Shellfish — Mollusks

Mollusks are the strangest creatures humans eat, and among the most delicious. Shell mounds document human consumption 300,000+ years back. The phylum spans 100,000 species — double the number of all vertebrates — from millimeter snails to giant squid. All share three body parts combined in vastly different ways: a muscular foot, a complex organ assembly, and a versatile mantle that secretes shell material.

The Adductor Muscle System

Bivalves (clams, mussels, oysters, scallops) open their shells with a spring-like hinge ligament and close them with adductor muscles. These muscles have two functionally different portions: