Can anyone identify this? what is it?

[marcus_the_clownfish]

i came home rigt now and noticed that my brain coral had fallen, when i went to pick it up with the net, i noticed that there was something under a rock. i managed to get a hold of it and put it in my little breeder tank. at first it was short and stubby like a fat worm, then after a while is started to stretch out and get thin. please someone tell what this guy is?

[Richard]

Looks like a peanut worm.

[marcus_the_clownfish]

what do they do? do i have to be worried? do i let him go or toss him out?

[Richard]

They are good guys, detrivores.

[merlin0883]

Yes, I would say it's a peanut worm too. The stripes close to the anterior end somewhat resemble those from khuli loaches. I have several that came in my live rock. They hate light.

[FireWater]

Looks similar to one that I have had in my nano for months. Comes out at night and looks like he is scraping the live rock. Has not seemed to harm anything yet- does knock alot of stuff around though. I was told peanut worm, but when I looked it up it did not match mine in coloration.