Any idea why this micromussa is closed up?

[dochou]

I've had it for about a year and it started off with 2 or 3 heads and now it has 20 or so.
In the past couple days, it's been closed up, while my 4 other micromussa's have been doing just fine. They're puffed up like usual. I feed them 2x per week and they all eat except the closed up one.
Water parameters are stable and as follows:
PH: 7.9
Alk: 9.5
Cal: 480
Mg: 1380
Phos: 0
Nitrate:0.2
NO new inhabitants except a sps frag that was dipped and thoroughly inspected before placing in the tank.

 

[dochou]

You can see the one next to it, on the right is fine.

 

[NewbieReefer11]

I'm no expert but may I ask what fish and or inverts there are in the tank?

 

[dochou]

Another one doing fine:

 

[dochou]

I'm no expert but may I ask what fish and or inverts there are in the tank?

Yellow tang. Blue tang. Tail spot blenny. 2 ocillaris clowns. And a cleaner shrimp and about 12 hernit crabs. They've all been there for over 2 years.

 

[Coralreefer1]

I see you have a hermit near by, it may be the culprit climbing on it causing it to close. How long has it been closed up?

 

[DSC reef]

I'd keep an eye on the hermits and cleaner shrimp. The coral itself looks healthy with no signs of recession. Sometimes when feeding hermits and shrimp can bother the coral by taking the food.

 

[dochou]

I agree, it looks closed due to hermits and shrimp climbing on it. When that happens the coral opens back up 5 minutes later.
In this case, the coral hasn't opened up for n5 days.

 

[dochou]

Anyone else?

 

[dochou]

Still no change from my micromusa.

 

[dochou]

Well, now it's back to normal. I have no idea why.

 

[Brad Miller]

Must have been an invert pestering it then

 

[DSC reef]

They can deflate time to time as well