Respiration rates of the fan mussel Pinna nobilis at different temperatures

We studied the bivalve Pinna nobilisin experimental conditions in order to measure its respiration rate(RR) and evaluate its adaptability to variable environments. We measured the RR of 30 fan mussels (34.0– 64.9 cm shell length) and produced RR profiles at three different temperatures: estimated optimum living temperature of 20 8C and minimum and maximum conformability temperatures (16 and 25 8C respectively). The fan mussel is a high oxygen consumer and RR is reduced at the conformability limits of temperature in comparison to the estimated optimum living temperature (T ¼ 16 8C, 3.1+ 1.2 mg O2 h 21 ; T ¼ 20 8C, 12.0+ 3.9 mg O2 h 21 ; T ¼ 25 8C, 8.5+ 3.8 mg O2 h 21 ; n ¼ 18 in each case). The data indicate that individuals were more stressed at 16 than at 25 8C. These observations will be of value for evaluating the potential distribution of P. nobilis, especially in shallow lagoons during summer when oxygen supply is potentially limiting.