Relations between morphology, buoyancy and energetics of requiem sharks

Authors

Gil Iosilevskii, Technion-Israel Institute of Technology
Yannis Papastamatiou, Department of Biological Sciences, Florida International UniversityFollow

Date of this Version

10-26-2016

Document Type

Article

Rights

by

Abstract

Sharks have a distinctive shape that remained practically unchanged through hundreds of millions of years of evolution. Nonetheless, there are variations of this shape that vary between and within species. We attempt to explain these variations by examining the partial derivatives of the cost of transport of a generic shark with respect to buoyancy, span and chord of its pectoral fins, length, girth and body temperature. Our analysis predicts an intricate relation between these parameters, suggesting that ectothermic species residing in cooler temperatures must either have longer pectoral fins and/or be more buoyant in order to maintain swimming performance. It also suggests that, in general, the buoyancy must increase with size, and therefore, there must be ontogenetic changes within a species, with individuals getting more buoyant as they grow. Pelagic species seem to have near optimally sized fins (which minimize the cost of transport), but the majority of reef sharks could have reduced the cost of transport by increasing the size of their fins. The fact that they do not implies negative selection, probably owing to decreased manoeuvrability in confined spaces (e.g. foraging on a reef).

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 License.

Comments

Originally published in Royal Society Open Science.

Identifier

FIDC006326

Recommended Citation

Gil Iosilevskii, Yannis P. Papastamatiou R. Soc. open sci. 2016 3 160406; DOI: 10.1098/rsos.160406. Published 26 October 2016