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Desempe?o biológico del callo de hacha Atrina maura y el mejillón Mytella strigata en diferentes regímenes de flujo de agua
Arrieche, D;Maeda-Martínez, AN;Farías-Sánchez, JA;Saucedo, PE;
Ciencias marinas , 2010,
Abstract: three water flow rates (3.1, 7.3, and 12.1 cm s-1) were used during a 26-day period to determine their effects on shell dimensions, tissue mass, condition index, biochemical composition of tissues, and mortality of the penshell atrina maura and mussel mytella strigata kept in an open-flow flume. these parameters were measured at the beginning and end of the trial and significant differences were determined using non-parametric comparisons of multiple independent samples. both species were able to withstand high seston loads and daily oscillations of temperature, which yielded negligible mortalities. both species were affected differently by water flow. atrina maura grew significantly larger above a flow of 7.3 cm s-1, which appears typical of species inhabiting tidal channels. at this flow, there was a significant increase in lipids and acylglycerols within the digestive gland, adductor muscle, and mantle tissue, accompanied by a significant decline in proteins and carbohydrates within the same organs. in contrast, the flow did not have a significant effect on m. strigata, except for increased lipid and acylglycerol reserves within body tissues at 3.1 and 7.3 cm s-1, and increased lipid and acylglycerol levels within the gonad at 7.3 and 12.1 cm s-1. digestive gland proteins, carbohydrates, and glycogen increased at the highest flow. data suggest that the penshell is a flow-conforming mollusk that prefers flows exceeding 7.3 cm s-1, and that the strigate mussel is a flow-regulating species in the range of flows that were studied.
Preliminary assessment of heavy metal levels in Mytella falcata (Bivalvia, Mytilidae) from Bacanga River estuary, S?o Luis, State of Maranh?o, Northeastern Brazil
CARVALHO, G. P. de;CAVALCANTE, P. R. S.;CASTRO, A. C. L. de;ROJAS, M. O. A. I.;
Revista Brasileira de Biologia , 2000, DOI: 10.1590/S0034-71082000000100003
Abstract: 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 concentrations of cu, pb and cd in the filter-feeding mytella falcata in the study area in comparison with the maximum values stablished to foods by the brazilian government (decree law no 55,871). finally, zn presented slightly higher values than the maximum ones stablished by the brazilian government.
Preliminary assessment of heavy metal levels in Mytella falcata (Bivalvia, Mytilidae) from Bacanga River estuary, S o Luis, State of Maranh o, Northeastern Brazil  [cached]
CARVALHO G. P. de,CAVALCANTE P. R. S.,CASTRO A. C. L. de,ROJAS M. O. A. I.
Revista Brasileira de Biologia , 2000,
Abstract: 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 concentrations of Cu, Pb and Cd in the filter-feeding Mytella falcata in the study area in comparison with the maximum values stablished to foods by the Brazilian Government (Decree Law No 55,871). Finally, Zn presented slightly higher values than the maximum ones stablished by the Brazilian government.
Anatomia funcional de Perna perna (Linné) (bivalvia, Mytilidae)
Narchi, Walter;Galv?o-Bueno, Mario Sérgio;
Revista Brasileira de Zoologia , 1997, DOI: 10.1590/S0101-81751997000100014
Abstract: perna perna (linné, 1758) occurs on the atlantic littoral from venezuela to uruguay. the main organ systems were studied in the living animais, particular attention being paid to the ciliary feeding and cleansing mechanisms in the mantle cavity. the anatomy, functioning of the stomach and the ciliary sorting mechanisms are described. the siphons belong to type a (yongf. 1948b), the ctenidia to type b( 1) (atkins 1936c) and the stomach is of type iii (purchon 1957) or section i (dinamani 1967) with sorting mecanisms of type a and b (reid 1965). a general comparison was made between the genera of the mytilidae known and some features of mytella soot-ryen, 1955.
Comparative cytogenetics of Carnegiella marthae and Carnegiella strigata (Characiformes, Gasteropelecidae) and description of a ZZ/ZW sex chromosome system
Terencio, Maria Leandra;Schneider, Carlos Henrique;Gross, Maria Claudia;Silva, Adailton Moreira da;Feldberg, Eliana;Porto, Jorge Ivan Rebelo;
Genetics and Molecular Biology , 2008, DOI: 10.1590/S1415-47572008000200011
Abstract: comparative cytogenetic analyses of hatchetfishes carnegiella marthae and carnegiella strigata (gasteropelecidae) from the rio negro basin were performed using conventional giemsa staining, silver (ag) -staining and c-banding. the diploid chromosome numbers of both species equaled 2n = 50 but their karyotypes were distinct. we found evidence for sex chromosomes in c. marthae since karyotype of males presented 20 m + 12 sm + 4 st + 14 a and zz st chromosomes while the females presented 20 m + 12 sm + 4 st + 14 a and zw st chromosomes of distinct size. conversely, c. strigata presented 4 m + 4 sm + 2 st + 40 a chromosomes without sex chromosome heteromorphism. karyotypes of both species had two nor-bearing sm chromosomes of distinct size indicating the presence of multiple nor phenotypes. the sex chromosome pair had specific c-banding pattern allowing identification of both z and w. this heteromorphic system has previously been described for the gasteropelecids.
