Acropora mesenterial filaments

[reefermadness55]

So I've had several corals in the past show their filaments (insides) but I've never seen it on any of my acroporas, this one is my first colony sized piece, and out of about 3 or 4 of the tips they are showing their filaments. IMO its usually from a type of stress, but I'm wondering who else has seen something like this before any other possible causes etc. The colony here also seems to have several very tiny Acro crabs living inside the coral, the colony seems to have grown around them almost and they have like dens with hole where they extend their filter feeding arms occasionally, but I doubt they are the cause, and yes I dip everything

 

[reefermadness55]

These are the pics of the filaments

 

[larcat]

A couple of ours consistently extend theirs when we feed the tank -- One is a millie, Red Planet, and Joe the Coral....

Certainly seen it from stress as well, but can also be feeding response.

 

[reefermadness55]

Thank you for the input! I wasn't sure what to think none of my other acros have done that (far as I've seen)

 

[JBNY]

I've had it occationally show up in different acros. I've never had problems with the coral because or after it. I think I was a little concerned first time I saw it, now I don't even think twice about. So I would say, don't worry about it.