Physiological energetics of the ribbed mussel Geukensia demissa (Dillwyn) in response to increased temperature

The effects of acute and prolonged increase in temperature on the components of the energy budget were determined for the ribbed mussel Geukensia demissa (Dillwyn). With the exception of absorption efficiency, all of the measured physiological parameters exhibited significant change in response to elevated temperature. Aerial respiration increased when temperature was increased from 15 to 25 ° C and then exhibited partial acclimation. Aquatic respiration increased similarly but did not exhibit significant acclimation during the 21 days of the experiment. Clearance rates increased with elevated temperature but then continued to increase over the course of the experiment. Ammonia excretion rate exhibited a minor increase upon acute exposure to 25 ° C, increased greatly during the 1st wk and returned to control values by the end of the experiment. The complex pattern of physiological response resulted in an improvement of energy balance upon exposure to elevated temperature and acclimation processes resulted in a further improvement of energy balance for the group maintained at 25 ° C relative to those maintained at 15 ° C.