La salinidad en las zonas costeras es uno de los parámetros ambientales más variables debido a los aportes de aguas continentales y sus efectos son importantes en los procesos osmoregulatorios de los invertebrados, particularmente los sésiles, como los bivalvos. Se conoce muy poco, acerca de los riesgos de la exposición prolongada abaja concentración de salinidad en Perna viridis y sus efectos sobre la condición fisiológica. En este estudio, P. viridis, una especie de importante en maricultura, fue expuesta a diferentes salinidades de 36, 16 y 12 ups, que se redujeron en 2 ups cada dos días hasta alcanzar ocho semanas, en las salinidades experimentales. Durante el período experimental se mantuvo el fotoperiodo en 12/12 y la temperatura de 25±1,5°C.Los organismos fueron alimentados diariamente con una mezcla de los monocultivos de microalgas (alrededor de -130000 células·mL )...

El biomonitoreo ambiental es una herramienta para valorar la presencia de contaminantes en el medio ambiente, particularmente los metales pesados, debido a su persistencia y toxicidad sobre el componente biótico. En el presente trabajo se determinaron las concentraciones de los metales pesados Zn, Cu, Cd, Cr, Pb y Ni en machos y hembras de Perna viridis (μg·g-1 peso seco), con la finalidad de evaluar la calidad ambiental en la localidad de Guayacán, estado Sucre, Venezuela, durante los meses de noviembre (2006), mayo-agosto (2007) y febrero (2008). Noviembre y agosto corresponden al período de lluvia, y mayo y febrero al de sequía. Los metales en el tejido blando se determinaron utilizando espectrofotometría de absorción atómica (ASS) y la precisión del método fue verificada utilizando el estándar de referencia de tejido NIST Oyster Tissue 1566ª. Las concentraciones de Zn, C...

Heavy metals in male and female specimens of the bivalve Atrina seminuda (Lamarck, 1819) were evaluated. The organisms were collected from Guayacán, Sucre State, Venezuela. The concentrations Cu, Cd, Cr, Ni, Pb, Fe and Zn were determined in the tissues: gonad (G), muscle (M), hepatopancreas (H) and rest (R) by inductively coupled plasma emission spectroscopy (ICP-OES) coupled to a Perkin Elmer brand equipment. The gonadosomatic index (IGS) showed significant differences (Kw= 31.68; P < 0.01), showing its highest value in February (19.67 ± 0.43) and the lowest in June (13.26 ± 0.43). Metal concentrations showed significant differences between the analyzed tissues; showing in general a greater accumulation of metals in the H and R. Significant monthly variations of metals were shown in the tissues with the highest concentrations of Cu, Cd, Cr, Ni and Zn between April and May. The PCA...

The Yaque Norte is one of the most important rivers in the Dominican Republic, it is used for consumption purposes, reserve dams, hydroelectric plants, irrigation and others; however, the evidence shows that many of the domestic and industrial effluents are discharged directly into its waters, without prior treatment. In the present work, a physicochemical and microbiological evaluation of surface waters in the upper, middle and lower basin of the Yaque del Norte River is carried out, using the Standard Methods for water analysis. The results show that there are no significant differences in the physicochemical parameters: pH, salinity, conductivity, turbidity, total solids and hardness; however, these parameters show alterations along the river. The levels of total coliforms, fecal or thermotolerant coliforms and Escherichia coli exceed the limits established in the Dominican regulation...

Benthic organisms have been proposed as good indicators of disturbance in marine environments, particularly because most toxins fall to the bottom of the sea affecting benthic communities. A non-invasive method for collecting coelomocytes was developed using the marine polychaete Eurythoe complanata with potential applications in xenobiotic toxicology. The extrusion method used produced the expulsion of 95% of the coelomic fluid, showing a greater efficiency than the puncture method in Lumbricus terrestris with regard to the total number of coelomocytes and cellular viability. The total coelomocyte count by this method was 6 -1 6 -12.6 x 10 cells·mL vs 1.4 x 10 cells·mL for the puncture method. The results indicate that coelomocyte numbers completely recover at 20 days after extrusion, using the total cell count, cell viability and differential count. This method was developed to study...