Giant Clams in the Whitsundays

As the Giant Clam takes such a long time to grow and have been harvested in the past to the point their numbers along the Great Barrier Reef have been dangerously reduced, Giant Clams are now fully protected in Australian waters. They usually begin life wedged in to small cracks and gaps in the reefs and rocks surounding the Whitsunday Islands and the Outer Reefs of the Great Barrier Reef. The cracks and gaps provide protection for the clam from predators as all the clam need to do is close (and they can do this quite quickly) and they are protected from all sides. As the Giant Clam grows bigger, it slowly enlarges the crack or gap much like the roots of a tree can open the cracks in concrete or a brick wall. 

Giant Clams come in a huge variety of colours. The shell itself is usually a dull brown colour that you might find bleached white when washed up along the beaches in the Whitsundays. The animal inside (A bivalve mollusc) has a coloured mantle which will vary from vivid geens, blues to purples and blacks. Often with all manner of other colours making up a kaleidoscope much like a crazed but beatiful art work. Along the mantle or 'lips' the Giant Clam has hundreds of tiny 'eyes'. Although the Clam cannot see details like we can, it can sense changes in light such as when a predator is nearby and casts a shadow over the Giant Clam. You can test this by waving your hand a couple of inches above an open clam and it will instantly close. The clam will usually re-open a few seconds later. Suprisingly a Giant Clam on the Great Barrier Reef can grow to weigh more than 200 kilograms, and reach a size well over 2 meters across. The Giant Clam can also live well over 100 years.

History

It has been part of popular mythology since man first entered the water, that the Giant Clam was dangerous and capable of snapping shut on a divers leg or arm drowning them and even feeding on them. Today, we know this is highly unlikely and infact the Giant Clam feeds from the Zooxanthellaethe which live on the mantle.

See also: Marine Life Whitsundays | Whitsunday Whales | Whitsunday Manta Rays | Giant Clams | Whitsundays Maori Wrasse | Whitsunday Turtles | Whitsunday Clown Fish | Coral Trout | Yellow Tail Fusilier | Whitsunday Giant Trevally | White Tip Reef Sharks | Whitsundays Batfish |