Body Shape and Stiffness of the Scorpaeniformes of the Salish Sea

Abstract

The objective of this study was to examine the body morphology of a variety of Scorpaeniform fishes in the Salish Sea in order to better understand how body shape and body stiffness change along a fish’s body and how they differ between closely related families of marine fishes in the same geographic location. Images were taken of 24 species in six families of Cottoidei fishes. Second moment of area, aspect ratio and fineness ratio were calculated and compared among families. Psychrolutidae had a significantly higher second moment of area than the other five families, and there were no significant differences among families for fineness ratio. Aspect ratios varied greatly among families with Psychrolutidae and Rhamphocottidae having the highest ratios, followed by Cottidae, Hemitripteridae and Liparidae, with Agonidae showing the lowest ratios. These results imply that ecology may be a better determinant in body shape and stiffness than evolution, as these closely related families showed significant variation among one another.