Plasticity and conservatism in sclerites of a Caribbean octocoral
- 139 Downloads
- 1 Citations
Abstract
Species level identification of octocorals is often based on the form of skeletal elements, the sclerites. Morphological variation in sclerites across and within habitats complicates both species delineation and the identification of specimens, both of which are essential for characterizing and understanding octocoral diversity. In order to quantify the effects of environmental plasticity on sclerite morphology, branches from the Caribbean gorgonian Antillogorgia bipinnata were removed from colonies at depths of 18 and 23 m and reciprocally transplanted between those sites and transplanted to an 8 m depth site for 7 months. Images of sclerites from those colonies were compared using elliptical Fourier analyses (EFA) of the sclerite outline. The length of scaphoids produced after transplantation was larger than those in older tissue, suggesting length was affected by the process of transplantation. Shape of scaphoids as detected in the EFA, differed between sites, and the reciprocal crosses suggest some of the difference was a plastic response to the environment. The results demonstrate the presence of some environmental plasticity in sclerite form. However, while detectable using EFA, the differences in form were not apparent in microscopical observations of the sclerites and thus would not affect identification of specimens nor traditional species delineation.
Keywords
Coral reef Norm of reaction Elliptical Fourier analysis Morphometrics, phenotypic plasticityNotes
Acknowledgments
We thank T. Higgs, J. Bilewitch, E.L. Mclean, and the crew of the R/V F.G. Walton Smith for their assistance in the field. Mary Alice Coffroth and Katharina Ditmar provided important guidance in the design and execution of the analyses, and we also thank Dr. Denise Ferkey for use of her Zeiss Axio Imager 2 microscope. EJ extends his gratitude and dedicates this work to his family Pamela, Elton, Ayana, and Nia who maintained a steady force of encouragement throughout this entire process. The research was supported by the U.S. National Science Foundation grants OCE-0327129 and OCE-0825625. The research was conducted with the permission of The Bahamas Department of Marine Resources.
References
- Bayer, F. M., 1961. The Shallow-Water Octocorallia of the West Indian Region: A Manual for Marine Biologist. Martinus Nijhoff, The Hague.Google Scholar
- Carlo, J., M. S. Barbeitos & H. R. Lasker, 2011. Quantifying complex shapes: elliptical fourier analysis of octocoral sclerites. Biological Bulletin 220: 224–237.PubMedGoogle Scholar
- Chang, W. L., K. J. Chi, T. Y. Fan & C. F. Dai, 2007. Skeletal modification in response to flow during growth in colonies of the sea whip, Junceella fragilis. Journal of Experimental Marine Biology and Ecology 347: 97–108.CrossRefGoogle Scholar
- Clavico, E. E. G., A. T. De Souza, B. A. P. Da Gama & R. C. Pereira, 2007. Antipredator defense and phenotypic plasticity of sclerites from Renilla muelleri, a tropical sea pansy. Biological Bulletin 213: 135–140.CrossRefPubMedGoogle Scholar
- Crampton, J. S., 1995. Elliptic Fourier shape analysis of fossil bivalves: some practical considerations. Lethaia 28:179–186.Google Scholar
- Debreuil, J., E. Tambutte, D. Zoccola, E. Deleury, J. M. Guigonis, M. Samson, D. Allemand & S. Tambutte, 2012. Molecular cloning and characterization of first organic matrix protein from sclerites of red coral, Corallium rubrum. Journal of Biological Chemistry 287: 19367–19376.CrossRefPubMedCentralPubMedGoogle Scholar
- Grigg, R. W., 1972. Orientation and growth form of sea fans. Limnology and Oceanography 17: 185–192.CrossRefGoogle Scholar
- Gutiérrez-Rodríguez, C., M. S. Barbeitos, J. A. Sánchez & H. R. Lasker, 2009. Phylogeography and morphological variation of the branching octocoral Pseudopterogorgia elisabethae. Molecular Phylogenetics and Evolution 50: 1–15.CrossRefPubMedGoogle Scholar
- Iwata, H. & Y. Ukai, 2002. SHAPE: a computer program package for quantitative evaluation of biological shapes based on elliptic Fourier descriptors. Journal of Heredity 93: 384–385.CrossRefPubMedGoogle Scholar
- Jeng, M. S., H. D. Huang, C. F. Dai, Y. C. Hsiao & Y. Benayahu, 2011. Sclerite calcification and reef-building in the fleshy octocoral genus Sinularia (Octocorallia: Alcyonacea). Coral Reefs 30: 925–933.CrossRefGoogle Scholar
- Prada, C., N. V. Schizas & P. M. Yoshioka, 2008. Phenotypic plasticity or speciation? A case from a clonal marine organism. BMC Evolutionary Biology 8: 47.CrossRefPubMedCentralPubMedGoogle Scholar
- Sanchez, J. A., C. Aguilar, D. Dorado & N. Manrique, 2007. Phenotypic plasticity and morphological integration in a marine modular invertebrate. BMC Evolutionary Biology 7: 122.CrossRefPubMedCentralPubMedGoogle Scholar
- Sanchez, J. A. & H. R. Lasker, 2003. Patterns of morphological integration in marine modular organisms: supra-module organization in branching octocoral colonies. Proceedings of the Royal Society London B 270: 2039–2044.CrossRefGoogle Scholar
- Scheiner, S. M., 1993. Genetics and evolution of phenotypic plasticity. Annual Review of Ecology and Systematics 24: 35–68.CrossRefGoogle Scholar
- Sethmann, I., U. Helbig & G. Worheide, 2007. Octocoral sclerite ultrastructures and experimental approach to underlying biomineralisation principles. Crystengcomm 9: 1262–1268.CrossRefGoogle Scholar
- Sultan, S. E., 2000. Phenotypic plasticity for plant development, function and life history. Trends in Plant Science 5: 537–542.CrossRefPubMedGoogle Scholar
- Tentori, E. & L. P. van Ofwegen, 2011. Patterns of distribution of calcite crystals in soft corals sclerites. Journal of Morphology 272: 614–628.CrossRefPubMedGoogle Scholar
- West, J., C. Harvell & A. Walls, 1993. Morphological plasticity in a gorgonian coral (Briareum asbestinum) over a depth cline. Marine Ecology Progress Series 94: 61–69.CrossRefGoogle Scholar
- West, J. M., 1997. Plasticity in the sclerites of a gorgonian coral: tests of water motion, light level, and damage cues. Biological Bulletin 192: 279–289.CrossRefGoogle Scholar