphons united throughout, covered by a periostracal, non-calcified tube; distinct proximal and distal siphons, the former translucent and soft, the latter muscular, with concentric rings. Xylophaga atlantica, previously known only from the western Atlantic, is reported for the first time in the Mediterranean Sea. Whether its presence in the Mediterranean indicates its natural distribution or reflects its recent introduction is unknown. Although xylophagaids have been previously reported to recruit heavily to wood deposited on the seabed, these four species colonized wood suspended 30 m above the seafloor.

  14. 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)

  15. 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 ...

  16. Molecular phylogeny of Arcoidea with emphasis on Arcidae species (Bivalvia: Pteriomorphia) along the coast of China: challenges to current classification of arcoids.

    Science.gov (United States)

    Feng, Yanwei; Li, Qi; Kong, Lingfeng

    2015-04-01

    The current classifications of arcoids are based on phenetic similarity, which display considerable convergence in several shell and anatomical characters, challenging phylogenetic analysis. Independent molecular analysis of DNA sequences is often necessary for accurate taxonomic assignments of arcoids, especially when morphological characters are equivocal. Here we present molecular evidence of the phylogenetic relationships among arcoid species based on Bayesian inference and Maximum Likelihood analyses of three nuclear genes (18SrRNA, 28SrRNA, and histone H3) and two mitochondrial genes (COI and 12S). Tree topologies are discussed by considering traditional arrangements of taxonomic units and previous molecular studies. The results confirm the monophyly of the order Arcoida, the family Noetiidae, and the subfamilies Anadarinae and Striarcinae, with support for the inclusion of the Glycymerididae in the Arcoidea. The subfamily Arcinae and the genera Arca, Barbatia, Scapharca, Anadara, and Glycymeris are non-monophyletic, suggesting that taxonomic issues still remain. The families Noetiidae, Cucullaeidae, and Glycymerididae appear as subgroups within, rather than sister groups to, the Arcidae. This study strongly suggests the need to carry out a taxonomic revision of the Arcoidea, especially the Arcidae, through combined analysis of morphological, paleontological, and molecular data.

  17. 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.

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

    Science.gov (United States)

    Huang, Xiao-Chen; Rong, Jun; Liu, Yong; Zhang, Ming-Hua; Wan, Yuan; Ouyang, Shan; Zhou, Chun-Hua; Wu, Xiao-Ping

    2013-01-01

    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.

  19. “TUBULAR GILLS” Extreme gill modification in the Thyasiroidea with the description of Ochetoctena tomasi gen. et sp. nov. (Bivalvia: Thyasiroidea)

    OpenAIRE

    Graham Oliver

    2014-01-01

    Three dimensional tubular structures of the ctenidium of some thyasirid bivalves are described for the first time. The classification of the thyasirid gill is modified accordingly into five types based on the number of demibranchs, reflection of the filaments and shape of the filaments, either rod, laminar or tubular. The tubular structure is seen in its most modified form in a chemosymbiotic abyssal species from the south-east Atlantic, which is described here as Ochetoctena tomasi gen et sp...

  20. 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.

  1. Changing collecting strategies of the clam Donax serra Röding (Bivalvia: Donacidae) during the Pleistocene at Pinnacle Point, South Africa.

    Science.gov (United States)

    Jerardino, Antonieta; Navarro, René A; Galimberti, Mariagrazia

    2014-03-01

    South Africa's Middle Stone Age (MSA) coastal sites have played a prominent role in documenting early evidence of systematic shellfish collection and adaptation to aquatic environments in the context of anatomically modern humans. Pinnacle Point 13B cave is important among these MSA sites not only because it holds the earliest yet known evidence for human use of marine resources (∼162 ka [thousands of years ago]), but because shellfish observations have been integrated more fully into discussions of MSA adaptations. This is particularly the case of Donax serra procurement on sandy beaches, where skills that are usually indicative of an aspect of behavioural modernity (in the context of hunting) were apparently used. In this paper, D. serra from 110 to 91 ka old assemblages are studied in detail by way of metrical analyses and relevant biological and ecological literature of this species. Existing seasonality studies derived from oxygen isotope analyses on the same molluscs are incorporated into this reconstruction. Shellfish appear to have been collected in winter over many millennia when D. serra are most nutritious due to high gonad content. A dramatic change in collection strategies took place during the same millennia-long period. Earliest systematic collection of D. serra consisted of mostly unselective procurement of animals in terms of shell size along the tidal gradient and beach depth. In later visits, people collected mostly larger individuals by narrowing their collection to the mid-intertidal. This change increased the efficiency of D. serra collection, which reflects a positive adaptive behaviour that endured into Later Stone Age (LSA) times.

  2. Mytilus antiquorum J. Sowerby, 1821, and other Pliocene mussels (Mollusca, Bivalvia) from the southern North Sea Basin

    OpenAIRE

    Vervoenen, M.; Wesselingh, F.P.; van Nieulande, F.A.D.

    2000-01-01

    Mytilus antiquorum J. Sowerby, 1821, is recorded from the Coralline Crag Formation of East Anglia (UK) and the Lillo Formation ( Oorderen, Kruisschans and Merksem members) of the Antwerp area (Belgium). The species is diagnosed on the basis of newly collected material and differentiated from modem European mussel species. The presence of M. antiquorum in the southern North Sea Basin is restricted to the Middle (Piacenzian) and early Late Pliocene (Gelasian). A possible occurrence of the spec...

  3. Mantle-shell complex reactions elicited by digenean metacercariae in Gaimardia trapesina (Bivalvia: Gaimardiidae) from the Southwestern Atlantic Ocean and Magellan Strait.

    Science.gov (United States)

    Ituarte, C F; Cremonte, F; Deferrari, G

    2001-12-20

    The host response to 3 different larval digeneans affecting Southwestern Atlantic and Magellanic populations of the bivalve Gaimardia trapesina (Lamarck, 1819) (Gaimardiidae) is described. Unencysted metacercariae of 2 species of Gymnophallidae and 1 species of Lepocreadiidae co-exist in the peripheral and general extrapallial spaces. Differences in host responses to stimuli generated by each parasite are described. Infections by Gymnophallidae gen. sp. 1 metacercariae elicit a mantle-shell complex reaction involving both alteration of the mantle epithelium (hyperplasia and metaplasia) and calcium carbonate deposition to form an incomplete calcareous covering of single larvae, comprising individual crystallites in an organic matrix. The calcareous covering covers only the posterior two-thirds of the larval body, having its anterior end free in the extrapallial space, which ensures survival of the larvae. The peculiar features of the host response result from a successful process of adjustment to the parasite's life cycle. Metacercariae of Gymnophallidae gen. sp. 2 occur in one or more small groups of up to 30 individuals, either in the general or in the peripheral extrapallial spaces. The outer mantle reaction includes hyperplasia and metaplasia of the epithelium adjacent to the larvae. Deposition of calcium carbonate did not occur. Lepocreadiidae gen. sp. metacercariae were observed exclusively in the general extrapallial space lodged in single shallow pits whose shape fit the parasite's body shape and size. In simultaneous infections, metacercariae of Gymnophallidae and Lepocreadiidae elicited different responses in an individual, which suggests that each parasitic entity involves a different stimulus to the host.

  4. Crecimiento, supervivencia y condición del callo de hacha Atrina maura (Sowerby, 1835 (Bivalvia: Pinnidae en el estero La Piedra, Sinaloa, México

    Directory of Open Access Journals (Sweden)

    Andrés Martín Góngora-Gómez

    2015-01-01

    Full Text Available Se evaluó el crecimiento y la supervivencia del callo de hacha Atrina maura (Sowerby, 1835 cultivado durante 15 meses (mayo 2010–agos - to 2011, en el estero La Piedra, municipio de Guasave, Sinaloa, México. Se adquirieron 3,000 semillas (61.50 ± 0.5 mm de longitud, 4.98 ± 0.2 g de peso promedio. Se registró la temperatura (26.15 ± 6.35ºC, el oxígeno disuelto (6.94 ± 1.67 mg/L, pH (6.79 ± 1.5 y la salinidad del agua (32.25 ± 7.25 ups quincenalmente. Los valores de crecimiento fi - nales fueron de 193.17 ± 11.50 mm, para la altura de la concha, y 156.54 ± 25.30 g para el peso. Se encontraron diferencias significativas en la altura de la concha y el peso total a lo largo del cultivo (P<0.05. La tasa de crecimiento fue de 0.29 mm/d y 0.33 g/d para la altu - ra de la concha y el peso, respectivamente. La relación morfométrica longitud-peso fue alométrica (2.39, y mostró una correlación positiva (r = 0.88. La supervivencia final fue de 92.79%. Los resultados muestran que en el estero La Piedra, Sinaloa, A. maura no alcan - zó la talla comercial ( ≥ 200 mm después de 15 meses de cultivo; presumiblemente, por la presencia de contaminantes en el agua. Se reco - mienda la realización de futuros cultivos de A. maura en el estero, considerando el efecto de las variables del medio ambiente en su crecimiento.

  5. 五种蚌的形态变异与判别分析%Morphological variations and discriminant analysis of five freshwater unionid species (Bivalvia: Unionidae)

    Institute of Scientific and Technical Information of China (English)

    魏开建; 熊邦喜; 赵小红; 龙良启; 王明学; 王卫民; 赵振山

    2003-01-01

    运用多变量形态度量学方法,采用6个形态性状对褶纹冠蚌、三角帆蚌、圆背角无齿蚌、椭圆背角无齿蚌和球形无齿蚌5种蚌的种间以及地理种群间的形态变异进行了研究.主成分分析构建了2个主成分,第一主成分受4个性状的影响,贡献率为54.17%;第二主成分受1个性状的影响,贡献率为34.08%.主成分分析和聚类分析表明,褶纹冠蚌与三角帆蚌形态相近,椭圆背角无齿蚌与球形无齿蚌外形相似.方差分析和t检验表明,褶纹冠蚌和三角帆蚌的不同地理种群分别表现出形态上的变异.建立了5种蚌的判别函数,三角帆蚌和圆背角无齿蚌的判别准确率均为100%,褶纹冠蚌、椭圆背角无齿蚌和球形无齿蚌的判别准确率依次为98.92%、86.36%和96.88%,总判别准确率为97.83%.

  6. SO-CALLED MIDDLE TRIASSIC "CLARAIA" (BIVALVIA) FROM GUANGXI, SOUTH CHINA%广西中三叠世的"克氏蛤"之订正

    Institute of Scientific and Technical Information of China (English)

    陈金华; 小松俊文

    2002-01-01

    描述报道广西中三叠世地层中一类形态相似于克氏蛤(Claraia)的双壳纲化石,经研究,发现海扇科的关键特征丝梳,认为不属于克氏蛤,而可能是Periclaraia属的一个新种;并初步探讨化石层的生态环境,认为可能是相对隔离的盆地中央区.新种是由海扇类进入隔离环境后经特化形成的;新种与克氏蛤的表面相似性是生活习性的相似性导致的形态趋同现象.

  7. 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.

  8. Analysis of Isozyme Diversities in Atrina pectinata Linnaeus (Mollusca,Bivalvia)%栉江珧同工酶多态性的分析

    Institute of Scientific and Technical Information of China (English)

    余祥勇; 王梅芳; 杨书婷; 桂建芳

    2005-01-01

    采用垂直板聚丙烯酰胺梯度凝胶电泳对栉江珧(Atrina pectinata Linnaeus)消化盲囊进行了5种酶(SOD、EST、MDH、ME、LDH)的同工酶分析.结果表明不同个体的同工酶表达呈现多态现象,个体间酶带带型既有相一致的共同特征谱带,又有较多的变异,5种酶均可把样品大致区分为差异明显的2种或3种类型,而且酶谱类型与形态类型基本对应,同工酶表达上的多样性表明栉江珧种内在生化遗传上存在较大的变异,具有较丰富的遗传多态性.

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

    Energy Technology Data Exchange (ETDEWEB)

    Arakawa, Jumpei; Sakamoto, Wataru [Division of Applied Biosciences, Graduate School of Agriculture, Kyoto Univ., Kyoto (Japan)

    1998-07-01

    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)

  10. 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.

  11. 越南沿海的双壳纲软体动物%Studies on the Bivalvia (Mollusca) of the Vietnam Coast

    Institute of Scientific and Technical Information of China (English)

    蔡英亚; 李海燕

    2002-01-01

    报道了越南沿海的双壳纲软体动物320种,隶属3亚纲、6目、26总科、41科、148属.从种类的组成中,帘蛤科有57种,蚶科32种,樱蛤科29种,贻贝科25种,鸟蛤科16种,牡蛎科14种,蛤蜊科13种,珍珠贝科和扇贝科各12种,紫云蛤科11种,竹蛏科10种,其他各科的种类均在7种以内.按种的性质而论,越南沿海主要是由热带种和亚热带种类组成,还有与珊瑚礁紧密联系的热带种.就越南沿海双壳纲软体动物分类区系而论,应属印度-西太平洋区的印尼-马来亚区.

  12. “TUBULAR GILLS” Extreme gill modification in the Thyasiroidea with the description of Ochetoctena tomasi gen. et sp. nov. (Bivalvia: Thyasiroidea

    Directory of Open Access Journals (Sweden)

    Graham Oliver

    2014-10-01

    Full Text Available Three dimensional tubular structures of the ctenidium of some thyasirid bivalves are described for the first time. The classification of the thyasirid gill is modified accordingly into five types based on the number of demibranchs, reflection of the filaments and shape of the filaments, either rod, laminar or tubular. The tubular structure is seen in its most modified form in a chemosymbiotic abyssal species from the south-east Atlantic, which is described here as Ochetoctena tomasi gen et sp. nov.

  13. Cadmium exposure affects mitochondrial bioenergetics and gene expression of key mitochondrial proteins in the eastern oyster Crassostrea virginica Gmelin (Bivalvia: Ostreidae)

    Energy Technology Data Exchange (ETDEWEB)

    Sokolova, Inna M. [Biology Department, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, NC 28223 (United States)]. E-mail: insokolo@uncc.edu; Sokolov, Eugene P. [Biology Department, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, NC 28223 (United States); Ponnappa, Kavita M. [Biology Department, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, NC 28223 (United States)

    2005-07-01

    Cadmium is a ubiquitous and extremely toxic metal, which strongly affects mitochondrial function of aquatic organisms in vitro; however, nothing is known about the in vivo effects of sublethal concentrations of this metal on mitochondrial bioenergetics. We have studied the effects of exposure to 0 (control) or 25 {mu}g L{sup -1} (Cd-exposed) Cd{sup 2+} on mitochondrial function and gene expression of key mitochondrial proteins in the eastern oyster Crassostrea virginica. Cadmium exposure in vivo resulted in considerable accumulation of cadmium in oyster mitochondria and in a significant decrease of ADP-stimulated respiration (state 3) by 30% indicating impaired capacity for ATP production. The decrease in state 3 respiration was similar to the level of inhibition expected from the direct effects of cadmium accumulated in oyster mitochondria. On the other hand, while no effect on proton leak was expected based on the mitochondrial accumulation of cadmium, Cd-exposed oysters in fact showed a significant decline of the proton leak rate (state 4 + respiration) by 40%. This suggested a downregulation of proton leak, which correlated with a decrease in mRNA expression of a mitochondrial uncoupling protein UCP6 and two other potential uncouplers, mitochondrial substrate carriers MSC-1 and MSC-2. Expression of other key mitochondrial proteins including cytochrome c oxidase, adenine nucleotide transporter and voltage dependent anion channel was not affected by cadmium exposure. Adenylate energy charge (AEC) was significantly lower in Cd-exposed oysters; however, this was due to higher steady state ADP levels and not to the decrease in tissue ATP levels. Our data show that adjustment of the proton leak in cadmium-exposed oysters may be a compensatory mechanism, which allows them to maintain normal mitochondrial coupling and ATP levels despite the cadmium-induced inhibition of capacity for ATP production.

