Weird Shell Armor Thing On Acanthophyllia

[Kerbash]

Hey,

TLDR: Deadly? Found weird shell thing attached to the skeleton of a bleached Acanthophyllia.

I just picked up an Acanthophyllia a few weeks ago and its been really bleaching bad, I thought it was because of the light but it's weird because I got three of them right next to each other and the other two are super happy. Anyway I was inspecting and on the side of it is this weird clam thing, I pulled it off and I think I might have accidentally killed the clam? Not sure what is it, it did close and respond to light too. around the size of a dime. It was attached to where the snail is now.

 

[LegalReefer]

Not sure exactly what that thing was, it looks like a bivalve of some sort, but it could also be two slipper snails maybe?

 

[ISpeakForTheSeas]

Can’t tell for sure - I’m assuming it was damaged in the process of pulling it off - but it looks like it might be a Windowpane Oyster, known for their translucent shells.

Would be a super cool, harmless hitchhiker if it was, but it most likely would have died after a while in your tank anyway (oysters are notoriously difficult to keep).

 

[Kerbash]

well an update, the clams that I pulled off are still alive, I put both of them in the sump for now and one of them is opening and closing himself again, the smaller one seems to have disappeared.

 

[Steve and his Animals]

Look like a species of oyster, I see them often in bigger, long-established reefs, usually in darker areas of the tank. Harmless filter feeders, and surprisingly hardy.