Enjoyed all over Italy. In pasta and risottos, in antipasti and soups, and also eaten raw—they're suppposed to be an aphrodisiac. In Campania, they are often served impepeta. Pugliesi stew them with tomatos, or put them in a tiella with rice and potatoes. This region is known for cozze pelata, 'hairy' mussels so-called from the filaments that attach to their shells.
The biggest Mediterranean mussel, called pinna, cozze pinna, or nacchera is rare and now strictly protected.
Mussels are best according to the Oyster Rule, only backwards—they taste better in months without an 'r', May-August, when they're not busy reproducing.
In Venice they are often called peòci.