  14. 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)

  15. 湘江长沙段的双壳类软体动物%Bivalvia Mollusca in the Changsha Section of Xiang River

    Institute of Scientific and Technical Information of China (English)

    胡自强; 杨海明; 胡少锋

    2004-01-01

    报道了湘江长沙段双壳类软体动物的调查结果,计有双壳类24种及3亚种(其中椭圆背角无齿蚌和橄榄蛏蚌为湖南省新记录种),分别隶属于双壳纲3科17属,其中主要是蚌科珠蚌亚科的种类.并对它们的种类组成、区系、分布、种群大小及栖息环境进行了分析,叙述了优势种的经济价值及利用前景.

  16. Optimize Artificial Environment for Live Bivalvia Purification and its effect%活双壳贝类净化人工环境优化设计与效应

    Institute of Scientific and Technical Information of China (English)

    张饮江; 徐文达; 周培根; 沈和定; 吴建中; 王艳

    2007-01-01

    根据双壳贝类生态生理特性,创建由水质处理、O3-UV组合消毒、调温监控等循环水系统组成,有利于双壳贝类张壳、排泄、存活等生理活动,以及避免引起再污染的最佳净化环境,促进贝类净化进程,保证了净化贝类的质量安全;研制高效实用的双壳贝类净化浅水槽模式.结果表明,毛蚶仅在30 h内就达到欧盟规定的净化标准,存活率达91%,快速有效.

  17. Características biológicas de una población de Pteria sterna(Bivalvia: Pteriidae en Zorritos, Tumbes, Perú

    Directory of Open Access Journals (Sweden)

    Elmer Ordinola

    2013-12-01

    Full Text Available Entre abril y noviembre de 2011 se analizó una población de Pteria sterna (Gould, 1851 que se encontraba adherida a una red de cerco hundida en Zorritos, Tumbes, Perú (3º40’30.7”S - 80º40’20.8”W. Los individuos presentaron tallas de 5 a 94 mm de altura valvar. La talla promedio se incrementó hacia finales del periodo evaluado. La estructura de tallas mostró la presencia de reclutas en la mayoría de meses evaluados, con máximos en abril y agosto. Se registraron cinco grupos de edad. La proporción sexual fue 1:1. Los desoves fueron continuos, a excepción de junio, con un máximo en noviembre. La relación altura valvar-peso total no mostró diferencias por sexos. El crecimiento de esta especie fue alométrico negativo. Las demás relaciones (potencial: peso del cuerpo-peso total, y lineales: peso del cuerpo-peso total y peso del talo – peso total presentaron elevadas correlaciones. El rendimiento del músculo (talo representó el 6.3% del peso total.

  18. 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.

  19. 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...

  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. 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

  4. An annually-resolved palaeoenvironmental archive for the Eastern Boundary North Atlantic upwelling system: Sclerochronology of Glycymeris glycymeris (Bivalvia) shells from the Iberian shelf

    Science.gov (United States)

    Freitas, Pedro; Monteiro, Carlos; Butler, Paul; Reynolds, David; Richardson, Christopher; Gaspar, Miguel; Scourse, James

    2015-04-01

    The seasonally variable western Iberia upwelling system, albeit placed at a crucial climatic boundary position to record high frequency climate events, lacks well-dated high-resolution records of environmental variability. Bivalve shells provide robust high-resolution archives of oceanographic and climatic variability on timescales of decades to millennia. In particular, the North Atlantic Ocean region has recently seen several noteworthy sclerochronological and geochemical reconstructions based on bivalve shells (mainly Arctica islandica) of high frequency oceanographic and climatic conditions during the last millennium. However, due to the absence of Arctica islandica and similarly long-lived bivalves, sclerochronological palaeoenvironmental studies of southern European coastal shelf seas are scarce. In particular, none of these studies focus on reconstructing the variability of an eastern boundary upwelling system. The relatively long-lived bivalve (>100 years) Glycymeris glycymeris occurs in European and North West African coastal shelf seas and provides a valid annually resolved archive of environmental conditions during growth. Annual growth increment width series from living G. glycymeris shells, collected in 2014 on the western Iberian continental shelf (ca. 35 m water depth), were used to construct a statistically robust, ca. 70-year long absolutely-dated chronology. Sub-annually resolved (11 to 22 samples per year) oxygen stable isotope (δ18Oshell) data covering three years of shell growth, together with the direct evaluation of the time of growth mark deposition in shells collected during the autumn and winter months, were used to constrain the season of growth and to evaluate the seasonal bias of the sea-surface temperature signal preserved in the δ18Oshelldata. The growth increment width and δ18Oshell series, once robustly calibrated against modelled and instrumental oceanographic and climatic series, potentially provide novel insights into the variability of the western Iberia upwelling system and the associated mechanisms. This study was financed and conducted in the frame of the Portuguese Fundação para a Ciência e Tecnologia (FCT) GLYCY Project (contract PTDC/AAC-CLI/118003/2010).

  5. Seasonal Variation in the Biochemical Constituents, Percentage Edibility and Condition Index of the Estuarine Clam, Soletellina diphos (Linnaeus, 1771 (Mollusca: Bivalvia: Veneroida: Psammobiidae

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    Vishwajeet M. Lagade

    2015-01-01

    Full Text Available A variety of biochemical analyses and condition indices have been employed by various authors all over the world to assess the chemical and health index of bivalves. In order to understand the effect of seasonal climate change on the nutritive value and physiological fitness of an estuarine population of the psammobiid Soletellina diphos on the West coast of India. The present study was under-taken in order to determine the seasonal fluctuations of the biochemical constituents in different parts of the body and the percentage edibility and condition index. This study has shown that seasonality is related to significant alterations in the biochemical constituents, percentage edibility and condition index (pS. diphos. These changes could be due to the clam’s seasonal activities, particularly those related to its reproductive cycle. Higher values of the protein and lipid contents were recorded during the post-monsoon period, whereas maximum concentrations of glycogen were detected during the winter season. On the other hand, the lowest protein and glycogen contents were recorded during summer, while minimal lipid contents were observed during the winter season. The Percentage Edibility (PE and Condition Index (CI significantly fluctuated during the annual cycle, with maximum values occurring during the post-monsoon period (September-October 2008 and the lowest values during winter (November-December 2008. Therefore, it seems that the best nutritive season for S. diphos is in the post-monsoon period (September-October, when the highest values of its biochemical composition, percentage edibility and condition index occur. However, during the summer season (April-May, the lowest levels of the organic constituents, the percentage edibility and the condition index were recorded. Hence, that season is not ideal from the nutritive point of view. The study concludes that the physiological activity, the nutritive value and the meat quality of the clam S. diphos are seasonally related. Moreover, such baseline information is important from the viewpoint of aquaculture, as it demonstrates the seasonal impact on the nutritive status, reproductive output and physiological fitness of S. diphos.

  6. 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.

  7. 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. 

  8. 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.

  9. Current knowledge on population studies on five continental molluscs (Mollusca, Gastropoda et Bivalvia of Santa Catarina State (SC, Central Southern Brazil region

    Directory of Open Access Journals (Sweden)

    A. Ignacio Agudo-Padrón

    2011-03-01

    Full Text Available Although still very scarce, available knowledge on population studies on continental (land and freshwatermolluscs in the territory of Santa Catarina State is shortly analyzed and discussed. Based on the IUCN“Restricted Distribution” criterion, a total of 54 nominal species, including 31 terrestrial gastropods, 15freshwater gastropods and 8 limnic bivalves, were considered strong candidates as threatened taxa. Out of allthese endangered species, only 5 limnic forms (2 gastropods and 3 bivalves were previously analysed, in someway, at population level.

  10. 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...

  11. 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 ...

  12. Combined Use of Morphological and Molecular Tools to Resolve Species Mis-Identifications in the Bivalvia The Case of Glycymeris glycymeris and G. pilosa

    Science.gov (United States)

    Holmes, Anna; Bušelić, Ivana; Thébault, Julien; Featherstone, Amy

    2016-01-01

    Morphological and molecular tools were combined to resolve the misidentification between Glycymeris glycymeris and Glycymeris pilosa from Atlantic and Mediterranean populations. The ambiguous literature on the taxonomic status of these species requires this confirmation as a baseline to studies on their ecology and sclerochronology. We used classical and landmark-based morphometric approaches and performed bivariate and multivariate analyses to test for shell character interactions at the individual and population level. Both approaches generated complementary information. The former showed the shell width to length ratio and the valve asymmetry to be the main discriminant characters between Atlantic and Mediterranean populations. Additionally, the external microsculpture of additional and finer secondary ribs in G. glycymeris discriminates it from G. pilosa. Likewise, landmark-based geometric morphometrics revealed a stronger opisthogyrate beak and prosodetic ligament in G. pilosa than G. glycymeris. Our Bayesian and maximum likelihood phylogenetic analyses based on COI and ITS2 genes identified that G. glycymeris and G. pilosa form two separate monophyletic clades with mean interspecific divergence of 11% and 0.9% for COI and ITS2, respectively. The congruent patterns of morphometric analysis together with mitochondrial and nuclear phylogenetic reconstructions indicated the separation of the two coexisting species. The intraspecific divergence occurred during the Eocene and accelerated during the late Pliocene and Pleistocene. Glycymeris pilosa showed a high level of genetic diversity, appearing as a more robust species whose tolerance of environmental conditions allowed its expansion throughout the Mediterranean. PMID:27669452

  13. [Egg ultrastructure in two Chilean moths: Ormiscodes socialis and Polythysana cinerascens (Lepidoptera: Saturniidae)].

    Science.gov (United States)

    Benítez-Mora, Alfonso; Olivares, Tania S

    2006-12-01

    The structure and ultra-structure of the eggs from Ormiscodes socialis (Feisthamel) and Polythysana cinerascens (Philippi) are described, considering shape, size, coloring when recently laid, oviposition type and aeropiles (quantity, distribution and proportion) in the micropilar area, among others. The ultra-structure is shown for primary cells, secondary cells, aeropiles and micropiles. A comparative table of the eggs of these species is presented and includes the previously described eggs of Adetomeris microphthalma (Philippi). Myoschilos oblonga Ruiz y Pavón (Santalaceae) is recorded as a new host for P. cinerascens.

  14. Ten new records of marine invertebrates from the Azores

    Directory of Open Access Journals (Sweden)

    WIRTZ, P.

    2009-01-01

    Full Text Available The sea anemones Telmatactis cricoides (Duchassaign, 1850 and Actinia n. sp., themolluscs Tonna galea Linnaeus, 1758, Vitreolina philippi (de Rayneval & Ponzi, 1854,Melanella n. sp., Phidiana lynceus (de Rayneval & Ponzi, 1854 and Anomia patelliformis(Linnaeus, 1761, the nemertine Baseodiscus delineatus (DelleChiaje, 1825 and the echinoderms Leptosynapta inhaerens (O. F. Müller, 1776 and Stichopus regalis (Cuvier, 1817, are here recorded from the Azores for the first time. The presence of the two starfishspecies Chaetaster longipes (Retzius, 1805 and Luidia ciliaris (Philippi, 1837 in the Azores is confirmed and the spawning behaviour of the sea urchin Echinocyamus pusillus (O. F. Müller, 1776 is described.

  15. A chromosomal analysis of four species of Chilean Chrysomelinae (Coleoptera, Chrysomelidae

    Directory of Open Access Journals (Sweden)

    Eduard Petitpierre

    2012-10-01

    Full Text Available Four species of Chilean leaf beetles in the subfamily Chrysomelinae have been cytogenetically analyzed, Blaptea elguetai Petitpierre, 2011, Henicotherus porteri Bréthes, 1929 and Jolivetia obscura (Philippi, 1864 show 2n = 28 chromosomes and a 13 + Xyp male meioformula, and Pataya nitida (Philippi, 1864 has the highest number of 2n = 38 chromosomes. The karyotype of H. porteri is made of mostly small meta/submetacentric chromosomes, and that of Jolivetia obscura displays striking procentric blocks of heterochromatin at pachytene autosomic bivalents using conventional staining. These findings are discussed in relation to previous cytogenetic data and current taxonomy of the subfamily.

  16. 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.

  17. 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...

  18. 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.

  19. 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

  20. 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

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Borzone

    2001-06-01

    Full Text Available 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 summer months. Histological analysis of gonadal tissue showed a continuous reproduction, with peaks of maturation on autumn and spring, Spawning was related with the increase of water temperature, that occurs twice a year in the region as a consequence of a particular hydrological characteristic of the inner continental shelf. Size frequency distribution showed a unique principal mode with slow if any displacement through time, indicating a long lived species.

  1. 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

    Directory of Open Access Journals (Sweden)

    Cíntia P. dos Santos

    2005-09-01

    Full Text Available 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 de um ano, no lago Guaíba, Praia do Veludo (30°12'35"S, 51°11'68"W, ao sul do município de Porto Alegre. Utilizou-se rede de plâncton com abertura de malha equivalente a 36 mm, filtrando-se a quantidade de 30 litros de água. Descrevem-se brevemente as diferentes fases larvais com parâmetros do comprimento. Primeiramente reconhece-se um estágio ciliado, desenvolvendo-se em trocófora (comprimento de 80 µm a 125 µm com quatro fases distintas, e valvadas com a larva "D" (120 µm a 150 µm, o veliger de charneira reta (150 µm a 190 µm, o veliger umbonado (190 µm a 220 µm e o pediveliger (220 µm a 250 µm. Quando pós-larvas ou plantígradas (comprimento em torno de 300 µm, começam a secretar o fio de bisso, permitindo a fixação ao substrato. Constatou-se a presença de larvas durante todos os meses amostrados, com picos nos meses de outubro a dezembro.Since the end of 1998 a small invasive bivalve, the golden mussel Limnoperna fortunei (Dunker, 1857, originating from Southeast Asia, is present in Southern Brazil. It was probably brought not intentionally in ballast water to the Guaíba Basin in Rio Grande do Sul State. In this environment, the golden mussel is causing macrofouling very rapidly with grate financial loss and damages to the native fauna and flora. Quali-quantitative samplings twice a month were performed during one year in the Guaíba lake, at Veludo Beach (30°12'35"S, 51°11'68"W southward of the municipality of Porto Alegre. Each time, 30 litters of water were filtered through plankton net with a mash opening of 36 mm. The different larval stages with the length parameters were briefly described. Different stages were recognized: five without valves and four valved. The first one recognized as a ciliated stage develops into the trocophora (length from 80 µm to 125 µm with four distinct stages. The valved stages include: the "D" - shaped (length 120 µm to 150 µm, the straight-hinged veliger (length 150 µm to 190 µm, umbonated-veliger (length 190 µm to 220 µm and pediveliger (length 220 µm to 250 µm. When pos-larvae or plantigrades (length about 300 µm, they secrete the byssus thread that permit fixation on the subtract. Larvae were present during all the samplings with strong October-December peaks.

