The effect of temperature on clearance rate and oxygen consumption of scallops, Chlamys farreri

Rates of particle clearance and oxygen consumption were measured over full natural ranges of seawater temperature (1degreesC to 30degreesC) experienced by the scallop Chlamys farreri cultured in Shandong Province, People's Republic of China, comparing both acclimated and non-acclimated responses. Particle clearance rate varied in hyperbolic relation with acclimated temperature of maximal values of 10 to 15 L h(-1) g(-1) dry wt, occurring in acclimated scallops between 20degreesC and 25degreesC, with significant reductions, at temperatures above about 26degreesC, particularly in non-acclimated scallops (P < 0.001). Oxygen consumption rate increased throughout the range of temperature. Based in part on responses defined here, a dynamic model of physiology and growth predicts that net energy balance becomes negative with short-term adjustments in seawater temperature from 15degreesC to above 26degreesC, when soft tissue wasting may be as much as 3.5% per day at 30degreesC. These predictions are consistent with the loss of condition reported by farmers under such conditions, and help to establish that similar naturally occurring transient increases in temperature have at least in part has been responsible for high coincident mortalities observed in cultured C. farreri during recent years.