Mesenterial filaments?

[hafer12]

?

 

[ChiCity]

Hard to tell from the pic because it’s captured in motion...
But I don’t think it is.
If they’re throwing mf, you’ll notice a little slime in the area too.
And I’m just not seeing that...

 

[hafer12]

 

[Kalyndrid]

This is from a bleached Coral. I was worried until I read the following article:
https://reefs.com/2011/07/23/when-corals-spill-their-guts/