  2. 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

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    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.

  3. PLICATOUNIO (GUANGXIPLICATOUNIO), A NEW NAME FOR PLICATOUNIO(GUANGXICONCHA) YAO AND YU, 1986 (BIVALVIA: PLICATOUNIONIDAE),PREOCCUPIED BY GUANGXICONCHA ZHANG, 1977 (BIVALVIA: LUNULACARDIIDAE)%新建广西褶珠蚌(新名)(Guangxiplicatounio nom.nov.)替代晚出名Guangxiconcha Yao and Yu,1986(非Guangxiconcha Zhang,1977)

    Institute of Scientific and Technical Information of China (English)

    方宗杰

    2007-01-01

    姚培毅、于菁珊(1986)为广西扶绥下白垩统的褶珠蚌类标本建立了一个新亚属Plicatounio(Guangxiconcha)Yao and Yu,以Plicatounio(Guangxiconcha)fortis Yao and Yu,1986(230页,图版1,图4;图版2,图3,6)作为模式种。

  4. Distribuição sazonal e reprodução de Neocorbicula limosa (Maton (Bivalvia, Corbiculidae no Lago Guaíba, Rio Grande do Sul, Brasil Seasonal distribution and reproduction of Neocorbicula limosa (Maton (Bivalvia, Corbiculidae in the Guaíba Lake, Rio Grande do Sul, Brazil

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    Teimo Focht

    2001-03-01

    Full Text Available Neocorbicula limosa (Maton, 1811 is the only species of that South American genus that occurs in the hydrographic basins of Rio Grande do Sul State, Brazil. Seasonal quantitative collections between 1995 and 1996 in the lake Guaiba were accomplished, with the aim to know the reproductive dynamics and environmental preferences of populations of N. limosa. A substratum constituted by medium to coarse sands at an 'average depth around 2m shown to be favorable to installation of population of N. limosa. The largest population density (2.496 ind./m² was registered in summer. Embryos at various development phases were registered inside individuals. The shell sizes of these individuals started from 8mm in length. The embryo's size could reach ¼ of the shell-mother's size, and their liberation occurs through the rupture of the gills.

  5. 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

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    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.

  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

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    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. 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

    OpenAIRE

    Junqueira, Andrea O. R.; Sergio Henrique G. da Silva; Maria Júlia M. Silva

    1989-01-01

    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...

  8. 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 ...

  9. 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...

  10. Increased recruitment rates indicate recovering populations of the sea urchin Diadema antillarum on Curacao

    NARCIS (Netherlands)

    Vermeij, M.; Debrot, A.O.; Hal, van der N.; Bakker, J.; Bak, R.P.M.

    2010-01-01

    Recruitment of the sea urchin Diadema antillarum philippi, 1845 was studied on artificial recruitment panels along the leeward coast of the island of Curaçao, southern Caribbean. Data were compared with historical data from the same coast that were collected before (1982-1983) and after (1984) the C

  11. 76 FR 33786 - Affirmative Decisions on Petitions for Modification Granted in Whole or in Part

    Science.gov (United States)

    2011-06-09

    ...). Petitioner: Wolf Run Mining Company, Route 3, Box 146, Philippi, West Virginia 26416. Mine: Sentinel Mine..., Arlington, Virginia 22209. All visitors must first stop at the receptionist desk on the 21st Floor to sign... the following petitions for modification: Docket Number: M-2008-021-C. FR Notice: 73 FR 31147 (May...

  12. 75 FR 16179 - Notice of Affirmative Decisions on Petitions for Modification Granted in Whole or in Part

    Science.gov (United States)

    2010-03-31

    ..., 2009). Petitioner: Wolf Run Mining Company, 1 Edmiston Way, Buckhannon, West Virginia 26201. Mine... (June 8, 2009). Petitioner: Wolf Run Mining Company, Rt. 3, Box 146, Philippi, West Virginia 26416. Mine... Notice (FR Notice) notifies the public that it has investigated and issued a final decision on...

  13. Redescription de l’Ostracode marin Sphaeromicola dudichi Klie, 1938, et sa présence dans l’Atlantique

    NARCIS (Netherlands)

    Roelofs, Jiet

    1966-01-01

    Sphaeromicola dudichi Klie, 1938, has been found for the first time in the Atlantic (Penpoull, N. coast of Brittany). No differences were found between Atlantic specimens and topotypes from Naples. The species was, like the types, associated with the amphipod Chelura terebrans Philippi, 1839. A comp

  14. Review of Cyrtomyia Bigot (Diptera, BomByliidae, Ecliminae) with a key to the Neotropical genera of Ecliminae and Cyrtomyia species

    OpenAIRE

    Carlos José Einicker Lamas; Paula Fernanda Motta Rodrigues

    2013-01-01

    The Neotropical genus Cyrtomyia Bigot has a distribution restricted to the Andean region of South America, with records only in Argentina and Chile. The genus is composed by two species, which are reviewed and redescribed herein: C. chilensis Paramonov, 1931 and C. pictipennis (Bigot, 1857). The main characters of the external morphology of adults are photographed. Illustrations of the male and female terminalia of C. chilensis are also included. An identification key to species is presented,...

  15. 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

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    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.

  16. Comparison between the mercury contamination in populations of Unio pictorum mancus (Mollusca, Bivalvia from two lakes of different trophic state: the oligo-mesotrophic Lake Maggiore and the eutrophic Lake Candia

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    Nicoletta RICCARDI

    2009-08-01

    Full Text Available This research was designed to evaluate the influence of mussel (Unio pictorum mancus size on mercury concentration in mussel soft tissues. It also evaluated the relationships between calcium, mercury and selenium in the mussel tissues. The mussel populations from the deep, meso-oligotrophic Lake Maggiore and the shallow, eutrophic Lake Candia were analyzed. The mean concentration of mercury in the tissues was 0.075 mg kg-1 in Lake Maggiore mussels and 0.033 mg kg-1 in Lake Candia mussels. The local mercury content in the mussel biomass per surface unit was about eleven-fold higher in Lake Maggiore (5.99 μg Hg m-2 than in Lake Candia (0.55 μg Hg m-2. This wide difference was due firstly to the larger population density (46.86 vs 6.93 ind m-2 and secondly to the higher individual content (0.128 vs 0.079 μg Hg ind-1 in Lake Maggiore than in Lake Candia. These differences in population density and individual mercury content are the result of both biological and environmental characteristics. Lake trophy and water renewal affect population density and individual growth rate, and ultimately determine their impact on biogeochemical cycles by regulating the mussel standing stock. The relationships between mercury, calcium and selenium were taken into account.

  17. 双壳纲贝类18S rRNA基因序列变异及系统发生%18S rRNA gene variation and phylogenetic analysis among 6 orders of Bivalvia class

    Institute of Scientific and Technical Information of China (English)

    孟学平; 申欣; 程汉良; 赵娜娜

    2011-01-01

    双壳纲贝类栖息于环境多变的海域,是一个形态学和生态学都具有多样性的类群,清晰而可靠的进化关系对于养殖与相关种类的管理具重要意义.然而,目前对双壳类宏观分子系统学研究的报道较少.研究用18S rRNA基因(18S)分析了双壳类3个亚纲贝类的系统发育关系.从GenBank下载帘蛤目、海螂目、贻贝目、胡桃蛤目、蚶目、珍珠贝目6个目94个种类的18S全/部分序列107个,通过ClustalX软件进行序列比对,用MEGA4.1软件和PHyML软件计算遗传距离,构建系统发育树,研究了双壳类18S变异规律及其在系统发生研究中的应用.结果显示18S有插入/缺失序列,存在长度多态性.序列比对显示有5段约30 70bp的保守区,4段约130 550bp的高变区.碱基组成平均为T:24.4%,C:23.6%,A:24.5%,G:27.5%.G+C含量为51.1%.在1796个比对位点中,变异位点占31.7%,简约信息位点占24.0%.目内科间遗传距离为0.003 0.043,目间遗传距离为0.026 0.093.NJ树和ML树显示贻贝目、珍珠贝目、胡桃蛤目、蚶目和海螂目的缝栖蛤科先分别聚为支持率很高(BPN=94 100)的单系支,后聚为一大支(BPN=100).蛤蜊科与帘蛤目的其他科分离形成一置信度很高的单系支(BPN=93).帘蛤科种类聚为置信度较低(BPN=60)的一支.海螂目、帘蛤目的种类没能完全聚到所属支系,彼此嵌套,缝栖蛤科的种类从海螂目中分离出来.18S资料揭示帘蛤目的蛤蜊科、海螂目的缝栖蛤科已经进化为独立的支系.

  18. 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.

  19. 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.

  20. Genetic diversity of the biofilm covering Montacuta ferruginosa (Mollusca, bivalvia) as evaluated by denaturing gradient gel electrophoresis analysis and cloning of PCR-Amplified gene fragments coding for 16S rRNA

    NARCIS (Netherlands)

    Gillan, D.C.; Speksnijder, Arjen; Zwart, G.; De Ridder, C.

    1998-01-01

    The shell of the bivalve Montacuta ferruginosa, a symbiont living in the burrow of an echinoid, is covered with a rust- colored biofilm, This biofilm includes different morphotypes of bacteria that are encrusted with a mineral rich in ferric ion and phosphate, The aim of this research was to determi

  1. Comportamiento luminiscente y preservación de la señal paleoambiental en las conchas de inocerámido (Bivalvia). Maastrichtiense inferior. Cuenca Vasco-Cantábrica

    OpenAIRE

    Gómez Alday, Juan José; Elorza, Javier

    2004-01-01

    Inoceramid shells from the Basque Arc Domain (Basque-Cantabrian Basin) have been studied to determine their behaviour under cathodoluminescence. The shells exhibit a luminescent zoning intimately related to their microstructure and the development of preferred paths of fluid circulation during diagenesis. The luminescent behaviour allows to establish a first classification of the shells according to their preservation degree that can be related to other geochemical and isotopic ev...

  2. 大连沿海几种腹足类和双壳类的营养成分分析%An Analysis of Nutritive Components of Some Gastropoda and Bivalvia in Dalian Coastline

    Institute of Scientific and Technical Information of China (English)

    陶平; 许庆陵; 谭淑荣

    2000-01-01

    对大连沿海所产的3种腹足类和8种双壳类的有机和无机成分进行了测定分析.分析结果表明:蛋白质、脂肪含量均有差异;大多可称之为高蛋白、低脂肪食品.无机营养素含量因种类而不同,但总的变化趋势差距不大.为开发和利用这些海洋贝类资源提供了营养评价的参考依据.

  3. 我国重要帘蛤科(Veneridae)贝类的16S rRNA序列系统学分析%MOLECULAR PHYLOGENY OF VENERIDAE (MOLLUSCA, BIVALVIA) BASED ON 16S rRNA SEQUENCES

    Institute of Scientific and Technical Information of China (English)

    赵婷; 吴琪; 潘宝平

    2013-01-01

    本文对我国隶属于帘蛤科(Veneridae)10个亚科、17个属、20种贝类的16S rRNA基因片段进行了系统学分析,上述动物的16S rRNA片段长度在438-648bp之间,利用PAUP软件包在对序列比对基础上构建了邻接系统树(NJ)和最大拟然系统树(ML).16S rRNA数据显示,我国帘蛤科贝类由三个主要分支组成,美女蛤亚科中的加夫蛤属(Gafrarium)可能是一个单型属,该属与美女蛤属合并为加夫蛤属比较恰当.帘蛤亚科与雪蛤亚科应属于不连续的分类单元.另外,青蛤亚科与仙女蛤亚科均应作为独立的亚科存在.本文的研究结论与修订后的帘蛤科形态分类观点一致.

  4. O Gênero Pholadomya Sowerby, 1823 (Mollusca: Bivalvia na Formação Jandaíra (Cretáceo Superior, Bacia Potiguar: Implicações Paleoecológicas e Paleogeográficas.

    Directory of Open Access Journals (Sweden)

    Natalia Pereira Benaim

    2008-06-01

    Full Text Available Pholadomya Sowerby, 1823 is an anomalodesmatan bivalve that dispersed during Mesozoic, like other Mollusks,colonizating the South Atlantic shallow seas, between Brazil and Africa. On brazilian Cretaceous the sources ofPholadomya are scarce, occurring in outcrops from Algodões Formation, Gramame Formation and Jandaíra Formation,where occurs the species Pholadomya baixaleitensis. Based on specimens from new outcrops of Jandaíra Formation,a new occurrence of P. cf. adversa and P. baixaleitensis are shown and a new morfotype for the genus is described. Itwas possible to infer that the species studied presented deep endobentonic habits, and burrowed slowly the sediment,probably living their whole life into the same cavity. During Campanian Pholadomya is known from Cameroon, France,Poland, Austria, Germany and other localities in United States of America, occurring in association with other tethyanmollusks. The records of the genus in the marginal equatorial basins enhance the fossil bivalve diversity, and agree withthe hypotesis of a south latitudinal range for the Tethyan Realm during Upper Cretaceous.

  5. 内蒙古宁城道虎沟地区中侏罗世非海相双壳类Ferganoconcha%NON-MARINE FERGANOCONCHA (BIVALVIA) FROM THE MIDDLE JURASSIC IN DAOHUGOU AREA, NINGCHENG COUNTY, INNER MONGOLIA, CHINA

    Institute of Scientific and Technical Information of China (English)

    姜宝玉

    2006-01-01

    Ferganoconcha是广泛分布于我国北部、中亚、西伯利亚和乌拉尔地区下、中侏罗统的一类非海相双壳类.Ferganoconcha sibirica的产出表明道虎沟地区道虎沟层与辽西地区的海房沟组和冀北地区的九龙山组层位相当,时代介于早侏罗世晚期至中侏罗世之间.结合昆虫和叶肢介化石反映的时代,认为道虎沟层的时代可能为中侏罗世早-中期.综合近年来在Ferganoconchidae的分类方面取得的进展,对F.sibirica进行了重新厘定.

  6. A NEW SUBGENUS MATSUMOTOINA (BIVALVIA)FROM THE ASIAN NON-MARINE CRETACEOUS%亚洲非海相白垩系一新亚属松本蚌

    Institute of Scientific and Technical Information of China (English)

    郭福祥

    1982-01-01

    @@ 本文建立一新亚属松本蚌Pseudohyria(Matsumotoina)subgen.nov.,并说明广义的Pseudohyria的地质时代是中、晚白垩世,狭义的Pseudohyria s.s.仍限于晚白垩世,新亚属属于中白垩世产物.

