What is this?

[NanaReefer]

7yrs reefing and don't laugh but this is my very first Acro that has survived longer then a month.
Up until today I've seen zero polyp extension. It wasn't bleaching, STNing or RTNing I decided to keep it.
Well hells bells I've got polyps!!! Yuppers seeing them on the encrusted part.
But I'm also seeing this long white string coming from the very tip top of the coral. What is it and need I worry, clip it off or what.

Sorry for the crappy pic but I'm using a flash light as this only shows up at night.

 

[CoralNerd]

Possibly the corals just slimming out. I'm not 100% sure.

 

[Tahoe61]

Could just be a night time feeding response with the piece showing mesenterial filaments, not uncommon and no worries.

 

[NanaReefer]

Thank you @Tahoe61. Very cool response to Reef Roids I'm thinking [emoji2]

 

[Tahoe61]

Yup exactly. When I add similar products to my tank I see the same response, feeding time.

 

[NanaReefer]

Do they go away? I fed the Roids day before yesterday.

 

[Robink]

Yes they'll go away. Mine do that for a few hours maybe when I feed the tank.
Is it there when the lights come on? Or only at night. If its still there when lights come on maybe get a better pic if its something else.

 

[NanaReefer]

Still there with lights on, not as much though.

 

[Tahoe61]

If the Montipora is in close proximity, the sps could be sending out mesenterial filaments as defensive maneuver. Mesenterial filaments are used both as a digestive mechanism and a defensive mechanism.

 

[NanaReefer]

Yup it's close, 2-3". Dang don't wanna move the Acro. Guess I could cut the Monti back. Any other suggestions?

On a side note the filaments have receded completely now.

 

[Salty1962]

The acro would probably win the battle and the monti may just grow around it. I had a purple monster that was growing through a hole created by the monti during their battle, looked pretty cool.