Clam, Mussell, or ?

[rick s]

Hello Everyone,

Something has attached (or is growing from) my clam. It looks like a clam, has a mantle, and retracts when something passes between it and the light.

So far, my (big) clam seems unaffected by it.
Do you think it is a clam, a mussell, or something else?
Leave it alone or pull it off?
If it is not a clam, toss it?

Thanks for the ID and info.

 

[Charlie Davidson]

It dosen't seem to be hurting anything... lets see it grow
I hope someone here can ID..

 

[Charlie Davidson]

ttt