Different algal symbionts explain the vertical distribution of dominant reef corals in the eastern Pacific

• Published in: Proceedings of the Royal Society. B, Biological sciences Vol. 271; no. 1549; pp. 1757 - 1763
• Main Authors: Iglesias-Prieto, R., Beltrán, V. H., LaJeunesse, T. C., Reyes-Bonilla, H., Thomé, P. E.
• Format: Journal Article
• Language: English
• Published: England The Royal Society 22.08.2004
• Subjects: Adaptation, Physiological - physiology; Algae; Animals; Anthozoa; Anthozoa - microbiology; Base Sequence; Biological taxonomies; Cluster Analysis; Coral reefs; Corals; Dinoflagellida - genetics; Dinoflagellida - physiology; Dinophyta; Fluorescence; Irradiance; Light; Light Gradient; Marine; Molecular Sequence Data; Niche Diversification; Pacific Ocean; Photosystem II; Polymorphism, Restriction Fragment Length; RNA, Ribosomal, 5.8S - genetics; Sequence Analysis, DNA; Species Specificity; Specificity; Symbiodinium; Symbiont Diversity; Symbionts; Symbiosis; Vertical distribution; Zooxanthellae; Pacific Ocean; Mexico, California Gulf; ISE, Mexico, California Gulf
• ISSN: 0962-8452; 1471-2954
• DOI: 10.1098/rspb.2004.2757

Symbiotic reef corals occupy the entire photic zone; however, most species have distinct zonation patterns within the light intensity gradient. It is hypothesized that the presence of specific symbionts adapted to different light regimes may determine the vertical distribution of particular hosts. We have tested this hypothesis by genetic and in situ physiological analyses of the algal populations occupying two dominant eastern Pacific corals, over their vertical distribution in the Gulf of California. Our findings indicate that each coral species hosts a distinct algal taxon adapted to a particular light regime. The differential use of light by specific symbiotic dinoflagellates constitutes an important axis for niche diversification and is sufficient to explain the vertical distribution patterns of these two coral species.