Id for critter

[Amberjade53]

 

[stanleo]

I think it might some species of isopods. I have been reading up on them and that one looks like one of the nasties that are parasitical to fish. I would try to get rid of it.

 

[Crabs McJones]

It almost looks like a Sphaeromatid isopod, but I've never seen one that large before

 

[Lovemyreef2015]

I agree it's in the sphaeromatidae family of isopods.