Physiological ecology of Patella. I. The effect of body size and temperature on metabolic rate

Abstract

The metabolic or respiratory rate, measured as the aerobic oxygen uptake, of the limpets Patella vulgata L. and P. aspera Lamarck was determined over a range of temperatures in January and in July. In order to determine the effects upon metabolism of adaptation to habitat, P. vulgata living at high shore levels were compared with those living at low shore levels.The respiratory rate is proportional to the power –0·3042 of the fresh body weight and the relationship is not affected by temperature or season, and is the same for both species.There is very little difference in the rates of respiration of equal weight individuals of P. aspera and either group of P. vulgata in January. In July the respiratory rate of low-level P. vulgata and of P. aspera is higher than in January whilst that of the high-level P. vulgata is little changed.The Q10 of respiration had a low value between the temperatures of 15–20° C in both species, and this is thought to represent a hitherto unrecognized form of acclimation to maintain metabolic constancy over the mean environmental temperature range. In P. vulgata low values of Q10 were correlated with high environmental temperatures. Lower Q10's were recorded in July than in January and, in addition, limpets which were adapted to the elevated temperature of high shore levels in July had lower Q10's than the limpets from low shore levels. This apparent acclimation of Q10 was not observed in P. aspera.The significance of the differences in metabolic rate and in Q10 are discussed in relation to acclimation and its importance in the ecological distribution of the two species.