Mussel Facts



  • Cockles and mussels belong to a group of molluscs called bivalves, which includes oysters, clams, scallops and razor shells.
  • Bivalve means having two valves and all these creatures have two halves to their shells, joined by a hinge that opens rather like that of a locket.
  • Most bivalves feed by filtering food from the water through a tube called a siphon.
  • Cockles burrow in sand and mud on the seashore. Mussels cling to rocks and breakwaters between the high and low tide marks. 288 Sea creatures
  • Oysters and some other molluscs line their shells with a hard, shiny, silvery white substance called nacre.
  • When a lump of grit gets into an oyster shell, it is gradually covered in a ball of nacre, making a pearl.
  • The best pearls come from the Pinctada pearl oysters that live in the Pacific Ocean. The world’s biggest pearl was 12 cm across and weighed 6.4 kg. It came from a giant clam.
  • Scallops can swim away from danger by opening and shutting their shells rapidly to pump out water. But most bivalves escape danger by shutting themselves up inside their shells.
  • A giant clam found on the Great Barrier Reef was over 1 m across and weighed more than 0.25 tons.
  • There are colonies of giant clams living many thousands of meters down under the oceans, near hot volcanic vents.
  • The swan mussel is a bivalve — a mollusc type of shellfish similar to clams and oysters on the seashore. It lives in lakes and slow, deep rivers. It draws a current of water into its shell, both for breathing and to filter out tiny particles of food.