Molluschi is the Italian term for mollusks, including octopus, Squid and shellfish, such as clams and mussels. They are invertebrate animal with a soft body and a hard shell,

although some mollusc do not bear shells It is also known as mollusco or crostaceo

bivalve
n. mollusk with two shells that are hinged together in the middle.gastropod
n. member of the mollusk family (i.e. snails, slugs, etc.)

cephalopod
n. any mollusk from the class Cephalopoda, any mollusk with tentacles that directly attach to its head (such as the octopus and cuttlefish)