Once fertilised, the eggs of the giant clam float around in the water for around 12 hours when the larvae hatches out. The giant clam larvae than begins to produce a shell and with just a few days, is big enough to find somewhere to settle on the sea floor.
Once a giant clam has found somewhere in the reef that it likes, it anchors itself onto the reef where it remains for the rest of its life. Giant clams are so successful within their environment that it is not uncommon for these giant molluscs to live for more than 100 years!