Oxygen Consumption of Red and White Muscles from Tuna Fishes

Abstract

Metabolic rates of unstimulated, minced preparations of red and white muscles from two species of Pacific tuna fishes (Katsuwonus pelamis and Thunnus obesus) were determined from respirometric measurements of oxygen consumption. Ratios of mean metabolic rates for red muscles to those of white muscles averaged 6.2 at five temperatures over the range of 5° to 35°C. Temperature coefficients (Q10's) for mean metabolic rates for both types of muscle were between 1.0 and 1.2 over the entire temperature range. Metabolic rates of tuna red muscles were equal to those of preparations of mixed red and white muscle from the white rat at 25° and 35°C, and were higher than the mammalian rates at lower temperatures.