Maxima clam hitchhiker or baby clam ?

[Taralynn23]

Have searched and searched to try to identify what the circled image is. At first I thought it was just apart of the maxima clam but noticed one of them had moved. The first picture is two weeks ago and the second I took to write this post.

Is it a hitchhiker i need to worry about or a baby clam ?

Any help would be great its driving me bonkers !!

 

[Kapachuka3]

I think its just a tiny clam or some type of bivalve. Its most likely a good thing ive got like ten of em and all they do is filter water.