[Coral-List] Survival of corals without zooxanthellae

[James Reimer]

Here is a recent paper dealing with aposymbiotic coral colonies in a species that is usually zooxanthellate:

Grant AJ, Starke-Peterkovic T, Withers KJ, Hinde R.

Aposymbiotic Plesiastrea versipora continues to produce cell-signalling molecules that regulate the carbon metabolism of symbiotic algae.
Comp Biochem Physiol A Mol Integr Physiol. 2004 Jun;138(2):253-9. 
PMID: 15275660 [PubMed - in process]

As well, I have unpublished data showing Zoanthus spp. living in the dark (no light at all) with clade C Symbidionium (but obviously they aren't doing much) for over 2 months with no problems besides a slight decrease in ZX concentrations - and the colonies all made a full recovery when returned to normal light levels (with normal water temp., salinity, etc.) 

Taken together with other data people have posted, it would seem to me that (species dependant again) some species can live/survive  (and grow in P. versipora's case) without light or photosynthesizing ZX. The next question would be how much competitiveness is lost (if lost) under such conditions...

James D. Reimer
JSPS Research Fellow
Extremobiosphere Research Center
Research Program for Marine Biology & Ecology
Japan Agency for Marine-Earth Science & Technology (JAMSTEC)
Natsushima 2-15
Yokosuka, Kanagawa
JAPAN 237-0061
jreimer at jamstec.go.jp