  7. TAXONOMIC STUDY ON MERETRIX( BIVALVIA, VENERIDAE) FROM CHINA SEAS%中国近海文蛤属(双壳纲,帘蛤科)的系统分类学研究

    Institute of Scientific and Technical Information of China (English)

    张素萍; 王鸿霞; 徐凤山

    2012-01-01

    长期以来,我国的文蛤分类存在着严重的问题和混乱现象,它已影响和制约了我国文蛤的水产养殖和遗传育种等相关研究.利用比较形态学和分子生物学技术,对我国沿海分布的文蛤属进行了系统的分类学研究,澄清了混淆种,修订了物种名称,确立了我国沿海文蛤的分类地位,对文蛤属的分类系统进行分子重建.结果表明短文蛤和丽文蛤为近缘种先聚到一起,然后与斧文蛤聚到一起,而琴文蛤、文蛤与该属其它3种文蛤的分歧时间较早.研究结果将为文蛤的分类研究、遗传育种、资源保护和利用提供科学依据.%Most species of bivalves in the genus Meretrix are important commercial clams and distributed in coastal areas of China. Whereas, species identification and classification within the genus Meretrix is frequently confused in literature, e. G. The specific name M. Meretix has been used for various species, which have seriously restricted the researches of Meretrix aquaculture and breeding program. In present study, we clarified the confusable species and revised the species name of five Meretrix species in Chinese coastal zones base on combination of morphological and molecular analyses. Furthermore, the geographic distributions of diese five Meretrix species were confirmed. Molecular phylogenetic analysis based on the CO I sequences showed that M. Petechialis and M. Lusoria cluster together then duster with M. Lamarckii, whereas M. Meretrix and M. Lyrata derived early from a common ancestor compared with the other three species.

  8. 关于晚二叠世克氏蛤类研究中的几个问题%DISCUSSION ON THE STUDY OF THE GENERA CLARAIA AND CLARAIOIDES (BIVALVIA) OF LATE PERMIAN AGE

    Institute of Scientific and Technical Information of China (English)

    方宗杰

    2003-01-01

    对当前二叠-三叠纪克氏蛤类研究中存在的几个问题进行讨论,并对杨逢清等(2002)提出的关于属一级划分的原则提出质疑.通过对Claraia tumida(Patte)的再研究,确认早三叠世的克氏蛤不存在足丝凹口内端呈明显扩大的类型.经过详细的讨论和比较,无论是从形态上,或是生态上,还是从生物地理学的角度,克氏蛤和类克氏蛤在晚二叠世都应被视为两个平行发展的属.类克氏蛤在二叠纪末全部灭绝,未留下任何后裔,它与克氏蛤之间并不存在演化关系.克氏蛤的地质历程是晚二叠世早期至早三叠世晚期,发现于俄罗斯北极区新地岛晚二叠世早期的Claraia novosemelica Lobanova是克氏蛤的最早代表,它应当位于克氏蛤演化的基干部位.

  9. 广东海陵岛沿海软体动物的分布%DISTRIBUTION OF CLASS BIVALVIA AND GASTROPODA MOLLUSCA IN THE INSHORE REGIONS OF HAILING ISLAND OF GUANGDONG

    Institute of Scientific and Technical Information of China (English)

    唐以杰; 林炜; 陈明旺; 钟诚; 杜晓捷

    2005-01-01

    对海陵岛沿海软体动物进行了采集调查,共鉴定180种,分属 60科. 其中双壳纲20科86种,占总数47.77%,腹足纲38科92种,占总数51.11%,多板纲1科1种,占总数0.56%,头足纲1科1种,占总数0.56%. 分析表明,其区系特点以南海亚热带-热带种和东海-南海亚热带种为主要成分.

  10. Sequence analysis of 18S rRNA gene of six Veneridae clams (Mollusca: Bivalvia)%6种帘蛤科贝类18S rRNA基因全序列比较分析

    Institute of Scientific and Technical Information of China (English)

    程汉良; 彭永兴; 王芳; 孟学平; 阎斌伦; 董志国

    2008-01-01

    对文蛤(Meretrix meretrix)、青蛤(Cyclina sinensis)、江户布目蛤(Protothaca jedoensis)、薄片镜蛤(Dosinia corrugata)、紫石房蛤(Saxidomus purpuraus)和菲律宾蛤仔(Ruditapes philippinarum)6种帘蛤科(Veneridae)贝类的18S rRNA基因序列进行了PCR扩增并测序,以期获得这一序列的基本特征,评估其种间变异程度,探讨这一序列在种类鉴定和分子系统发育等研究中的应用价值.测序结果表明,文蛤、青蛤、江户布目蛤、薄片镜蛤、紫石房蛤和菲律宾蛤仔18S rRNA基因序列全长分别为1 900bp、1 838bp、1 831 bp、1 831 bp、1 829bp和1 833bp.序列中A、T、C和G碱基的平均含量分别为24.0%、24.0%、24.2%和27.8%.用MEGA软件对6种帘蛤18S rRNA基因全序列进行了分析,对位排列后的总长度1 906bp,其中变异位点210个,简约信息位点28个,si/sv=1.4(46/32).从GenBank下载了7种帘蛤科贝类18S rDNA全序列,与本研究实测的6种帘蛤一起用MegAlign软件对其18S rDNA序列进行了比对,物种间序列相似百分比为88.7%~99.7%.文蛤与其他12物种间序列差异较大,序列差异百分比均超过了10%,其他各物种间序列差异百分比不超过3%.以异韧带亚纲(Anomalodesmata)笋螂目(Pholadomyoida)的Lyonsia floridana和Cardiomya costellata为外群,采用相邻连接法(NJ)和最大简约法(MP)构建了帘蛤科贝类的系统发育树,其拓扑结构显示雪蛤亚科(Chioninae)、帘蛤亚科(Venerinae)和镜蛤亚科(Dosiniinae)的种类首先聚在一起,形成一个聚类簇;缀锦蛤亚科(Tapetinae)、卵蛤亚科(Pitarinae)、仙女蛤亚科(Callistinae)、青蛤亚科(Cyelininae)和文蛤亚科(Meretricinae)的种类先后分别单独聚成一枝;最后所有帘蛤科物种聚为一枝,与外群相区别,说明18S rDNA序列适合作为帘蛤科系统发育研究的分子标记.

  11. Phylogenetic Analysis of Veneridae (Mollusca: Bivalvia) based on Mitochondrial 16S rDNA%基于16S rDNA序列的帘蛤科贝类分子系统发育研究

    Institute of Scientific and Technical Information of China (English)

    程汉良; 周旻纯; 陈冬勤; 彭永兴; 董志国; 易乐飞; 孟学平; 申欣

    2012-01-01

    对21种帘蛤科贝类线粒体16S rRNA基因片段的核苷酸序列进行了分析,以探讨这一序列在种质鉴定、分子系统发育研究中的应用价值.试验结果表明,所有物种扩增片段长度504~642 bp,具有明显的长度多态性,序列A+T含量59.2%~69.0%,明显高于GC含量.物种间共有变异位点447个,其中简约信息位点351个.以16S rDNA片段序列为标记,以中国蛤蜊做外群,构建了帘蛤科贝类的系统发生树,拓扑结构显示,帘蛤科贝类形成3个明显类群,缀锦蛤亚科的13个种形成一个单系群,其结点自展值为93%.第二类群由雪蛤亚科、帘蛤亚科和镜蛤亚科的种类组成,结点自展值为87%.第三类群由仙女蛤亚科、青蛤亚科、楔形蛤亚科和文蛤亚科的种类组成,结点自展值为100%.结合拓扑结构分析和序列比对分析,本研究支持将短文蛤和丽文蛤订为文蛤的同物异名的观点,建议将丽文蛤和短文蛤订为文蛤的地理亚种;支持将薄片镜蛤和Dosinia angulosa订为2个独立种的观点;宜将波纹巴非蛤和织锦巴非蛤订为2个独立种.

  12. Molecular classification and morphological traits of two species of Meretrix ( Mollusca, Bivalvia)%浙江和广西两种文蛤的分子鉴定及形态特征分析

    Institute of Scientific and Technical Information of China (English)

    董迎辉; 姚定余; 林志华; 姚韩韩; 陆荣茂

    2011-01-01

    以文蛤如东群体(RD)和北海群体(BH)为对照群,利用线粒体CO Ⅰ基因序列分析技术对苍南文蛤(CN)和北海白壳文蛤(BW)进行了分子鉴定.结果表明,苍南文蛤和斧文蛤的碱基组成非常相似,通过文蛤属贝类基因序列同源性比对和分子系统聚类分析发现,苍南文蛤CN1、CN2与斧文蛤的同源性分别达到100.0%、99.2%,在依据遗传距离构建的系统进化树上,2个苍南文蛤也与斧文蛤单独聚为一支,据此将苍南文蛤确定为斧文蛤,此结果将斧文蛤的分布区域向北扩展到了浙江南部沿海,修正了现有文献中记载的仅在我国南海诸省分布的说法;而自壳文蛤与其它6种文蛤的基因序列同源性都不高(79.6%~85.3%),在系统进化树上单独分出一支,明显是独立于这些文蛤之外的新种.斧文蛤、白壳文蛤与文蛤群体COⅠ基因的遗传多样性分析显示,文蛤BH群体的变异位点数、单倍型数和核苷酸多样性指数均最大,斧文蛤其次,而白壳文蛤10条基因序列完全相同,未发生任何核苷酸位点变异,说明其遗传多样性很低.应用方差分析和Tukey多重比较,分析了斧文蛤、白壳文蛤与文蛤群体的形态差异,发现斧文蛤的壳长明显大于壳高,且SMW/TW、IW/TW 2个参数与文蛤、白壳文蛤群体差异显著(P<0.05);而白壳文蛤的壳宽指数大、壳型相对膨胀,SW/SL和SW/SH值均最大,与文蛤和斧文蛤群体差异显著(P<0.05).本研究结果可为文蛤属贝类种间鉴别、种质资源保护及系统进化研究提供基础资料.%Although many species of the genus Meretrix are commercially-important cultured bivalves,the taxonomy of Meretrix is still in argument over several discrepancies among scientists in the world. Compared with the groups of Meretrix meretrix (RD & BH) ,two groups of Meretrix clam( CN & BW), collected from Cangnan and Beihai, were phylogenetically analyzed and molecularly classified based on partial sequences of the mitochondrial CO Ⅰ gene. The results indicated that the base sequence of CN group and M. lamarckii with similar composition was the highest in homology of 100.0% and 99.2% .respectively. Phylogenetic NJ and UPGMA tree of Meretrix based on genetic distance also showed that CN1 and CN2 were clustered together with M. lamarckii firstly. Therefore we classified CN group as M. lamarckii, which extended the geographic distribution of M. lamarckii from Taiwan to the southern coast of Zhejiang and corrected the existing document claims. But,the BW group shared low sequence homology(79. 6% -85. 3% ) with other six species of Meretrix and formed much independently cluster beyond among groups. Number of polymorphic sites, indexes of haplotype diversity and nucleotide diversity revealed that the level of genetic diversity from high to low was BH > M. lamarckii > RD > BW. The CO Ⅰ gene sequences of BW group showed very low genetic diversity and no nucleotide variation among 10 individuals. The morphological characters of M. lamarckii, BW and M. meretrix were analyzed using statistical analysis of AMOVA and Tukey' s multiple comparisons for seven morphological traits. Three morphological parameters, including SH/SL,SMW/TW and IW/TW,of M. lamarckii differed significantly with M. meretrix and BW (P < 0.05). BW with relatively expanded shell shape differed significantly with M. meretrix and M. lamarckii in parameters of SW/SL and SW/SH( P <0.05). These results can be expected to provide basic data for the studies of species identification, germplasm conservation and phylogeny.

  13. 蚌科20种蚌类肛门的比较解剖及其系统学意义%COMPARATIVE ANATOMY OF THE ANUS OF 20 UNIONID SPECIES (BIVALVIA: UNIONIDAE) AND ITS SYSTEMATIC SIGNIFICANCE

    Institute of Scientific and Technical Information of China (English)

    舒凤月; 吴小平

    2005-01-01

    对蚌科11属20种蚌类肛门进行了比较解剖研究.结果表明,蚌科肛门的结构特征具有重要的分类学价值,肛门类型、肛门相对后闭壳肌位置、肛门壁内表面是否具纵嵴、肠沟终止位置等特征因种类不同而有明显差异,可作为分类依据之一.

  14. 基于CO Ⅰ的中国西施舌DNA条形码%DNA Barcodes of Clam Coelomactata antiquata (Bivalvia: Veneroida)in China Based on CO Ⅰ Gene

    Institute of Scientific and Technical Information of China (English)

    孟学平; 高如承; 申欣; 郑雯雯; 赵娜娜; 程汉良; 田美

    2011-01-01

    以我国大连(DL)、日照(RZ)、启东(QD)、长乐(CL)、漳州(ZZ)和北海(BH)6个野生群体西施舌为研究对象,用引物LCO1490和HCO2198扩增线粒体细胞色素C氧化酶亚基Ⅰ(COⅠ)基因片段序列,PCR产物双向测序,用ClustalX进行DNA序列比对,用MEGA4.1和PhyML软件构建NJ树和ML树,用Arlequin3.11软件进行分子方差分析,研究CO Ⅰ这一特定基因区段作为DNA条形码在识别西施舌地理群体的可行性和有效性.结果获得658 bp的CO Ⅰ核苷酸片段,其T、C、A、G含量分别为42.4%、14.8%、21.8%、21.0%,A+T(64.2%)含量明显高于G+C含量.变异位点占15.3%(101/658),其中简约信息位点占14.1%.群体内遗传距离为0.0020~0.0043,群体间遗传距离为0.0024~0.0883.群体间氨基酸序列无变异.长乐、漳州群体(DH组)与其他群体(HB组)间有显著的遗传分化(FST=0.956~0.970).NJ树和ML树显示长乐、漳州群体聚为一支,北方的大连、日照、启东群体和南方的北海群体聚为置信度较高的另一支(BPN=99),2支间的遗传距离为0.0837,是2支内群体间遗传距离的17.8~23.5倍.本研究结果表明,CO Ⅰ基因片段序列作为鉴定福建西施舌条形码是可行的,但不能将其余群体区别开来.

