Abstract
Durophagy is the ability to consume hard-shelled or exoskeleton bearing preys and requires teeth that are functionally adapted for crushing and grinding. In this study, structure and mechanical properties of teeth from two durophagous species, zebra shark and parrotfish were investigated. Zebra shark have multiple rows and series of tricuspid shaped teeth, forming an ideal surface capable of crushing mollusks and crustaceans. Parrotfish pharyngeal teeth are arranged in comb-like series, grinding and crushing the algae on the coral. Microstructural features of teeth were characterized by SEM focusing on the orientation of nano-sized apatite crystallites in enameloid. Elemental analysis was carried out by Raman Spectroscopy and Electron Probe Microanalyzer (EPMA). Mechanical properties were evaluated by Nano-indentation and nano-scratch tests in both dry and rehydrated conditions. Wear tests were further performed to examine the ability of abrasion resistance. Grinding mechanisms and design strategies between species were discussed.