Hopkins Marine Station Student Paper

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(full paper is archived in the Miller Library)

Title: The cost of locomotion in the sevengill shark Notorynchus cepedianus
Student Author(s): Hagan, Kevin T.
Pages: 18
Location: Final Papers Biology 175H
Date: June 1990
Abstract: The cost of locomotion is defined as the energetic cost of transporting one unit of body mass one unit distance. Previous experiments reported that the cost of locomotion in swimming fish of sizes .001 to 1 kg follows a common trend: as body mass increases, the cost of locomotion decreases. In this study, costs of locomotion were calculated for sevengill sharks, Notorynchus cepedianus, of weights 10.3 to 51 kg. The costs calculated followed the trend previously reported. The sharks used in this study represent the largest swimming fish for which the cost of locomotion has been calculated and demonstrate that the cost of locomotion trend holds for animals upward of 50 kg. Average swimming velocities were also calculated in order to compare them to a cost-optimization model based on the hypothesis that an unmolested fish will swim at a velocity that requires the least energy expenditure. In this study, swimming velocities varied from .31 to .44 m/s over a total body length range of 1.34 to 2.21 m. These velocities are lower than those predicted by the cost-optimization model and those observed in two other shark species.