Giant clam

Tridacna gigas · The giant clam is the largest living bivalve mollusc, found on shallow coral reefs of the South Pacific and Indian oceans.

Giant clam
Photo: Nhobgood Nick Hobgood, CC BY-SA 3.0
Giant clam
Photo: Togabi, CC BY-SA 4.0
Giant clam
Photo: Charles J. Sharp, CC BY-SA 4.0

Taxonomy

KingdomAnimalia
PhylumMollusca
ClassBivalvia
OrderCardiida
FamilyCardiidae
GenusTridacna
SpeciesTridacna gigas

Where it lives

Shallow coral reefs of the tropical western Pacific and eastern Indian Ocean.

Fun facts

  • Giant clams can weigh more than 200 kilograms and live for more than 100 years in the wild.
  • Giant clams farm algae in their own bodies, getting most of their food from the sunlight-loving algae living in their mantle.
  • A giant clam's mantle edge is covered with hundreds to thousands of tiny pinhole eyespots.
  • Giant clams can sense light changes and moving objects, and may even see UV light, which could be unique among molluscs.

Play it

The Giant clam was the creature in a regional daily on October 25, 2026. Can you identify tomorrow's from its photos? Every day brings a new creature to place from kingdom to genus, map and name.

Play today's creature or replay a past daily

Facts and taxonomy adapted from Wikipedia (CC BY-SA 4.0).