Is this a clam?

[Tesk]

I've had this frogspawn for few weeks arrived pretty beat up with 2 dead heads, black sponge on it as well, I did get some money back

Just noticed the side of it open and close a little.

What is that?!

 

[Sharkbait19]

No pics attached

 

[vetteguy53081]

I've had this frogspawn for few weeks arrived pretty beat up with 2 dead heads, black sponge on it as well, I did get some money back

Just noticed the side of it open and close a little.

What is that?!

Will be hard to assess without a picture under white lighting.
If you are seeing as below, often regarded As a clam is a Bi-valve which is related to scallops and is a filter feeder

 

[Tesk]

 

[vetteguy53081]

Yep - Bi-Valve. Enjoy it as it does not live long in aquarium

 

[Sharkbait19]

Agreed it’s a bivalve - I had one come in on one of my frogspawns as well. Nice while it lasted and didn’t harm the coral.