QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online April 17, 2009
Journal of Experimental Biology 212, 1413-1420 (2009)
Published by The Company of Biologists 2009
doi: 10.1242/jeb.020636

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Horton, J. M. Articles by Summers, A. P. Search for Related Content PubMed Articles by Horton, J. M. Articles by Summers, A. P. Social Bookmarking                         What's this?

The material properties of acellular bone in a teleost fish

Jaquan M. Horton^* and Adam P. Summers

Department of Ecology and Evolutionary Biology, University of California Irvine, CA 92697, USA and Friday Harbor Laboratories, University of Washington, Friday Harbor, WA 98250, USA

^* Author for correspondence (e-mail: jhorton{at}uci.edu)

Accepted 11 February 2009

Several lineages of teleost fishes have independently derived skeletons composed solely of acellular bone, a tissue without obvious advantages over bone that has osteocytes in the matrix. There is no consensus for the functional role of acellular bone, as factors such as salinity, activity level and gross morphology have been shown to be poor predictors of acellularity. We used a three-point bending method to test the hypothesis that the material stiffness (elastic modulus) of acellular bone is higher than that of cellular bone, which could be evidence that material properties were a selective pressure in the evolution of this unusual skeletal material. The acellular ribs of Myoxocephalus polyacanthocephalus are curved, hollow beams that decrease in size both distally and posteriorly along the rib series. First and second moments of area decreased distally and caudally in all individuals. Young's modulus (E) ranged from 3.67 to 8.40 GPa, with a mean of 6.48 GPa. The flexural stiffness (EI) differed significantly between ribs, and the hollow cylinder morphology increased the flexural stiffness by 12.0% over a solid, circular cross-section rod with the same area. Contrary to our expectations, acellular bone is not stiffer by virtue of fewer lacunae but instead falls at the very low end of the range of stiffness seen in cellular bone. There remains the possibility that other properties (e.g. fatigue resistance, toughness) are higher in acellular bone.

Key words: acellular bone, material properties, Young's modulus, stiffness, ribs

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?