COMPARISON OF THE EFFECTS OF COPPER ON RESPIRATION AND ITS ACCUMULATION IN TISSUE IN THE HARD CLAM MERETRIX LUSORIA

A sensitive monitoring system was set up to continuously measure disso lved oxygen concentrations in order to study the effects of copper tox icity on the hard clam, Meretrix lusoria. Respiration in M. lusoria wa s repressed within 1 hr after adding the hard clams to sea water conta ining copper concentrations greater than 14 ppb at both 25 degrees C a nd 30 degrees C. Liver tissue of M. lusoria began to accumulate copper within 24 hr, when the hard clams were submerged in sea water at 30 d egrees C with a concentration of 18.6 ppb copper. However, the liver d id not accumulate copper within 14 d, when the hard clams were treated with either 15.4 or 17.3 ppb copper. Neither foot nor gill tissue acc umulated copper within 14 d for treatments with 15.4, 17.3, and 18.6 p pb, respectively. The results indicate that continuous measurement of respiration was more efficient in revealing the copper toxicity in the hard clam than the tissue accumulation test.