Finite element modeling of shell shape in the freshwater turtle Pseudemys concinna reveals a trade-off between mechanical strength and hydrodynamic efficiency.

摘要: Aquatic species can experience different selective pressures on morphology in flow regimes. Species inhabiting lotic regimes often adapt to these conditions by evolving low-drag (i.e., streamlined) morphologies that reduce the likelihood of dislodgment or displacement. However, hydrodynamic factors are not only influencing organismal and shapes well suited may compromise performance other roles. We investigated possibility morphological trade-offs turtle Pseudemys concinna. Individuals living environments have flatter, more streamlined shells than those lentic environments; however, this flatter shape also make less capable resisting predator-induced loads. tested idea “lotic” shell weaker “lentic” shapes, concomitantly examining effects sex. Geometric morphometric data were used transform an existing finite element model into a series models corresponding individual turtles. Models assigned identical material properties loaded under conditions, stresses produced eight loads extracted describe strength shells. “Lotic” significantly higher indicating former is latter. Females had stronger males, although differences consistent between conclude that, despite potential for many-to-one mapping onto strength, P. concinna experiences trade-off mechanical performance. This be evident many any aquatic depend defense. evolution body size provide avenue escape from some cases, as changes drastically affect while having little effect J. Morphol. 2011. © 2011 Wiley-Liss, Inc.