  15. 橄榄蛏蚌血细胞形态及吞噬能力的初步研究%A Preliminary Study on Morphology and Phagocytic Ability of Hemocytes from Solenaia oleivora (Bivalvia: Unionidae)

    Institute of Scientific and Technical Information of China (English)

    李乾坤; 张桂蓉; 魏开建; 王亚妮; 郭向召; 陈在林; 鄢国新

    2012-01-01

    对橄榄蛏蚌(Solenaia oleivora)血细胞的形态特征和吞噬作用进行了初步研究.基于瑞氏染色后血细胞的形态、颜色、大小等特征,可将橄榄蛏蚌的血细胞分为大颗粒细胞、小颗粒细胞、透明细胞、类淋巴细胞共4种类型.透明细胞的直径最大,小颗粒细胞次之,类淋巴细胞最小;透明细胞的胞核直径最大,小颗粒细胞次之,大颗粒细胞最小.类淋巴细胞的核质比最大(0.67),其他3种细胞的核质比为0.37 ~0.48.4种血细胞所占比例以小颗粒细胞最高(43.6%),透明细胞次之(36.6%),类淋巴细胞最低(7.0%).橄榄蛏蚌平均血细胞浓度为(4.21±1.51)×105个/mL,个体的血细胞浓度与体重(或壳长)不相关(P>0.05),不同体重组(或壳长组)的平均血细胞浓度无显著差异(P>0.05).在37℃体外吞噬试验中,橄榄蛏蚌血细胞对金黄色葡萄球菌的吞噬比例为(43.6±7.0)%,吞噬指数为(0.743±0.145).4种血细胞中,小颗粒细胞的吞噬比例最大(0.288±0.061),类淋巴细胞不具吞噬能力.

  16. 蚌科钩介幼虫的比较形态学研究Ⅱ.六个种幼虫的形态%A COMPARATIVE STUDY ON GLOCHIDIAL MORPHOLOGY OF UNIONIDAE (BIVALVIA)

    Institute of Scientific and Technical Information of China (English)

    吴小平; 梁彦龄; 王洪铸; 欧阳珊

    2000-01-01

    研究了真柱矛蚌、剑状矛蚌、洞穴丽蚌、角月丽蚌、三角帆蚌、褶纹冠蚌等六种蚌的育儿囊的类型和钩介幼虫的形态,应用光镜及扫描电镜对钩介幼虫的形态结构进行了观察和比较.结果表明,真柱矛蚌、剑状矛蚌、三角帆蚌、褶纹冠蚌的育儿囊为外鳃类同生型,洞穴丽蚌、角月丽蚌的育儿囊为外鳃类四生型;钩介幼虫可分为二类:真柱矛蚌、剑状矛蚌、褶纹冠蚌为有钩型,三角帆蚌、洞穴丽蚌、角月丽蚌为无钩型.一些细微结构在不同种之间也存在着差异.

  17. 帘蛤科贝类rDNA内转录间隔区序列的研究%Study on Sequences of Ribosomal DNA Internal Transcribed Spacers of Clams Belonging to the Veneridae Family (Mollusca: Bivalvia)

    Institute of Scientific and Technical Information of China (English)

    程汉良; 夏德全; 吴婷婷; 孟学平; 吉红九; 董志国

    2006-01-01

    根据18S rDNA、5.8 S rDNA和28 S rDNA保守序列设计引物,应用聚合酶链式反应(PCR)扩增了文蛤(Meretrix meretrix L.)、青蛤(Cyclina sinensis G.)、硬壳蛤(Mercenaria mercenaria L.)和江户布目蛤(Protothaca jedoensis L.)4种帘蛤科贝类的第一内转录间隔区(ITS1)和第二内转录间隔区(ITS2)序列,并进行了测序.结果表明,文蛤、青蛤、硬壳蛤和江户布目蛤的ITS1扩增产物大小分别为978 bp、663 bp、757 bp和942 bp,GC含量分别为61.55%、60.78%、62.48%和64.86%~64.97%,其中ITS1序列长度分别为900bp、585 bp、679 bp和864 bp,是迄今已报道双壳贝类中变化范围最大的,GC含量分别为61.67%、61.03%、63.03%和65.51%~65.62%,江户布目蛤种内ITS1序列有个体差异;ITS2扩增产物大小分别为644 bp、618~620bp、593 bp和513~514 bp,GC含量分别为61.18%、61.29%~61.81%、62.73%和61.48%~61.60%,其中ITS2序列长度分别为412bp、386~388 bp、361bp和281~282 bp,GC含量分别为65.29%、65.21%~66.06%、67.87%和67.38%~67.62%,青蛤和江户布目蛤种内ITS2序列有个体差异.4种蛤ITS1和ITS2序列种间差异很大,有明显的长度多态性,ITS2种间序列相似度73.0%~89.1%,与ITS1的种间序列相似度48.7%~81.5%相比略高.此外,在4种蛤ITS1和ITS2序列中各发现2个与rRNA加工有关的保守区.通过对ITS1和ITS2序列的组装获得了4种蛤5.8S rRNA基因完整序列,序列长度都是157 bp,GC含量57.96%~58.60%,4种蛤5.8S rRNA基因相对保守,种间序列差异度0-6.0%,共有10个变异位点,其中转换4处,颠换6处,硬壳蛤和江户布目蛤5.8S rRNA基因序列完全相同.以ITS2序列(包含5.8S rRNA和28S rRNA基因部分序列)为标记,调用北极蛤科的Arctica islandica相应序列数据作外群,构建了帘蛤科贝类的系统发育树,其拓扑结构显示江户布目蛤与硬壳蛤亲缘关系最近,青蛤与其他3物种的亲缘关系最远.%The first and second internal transcribed spacer (ITS1 and ITS2) regions of the ribosomal DNA from four species,Meretrix meretrix L., Cyclina sinensis G., Mercenaria mercenaria L., and Protothaca jedoensis L., belonging to the family Veneridae were amplified by PCR and sequenced. The size of the ITS 1 PCR amplification product ranged from 663 bp to 978 bp,with GC contents ranging from 60.78% to 64.97%. The size of the ITS1 sequence ranged from 585 bp to 900 bp, which is the largest range reported thus far in bivalve species, with GC contents ranging from 61.03% to 65.62%. The size of the ITS2 PCR amplification product ranged from 513 bp to 644 bp, with GC contents ranging from 61.29% to 62.73%. The size of the ITS2sequence ranged from 281 bp to 412 bp, with GC contents ranging from 65.21% to 67.87%. Extensive sequence variation and obvious length polymorphisms were noted for both regions in these species, and sequence similarity of ITS2 was higher than that of ITS1 across species. The complete sequences of 5.8S ribosomal RNA gene were obtained by assembling ITS1 and ITS2 sequences,and the sequence length in all species was 157 bp. The phylogenetic tree of Veneridae clams was reconstructed using ITS2-containing partial sequences of both 5.8S and 28S ribosomal DNA as markers and the corresponding sequence information in Arctica islandica as the outgroup. Tree topologies indicated that P. jedoensis shared a close relationship with M. mercenaria and C.sinensis, a distant relationship with other species.

  18. 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.

  19. Sequence analysis of the ribosomal DNA internal transcribed spacer region in some clam species (Mollusca: Bivalvia: Veneroida)%几种帘形目贝类rDNA ITS序列的比较

    Institute of Scientific and Technical Information of China (English)

    刘相全; 包振民; 胡景杰; 王师; 方建光; 王如才

    2007-01-01

    扩增并测序了4种帘形目和1种蚶目贝类(外群)核糖体DNA的转录间隔区(ITS)序列.帘形目贝类序列长度在874bp到1466bp之间,GC含量在62%到67%之间,ITS序列在相近的3种帘蛤科贝类之间表现出长度保守性和碱基组成的相似性.采用ITS1,ITS2,以及ITS1与ITS2的连接序列进行聚类,结果表明:2种蛤仔聚为一枝,表现出较近的亲缘关系,帘蛤科的3种贝类聚在一起,再与同属帘形目的缢蛏相聚.研究的结果揭示了帘形目贝类的系统发生关系.

  20. 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].

  1. MOLECULAR PHYLOGENY OF TAPETINAE (MOLLUSCA, BIVALVIA) BASED ON MTDNA SEQUENCE%缀锦蛤亚科(Tapetinae)贝类线粒体DNA序列的系统学分析

    Institute of Scientific and Technical Information of China (English)

    潘鹤婷; 袁媛; 吴琪; 张素萍; 潘宝平

    2008-01-01

    采用线粒体16S rRNA和COI序列扩增和测序方法,对隶属于缀锦蛤亚科5属7种动物进行了系统学分析.经Clustal x多重比对和PAuP 4.10 软件分析,得到种间序列的遗传距离并构建了邻接(NJ)系统树.实验数据显示,缀锦蛤亚科为遗传连续的同源类群,其中的浅蛤属(Gomphina)、缀锦蛤属(Tapes)和蛤仔属(Ruditapes)亲缘关系较近,结果与Fischer-Piette等(1971)的缀锦蛤亚科的分类方案基本一致.另外,菲律宾蛤仔R.philippinarum 和杂色蛤仔 R.variegata是蛤仔属在印度洋和太平洋海区的一个组群,尽管两种贝类有明显的重叠分布区和相近的贝壳形态,但二者间的16S rRNA 和COI序列遗传距离均达到了物种间差别.结果支持庄启谦(2001)有关菲律宾蛤仔与杂色蛤仔的形态分类及分布区划分的观点.

  2. Discovery of the Bivalvia Qiyangia Assemblage in Northern Qiangtang Area and Its Stratigraphic Significances%羌北双壳类祁阳蚌组合的发现及其地层学意义

    Institute of Scientific and Technical Information of China (English)

    李乾; 陆刚; 张能; 莫丽群; 许华; 唐朝霞; 卫小彦

    2006-01-01

    藏北羌塘盆地独雪山地区,在原先认为不整合于早侏罗世火山岩系之上的"中侏罗统雀莫错组"中,新近发现了一套早侏罗世淡水双壳类祁阳蚌(Qiyangia)组合,表明羌北盆地存在早侏罗世沉积地层,其为一套海陆交互相沉积的粗碎屑岩→灰岩→细碎屑岩夹灰岩,下侏罗统与中侏罗统为连续沉积.据此资料,该区侏罗系目前采用的岩石地层单位系统及地层的对比认识存有问题,文章对此套早侏罗世沉积的岩石地层划分方案进行了讨论,指出雁石坪地区的侏罗系岩石地层系统作为等时的地层单位运用于羌北盆地北西部并不适宜,羌北盆地已有的地层系统格架有必要重新认识.

  3. The biology and functional morphology of Coralliophaga lithophagella (Bivalvia: Arcticoidea: Trapezidae): An abyssate, deep-water, nestler from the Açores. With comparative notes on the estuarine Trapezium liratum from Hong Kong

    Science.gov (United States)

    Morton, Brian

    2014-04-01

    Coralliophaga lithophagella is a nestler of basaltic rocks in the deeper waters (˜57-360 m) of the Açores and of shallower limestone karst in the Mediterranean where it predominately occurs in empty lithophagine burrows. In the Açores, because of low oceanic productivity and the basaltic, un-boreable, substratum, C. lithophagella is but 50% the shell length of continental European conspecifics and the shell's postero-dorsal margin is growth elevated to enhance particle capture. This is also achieved with relatively enormous ctenidia, minute labial palps and a simplified intestine. Unusually amongst the Trapezidae, C. lithophagella is abyssate and the foot is reduced. Also atypically, and during ontogeny, the shell enlarges postero-dorsally to facilitate particle capture. Anatomical features of the representatives of the constituent genera of the Trapezidae are compared one with another and with Arctica islandica (Arcticidae), the constituent families of the Arcticoidea. It is concluded that the Trapezidae constitutes a discrete clade of epibenthic nestlers, possibly descended from an endobenthic arcticoid ancestor, and showing a trend towards a reduction in shell and hinge complexity. The status of Fluviolanatus subtorta with mantle margins filled with single-celled algae and putatively assigned to the Trapezidae, awaits molecular confirmation.

  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. 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.

  6. Aspectos paleontológicos del Muschelkalk de la zona de Calanda (Provincia deTeruel)

    OpenAIRE

    Márquez-Aliaga, Ana; Márquez, L.; March, M.; Goy Goy, A.; Brito, J. M.

    1987-01-01

    [ES] El hallazgo de numerosos fósiles en el Muschelkalk superior del anticlinal de Calanda, motivó la realización de un muestreo detallado del mismo, así como el estudio de su bio-microfacies. Referente a la macrofauna, se hallan bien representados los bivalvos y en general con buen estado de conservación. Las especies Pseudocorbula gregaria (MUSTER), Placunopsis teruelensis WURM, Lakevellia subcostata (GOLDFUSS), Modiolus myoconchaeformis (PHILIPPI) y Gervillia joleaudi ...

  7. A Comparison of Burden of Disease from Toxic Waste Sites with other Recognized Public Health Threats in India, Indonesia and the Philippines

    OpenAIRE

    Jack Caravanos; Lina Hernandez Gutierrez; Bret Ericson; Richard Fuller

    2014-01-01

    Background. Although toxic waste sites have been well investigated in many developed countries, their prevalence and health impact have not been well documented in low and middle income countries where risks attributable to environmental pollution are generally higher than in developed nations. Methods. We compared the burden of disease from toxic waste sites expressed in disability-adjusted life-years (DALYs) with the same measurement for other threats in India, Indonesia and the Philippi...

  8. On the diphyletic origin of the Oncaeidae Giesbrecht, 1892 (Copepoda: Poecilostomatoida) with a phylogenetic analysis of the Lubbockiidae fam. nov.

    OpenAIRE

    Huys, R.; Böttger-Schnack, R.

    1997-01-01

    The monophyly of the Oncaeidae was tested using cladistic methodology. The family (as it is currently recognised) comprises two distinct lineages that do not share a sistergroup relationship and have colonized the open pelagic environment independently. Under the revised family concept the Oncaeidae encompasses only the genera Conaea Giesbrecht, Epicalymma Heron and the type-genus Oncaea Philippi which is regarded as a paraphyletic (or possibly polyphyletic) taxon. A new family Lubbockiidae i...

