Critter Identification

[jmeunier]

I'm setting up a new 150G. It's currently cycling with about 150lbs of Fiji live rock. My ammonia levels are off the chart right now---but, I appear to have some sort of critter thriving in this environment.

It's about 1.5 inches long, gray, with some black stripes. Has a sucker-like mouth, and is clinging on to a piece of the rock. Any ideas what this is? I thought the ammonia levels would kill everything off?

I'm mainly wondering because I don't know if I should be concerned about it---if it's going to be prolific and/or harmful to the tank in the long-term.

Thanks!

 

[melosu58]

Moved to ID forum

 

[Devilishturtles]

Any chance you can get a picture?

 

[jmeunier]

Picture

Here's the best pic I can get of it through the glass.

 

[MT79]

It's a peanut worm. They're beneficial scavengers, and are good to have.

 

[roka64]

I agree, I just found one of those after over a year, in my tank. You will be surprised what critters will survive a cycle.

 

[Ziggy953]

That's a great shot of it too!! Usually they vanish when any light hits them!