Relationship between summated tissue respiration and body size in a marine teleost, the porgy Pagrus major

Abstract

Our hypothesis that the regular decrease in the mass-specific rate of metabolism with increasing body mass can be explained principally by a combination of a decrease in the rate of tissue respiration and an increase in the relative size of tissues of low metabolic activity with increasing body mass was examined with a marine teleost, the porgy Pagrus major. Summated oxygen consumption rate in vitro of an individual (M_{in vitro}) was calculated from an allometric relationship of mass of an organ or part (P) to body mass (W) as P=kW^s, and another allometric relationship of rate of tissue respiration in vitro (Qo₂) to body mass (Qo₂=cW^d), determined with 28 organs and parts. The relationship between M_{in vitro} (μmol O₂/h) at 20°C and W (g) was expressed by the formula M_{in vitro}=5.30W^0.816 in fish weighing 0.01-1000 g. The mass exponent 0.816 was very close to that (0.821) in another formula (M_{in vivo}=16.88W^0.821) determined in our previous study at 20°C with intact porgy weighing 0.005-270 g. These results indicate that our hypothesis is quantitatively valid.