Regresar

Energetic reserves and molecular index of condition in Lima (Ctenoides) scabra exposed to crankcase oil

Abstract:

Used crankcase oil of automobiles is a potential source of hazardous contaminants, which upon reaching coastal ecosystems may affect adversely the biota. The bivalve associated to coralline reefs have been recognized as biological sensors to assessing the impact of stressing chemical substances in these marine ecosystems by means of use of biomarkers, especially changes in chemistry composition. In order to determine energetic substrate levels (protein, lipid and carbohydrate) and molecular ratios of condition (RNA/DNA and Protein/DNA) in the mantle of fire scallop Lima (Ctenoides) scabra exposed to water-soluble fraction (WSF), obtained from a mixture of used lubricants of automobile engines, a static bioassay was realized with sublethal concentrations of 0, 10-3%, 10-2% y 10-1%, during 7 and 13 days. Individuals were collected from Gulf of Santa Fe, Sucre state, Venezuela; and maintained in seawater aquaria system with changes of WSF and food (microalgae) inter-daily, under controlled conditions. Carbohydrate and protein levels, molecular ratios of condition showed increase in organisms exposed to WSF, during some exposure periods, however lipid levels did not differ in relation to the treatments. In the mantle of L. scabra certain biochemical adjustments of importance were evidenced, such as accumulation of energetic macromolecules and molecular ratios increased, indicating that production of protein may be associated to molecular defense against complex mixtures of xenobiotics.