What are these spots on my monti?

[keithschon]

Trying to figure out if I should be worried about my encrusting montipora. Overall looks very healthy--consistent growth, good color, good polyp extension. But it has a bunch of white dots on it. I wasn't too worried until I saw the larger white patch by one margin with filaments trailing off it. Anybody know what causes this? Is this damage from a pest organism? It's an encrusting coral on a large rock, so it would be super inconvenient to dip.

They look blue-grey in the photo, but they are actually bright white.

 

[H2OPlayar]

It looks like something is stinging it. Do you have a chalice or something else with sweeper tentacles nearby?

 

[Kremis]

monti nudis ?

 

[keithschon]

@H2OPlayar : Nope, nothing with sweepers is anywhere near it.

@Kremis : Never dealt with those before. I'll have to research them. Is there a quick way to tell if I have them?

 

[BAYMAC]

Setosa are finicky. Mine had spots that died at times. I wonder if its that?

 

[Kremis]

@H2OPlayar : Nope, nothing with sweepers is anywhere near it.

@Kremis : Never dealt with those before. I'll have to research them. Is there a quick way to tell if I have them?

Look under/around the edges for these, they are very small. Or give it a dip and see if any fall off

 

[MolaMola]

They are mostly nocturnal, so check at night or early AM

 

[keithschon]

@BAYMAC : Not actually a setosa. Completely encrusting. The "fingers" on the top are the shape of the frag I bought it on, some kind of rock cut into a square. But I'm hoping that it's close to what you say, a non-infectious issue.

 

[keithschon]

Update: have failed to find any nudibranchs. Patches are getting better. My best guess is that it got physically scraped or stung somehow, but the damage is not ongoing.

 

[MolaMola]

I was just now looking for this thread to ask how it was going! So glad to hear it is not nudis.