RESISTANCE OF BIVALVES TO ANOXIA AS A RESPONSE TO POLLUTION-INDUCED ENVIRONMENTAL-STRESS

The effect of environmental pollution stress factors on anoxic surviva l time was established in three bivalve molluscs (Mytilus edulis, Scap harca inaequiualvis and Venus gallina). In order to study relationship s with energy status of the cell and ATP turnover rates the accumulati on of fermentative end-products and changes in the glycogen, the adeny late phosphate and the phosphoarginine pool were also estimated. The r esponse among the different species was not consistent. In contrast to Scapharca inaequivalvis, in Mytilus edulis and Venus gallina, accumul ated cadmium reduced the tolerance to anoxic conditions. In Mytilus ed ulis this was accompanied with enhanced metabolic activity indicating a higher anaerobic ATP utilization rate. Additional evidence from lite rature shows that the anoxic survival response of mussels is a simple method to judge whether environmental variables might have perturbing effects on cellular processes which lead to reduced fitness.