  9. Effect of Pollen from Different Plant Species on Development of Typhlodromus pyri (Sheuten (Acari: Phytoseiidae Efecto del Polen de Diferentes Especies Vegetales sobre el Desarrollo de Typhlodromus pyri (Sheuten (Acari: Phytoseiidae

    Directory of Open Access Journals (Sweden)

    Paulina Bermúdez

    2010-09-01

    Full Text Available Typhlodromus pyri (Sheuten (Acari: Phytoseiidae is a phytoseiid mite with a high potential in controlling the false Chilean mite (Brevipalpus chilensis Baker; Acari: Tenuipalpidae. The purpose of this study was to determine the effect of different plant species pollen as a complementary food in the development of T. pyri when its prey is in low levels of availability. Mites were individually placed on black plastic boxes with pollen and maintained at a temperature of 26 ± 2 °C, 70 ± 5% relative humidity (RH, and a photoperiod of 16:8 h (L:D. Postembryonic development of T. pyri was studied in 11 pollen species, as well as in a mixed diet of Hirschfeldia incana (L. and B. chilensis. Results show that H. incana was the only pollen in which there was no mortality (P > 0.05 along with the control (Oxalis pes-caprae L.. Mean duration from egg to adult with H. incana was 8.70 ± 1.66 d, protonymph 3.27 ± 0.21 d, and deutonymph 2.90 ± 1.45 d (P > 0.05. The mix feeding of T. pyri did not show any significant differences neither in the mean time from egg to adult, nor in mortality by feeding only with B. chilensis. Survival curves of T. pyri fed only with H. incana pollen, combined with B. chilensis, and only with B. chilensis are higher in the first 14 d of life. The sex ratio was not significantly affected by being fed only with H. incana pollen, B. chilensis, or by a combination of both.Typhlodromus pyri (Sheuten (Acari: Phytoseiidae es un ácaro que presenta un alto potencial de uso para el control de la falsa arañita roja de la vid (Brevipalpus chilensis Baker; Acari: Tenuipalpidae. El objetivo de este estudio fue determinar el efecto del polen de diferentes especies vegetales como alimento complementario para T. pyri cuando escasea su presa. Los parámetros post-embrionarios de T. pyri se estudiaron en 11 especies de polen, en una dieta mixta de polen de Hirschfeldia incana (L. y B. chilensis. Los ácaros se colocaron individualmente sobre

  10. Review of Cyrtomyia Bigot (Diptera, BomByliidae, Ecliminae with a key to the Neotropical genera of Ecliminae and Cyrtomyia species

    Directory of Open Access Journals (Sweden)

    Carlos José Einicker Lamas

    2013-01-01

    Full Text Available The Neotropical genus Cyrtomyia Bigot has a distribution restricted to the Andean region of South America, with records only in Argentina and Chile. The genus is composed by two species, which are reviewed and redescribed herein: C. chilensis Paramonov, 1931 and C. pictipennis (Bigot, 1857. The main characters of the external morphology of adults are photographed. Illustrations of the male and female terminalia of C. chilensis are also included. An identification key to species is presented, and the species distribution is briefly discussed.

  11. Ophiuroidea das regiões antártica e subantártica: 1. sobre três espécies de Gorgonocephalidae e Ophiacanthidae Ophiuroidea from antarctic and subantarctic regions: 1. on three species of Gorgonocephalidae and Ophiacanthidae

    Directory of Open Access Journals (Sweden)

    Ana Maria Gouveia Monteiro

    1983-01-01

    Full Text Available É estudada a distribuição geográfica e a variação de caracteres morfológicos de três espécies de ofiuroides (OpiLacantha antartica, Astrotoma agassizzi e Gorgonecephalus chilensis das regiões Antártica e Subantãrtica. São também apresentadas observações sobre biologia reprodutiva.The geographical distribution and the variation of morphological characters of three (Gorgonecephalus chilensis, Astroma agassizii, Ophiacantha antartica from the Antarctic and Subantarctic regions are studied. Observations on reproductive biology are presented.

  12. A case of associated occurrence of the crab Lauridromia inter-media (Laurie, 1906) (Crustacea: Decapoda: Dromiidae) and the actinian Nemanthus annamensis Carlgren, 1943 (Anthozoa: Actiniaria: Nemanthidae)

    NARCIS (Netherlands)

    Lavaleye, M.S.S.; Hartog, den J.C.

    1995-01-01

    Members of the crab family Dromiidae tend to cover their carapace mostly with sponges or colonial tunicates. More rarely are used other objects or organisms such as solitary Tunicata, Zoantharia (= encrusting anemones), valves of Bivalvia, etc.; a review of these is presented. A new association of a

  13. On the establishment of two more alien mollusca (Chama aspersa Reeve, 1846 and Chama asperella Lamarck, 1819 in the eastern Mediterranean

    Directory of Open Access Journals (Sweden)

    P. OVALIS

    2012-12-01

    Full Text Available The Indo-Pacific bivalvia Chama aspersa Reeve, 1846 and Chama asperella Lamarck, 1819 are recorded for the first time in Greek waters. These findings represent a considerable expansion in the eastern Mediterranean. Ship fouling is assumed as the most probable transportation means. However, natural dispersal via the Suez Canal is feasible as well.

  14. The complete mitochondrial genome of Scutopus ventrolineatus (Mollusca: Chaetodermomorpha) supports the Aculifera hypothesis

    OpenAIRE

    Osca, David; Irisarri, Iker; Todt, Christiane; Grande, Cristina; Zardoya, Rafael

    2014-01-01

    Background With more than 100000 living species, mollusks are the second most diverse metazoan phylum. The current taxonomic classification of mollusks recognizes eight classes (Neomeniomorpha, Chaetodermomorpha, Polyplacophora, Monoplacophora, Cephalopoda, Gastropoda, Bivalvia, and Scaphopoda) that exhibit very distinct body plans. In the past, phylogenetic relationships among mollusk classes have been contentious due to the lack of indisputable morphological synapomorphies. Fortunately, rec...

  15. Redescription of Oulactis concinnata (Drayton in Dana, 1846) (Cnidaria: Anthozoa: Actiniidae), an actiniid sea anemone from Chile and Perú with special fighting tentacles; with a preliminary revision of the genera with a “frond-like” marginal ruff

    NARCIS (Netherlands)

    Häussermann, V.

    2003-01-01

    Two species of sea anemones with a conspicuous marginal ruff of frond-like structures encompassing the tentacular crown occur on the Chilean coast. Oulactis concinnata (= Isoulactis chilensis) (Drayton in Dana, 1846) is re-described in detail and further information is provided for Oulactis coliumen

  16. Review of Cyrtomyia Bigot (Diptera, BomByliidae, Ecliminae with a key to the Neotropical genera of Ecliminae and Cyrtomyia species

    Directory of Open Access Journals (Sweden)

    Carlos José Einicker Lamas

    2013-01-01

    Full Text Available The Neotropical genus Cyrtomyia Bigot has a distribution restricted to the Andean region of South America, with records only in Argentina and Chile. The genus is composed by two species, which are reviewed and redescribed herein: C. chilensis Paramonov, 1931 and C. pictipennis (Bigot, 1857. The main characters of the external morphology of adults are photographed. Illustrations of the male and female terminalia of C. chilensis are also included. An identification key to species is presented, and the species distribution is briefly discussed.O gênero Neotropical Cyrtomyia Bigot tem uma distribuição restrita à região Andina da América do Sul, com registros assinalados apenas para a Argentina e Chile. O gênero é composto por duas espécies, que são aqui revisadas e redescritas: C. chilensis Paramonov, 1931 e C. pictipennis (Bigot, 1857. Os principais caracteres da morfologia externa dos adultos estão fotografados. Ilustrações das terminálias de machos e de fêmeas de C. chilensis também são incluídas. Uma chave de identificação para as espécies é apresentada e a distribuição das espécies é brevemente discutida.

  17. Studies in Moraceae II. The genus Clarisia Ruiz et Pavon and its synonyms, with a discussion of the generic name

    NARCIS (Netherlands)

    Lanjouw, J.

    1936-01-01

    The Moraceous genus Clarisia was described by Ruiz et Pavon in 1794 in ”Florae Peruvianae, et Chilensis Prodromus” p. 128. This generic name must be rejected, if it is not placed on the list of Nomina Generica Conservanda, as in 1792 there had already been published a genus of this name by Pedro Aba

  18. Disjoint geographical distribution of intertidal and nearshore benthic invertebrates in the Southern Hemisphere Distribuciones geográficas disyuntas de invertebrados bentónicos intermareales y del submareal somero en el Hemisferio Sur

    OpenAIRE

    Castilla, Juan C.; RICARDO GUIÑEZ

    2000-01-01

    Biogeographical explanations for the extant and paleo disjoint geographical distribution in the southern hemisphere of five species of nearshore marine benthic invertebrates: Gaimardia trapesina, Ostrea chilensis, Pyura stolonifera taxonomic complex, Aulacomya ater and Concholepas concholepas, showing distinctive reproductive strategies and early life history characteristics are reviewed and analyzed. Through the use of published and new information we contrasted the following hypotheses: a) ...

  19. Identidad y distribución geográfica de Stemodia durantifolia (Plantaginaceae en la Argentina

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    María de las Mercedes Sosa

    2012-12-01

    Full Text Available Stemodia durantifolia es una especie con dos variedades que crece desde California hasta Chile. La variedad típica se ha citado en trabajos previos para la Argentina y la otra variedad, chilensis fue mencionada hasta el momento para Chile. En este trabajo se descarta la presencia de la variedad típica en el país, se da a conocer su área de distribución y se cita por primera vez a la variedad chilensis para la Argentina. Se describen e ilustran las dos variedades, se incluye un mapa de distribución y una clave para separarla de las restantes especies que crecen en Argentina.Identity and geographical distribution of Stemodia durantifolia (Plantaginaceae in Argentina. The typical variety has been cited in previous studies for Argentina, and the other variety, chilensis, was mentioned so far in Chile. This work rules out the typical variety in the country, describes its geographical distribution and cites for the first time the var. chilensis for Argentina. A description, illustration and a map of distribution of the species with these two varieties are provided, as well as a key to distinguish the other Argentinean species.

  20. A new species of Oxelytrum Gistel (Coleoptera, Silphidae) from southern Argentina, with a key to the species of the genus

    Science.gov (United States)

    Oliva, Adriana

    2012-01-01

    Abstract A new species of the forensically interesting genus Oxelytrum Gistel (Coleoptera, Silphidae), Oxelytrum selknan, is described from Santa Cruz and Tierra del Fuego provinces, Argentina. The new species resembles Oxelytrum biguttatum (Philippi) in outer aspect, but has different male genitalia, in particular a median lobe longer than the paramera. All the described species of Oxelytrum have the median lobe shorter than the paramera. The internal sac, as far as it could be reconstructed from dry-pinned specimens, also shows differences between the two species. A key to the species of Oxelytrum is given and illustrated. PMID:22773910

  1. A new species of Oxelytrum Gistel (Coleoptera, Silphidae) from southern Argentina, with a key to the species of the genus.

    Science.gov (United States)

    Oliva, Adriana

    2012-01-01

    A new species of the forensically interesting genus Oxelytrum Gistel (Coleoptera, Silphidae), Oxelytrum selknan, is described from Santa Cruz and Tierra del Fuego provinces, Argentina. The new species resembles Oxelytrum biguttatum (Philippi) in outer aspect, but has different male genitalia, in particular a median lobe longer than the paramera. All the described species of Oxelytrum have the median lobe shorter than the paramera. The internal sac, as far as it could be reconstructed from dry-pinned specimens, also shows differences between the two species. A key to the species of Oxelytrum is given and illustrated. PMID:22773910

  2. Anatomía sistemática de la lámina foliar del género Distichils (Poaceae)

    OpenAIRE

    López Soto, María Martina

    2012-01-01

    Se hizo un estudio anatómico-sistemático de seis especies y once variedades del género Distichlis Raf. Los taxa incluidos son: D. australis (Speg.) C. B. Villamil; D. humilis Philippi; D. palmeri (Vasey) Fassett; D. scoparia (Kunth) Arechav. var. scoparia y var. erinacea (Beetle) Nicora y D. spicata (L.) E. Greene, ésta última integrada, según Beetle, por nueve variedades: var. spicata, var. andina Beetle, var. borealis Beetle. var. divaricata Beetle. var. mendocina Beetl...

  3. Dos nuevas especies de Stellaria de America del Sur, con una descripción de Stellaria arvalis F. Phil.

    Directory of Open Access Journals (Sweden)

    Troels Myndel Pedersen

    2010-11-01

    Full Text Available

    Se describen como nuevas dos especies de Stellaria de Sudamérica andina (Bolivia y Norte argentino, y Chile central. Se da una descripción amplia de Stellana arvalis F. Phil., considerando que es incompleta la descripción de Stellaria cuspidata var. alsineformis Naud., que por referencia directa da validez al nombre dado por Federico Philippi.

  4. Disease: H00332 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available H00332 Listeriosis Listeriosis is a severe foodborne infection with high case fatal.... J Infect 64:19-33 (2012) PMID:19332898 (description) Rebagliati V, Philippi R, Rossi M, Troncoso A Prevention of food... Stephan R Listeria monocytogenes: food-borne pathogen and hygiene indicator. Rev...ieving continuous improvement in reductions in foodborne listeriosis--a risk-based approach. J Food Prot 68:... assessment of Listeria monocytogenes in ready-to-eat foods: the FAO/WHO approach. FEMS Immunol Med Microbiol 35:263-7 (2003) ...

  5. 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.

  6. 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.

  7. 基于rDNA ITS序列研究蚌科6种类的系统发生关系%The Phylogenetic Analysis of 6 Bivalvia Species(Unionidae)Based on the Sequences of Ribosomal DNA Internal Transcribed Spacer

    Institute of Scientific and Technical Information of China (English)

    许志强; 葛家春; 李晓晖; 霍光明; 潘建林

    2009-01-01

    通过测定核糖体转录间隔区ITS1以及ITS2序列研究了江苏地区蚌科(Unionidae)6种常见贝类--褶纹冠蚌(Cristaria plicata)、三角帆蚌(Hyriopsis cumingii)、背角无齿蚌(Anodneta woodiana woodiana)、扭蚌(Arconaia lanceolata)、圆顶珠蚌(Unio douglasiae)以及背瘤丽蚌(Lamprotula leai)的系统发生关系.结果显示:6种蚌的ITS1 序列长度介于354~439 bp之间,平均G+C百分含量为52.7%;ITS2序列长度介于287~354 bp之间,平均G+C百分含量为51.2%.对6种贝类的相关序列进行比对,ITS1的比对长度包括501个位点,其中有364个变异位点和99个简约信息位点;ITS2的比对长度包括381个位点,其中有259个变异位点和66个简约信息位点.以虾夷扇贝(Mizuhopecten yessoensis)为外群,采用邻接法(NJ)分析6种贝类的系统发生关系,贝类明显聚合为3个类群:类群Ⅰ包括三角帆蚌(H.culingii)和背瘤丽蚌(L.leai),类群Ⅱ包括扭蚌(A.lanceolata)和圆顶珠蚌(U.douglasiae),类群Ⅲ由背角无齿蚌(A.woodiana woodiana)和褶纹冠蚌(C.plicata)组成.

  8. COI-based DNA Barcoding in Tapetinae Species (Mollusca, Bivalvia, Veneridae) Along the Coast of CHINA%基于COI序列的DNA条形码在中国沿海缀锦蛤亚科贝类中的应用分析

    Institute of Scientific and Technical Information of China (English)

    陈军; 李琪; 孔令锋; 郑小东; 于瑞海

    2010-01-01

    该研究探讨了将COI序列应用于中国沿海缀锦蛤亚科贝类物种鉴定的可行性,获得了该亚科5属11种贝类51个个体的43个单倍型序列.碱幕替换饱和性分析表明,颠换未出现饱和现象,而转换在序列分化达到10%至15%时即到达饱和.单倍犁Hap33可能是由杂交引起的,排除此瞥倍型,种内个体间遗传距离在0%到2.02%之间,平均为0.46%,属内不同种个体间遗传距离在17.21%~32.24%之间,平均为24.96%,存在条形码问隙:11种缀锦蛤哑科贝类在邻接树和贝叶斯树上都独立的单系群.该研究表明,基于COI的DNA条形码技术能够将研究所涉及的约98%的缀锦蛤亚科贝类鉴定剑种的水平,因此,利用DNA条形码技术可以对缀锦蛤亚科贝类进行有效地分类鉴定.

