Just as crabs, seashells are considered as delicacy by both humans and many marine species.
Unfortunately, their flesh is soft and tender and hold very weakly when used as bait. Salted shellfish meat is much tougher and can be used as bait for many fish species.
The Great Mediterranean Scallop is an edible saltwater clam in the family Pectinidae. It is endemic to the Mediterranean Sea and very similar to The Great Scallop (Pecten Maximus), which has much larger distribution.
Blue Mussel - Mytilus Edulis - is also known as common mussel. There are several, very similar, subspecies which can hybridise with each other, if present at the same location.