Abstract
Both spatial and temporal variation in environmental conditions can favour intraspecific plasticity in animal form. But how precise is such environmental modulation? Individual Balanus glandula Darwin, a common northeastern Pacific barnacle, produce longer feeding legs in still water than in moving water. We report here that, on the west coast of Vancouver Island, Canada, the magnitude and the precision of this phenotypic variation is impressive. First, the feeding legs of barnacles from protected bays were nearly twice as long (for the same body mass) as those from open ocean shores. Second, leg length varied surprisingly precisely with wave exposure: the average maximum velocities of breaking waves recorded in situ explained 95.6-99.5% of the variation in average leg length observed over a threefold range of wave exposure. The decline in leg length with increasing wave action was less than predicted due to simple scaling, perhaps due to changes in leg shape or material properties. Nonetheless, the precision of this relationship reveals a remarkably close coupling between growth environment and adult form, and suggests that between-population differences in barnacle leg length may be used for estimating differences in average wave exposure easily and accurately in studies of coastal ecology.
Full Text
The Full Text of this article is available as a PDF (562.7 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Appleton R. D., Palmer A. R. Water-borne stimuli released by predatory crabs and damaged prey induce more predator-resistant shells in a marine gastropod. Proc Natl Acad Sci U S A. 1988 Jun;85(12):4387–4391. doi: 10.1073/pnas.85.12.4387. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kemp P., Bertness M. D. Snail shape and growth rates: Evidence for plastic shell allometry in Littorina littorea. Proc Natl Acad Sci U S A. 1984 Feb;81(3):811–813. doi: 10.1073/pnas.81.3.811. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Palumbi S. R. Tactics of acclimation: morphological changes of sponges in an unpredictable environment. Science. 1984 Sep 28;225(4669):1478–1480. doi: 10.1126/science.225.4669.1478. [DOI] [PubMed] [Google Scholar]
- Sebens K. P. Water flow and coral colony size: Interhabitat comparisons of the octocoral Alcyonium siderium. Proc Natl Acad Sci U S A. 1984 Sep;81(17):5473–5477. doi: 10.1073/pnas.81.17.5473. [DOI] [PMC free article] [PubMed] [Google Scholar]