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Walking versus breathing: mechanical differentiation of sea urchin podia corresponds to functional specialization.

Publication ,  Journal Article
Leddy, HA; Johnson, AS
Published in: The Biological bulletin
February 2000

The podia of sea urchins function in locomotion, adhesion, feeding, and respiration; but different podia on a single urchin are often specialized to one or more of these tasks. We examined the morphology and material properties of podia of the green sea urchin, Strongylocentrotus droebachiensis, to determine whether, despite apparent similarities, they achieve functional specialization along the oral-aboral axis through the differentiation of distinct mechanical properties. We found that oral podia, which are used primarily for locomotion and adhesion, are stronger and thicker than aboral podia, which are used primarily for capturing drift material and as a respiratory surface. The functional role of ambital podia is more ambiguous; however, they are longer and are extended at a lower strain rate than other podial types. They are also stronger and stiffer than aboral podia. In addition, all podia become stronger and stiffer when extended at faster strain rates, in some cases by nearly an order of magnitude for an order of magnitude change in strain rate. This strain-rate dependence implies that resistance to rapid loading such as that imposed by waves is high compared to resistance to slower, self-imposed loads. Thus, the serially arranged podia of S. droebachiensis are functionally specialized along an oral-aboral axis by differences in their morphology and mechanical properties.

Duke Scholars

Published In

The Biological bulletin

DOI

EISSN

1939-8697

ISSN

0006-3185

Publication Date

February 2000

Volume

198

Issue

1

Start / End Page

88 / 93

Related Subject Headings

  • Sea Urchins
  • Animals
  • 31 Biological sciences
  • 06 Biological Sciences
 

Citation

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Leddy, H. A., & Johnson, A. S. (2000). Walking versus breathing: mechanical differentiation of sea urchin podia corresponds to functional specialization. The Biological Bulletin, 198(1), 88–93. https://doi.org/10.2307/1542806
Leddy, H. A., and A. S. Johnson. “Walking versus breathing: mechanical differentiation of sea urchin podia corresponds to functional specialization.The Biological Bulletin 198, no. 1 (February 2000): 88–93. https://doi.org/10.2307/1542806.
Leddy, H. A., and A. S. Johnson. “Walking versus breathing: mechanical differentiation of sea urchin podia corresponds to functional specialization.The Biological Bulletin, vol. 198, no. 1, Feb. 2000, pp. 88–93. Epmc, doi:10.2307/1542806.
Journal cover image

Published In

The Biological bulletin

DOI

EISSN

1939-8697

ISSN

0006-3185

Publication Date

February 2000

Volume

198

Issue

1

Start / End Page

88 / 93

Related Subject Headings

  • Sea Urchins
  • Animals
  • 31 Biological sciences
  • 06 Biological Sciences