What is this?

[Ron Reefman]

OK, I do some collecting in the Florida Keys, some of you may follow me in my Collecting & Snorkeling thread (the link to it is in my signature below).

Anyway, I just got home and in my collection of snails, clams, a serpent star and a sea cucumber I found a couple of these in my holding tank:



I've seen them once before and couldn't ID them. But I tossed them into my tank and when I rebuilt my tank, I found a couple attached to some rock. This time I found 2 more in with my collection when I got home. The left edge seems to attach to a rock, the middle 2/3rds or 3/4ths is hard like shell or bone. The right hand edge is a narrow oval and looks a bit like algae. They are small and they seem to grow. The bigger one in this photo is about 1/4 inch tall and wide, maybe 1/8th on an inch thick.

Any help?

 

[cdemoss01]

@ISpeakForTheSeas may be able to help.

 

[ISpeakForTheSeas]

@ISpeakForTheSeas may be able to help.

My first thought would be some kind of "oyster" like a hammer oyster, but I'm honestly not sure from the pics. Any chance you could get pics of them against a solid background (preferably black or white) and from a variety of angles?

 

[StartingATank]

Not sure, but it faintly looks like an abalone shell from the inside

 

[Ron Reefman]

I'll see what I can do. I have already placed them in a couple of holes in the rocks in my tank. No promises.