Meeting Abstract

2.3  Tuesday, Jan. 4  Evolutionary dynamics of the boxfish carapace II: functional diversity ALFARO, ME*; MARCROFT, TA; VAN WASSENBERGH, S; SLATER, GS; Univ. of California, Los Angeles; Univ. of California, Los Angeles; Univ. Antwerpen; Univ. of California, Los Angeles michaelalfaro@ucla.edu

The carapace is thought to confer both mechanical defense and hydrodynamic stability to aracanid and ostraciid boxfishes though little is known about the functional consequences of the conspicuous morphological diversity found within these clades. To test whether shape influences carapace strength we use finite element analysis to simulate dorso-ventral biting forces on 25 three-dimensional models representing the morphological diversity of extant boxfishes. To assess the influence of shape on hydrodynamic properties, we use computational fluid dynamics to simulate flow around our models under a range of angles of attack. Drag coefficients ranged between 0.129 (Ostracion cubicus) and 0.168 (Anoplocapros lenticularis). Frontal surface area was good predictor of the total drag force on volume-standardized while variation in viscous shear forces between the species was negligibly low. Phylogenetic comparative analyses reveal the functional properties of reconstructed ancestral carapace morphologies and evolutionary relationship between mechanical defense and hydrodynamic stability.