The skeletal isotopic composition as an indicator of ecological and physiological plasticity in the coral genus Madracis

• Published in: Coral reefs 2003-12, Vol.22 (4), p.370-380
• Main Authors: MAIER, Cornelia, PÄTZOLD, Jürgen, BAK, Rolf P. M
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Animals; Autoecology; Biological and medical sciences; Coral reefs; Fundamental and applied biological sciences. Psychology; Madracis; Photosynthesis; Physiology; Plasticity; Protozoa. Invertebrata; Sea water ecosystems; Synecology
• ISSN: 0722-4028; 1432-0975
• DOI: 10.1007/s00338-003-0348-8

Three species of the reef coral genus Madracis display skeletal isotopic characteristics that relate to depth, colony topography, and consequently to coral physiology. The joint interpretation of skeletal δ^sup 13^C and δ^sup 18^O provides information on the ecological plasticity and adaptation to depth of a coral species. Isotopic results are most easily understood in terms of "kinetic" effects, which reduce both δ^sup 18^O and δ^sup 13^C below isotopic equilibrium values, and "metabolic" effects, which only influence the skeletal δ^sup 13^C. Madracis mirabilis is adapted to depths shallower than 20 m, and shows the greatest range in kinetic effects and the strongest metabolic ^sup 13^C enrichments caused by symbiont photosynthesis. Madracis formosa lives deeper than 40 m, and shows a reduced range of kinetic effects and relatively weak metabolic ^sup 13^C enrichments. Madracis pharensis inhabits depths from 5 to >60 m, and does not attain the strength of kinetic effects of either of the other two species, apparently because it is not quite as well adapted to rapid growth at either extreme.[PUBLICATION ABSTRACT]