White roots/sand mat

[Dan P]

These have been growing in the back corner behind live rock. I noticed the sand had become a hard mat there a while back and the white things more recently. When I pulled them up to put in front for pics, the white cords pulled up about a 1/4” layer of sand mat with them.

Wasn’t sure where to post. Not really a critter per say.

 

[KJ]

Sponges harmless filter feeder.

 

[Dan P]

Thanks KJ, that’s good then. I have some other sponges as well, I just didn’t recognize these as those.

 

[KJ]

Thanks KJ, that’s good then. I have some other sponges as well, I just didn’t recognize these as those.

YW