plate coral split through mouth?

[hammcd]

this afternoon i noticed my normally healthy plate coral looks as if its mouth is split wider and i can actually see some of the skeleton...i suppose this is the end of the coral?..the tisue around it looks healthy but just a whole and the "lips" of the mouth do not appear joined as usual

what could have caused this

 

[lilrobb]

Pooping

 

[hammcd]

hmm ive seen it poop before..this loks like someone took a scalpel and sliced the mouth about 3 mm wider

 

[jennm]

They don't split... ie break their skeleton.

Not sure what's going on with yours but they don't break themselves in 2.

Jenn