The authors thank Mr. JQ Yao for assistance in sample collecting. We also acknowledge Dr. Vengatesen Thiyagarajan's group at Hong Kong University for providing assistance in FESEM imaging. Supports for this work from the Early Career Scheme (ECS) of Hong Kong RGC (Grant No. 533312), the Departmental General Research Funds and Internal Competitive Research Grants (4-ZZA8, A-PM24, G-UA20) from the Hong Kong Polytechnic University and the Natural Science Foundation of China (Grant No. 11072273) are acknowledged.
Mechanics of Pharyngeal Teeth of Black Carp (Mylopharyngodon piceus) Crushing Mollusk Shells†
Article first published online: 4 MAR 2013
Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Advanced Engineering Materials
Volume 15, Issue 8, pages 684–690, August 2013
How to Cite
He, C., Zhou, W., Wang, H., Shi, S.-Q. and Yao, H. (2013), Mechanics of Pharyngeal Teeth of Black Carp (Mylopharyngodon piceus) Crushing Mollusk Shells. Adv. Eng. Mater., 15: 684–690. doi: 10.1002/adem.201200304
- Issue published online: 2 AUG 2013
- Article first published online: 4 MAR 2013
- Manuscript Accepted: 17 JAN 2013
- Manuscript Received: 3 OCT 2012
Mollusks such as snail and mussels adopt hard shells to protect their vulnerable bodies. Recent studies on biomaterials have revealed that these shells especially the nacre layers exhibit excellent mechanical properties, inspiring a number of biomimetic endeavors. Nevertheless, in nature, there is a species of fish called Mylopharyngodon piceus or black carp, whose main diet is exactly snails and mussels. Does such unique diet imply that the pharyngeal teeth of black carp, its major masticatory apparatus, are superior to the mollusk shells in mechanical properties? In this paper, structural and mechanical characterizations are conducted on the pharyngeal teeth of black carp, showing that enameloid, the outermost layer of black carp teeth, possesses similar elastic modulus and hardness in comparison to those of the pond snail shells. To shed light on the mechanics underlying the capability of pharyngeal teeth to crush mollusk shells, parametric studies on the geometry of the shells are conducted by means of finite element method. It is found that whether a mollusk shell is crushable or not, for given pharyngeal teeth, depends on the radius (R) and thickness (t) of the shell. A predation map for black carp teeth is constructed by delimiting the t–R plane into three phasic regions corresponding to three possible consequences of the mechanical competition between pharyngeal teeth and shells. It is interesting to notice that all the freshwater shells chosen at random fall in the crushable regime while the seashells do not necessarily. This feature of black carp teeth can be speculated as a result of evolution in response to its freshwater diet.