Symbiodiniumspp. in colonies of eastern PacificPocilloporaspp. are highly stable despite the prevalence of low-abundance background populations

• Published in: Marine ecology. Progress series (Halstenbek) Vol. 462; pp. 1 - 7
• Main Authors: McGinley, Michael P., Aschaffenburg, Matthew D., Pettay, Daniel T., Smith, Robin T., LaJeunesse, Todd C., Warner, Mark E.
• Format: Journal Article
• Language: English
• Published: Inter-Research 21-08-2012
• Subjects: Animal communities; Bleaching; Coral reefs; Corals; FEATURE ARTICLE; Polymerase chain reaction; Population dynamics; Population ecology; Product category rules; Symbionts; Symbiosis
• ISSN: 0171-8630; 1616-1599

A shift in the dominantSymbiodiniumspecies within a coral colony may allow rapid acclimatization to environmental stress, provided that the new symbiont is better suited to prevailing conditions. In this study, theSymbiodiniumdiversity inPocilloporacorals was examined following a cold-water bleaching event in the Gulf of California. Individual colonies were differentially impacted by this event based upon their association with either theSymbiodiniumITS-2 type C1b-c (sensitive) or ITS-2 type D1 (tolerant). Real-time PCR indicated a high prevalence of an alternate and compatibleSymbiodiniumsp. (i.e. C1b-c or D1) residing at low-abundance background levels within many colonies both during and after a 1 yr recovery interval (46 to 52%). However, despite the potential for ‘switching,’ the dominant resident symbiont remained at high abundance during the recovery, with only 2 of 67 colonies (3%) undergoing a change to the otherSymbiodiniumtype.Pocilloporaresiding in the Gulf of California therefore maintain long-term associations dominated by a specificSymbiodiniumsp., where potential competition by a second symbiont type is suppressed despite the temporary change in environmental conditions that would favor a shift in symbiosis toward a more stress-tolerant species.