Some kind of bivalve?

[legrunt]

Anyone have any idea what these are underneath my wall hammers? At first, I thought it was the skeleton eroding, but then I saw it move, and realised it must be some sort of bivalve. I poked it, and sure enough, it closed up.

 

[vetteguy53081]

The angle of pic makes it hard to tell but a possibility

 

[legrunt]

The one circled in red is still slightly open, but there are more behind it, circled in green. They closed up after being poked.

 

[legrunt]

Here's another shot of them opened up.

 

[legrunt]

Anyone got any clue?

 

[legrunt]

#reefsquad ?

 

[vetteguy53081]

Appears to be. They are a member of scallop grouping resembling a scallop or mussel than a clam

 

[legrunt]

Harmful?