Navegando por Assunto "Crassostrea gasar"

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Acesso aberto (Open Access)
Avaliação sanitária de água de cultivo e de ostras da zona do salgado, nordeste do Estado do Pará - Brasil
(Universidade Federal do Pará, 2011-04-19) KIYATAKE, Daniela Mayumi; RIBEIRO, Karla Tereza Silva; http://lattes.cnpq.br/2654817572738748; PAIVA, Rosildo Santos; http://lattes.cnpq.br/0510818763187669
The cultivation of oyster species of the genus Crassostrea is expanding in the northeast of the Brazilian state of Pará. This study analyzes the sanitary quality of the oysters and the water in which they are cultivated in the local municipality of São Caetano de Odivelas and Curuçá. Samples were collected monthly between June, 2009, and May, 2010. Water samples were collected from the flood and the ebb tides, and approximately 15 oysters were obtained each month. Coliform concentrations were determined using the multiple-tube fermentation technique, followed by the biochemical identification of the bacteria and determination the susceptibility profile of Escherichia coli isolated from oysters and water samples. The geometric mean concentration of thermotolerant coliforms in the water was 119 MPN/100 mL in São Caetano de Odivelas and 163,21 MPN/100 mL in Curuçá, well above the limit of 43 MPN/100 mL established by the Brazilian National Environment Council (CONAMA). As Brazilian legislation on the sanitary quality of bivalve mollusks covers only the processed product, the European Union legislation, which assigns oysters for raw consumption to three sanitary classes, was adopted for the evaluation of the results of the present study. In São Caetano de Odivelas only two of the samples collected during this study were assigned to class A, seven samples to class B and three samples to class C. While in Curuçá three samples were assigned to class A, seven samples to class C and two samples to class C. The results suggest the need for mitigation measures to ensure the health quality of the oysters, such as the application of methods of depuration.
Acesso aberto (Open Access)
Estudo da biologia reprodutiva de Crassostrea gasar (Adanson, 1757) no nordeste paraense
(Universidade Federal do Pará, 2012-04-30) PAIXÃO, Leonardo Fernandes da; FERREIRA, Maria Auxiliadora Pantoja; http://lattes.cnpq.br/1832728101486131; ROCHA, Rossineide Martins da; http://lattes.cnpq.br/4371300451793081
The present study analyzed gonadal development in Crassostrea gasar from an Amazonian estuary and characterized the relationship between the reproductive cycle and the variation in abiotic factors. Samples of approximately 20 oysters were collected each month between August, 2009, and December, 2010. The study period was divided into four seasonal periods (dry, dry-rainy transition, rainy, and rainy-dry transition). The salinity, pH, temperature, and dissolved oxygen concentration of the water were measured in situ during the collection of specimens. The gonads were dissected and analyzed histologically. A total of 353 specimens were collected, of which 190 were female, 161 were male, and two were hermaphrodite. Histologically, the specimens were classified in four gonadal stages: I – immature; II – maturing; III – mature, and IV – spawned (females) and spermiated (males). Of the abiotic factors analyzed, only salinity and rainfall varied significantly over the study period, with correlations being found between these factors and gonadal maturation, suggesting that they influence the reproductive cycle of the species. A predominance of mature (stage III) and maturing individuals were recorded during the rainy and rainy-dry periods (low salinity and high rainfall), whereas immature (I) and spawned/spermiated (IV) specimens were more common during the dry and dry-rainy periods (high salinity and low rainfall). Given this, the collection of seeds for farming would be recommended during the latter period, when spawned/spermiated oysters were more common.
Acesso aberto (Open Access)
Novel Microsatellite Markers for Brazilian Mangrove Oysters ( Crassostrea gasar ) and their Cross-Amplification in Crassostrea rhizophorae
(Universidade Federal do Pará, 2016-08) BALDEZ, Renata do Socorro Corrêa; MELO, Mauro Andre Damasceno de; SAMPAIO, Maria Iracilda da Cunha; TAGLIARO, Claudia Helena
A microsatellite CT/GT enriched genomic library was developed for Crassostrea gasar and twelve new polymorphic loci were isolated and characterized. The markers were successfully amplified from 25 individuals of Crassostrea gasar and 11 cross-amplified individuals of Crassostrea rhizophorae. There was no evidence of linkage between loci in either species.