Worm ID. Friend or Foe

[WaterWerks]

Some type of worm. Looks to have borrowed into the live rock. Haven’t seen the mouth/face yet. Seems to be just cleaning the rock scape.
Video prob won’t post. It’s about mid way up in the photo. Drags its mouth against the rocks.

 

[NonstopSoda]

Looks like vermentid worm, a foe. Grows like crazy and can grow on corals with skeletons

 

[Sumbub]

It could be a peanut worm. You rarely see the body unless you break the rock.

 

[WaterWerks]

Looks like vermentid worm, a foe. Grows like crazy and can grow on corals with skeletons

Doesn’t seem to have a shell or tube. It runs in and out of its burrow

 

[WaterWerks]

Really extending out in this picture with light almost fully off

 

[IKD]

Great photo. No idea about worms.

@ISpeakForTheSeas

 

[BristleWormHater]

Sit back and wait for @ISpeakForTheSeas to get here

 

[ISpeakForTheSeas]

Yeah that's either a peanut worm (sipunculan) or a ribbon worm (nemertean) - if it's a ribbon worm, it'll have a pretty crazy looking proboscis it sticks out to hunt with (the proboscis and worm would be toxic); if it's a peanut worm it'll basically look like it has a little mop or just a small ring of tentacles around the mouth to feed with.

Ribbon worms can be harmful to a tank (and you shouldn't touch them with bare skin); peanut worms are harmless/beneficial.

In this case, I'm inclined to think peanut worm, but I can't say for sure.

 

[WaterWerks]

Great photo. No idea about worms.

@ISpeakForTheSeas

Yeah that's either a peanut worm (sipunculan) or a ribbon worm (nemertean) - if it's a ribbon worm, it'll have a pretty crazy looking proboscis it sticks out to hunt with (the proboscis and worm would be toxic); if it's a peanut worm it'll basically look like it has a little mop or just a small ring of tentacles around the mouth to feed with.

Ribbon worms can be harmful to a tank (and you shouldn't touch them with bare skin); peanut worms are harmless/beneficial.

In this case, I'm inclined to think peanut worm, but I can't say for sure.

Watching it scrape the rocks. I didn’t see any tentacles reaching out. More like opening its mouth and then scraping it closed on the red rocks.

 

[ISpeakForTheSeas]

Watching it scrape the rocks. I didn’t see any tentacles reaching out. More like opening its mouth and then scraping it closed on the red rocks.

Yeah, that's most likely a peanut worm of some kind then.