  9. 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.

  10. FROM MORPHOLOGICAL APPROACH TO PARACLADISTIC APPROACH: A BRIEF INTRODUCTION TO THE NEW CLASSIFICATION OF THE UPDATED VERSION OF BIVALVIA TREATISE%从形态分类到准分支系统分类——修订版Treatise双壳纲卷分类系统简介

    Institute of Scientific and Technical Information of China (English)

    方宗杰

    2014-01-01

    修订版Treatise双壳纲卷首卷即将正式出版,其分类系统的纲要已提前公开发表.在古生物学家、现代生物学家和分子生物学家的共同努力下,终于顺利地实现了化石和现生双壳类分类系统的初步融合,与1969版的形态分类相比,整个分类系统已经面目全非.为此,有必要全面介绍其分类方法和原则,介绍新分类系统带来的种种重大变化.新分类系统将进化学派的系统发育概念与分支系统分析方法的合理内核有机结合,发挥后者在方法论方面的优势,摒弃其系统发育即分岐演化的错误概念和某些不合理的分类学原则,如拒绝接受并系群和姐妹群必须具有相同级序等;充分发挥林奈系统的长处并加以改进,形成由共同衍征主导同时也考虑前进演化的林奈式级序体系,准分支系统分类方法由此形成.新方法兼顾分支发生和进化级这两个不同的方面,注重恢复可能的祖-裔关系;主要根据系统树但借鉴分支图方法来确定级序格架,将级序与系统树的分枝点对应,即与衍征的分歧时间对应,使级序的划分不再主观任意;一般将姐妹分类单元置于同一级序,必要时将并系群与其后裔类群置于同一级序,而姐妹群则可能被置于不同的级序.采用近亲单元和准近亲单元分别作为无级序的单系群和并系群的标识,解决了将化石分类群融入现代生物分类系统的技术难题,可简化并有效地保持分类系统的稳定性.新方法使双壳纲完成从形态分类向准分支系统分类的转变,这代表着分类学未来发展的新趋势,而林奈式级序体系则为林奈系统今后的改革提供了新的范例.

  11. 基于线粒体细胞色素c氧化酶亚基I基因序列的帘蛤科贝类分子系统发育研究%Phylogenetic analysis of Veneridae (Mollusca: Bivalvia) based on the mitochondrial cytochrome c oxidase subunit I gene fragment

    Institute of Scientific and Technical Information of China (English)

    程汉良; 彭永兴; 董志国; 易乐飞; 孟学平; 申欣; 周旻纯; 陈冬勤

    2013-01-01

    对21种帘蛤科贝类线粒体细胞色素c氧化酶亚基I(cytochrome c oxidase subunit I,COI)基因核苷酸序列进行了分析,以探讨这一序列在种质鉴定、分子系统发生研究中的应用价值.测序结果表明,所有物种扩增片段长度均为707 bp(含引物),序列A+T含量(62.4%-67.8%)明显高于G+C含量.物种间共有变异位点379个,其中简约信息位点334个;此区段共编码235个氨基酸,种间共有氨基酸变异位点100个.以COI基因片段序列为标记,用中国蛤蜊(Mactra chinensis)作外群,构建了35种帘蛤科贝类(其中14种贝类COI序列从GenBank下载)的系统发生树,结合拓扑结构分析和序列比对分析,结果表明:支持将短文蛤(Meretrix petechinalis)和丽文蛤(M.lusoria)订为文蛤(M.meretrix)的同物异名的观点,建议将丽文蛤和短文蛤订为文蛤的地理亚种;支持将薄片镜蛤(Dosinia corrugata)和D.angulosa订为2个独立种的观点;认为将波纹巴非蛤(Paphia undulata)和织锦巴非蛤(P.textile)订为2个独立种是合适的.COI基因序列含有丰富的遗传信息,适合作为帘蛤科贝类种群遗传结构和系统发生研究的分子标记.

  12. Sequence Analysis on Mitochondrial 16S Rrna Gene Fragments and ITS2 Loci in Three Species of Mactradae (Mollusca: Bivalvia)%蛤蜊科3种贝类16SrRNA基因片段及ITS2核苷酸序列分析

    Institute of Scientific and Technical Information of China (English)

    孟学平; 高如承; 董志国; 阎斌伦; 程汉良; 李艳杰; 陈建安

    2006-01-01

    利用PCR技术分别扩增连云港及启东沿海蛤蜊科的西施舌(Coelomactra antiquata)、中国蛤蜊(Mactra chinensis)和四角蛤蜊(Mactra veneriformis)3种双壳贝的16S rRNA基因片段和ITS2核苷酸序列,测序后用DNA star软件分析了核苷酸差异.结果显示:三种贝类16S rRNA基因片段长度相同,均为306bp(去除引物),核苷酸存在多态性,共有45个变异位点,54个核苷酸发生了变异,全部为碱基置换.西施舌与中国蛤蜊此片段核苷酸的同源性为88.9%,与四角蛤蜊的同源性为88.6%,中国蛤蜊与四角蛤蜊的同源性为90.6%.三种蛤蜊ITS2序列分别为390 bp(西施舌)、441 bp(四角蛤蜊)和466 bp(中国蛤蜊),存在长度多态性,ITS2核苷酸差异分析结果显示,西施舌与中国蛤蜊的同源性为70.9%-71.1 %,西施舌与四角蛤蜊的为70.5%-71.0 %,中国蛤蜊与四角蛤蜊的同源性为88.1%-88.8%.ITS2序列分析结果与16S rRNA基因片段分析结果一致,2种分子分析法均显示中国蛤蜊与四角蛤蜊的亲缘关系近.

  13. MOLECULAR PHYLOGENY OF MERETRIX(MOLLUSCA, BIVALVIA)BASED ON 16S rRNA GENES AND ITS1 SEQUENCES%文蛤属(Meretrix)16S rRna基因及ITS1序列的系统学分析

    Institute of Scientific and Technical Information of China (English)

    潘宝平; 吴琪; 张素萍; 宋林生; 卜文俊

    2006-01-01

    利用线粒体16S rRNA基因片段及核糖体DNA转录间隔区ITS1序列分析的方法,以近缘属的青蛤(Cyclina sinensis)为外群,对文蛤属的文蛤(M.meretrix)、丽文蛤(M.lusoria)、帘文蛤(M.lyrata)和斧文蛤(M.lamarckii)4种贝类进行了系统学研究.经ClustalX多重比对及DNAsp软件分析后,用PAUP4.0分析软件,计算出种间序列的碱基转换/颠换频率,利用邻接法NJ构建系统发育树.结果表明,帘文蛤与该属其他三种的分歧时间较早,两类序列与其他种类间的相对遗传距离分别在0.25866-0.28218和0.15644-0.20104之间.文蛤与丽文蛤间的16S rDNA及ITS1序列间的遗传距离仅为0.04805和0.04201,拓扑结构图显示关系很近,并且二者的分布区大面积重叠,其序列间的转换/颠换频率接近种内单元型(haplotype)间的序列变化,鉴于它们的贝壳形态有一定差别,应归为同一个种内的不同地理亚种比较恰当.

  14. 双壳类软体动物精子发生及其在系统演化研究中的应用前景%SPERMATOGENESIS OF BIVALVIA AND ITS PROSPECTIVE APPLICATION IN THE STUDY OF PHYL OGENETIC DEVELOPMENT

    Institute of Scientific and Technical Information of China (English)

    竺俊全; 杨万喜

    2002-01-01

    综述了双壳类软体动物精子发生及精子形态结构方面的研究进展.指出双壳类软体动物精子发生过程中精细胞分化具有种、属特异性,精细胞分化的细节是区别个体外部形态很近的物种的依据;精子的形态结构具有种的特征,精子结构的比较研究将成为双壳类软体动物系统演化研究的重要方法之一.

  15. 双壳纲八种贝类的核DNA定量分析及其与进化地位关系的初步探讨%Quantitative Analysis of DNA Contents of Eight Species Belonging to Bivalvia and Primary Discussion on the Relationship Between C-Values and Evolutionary Degrees

    Institute of Scientific and Technical Information of China (English)

    王昭萍; 高凌云; 于瑞海; 黎筠

    2007-01-01

    运用流式细胞仪测定了双壳纲8种贝类的细胞核DNA含量.结果显示,测定贝类的DNA含量分别为(pg):太平洋牡蛎,2.06±0.03;东方海笋,2.11±0.07;近江牡蛎,2.18±0.13;结蚶,2.59±0.10;青蚶,3.08±0.23;砂海螂,3.24±0.28;缢蛏,3.85±0.10;日本镜蛤,5.00±0.20.双因素方差分析表明,同种贝类个体间DNA含量的差异不显著(p>0.05),仅占总差异的0.12%;而种间差异极为显著(p<0.01),比例高达97.45%.本实验所测8种贝类的DNA含量与其进化地位间未呈现出明显的相关性.

  16. Analysis of Genetic Diversity in Populations of Two Commercial Species of Mercenaria mercenaria and Cyclina sinensis (Bivalvia Veneridae) Based on ITS-1 Sequence%帘蛤科两种经济贝类种群的ITS-1序列遗传多样性分析

    Institute of Scientific and Technical Information of China (English)

    吴琪; 潘鹤婷; 潘宝平

    2007-01-01

    利用核糖体DNA转录间隔区ITS-1序列对硬壳蛤(Mercenaria mercenaria)的养殖群体和青蛤(Cyclina sinensis)的野生种群遗传多样性进行了分析.经过PCR扩增、连接与测序后,得到硬壳蛤ITS-1的长度为718~724 bp,青蛤的为665~683 bp,序列用ClustalX 1.83多重比对后,在725 bp组成的同源片段中有714个碱基序列为保守位点,通过DNAsp软件分析,该种群的核酸多态性指数Pi为0.003 02,每位点Eta为0.003 04,并检测出4个单倍型(Haplotype)序列.青蛤在由695 bp组成的同源片段中有644个碱基序列为保守位点,该种群的Pi为0.030 71,每位点Eta为0.037 8,共测出6个单倍型(Haplotype)序列.利用PAUP4.10软件计算出每个种群内单倍型序列间的相对遗传距离,其中,硬壳蛤的遗传距离仅为0.0014~0.005 6,说明其DNA遗传多样性的丰度较低;而野生青蛤种群的遗传距离为0.003 6~0.010 5,说明其遗传多样性比较丰富.文章还初步讨论了双壳类遗传多样性变动的因素及种质保护等问题.

  17. Fluorescent amplified fragment length polymorphism (fAFLP)analysis of population genetic diversity and species relationships of four species of cultured clams in family Veneridae (Mollusca: Bivalvia)%帘蛤科4种养殖蛤群体遗传多样性和种间关系的fAFLP分析

    Institute of Scientific and Technical Information of China (English)

    彭永兴; 程汉良; 夏德全; 吴婷婷; 孟学平; 吉红九; 董志国

    2008-01-01

    利用荧光标记扩增片段长度多态性(fAFLP)技术对文蛤(Meretrix meretrix)、青蛤(Cyclina sinensis)、菲律宾蛤仔(Ruditapes philippinarum)和硬壳蛤(Mercenaria mercenaria)4种帘蛤科贝类的群体遗传多样性和种间关系进行了研究.选择EcoR Ⅰ/Mse Ⅰ进行酶切,使用6个E+3/M+3引物组合进行扩增,共获得1096个位点,多态位点比率95.1%,片段长度50~456 bp.其中,文蛤、青蛤、菲律宾蛤仔和硬壳蛤分别得到681,715,702和694个位点,相应的多态位点比率为76.8%,81.7%,83.0%和75.1%,得到17个种特异性位点,可作为4物种特征标记.分析了群体遗传相似系数和遗传多样性指数以及种间遗传相似系数.结果表明,硬壳蛤群体遗传相似系数最高(0.670 9),遗传多样性指数最低(0.236 0);菲律宾蛤仔群体遗传相似系数最低(0.592 5),遗传多样性指数最高(0.261 8);根据遗传相似系数采用UPGMA法构建了4物种32个体的聚类图,表明文蛤与菲律宾蛤仔遗传关系最近,青蛤与其他3物种遗传关系较远.

  18. Sequence analysis of mitochondrial COI gene fragment of six Veneridae clams ( Mollusca: Bivalvia) and four populations of Meretrix meretrix%6种帘蛤科贝类及4个地理种群文蛤线粒体COI基因片段序列分析

    Institute of Scientific and Technical Information of China (English)

    程汉良; 夏德全; 吴婷婷; 孟学平; 吉红九; 董志国; 陈淑吟

    2007-01-01

    对文蛤(Meretrix meretrix L,1758)、青蛤(Cyclina sinensis G.,1791)、硬壳蛤(Mercenaria mercenaria L,1758)、江户布目蛤(Protothaca jedoensis L,1874)、薄片镜蛤(Dosinia corrugata R.,1850)和菲律宾蛤仔(Ruditapes philippinarum A.,1850)6种帘蛤科贝类和4个地理种群文蛤(大连、连云港、湛江、防城港)的细胞色素c氧化酶亚基Ⅰ(COI)基因片段的核苷酸序列进行了分析,以探讨这一序列在种质鉴定、种群遗传结构和分子系统发生研究中的应用价值.测序结果表明,所有物种扩增片段长度均为709 bp,序列A+T含量(62.2%~67.6%)明显高于GC含量.物种间共有变异位点311个,其中简约信息位点202个;文蛤4个地理种群间共有变异位点46个,其中简约信息位点2个.此区段共编码235个氨基酸,种间共有氨基酸变异位点85个;文蛤种群间只有1个氨基酸变异位点.以COI基因片段序列为标记,用大竹蛏(Solen grandis)作外群,构建了帘蛤科贝类的系统发生树,其拓扑结构显示4个地理种群文蛤首先聚为1个单元,然后与青蛤聚在一起,最后所有帘蛤科物种聚为一枝,与外群相区别,其结果与传统形态分类基本一致,说明COI基因适合作为该科贝类种群遗传结构和系统发生研究的分子标记.

  19. MACROINVERTEBRATES COMPOSITION IN THE BLIZNEC STREAM, SECOND AND THIRD MAKSIMIR LAKE

    Directory of Open Access Journals (Sweden)

    Marina Piria

    2004-06-01

    Full Text Available Qualitative and quantitative macroinvertebrates in spring period was investigated during two years in the first and second Maksimir Lake and Bliznec stream. The domination of Gastropoda was outstanding at these three investigated sites. From time to time stronger development of Gastropoda, Bivalvia, Diptera and Crustacea was noted at the second Maksimir Lake. Gastropoda was dominant at the third Maksimir Lake (from 1.484 to 2.506 g m–2 while Crustacea, Oligochaeta and Hirudinea made important biomass. Species density in the Bliznec stream was quantitative higher than the one at other stations. The dominant group was Gastropoda (from 0.568 to 3.026 g m–2 and there was higher development of Trichoptera, Crustacea, Diptera, Heteroptera and Bivalvia (Table 3 and 4. Bliznec stream water quality, observed by biological method given by Kerovec, ranged from polluted to highly polluted.

