Changes in respiration and ionic content in tissues of freshwater mussel exposed to methyl parathion toxicity.

Oxygen consumption and sodium, potassium and calcium concentration were determined in the freshwater mussel, Lamellidens marginalis, and its tissues during methyl parathion (MP) toxicity. A transient increase followed by decrease in whole animal or tissue respiration as a function of time was observed. Greater loss of calcium by the mantle, sodium by the gill, and calcium and sodium by the hepatopancreas and foot was observed. As compared to calcium and sodium, the loss of potassium by the tissues was less.