THE EFFECTS OF COPPER ON THE RESPIRATION OF OYSTER CRASSOTREA-GIGAS (THUNBERG)

Continuous recording of respiration showed that the metabolic rate of oyster, Crassotrea gigas (Thunberg), was affected when the concentrati on of copper was higher than 25 ppb in sea water. The animal's reseira tion was more sensitive to the copper ion at 30-degrees-C than at 25-d egrees-C. In accumulation tests, significant amounts of copper were ac cumulated in the liver at a concentration of 30 ppb in two weeks, whil e only slight accumulations were found at 28 and 25 ppb. However, the effects of copper on respiration were observed at the copper concentra tion of 25 ppb when respiration was recorded continuously. The results indicate that continuous recording of respiratory rate is more sensit ive than conventional methods for accumulation to study the effects of copper on oyster.