Maybe If I just try to actually buy one and put in my tank... I'm talking more about random clams that attach to the rock with beadlet anemones
Yes they have a curved purple black shell and attached to rock by short hairs called its beard. They don’t last very long in our tanks even feeding them live plankton ever day in the natural environment they are high and dry for several hours due to the tide going in and out so maybe they need a certain amount of time out of water. One filter feeder that is fine under water constantly is oysters they also are brilliant for filtering water you need to feed them live plankton to keep them alive. The only thing with shellfish is when they die they die quick and can pollute your tank so you need to keep an eye on them
