Found this yellow and orange worm! What is it?

[Schulks]

it stretches out to about 3 inches and arrived on gulf live rock.

 

[taytay_1119]

Phyllodoce lamelligrea? I’d take it outta the tank.

 

[ISpeakForTheSeas]

Yeah, definitely a Phyllodocid, probably a Phyllodoce species - they tend to be carrion-feeders, but they may go for worms as well as dying snails, dying clams, or other moribund livestock.

Some Phyllodoce spp. are harmless detritivores (CUC), but others are thought to be carnivorous - typically preying on other worms or snails from what I've seen.

Pages 228-232 of the link below discusses the known feeding habits of various Phyllodocidae species, including a few Phyllodoce spp. - generally, it seems these guys would probably be safe for fish and inverts except for snails and other worms (tube building worms specifically). For the sake of not needing to replace CUC, I'd probably say to pull it as a precaution, especially since you've already seen one interacting with a snail.

Diet of Worms Emended: An Update of Polychaete Feeding Guilds

Diet of Worms Emended: An Update of Polychaete Feeding Guilds

www.academia.edu

 

[Townes_Van_Camp]

Yeah, definitely a Phyllodocid, probably a Phyllodoce species - they tend to be carrion-feeders, but they may go for worms as well as dying snails, dying clams, or other moribund livestock.

That doesn't sound all bad.

 

[ISpeakForTheSeas]

That doesn't sound all bad.

Yeah, they might go for small things like pods and dying things, but otherwise, they should basically just be CUC like regular bristleworms.