I've got two pieces of very porous live rock. Every now and then I will see a "poof" of what looks like fine sand, grey in color, come out of some of the small holes in the rock. As this "sand" accumulates either on the rock or the crushed coral substrate, a creature with very long, translucent tentacles kind of scoops the sand up with it's tentacles and brings it towards it's "mouth". I've never been able to actually see it's mouth though.
Two questions. 1. What is shooting out this fine sand from the holes in the LR and 2. what is the creature with long tentacles eating this stuff?
Two questions. 1. What is shooting out this fine sand from the holes in the LR and 2. what is the creature with long tentacles eating this stuff?