Metabolic rate in relation to temperature and swimming speed, and the cost of filter feeding in Atlantic menhaden, Brevoortia tyrannus

Abstract

Respiration rates of nonfeeding adult menhaden induced to swim against currents of various speeds in a large circular flume at 10°, 15°, and 20°C were measured in order to quantify the cost of swimming separately from total metabolic expenditure during filter feeding. Standard metabolic rates of 0.040, 0.073, and 0.087 mg O2/(g wet wt. h) at 10°C, 15°C, and 20°C were estimated by extrapolation of the relationship of swimming speed and metabolic rate to zero swimming speed. We determined that when menhaden filter-feed at 20°C, at the preferred swimming speed of 41.3 cm/s, filtering and specific dynamic action (SDA) account for 59% of total energetic expenditures. The cost of locomotion was only about 23% of the total expenditure. Our results are compared with routine oxygen consumption rates of larval and juvenile menhaden as a function of temperature and with extensive metabolic data for sockeye salmon