Some help with identify this freebie please?

[Reef_scuba]

Hi R2R,

Need some help with your expertise! Who's this (not so little) guy? [emoji106]

He looks like a clam.. thumb top size.. has alge growing on him, has been seen on the tank glass and now in with my live rock.

Also! I've had cooper in my tank before.. quiet some time ago now.. could this be a good sign that it's finally gone?!

Thanks everyone!

 

[Mike N]

Bivalve of some kind (scallop?) for sure.
Yes, they are sensitive to copper and nitrate, so its a good sign.

 

[KJ]

A+^^^^^Bivalve

 

[Reef_scuba]

Great!! Thanks guys