Is this a peanut worm?

I was re-curing some of my rock that was in my nano that was infested with diatoms and this happened to find its way into my skimmer output trap. At first I thought it was rubble rock until I felt it was soft. I don't know exactly what it is, but I have it in its own container in the water so it can't escape again. Are these tank safe? Yesterday, the little white donut shaped end had a long tube coming out of it, it's retracted it again today. I put a little bit of phyto in the water, it doesn't seem to like it. Thanks.

 

almost looks like the base of a large feather duster?

 

Looks like a peanut worm, and yes they are reef safe and beneficial, they eat detritus.

 

Yes it is a peanut worm! Great for a reef aquarium and yet just another example of the plethora of life within our aquariums benthic areas, some we can see while others remaining cryptic and secretive!

 

Awesome, thanks guys! I'll stick this kid in my 20G tank, unless my fish will attempt to eat it?

 

I have one (that I know of) and the fish have never messed with it. I didn't know it was there until I kept noticing poop like stuff in a gray cylinder form in the morning, always in the same place. So I took a flashlight at night and looked in the area and found it, it will retract quickly from the flashlight though.

The rock it was in has almost been totally taken over by GSP and I've been wondering where it went, this morning I found poop in a new place, I think it moved...

 

Ok, well hopefully my damsels and maroon will leave it alone. I thought about putting it in my fuge, but it may not get anything to eat in there.

 

You would be surprised what you will find or your peanut worm will find for food in the fuge!!!

 

I put it in my fuge afterall. I stuck the peanut in my DT and my maroon went right after it and put it into the anemone's tentacles. I didn't have the heart to leave it there, so I retrieved it with feeding tongs and put it into the fuge. My fuge is only a couple weeks old right now, so nothing is really in it except for crud from the DT.