Need an ID on this hitchhiker

[FrostyNYC]

I just got a new piece of live rock with shrooms on and and I found THIS:

I searched the rock over and over, found one apistasia (killed it) and a lot of worms, a few pods, and I missed THAT huge thing. It was only at the last second that I saw it. It's green and black, and about 3/4 of an inch long. Its very very flat and looks to have a segmented carapace. It's moved a tiny bit in the last half hour or so. Any ideas on what this thing could be?

 

[FrostyNYC]

Think I got it... is it a chiton?

Websites say they can leave rasp-marks on acrylic tanks. Should I worry?

 

[pagojoe]

Yep, it's a chiton. I wouldn't worry about it.

Cheers,



Don