30 Nov 2018

The giant clam is the largest living bivalve mollusc. Sometimes so big, weighing over 200kg! They can also live longer than the average human, at around 100 years in the wild. These bottom feeding behemoths will find their home on the reef and remain there for their entire life.

The giant clam spends its days feeding on passing plankton, which it syphons from the water  it draws through its large opening. It also feeds on the sugars and proteins produced by the billions of algae that live within its tissues, they are pretty fair creatures and offer the algae a safe home and regular access to sunlight in exchange. The stunning colours on this incredible creature vary and its impossible to distinguish particular species from this trait. Most of the physical beauty of the clam is actually due to the algae within the clam, as the clam's pigmentation figures in stark contrast to the algae's.

The bright coloured circles on the clam's flesh are called iridophores, which direct sunlight onto its mantle, if the clam isn't getting enough light, it extends its mantle out of its shell and reduces the colour pigmentation to offer it more. Every clam starts out a male before becoming a hermaphrodite (producing eggs and sperm) which allows them to reproduces with any member of thier species. The largest clam can release up to 500 million eggs at a time! Don't believe the myths, clams cannot trap a passing snorkeller or diver!