Sperm ultrastructure of Mytella (Bivalvia) populations from distinct habitats along the northern coast of S?o Paulo State, Brazil
Orlandi Introíni,Gisele; Martins Maester,Fernanda; Pedini Pereira Leit,Fosca; Recco-Pimentel,Shirlei Maria;
Biocell , 2010,
Abstract: ultrastructural analyses of bivalve spermatozoa are relevant in studies that aim to identify taxonomic traits for the purposes of discriminating species and conducting phylogenetic studies. in the present work, spermatozoa of mussel specimens of the genus mytella, collected from two populations living in distinct habitats, were examined by electron microscopy. the objective was to identify sperm ultrastructural taxonomic traits that could be used to differentiate mytella species. the specimens were from populations that live in intertidal zones on the southeast coast of brazil, either buried in muddy-sand sediment or anchored to rocky substrates. the acrosomal vesicle was conical and long, the axial rod extended from the nucleus to the acrosome, the nucleus was an oblate spheroid with a condensed chromatin, the intermediate portion contained mitochondria encircling a pair of centrioles, and there was a single flagellum. the sperm was of a primitive type. the spermatozoon ultrastructure did not distinguish the specimens buried in muddy-sand sediment from those anchored to rocky substrates. the data suggest that the specimens analyzed, despite living in distinct habitats, belong to the same species, which conchological analyses identified as m. charruana. the presence of an axial rod in their sperm cells supports the inclusion of m. charruana in the subfamily mytilinae.
Sperm ultrastructure of Mytella (Bivalvia) populations from distinct habitats along the northern coast of S o Paulo State, Brazil  [cached]
Gisele Orlandi Introíni,Fernanda Martins Maester,Fosca Pedini Pereira Leit,Shirlei Maria Recco-Pimentel
Biocell , 2010,
Abstract: Ultrastructural analyses of bivalve spermatozoa are relevant in studies that aim to identify taxonomic traits for the purposes of discriminating species and conducting phylogenetic studies. In the present work, spermatozoa of mussel specimens of the genus Mytella, collected from two populations living in distinct habitats, were examined by electron microscopy. The objective was to identify sperm ultrastructural taxonomic traits that could be used to differentiate Mytella species. The specimens were from populations that live in intertidal zones on the southeast coast of Brazil, either buried in muddy-sand sediment or anchored to rocky substrates. The acrosomal vesicle was conical and long, the axial rod extended from the nucleus to the acrosome, the nucleus was an oblate spheroid with a condensed chromatin, the intermediate portion contained mitochondria encircling a pair of centrioles, and there was a single flagellum. The sperm was of a primitive type. The spermatozoon ultrastructure did not distinguish the specimens buried in muddy-sand sediment from those anchored to rocky substrates. The data suggest that the specimens analyzed, despite living in distinct habitats, belong to the same species, which conchological analyses identified as M. charruana. The presence of an axial rod in their sperm cells supports the inclusion of M. charruana in the subfamily Mytilinae.
A new occurrence of Limnoperna fortunei (Dunker 1856) (Bivalvia, Mytilidae) in the State of S?o Paulo, Brazil
Avelar, W. E. P.;Martim, S. L.;Vianna, M. P.;
Brazilian Journal of Biology , 2004, DOI: 10.1590/S1519-69842004000500002
Abstract: the freshwater mussel limnoperna fortunei (dunker 1856) (bivalvia, mytilidae) has been found in the paraná river, near rosana, s?o paulo. this is the first record of this specie in s?o paulo state. this population of limnoperna fortunei seems to be young and in a colonization process.
Occurrence, population dynamics and habitat characterization of Mytella guyanensis (Lamarck, 1819) (Mollusca, Bivalvia) in the Paraíba do Norte river estuary
Nishida, Alberto Kioharu;Leonel, Rosa Maria Veiga;
Boletim do Instituto Oceanográfico , 1995, DOI: 10.1590/S0373-55241995000100004
Abstract: a survey of mytellaguyanensis occurrence and population dynamics were performed in the paraíba do norte river estuary. the characterization and the influence of temperature, salinity and substrate, as well as the associated fauna and flora on the population were also examined. mytella guyanensis lives buried in the substrate of the mangrove intertidal zone of the paraíba do norte river estuary, from the mouth to 24 km upriver. average annual density of this bivalve species was 5.2 individuals per m2, with a predominantly aggregated distribution. the most frequent size was between 4.5 and 5.5 cm in length. analysis of the substrate demonstrated the presence of two types of substrates in relation to the percentage of silt and clay and the water content. besides interfering in the population density, the substrate heterogeneity may be a decisive factor in aggregation. eight species of crustacean decapods and one bivalve species were identified as associated fauna.
Occurrence, population dynamics and habitat characterization of Mytella guyanensis (Lamarck, 1819) (Mollusca, Bivalvia) in the Paraíba do Norte river estuary
Nishida, Alberto Kioharu;Leonel, Rosa Maria Veiga;
Brazilian Journal of Oceanography , 1995, DOI: 10.1590/S1679-87591995000100004
Abstract: a survey of mytellaguyanensis occurrence and population dynamics were performed in the paraíba do norte river estuary. the characterization and the influence of temperature, salinity and substrate, as well as the associated fauna and flora on the population were also examined. mytella guyanensis lives buried in the substrate of the mangrove intertidal zone of the paraíba do norte river estuary, from the mouth to 24 km upriver. average annual density of this bivalve species was 5.2 individuals per m2, with a predominantly aggregated distribution. the most frequent size was between 4.5 and 5.5 cm in length. analysis of the substrate demonstrated the presence of two types of substrates in relation to the percentage of silt and clay and the water content. besides interfering in the population density, the substrate heterogeneity may be a decisive factor in aggregation. eight species of crustacean decapods and one bivalve species were identified as associated fauna.
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