Blotch

[BKLYN651]

This white blotch appeared on my montipora in last few days! What is it?

 

[F i s h y]

That looks like an area of bleeching. The polyps in that spot have either lost their symbiotic algae or died completely. Could be caused by a number of things, for instance a fish using it as a perch... monitor the coral it may come back in that area or it may continue to decline. If it does decline it may require fragging to save any viable parts.

 

[BKLYN651]

My hawkfish and black sailfin uses this spot a lot. Being used as a perch seems like a cause. I will watch to see if it gets bigger. Thanks