Giant Clam

Giant clam (Derek Keats / CC BY)

The giant clam is the world’s largest extant bivalve mollusk, reaching 120 centimeters (47 inches) across. It has an average lifespan of about one hundred years. Giant clams are filter feeders. Their diet consists of plankton. Symbiotic algae provide them with supplementary nutrients. The giant clam is not considered dangerous to humans.

Inhabits the Indo-Pacific Ocean.

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This supplemental online resource accompanies the book Scuba Diving Hand Signals by Lars Behnke, available on Amazon.