Slug / worm like gulf hitchhiker

[Nick711]

Thought this guy was dead at the bottom of my live rock box, but when I put it in the holding container and it spread out and moved around a bit. About an inch long. When touched, it curls up into a tight ball. Hard to get a good picture, but reddish in color. See pics attached. You can see him near the heater. Any help is appreciated!

 

[Saltyreef]

Looks like an isopod

 

[ISpeakForTheSeas]

Yeah, with rolling into a ball that basically narrows it to either an isopod (the harmless kind) or a chiton (almost all of which are also harmless).

If it has legs, it's an isopod; if it has a snail-like foot, it's a chiton.

 

[Nick711]

Looks like an isopod

thanks for the quick reply!
didn’t know if it could’ve been a chiton and hard to get a close enough look to see if it has “legs”, which I guess could confirm an isopod.

 

[Saltyreef]

thanks for the quick reply!
didn’t know if it could’ve been a chiton and hard to get a close enough look to see if it has “legs”, which I guess could confirm an isopod.

It actually does look like a chiton vs isopod

 

[Nick711]

I finally have a better picture of the underside, and believe it to be a Chiton given the snail-like underside

 

[ISpeakForTheSeas]

I finally have a better picture of the underside, and believe it to be a Chiton given the snail-like underside

Looks like one to me - should be a harmless algae-eater.