As part of the Catlin Seaview survey, Professor Ove Hoegh-Guldberg explain from underwater what a Tridacna gigas, better known as giant clam, is up close.

The giant clam is native to the coral reefs and can be found in the flats of coral sand, growing up to 1m or more in length. To be able to grow that big the Clam has adopted techniques to absorb nutrients from their surroundings: filter feeding and symbiotic feeding. These have enabled the giant clam to become one of the more impressive creatures found in the reef.