That is indeed my friends Clam in her 240G Reef. It was my teenager that posted that pic. She asked my what type of clam it is and we can not be sure. Even when I held it in my hands and had several experienced reefers around nobody was sure. Some speculate it's a hybrid.

Anyway, I said she could post it and see if anyone could ID it for sure. It's the huge one in the pic.