Fig. 1. Temperature effects on respiration rates (A), respiratory control and P/O ratio (B) of isolated oyster mitochondria. Respiration rates were measured after addition of ADP (state 3), after all ADP was used up (state 4) and in the presence of oligomycin (state 4+) in isolated oyster mitochondria at different temperatures. Respiratory control ratios were determined as the ratio of state 3 over state 4 respiration (RCR) or state 4+ respiration (RCR+) at different temperatures, and phosphorylation efficiency (ADP/O). Asterisks denote values that are significantly different from those of the respective controls measured at 15°C. Values are means ± S.E.M., N=6–8.