Please help ID

[epidemicsparc]

This tank is about 3 months old 55 gallon. I was hunting around with a flashlight and found this arm like body piece. It was light sensitive as when I get near where I believe the body was, the arm was drawn back inside, but light directly on it did not seem to bother the arm. I have 4 Clowns, 1 Goby, 2 serpent stars and some corals along with carious cleanup crew. Tried to get a better picture with a better camera, but it went in to hiding. It hangs out underneath the rock where my Goby is if that helps any. Just want to make sure it's not something I need to get out of my tank.

 

[SparseReef]

It's a bristleworm. They're great worms to keep since they only eat detritus and decaying matter. They'll reproduce in your tank to a population level that can survive on any excess matter in your tank. Lots of people go crazy when they seem them because they think they'll kill everything they encounter, but these ones are completely harmless. There are bristleworms that are predatory, but the black/brown and pink ones aren't those. As an example, I have two living under one of my rocks that are at least 14" long and I've seen peppermint shrimp (~1") steal food from them with no repercussioins. I personally like to feed them pellets when I see them, but that's mostly because I want to try to grow a freakishly huge one. Also, if you get a red led flashlight, you'll probably be able to watch them at night without scaring them.

Hope that helps. Enjoy them, just like all the other cool stuff that grows out of the live rock.

 

[AfricaOffroad]

What do the predatory worms look like?