65.7 Jan. 7 Scaling of aerobic metabolism in epipelagic squid TRUEBLOOD, Lloyd A.*; ROSA, Rui A.; BIRDEN, Leanne E.; SIEBEL, Brad A.; University of Rhode Island; University of Rhode Island; University of Rhode Island; University of Rhode Island firstname.lastname@example.org
Mass-specific rates of metabolism (B) typically decline with increasing body mass (M) according to B= b0Mb, where b0 is a normalization constant independent of mass and b is a scaling coefficient that is often assumed to reflect geometrical constraints on exchange processes. The value of this scaling coefficient varies in the literature, but quarter power (-0.25) is common and is widely accepted as a biological law. Most studies examining this phenomenon have focused on vertebrates while much less is known about metabolic scaling in invertebrates. This study examines oxygen consumption rates and activities of mitochondrial enzymes in epipelagic squids, active Cephalopod Molluscs, over more than five orders magnitude size range (0.1 g – 17 kg). Metabolism in the three families examined (Lolignidae, Ommastrephidae, and Gonatidae) scaled nearly isometrically, with coefficients ranging from –0.02 to –0.11. Small squid have mass-specific metabolic rates similar to shrews and hummingbirds at comparable temperatures. However, the shallow scaling slopes reflect a demand for energy in large squid higher than any reported organism in the same size class. This unusual scaling relationship may be the result of a unique tubular geometry and reliance cutaneous respiration, or cost-of-transport scaling for jet-propelled swimming.