The Jaws of Nereis: Microstructure and Mechanical Properties

摘要

The jaws of the marine worm Nereis sp. are made of protein fibers and are reinforced by zinc. Here we study a transverse section through the jaw using optical microscopy and nanoindentation. Optical microscopy images demonstrate a complex microstructure which includes channels that extend throughout the jaw. We suggest that these channels may be related to jaw remodeling. The mechanical results reveal spatial variations in both indentation hardness and reduced modulus. Specifically, the toothed side of the jaw (used for grasping food) is harder than the remainder of the jaw and the very exterior surface is hardest.