What Type of Worm Is This?

[tmRoth]

I bought a frag with a single mushroom on it today, and after a dip and a rinse this guy came crawling out from under the mushroom as soon as I put it in the tank. (I failed to lift up the mushroom and rinse between it and the frag disk.) It crawled back into hiding as I retrieved the frag, but I did some more intense cleaning under the mushroom and was able to force it out. I can't match it up with any photos here or in a Google search and was wondering if anyone recognizes it? It's an inch long when it stretches out.

 

[JoJosReef]

I bought a frag with a single mushroom on it today, and after a dip and a rinse this guy came crawling out from under the mushroom as soon as I put it in the tank. (I failed to lift up the mushroom and rinse between it and the frag disk.) It crawled back into hiding as I retrieved the frag, but I did some more intense cleaning under the mushroom and was able to force it out. I can't match it up with any photos here or in a Google search and was wondering if anyone recognizes it? It's an inch long when it stretches out.

View attachment 3044847

Not sure, but I have a few of these in my two tanks and I've never seen them eating anything but picking on the live rock, except one that just went for it and grabbed a small piece of nori I was trying to feed to a turbo. It couldn't take the whole thing but managed to pull some of it into its hole. I think they are detritivores and not bad guys.

 

[tmRoth]

Not sure, but I have a few of these in my two tanks and I've never seen them eating anything but picking on the live rock, except one that just went for it and grabbed a small piece of nori I was trying to feed to a turbo. It couldn't take the whole thing but managed to pull some of it into its hole. I think they are detritivores and not bad guys.

Thanks for the info - that's good to know in case there's another one that I missed.

 

[Soren]

@tmRoth
It kind of looks like a dorvilleidae worm to me, but hard to get a conclusive ID without more close-up pictures, especially of the head.
If it is a dorvilleidae worm, they are typically considered harmless/beneficial clean-up crew.

There are some types of worms that burrow into corals, but I'm not familiar with that ID.

 

[tmRoth]

@tmRoth
It kind of looks like a dorvilleidae worm to me, but hard to get a conclusive ID without more close-up pictures, especially of the head.
If it is a dorvilleidae worm, they are typically considered harmless/beneficial clean-up crew.

There are some types of worms that burrow into corals, but I'm not familiar with that ID.

All the dorvilleidae have "legs" in the photos I see, but mine seems to be smooth-sided. Although this one is so small, the legs may just not be noticeable. Thanks.

 

[Soren]

All the dorvilleidae have "legs" in the photos I see, but mine seems to be smooth-sided. Although this one is so small, the legs may just not be noticeable. Thanks.

I could not tell in your photo for sure, but dorvilleidae do have legs. The head on yours also does not look enough like a dorvilleidae to confirm ID.

 

[JoJosReef]

It's not a dorvillidae, I'm pretty sure of that. I've had both this and Dorvillidae in my tanks and the Dorvillidae have characteristic 4-prong antennas and legs. This one has a smooth white/tan head and smooth(er) body like an earthworm. I've seen these called peanut worms in R2R often, but doesn't exactly track with Sipunculans (https://ucmp.berkeley.edu/sipuncula/sipuncula.html) as these seem somewhat segmented like annelids, and I haven't seen the same type of head on these as the pics of peanut worms (http://www.reefkeeping.com/issues/2004-04/rs/index.php). So I'm imagining that these are some type of community mischaracterized annelid/detritus worms. My thoughts!