  20. 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.

  1. Nuevos registros de bivalvos marinos para el Perú

    Directory of Open Access Journals (Sweden)

    Carlos Paredes

    2013-03-01

    Full Text Available Seis especies de Bivalvia: Adrana sowerbyana (Orbigny, 1845; Malletia goniura Dall, 1890; Mytilus strigatus Hanley, 1843; Leiosolenus spatiosa (Carpenter, 1857; Pinna rugosa G.B. Sowerby I, 1835 y Delectopecten zacae (Hertlein, 1935 se reportan por primera vez para aguas peruanas. Se da información sobre la distribución, el hábitat y comentarios relevantes de cada una de las especies.

  2. 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...

  3. 福島県東棚倉地域久保田層から産出するAnadara 属二枚貝化石の形態測定

    OpenAIRE

    鈴木, 拓馬; 林, 広樹

    2015-01-01

    The taxonomic classification of the genus Anadara (Bivalvia) from the Miocene Kubota Formation in the eastern Tanagura area has been controversial in previous studies, because there are wide ranges in its shell variation. The present study conducts morphometric analyses of fossil Anadara collected from three localities (Kamitoyo, Kubota, and Tanaka) of the formation as a basic study to describe the morphologic variation through time and space. As a result, the Kamitoyo population can be disti...

  4. The Benthic Macroinvertebrate Fauna of Sarikum Lake and Spring Waters (Sinop)

    OpenAIRE

    Akbulut, Mehmet; Oztürk, Mehmet; Öztürk, Meral

    2002-01-01

    Abstract In this study, the community composition of benthic macroinvertebrate fauna from Sarikum Lake and spring waters were investigated monthly between June 1995 and May 1996. Physico-chemical parameters of the sampling stations were measured. The fauna were represented with 26 species belonging to 6 systematic groups (Gastropoda, Bivalvia, Insecta (larvae), Crustacea, Polychaete and Turbellaria classis). Insecta was found as predominant in respect to species diversity. The species b...

  5. Les Bivalves et Gastéropodes du Bruxellien inférieur de la Belgique (Eocène moyen)

    OpenAIRE

    Glibert, M.

    1985-01-01

    This paper presents a systematic revision of the Bivalvia and Gastropoda from the Aalter Sands (at Aalter, province of Oost-Vlaanderen) and the first description of those from the Oedelem Sands (at Oedelem, province of West-Vlaanderen). Both horizons are of Middle Eocene age. Together they form the lower part of the Bruxellian (Bl or Formation of den Hoorn). The Oedelem Sands with Venericardia carinata are the older part of this formation, whereas the Aalter Sands with Megacardita planicosta ...

  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. On a record of Dardanus venosus (H. Milne Edwards (Crustacea, Anomura from the São Paulo State, Brazil

    Directory of Open Access Journals (Sweden)

    Fernando Luis Medina Mantelatto

    2001-03-01

    Full Text Available The present work is the first report of Dardanus venosus (H. Milne Edwards, 1848 in São Paulo State and extends the range of this species in the western Atlantic farther to the south in the Brazilian region. A total of twenty two males (mean shield length: 7.56 ± 1.62 mm, 4.7 to 10.9 mm, and fifteen females (7.25 ± 2.53 mm, 4.3 to 14.5 mm were collected in 1987, 1998, 1999 and 2000 by scuba diving from three areas of Anchieta Island (23º33'S, 45º05'W in the Ubatuba region, and south of São Sebastião Island (23º57.8'S, 45º16'W, northern coast of São Paulo State. No ovigerous females were captured during the study period. Shells of eleven gastropod species were occupied by D. venosus: Astraea latispina (Philippi, 1844, A. olfersii (Philippi, 1846, A. phoebia Roding 1798, Calliostoma bullisi Clench & Turner 1960, Chicoreus tenuivaricosus (Dautzenberg, 1927, Cymatium parthenopeum (von Salis, 1793, Olivancillaria urceus (Röding, 1798, Phalium granulation (Born, 1778, Stramonita haemastoma (Linnaeus, 1767, Strombus pugilis Linnaeus, 1758 and Zidona dufresnei (Donovan, 1823.

  8. 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.

  9. Illustrated key for identification of the species included in the genus Leptoglossus (Hemiptera: Heteroptera: Coreidae: Coreinae: Anisoscelini), and descriptions of five new species and new synonyms.

    Science.gov (United States)

    Brailovsky, Harry

    2014-05-05

    Five new species of Leptoglossus are described: L.caicosensis from Turks and Caicos Island, L. egeri and L. impensus from Bolivia, L. franckei from Costa Rica, and L. polychromus from Ecuador, Cooperative Republic of Guiana (British Guiana), and French Guiana. Leptoglossus argentinus Bergroth is synonymized under L. chilensis chilensis (Spinola) and Narnia anaticula Brailovsky & Barrera under Leptoglossus occidentalis Heidemann. Dorsal view drawings and key to the 61 known species and 1 subspecies are included; a complete checklist, and the position of each species within the species-group defined herein, are given except for two species L. macrophylus Stål and L. polychromus sp.nov., that are insertae-sedis. The pronotal disk, hind legs, and male genital capsule of the new species here described are illustrated.

  10. Genetic composition of Mytilus species in mussel populations from southern Chile Composición genética de especies de Mytilus en poblaciones de mejillón del sur de Chile

    Directory of Open Access Journals (Sweden)

    María Angélica Larraín

    2012-11-01

    Full Text Available Mussels are one of the most cultivated and commercialized bivalves worldwide and in southern Chile its culture represent an important economic activity. The species identification within the Mytilus genera, by morphological features, is unreliable, so we used a polymorphism RFLP in the gene encoding the polyphenolic adhesive protein as a species-specific genetic marker to describe Mytilus species diversity in southern Chile, and evaluate possible applications in traceability, food quality and safety. Using Me 15-16 marker most mussels were M. chilensis, finding no other pure individuals; however, putative hybrids of M. chilensis x M. trossulus and M. chilensis x M. galloprovincialis were detected. There was no evidence of M. edulis. The presence of the M. trossulus allele, faraway from its distribution area, demands further analysis with different genetic markers to allow a better understanding of its origin. In addition, the correspondence between markers that distinguishes northern from southern hemisphere M. galloprovincialis, with those who discriminates between M. chilensis and M. galloprovincialis would contribute to the taxonomic status of Chilean blue mussels. In Chile, the genetic composition of Mytilus indicates that geographical origin of mussels and its traceability cannot be established merely from the identification of the species. The use of other markers would be required.Los mejillones son una de las especies de bivalvos más cultivadas y comercializadas, en el sur de Chile donde su cultivo representa una actividad económica importante. La identificación de la especie dentro del género Mytilus, basada en las características morfológicas no es confiable por lo que se utilizó un polimorfismo RFLP en el gen que codifica la proteína adhesiva polifenólica como marcador genético específico de la especie para describir la diversidad de especies Mytilus en el sur de Chile, y evaluar posibles aplicaciones en trazabilidad

  11. Comparison between the polypeptide profile of halophilic bacteria and salt tolerant plants.

    Science.gov (United States)

    Muñoz, G; González, C; Flores, P; Prado, B; Campos, V

    1997-12-01

    Changes in the polypeptide profile induced by salt stress in halotolerant and halophilic bacteria, isolated from the Atacama desert (northern Chile), were compared with those in the cotyledons of Prosopis chilensis (Leguminoseae) seedlings, a salt tolerant plant. SDS-PAGE analyses show the presence of four predominant polypeptides, with molecular weights around 78, 70, 60 and 44 kDa respectively, both in bacteria and in cotyledons from P. chilensis seedlings raised under salt stress conditions. Moreover, the 60 and 44 kDa polypeptides seem to be salt responsive, since their concentration increases with increasing NaCl in the growth medium. Our results suggest a common mechanism for salt tolerance in prokaryotes and in eukaryotes.

  12. The Polytene Chromosomes of Cnesia dissimilis (Edwards and Three Species of Gigantodax Enderlein (Diptera: Simuliidae from Lanin National Park (Argentina

    Directory of Open Access Journals (Sweden)

    Cecilia L Coscarón Arias

    1998-07-01

    Full Text Available Cytological studies were made on larvae of Gigantodax marginalis, G. chilensis, G. fulvescens and Cnesia dissimilis from four creeks in Lanin National Park, Neuquen province, Argentina. Chromosome maps and idiograms of these species are presented. The following inversions were observed: G. marginalis: IL-1 (X-linked inversion, IL-2 (Y-linked inversion, IIS-1.2, IIL-1, IIIL-4,5; G. chilensis: IL-4 (X-linked inversion, IIS-1.2, IIIL-4,5; G. fulvescens:IL-1 (X-linked inversion, IL-3 (Y-linked inversion, IIS-1.2, IIL-1, IIIL-4,5; C. dissimilis: IL-1, IL-5, IIIL-1. Karyological information was used to construct a cladogram and Cnesia sp. Was found to show close resemblance to the three Gigantodax spp.

  13. Algunas observaciones en sangre de la tortuga terrestre argentina

    Directory of Open Access Journals (Sweden)

    Troiano, Juan Carlos

    1986-01-01

    Full Text Available Se describen las observaciones hechas en sangre de 30 ejemplares de tortuga terrestre argentina (Geochelone chilensis, discutiendo la técnica adecuada para toma de muestras de sangre. Además, se evalúan parámetros de química hemática y se detalla la morfología de las diferentes series celulares, comparando las datos obtenidos con especies exóticas afines. It is described the observations made in blood from 30 specimens of argentine terrestrial turtle (Geochelone chilensis, discussing the adecuate technique from blood sampling. Moreover it is evaluated blood chemistry parameters and it is detailed the morphology of the diferents cells series, compared the dates with related exotic species.

  14. Seasonal and vertical distribution of medusae in Aysén region, southern Chile Distribución estacional y vertical de medusas en la región de Aysén, sur de Chile

    OpenAIRE

    Viviana Bravo; Sergio Palma; Nelson Silva

    2011-01-01

    Medusae collected in winter and spring 2007 were analyzed in a longitudinal transect made between the Boca de Guafo and Elefantes Fjord, southern Chile. A total of 30 species were identified, Hydromedusae (29) and Scyphozoa (1), where Bougainvillia macloviana, Hybocodon chilensis, Hydractinia tenuis, Laodicea pulcra, L. undulada, Modeeria rotunda and Chrysaora plocamia represent new records for the area. A significant increase in the jellyfish abundance was higher in spring than in winter (fo...

  15. Evaluación de la calidad del aceite de once semillas de leguminosas del desierto sonorense

    OpenAIRE

    Ortega-Nieblas, M.; Vlázquez-Moreno, L.; Robles-Burgueño, M. R.

    1996-01-01

    In order to generate information that lead to an efficient and diversifícate use of the natural resources that the Sonoran Desert offers, as it is the great variety of Leguminosae or Fabaceae plants, oils from seeds or Prosopis chilensis, Prosopis velutina (mezquite), Cercidium floridium (palo azul), Cercidium praecox (palo de brea), Acacia constricta (vinorama), Acacia cymbyspina (chirahui),

  16. La infección de cangrejos procedentes del valle de Condebamba (Cajamarca por metacercarias de Paragonimus

    Directory of Open Access Journals (Sweden)

    Manuel Tantaleán V.

    2014-06-01

    Full Text Available En los meses de febrero y julio de 1973 se colectaron cangrejos del Valle de Condebamba (Cajamarca correspondientes a Pseudothelphusa chilensis, 69 de ellos (34 machos y 35 hembras fueron examinados, buscando metacercarias de Paragonimus; 22 (64.7% de los machos y 29 (28.85 % de las hembras resultaron infectados con metacercarias, o sea 52 (72.46% de los 69 cangrejos estaban infectados, esta cifra es coincidente con la obtenida por Cuba y cols. (1974.

  17. Paragonimus y Paragonimiasis en el norte peruano. Proceso del desarrollo de Paragonimus peruvianus Miyazaki¡ Ibañez y Miranda¡ 1969 en Felis cati L. gato doméstico infectado experimentalmente.

    Directory of Open Access Journals (Sweden)

    Nicanor Ibáñez H.

    2014-06-01

    Full Text Available Se ha estudiado el proceso del desarrollo de Parogonimus peruvianus Miyazaki, Ibóñez y Miranda, 1969 en el gato doméstico, Felis cati L. infectado experimentalmente mediante la administración oral de metacercarias del parasito extraídas de ejemplares de Pseudothelphusa chilensis Milne Edwards, 1843 procedentes de áreas endémicas.

  18. Antimicrobial evaluation of Huilliche plant medicine used to treat wounds

    DEFF Research Database (Denmark)

    Mølgaard, Per; Holler, Jes Gitz; Asar, Betül;

    2011-01-01

    Ethnopharmacological relevanceThe traditional use of 40 plant species used for treatment of wounds and associated infections by the Huilliche people of Chile was evaluated against bacterial and fungal human pathogens, especially including wound pathogens. Materials and methodsThe extracts were......). ResultsThirteen of the plant species have interesting antimicrobial activities, with that of Acaena argentea, Aristotelia chilensis, Blechnum chilense, Francoa appendiculta, Gevuina avellana and Laureliopsis philippiana being the most noteworthy. ConclusionsThe findings in the manuscript support the...

  19. Chemotaxonomic Fingerprinting of Chilean Lichens Through Maldi and Electrospray Ionization Mass Spectrometry

    OpenAIRE

    Leonardo Silva Santos; Maria del Pilar Camarantin Soriano; Yaneris Mirabal-Gallardo; Veronica Carrasco-Sanchez; Fabiane Manke Nachtigall; Iris Pereira; Eugenia Pereira

    2015-01-01

    The aim of this work was to study a fast, new, sensitive, and simple method for the chemotaxonomic classification of Chilean lichens (Teloschistes chrysophthalmus, Ramalina farinacea, Usnea pusilla, Ramalina chilensis and Stereocaulon ramulosum) using MALDI-TOF-MS and UPLC-ESI(-)-MS data. Lichens soluble proteins fingerprints were acquired by MALDI-TOF-MS and they were analyzed by chemometric (PCA). Lichens organic extracts fingerprints were obtained by UPLC-ESI(-)-MS. MALDI-TOF-MS associated...

  20. Chilean Native Fruit Extracts Inhibit Inflammation Linked to the Pathogenic Interaction Between Adipocytes and Macrophages

    OpenAIRE

    Reyes-Farias, Marjorie; Vasquez, Karla; Ovalle-Marin, Angelica; Fuentes, Francisco; Parra, Claudia; Quitral, Vilma; Jimenez, Paula; Garcia-Diaz, Diego F.

    2015-01-01

    Obesity is characterized by an increase in the infiltration of monocytes into the adipose tissue, causing an inflammatory condition associated with, for example, the development of insulin resistance. Thus, anti-inflammatory-based treatments could emerge as a novel and interesting approach. It has been reported that Chilean native fruits maqui (Aristotelia chilensis) and calafate (Berberis microphylla) present high contents of polyphenols, which are known for their antioxidant and anti-inflam...