rolli polli bugs on frag

[sunkool]

I found theese little bug type things on a new frag I got. I can not take a pic because it is so small. They are about a cm long. It looks like a rolli polli bug (pill bug)

The only thing diffrent is that it is light grey
It rolls up into a ball if you take it out of the water.

Any one know what they are?

 

[sunkool]

 

[Opcn]

Rolli polli bugs are isopods, isopods live under water too. your picture isn't very good, so it could also be a chiton, does it have legs or a snail like foot?

 

[sunkool]

it has snail like feet. I tried about 30 pics and could not zoom in any closer.

 

[Opcn]

snail like foot, not feet, thats a chiton, they also have a leathery skirt if you can get a close enough look.