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Unread 01/03/2002, 11:14 AM   #21
rshimek
Moved On
 
Join Date: Oct 1999
Posts: 24,538
Quote:
Originally posted by GSB
Hi,

Could you direct us to the studies that have shown that 300-400 species cannot survive temperatures below this? In fact, can you show us any sps study that has demonstrated that a single coral cannot survive in 78 degree water?

First define what an sps coral is. This simply can't be done, as this is not a term that can be used.

Numerous corals in nature will not be found in where the temperature dips that low. Go to books that show maps of where coral species occur.

Then look at the lowest temperatures found at the edges of their ranges. They do not grow below that temperature. You will find that for a great many of them, they never see temperatures below 78. However, most can survive poorly at those temperatures.

You will find references to low thermal tolerances and corals here:
http://www.rshimek.com/reef/tempsal.htm

[b]Regarding your comment about bacteria, in one study corals infected with Vibrio survived in cooler water but succumbed in warmer water, so there is some evidence that corals can handle infection better in cooler water (perhaps because of slower bacteria growth).[b]

Just the opposite, actually...

You need to actually read these studies I suspect. The coral in question is Oculina patagonica. This coral is a Red Sea species invading the Mediterranean sea (a cold sea without much coral) in the region of the Israeli coast. In this area, it gets infected with Vibrio shiloi a species which does indeed cause temperature dependent bleaching in this coral, in this particular non-normal habitat; which tends to kill the coral. This particular habitat is signficantly cooler than where the coral is normally found, and this method of mortality is, in fact, a good example of how low temperatures limit coral distribution. In this case, the coral seems to adapt to the low temperatues, but when slight, but normal for the area, elevations then do occur, a pathogen which doesn't harm the coral in its normal habitat can kill it in the cooler one.

Here are couple of recent references on this interaction. You can back track to some others through them:

Kushmaro, A., E. Banin, Y. Loya, E. Stackebrandt and E. Rosenberg. 2001. Vibrio shiloi sp. nov., the causative agent of bleaching of the coral Oculina patagonica. International Journal of Systematic and Evolutionary Microbiology. 51:1383-1388.

Banin, E., T. Israely, M. Fine, Y. Loya and E. Rosenberg. 2001. Role of endosymbiotic zooxanthellae and coral mucus in the adhesion of the coral-bleaching pathogen Vibrio shiloi to its host. Fems (Federation of European Microbiological Societies) Microbiology Letters. 199:33-37.




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