Amber Penshell GALLERYPinna carnea
The Amber Penshell is a bi-valve, which means it has two shell pieces, called valves, that are hinged together with a ligament. At rest, the shell is open, and it takes muscle effort to close. Amber Penshells are a filter feeder, drawing water into it's siphon and filtering it for oxygen and food particles before expelling it out through a second siphon. They inhabit every type of environment, from rocky area, to soft sand. Their shells can be quite thick and stiff, (probably as they mature) or thin and translucent. I'm going to guess that the "feeler fingers" on the opening edges of the shells are to sense intruders, and trigger the closing of the shell.