Sea cucumbers are another type of echinoderm, related to starfish, that you will find these on the seafloor in the Whitsundays and Great Barrier Reef. They are a funny sight and resemble a cucumber or slug-like creature that does little moving. They are extremely common in the Whitsunday Islands and you are always likely to see one on the seabed during a dive or snorkel. They are scavengers of the sea and feed on debris which settle on the seafloor, working like a vacuum, sucking it’s food into its body and expelling sand out the other side, keeping any food that comes in along the way.. Sea cucumbers breathe by drawing water in and expelling it through their respiratory glands, absorbing any oxygen they draw in.. Through the same type of motion, they collect debris and decaying matter from the sea floor, which is where they get their sustenance.
There are over 200 types of sea cucumbers that live in Australian waters, with some of the most interesting species found on the Great Barrier Reef. They come in a variety of shapes and sizes, but are mostly are known for their peculiar defense mechanism, where they out a squirt a sticky white substance that will tangle and trap any predators. Some species can actually alter their bodies as a defence mechanism, shooting some of their internal organs out of their bodies, so predators will eat that instead of them. They will quickly regrow any missing organs, as they are able to regenerate missing body parts, the same as a sea star.
While sea cucumbers are an interesting creature, it’s important to leave them alone, refraining from handling them. This can cause them unnecessary stress, which may interrupt their life cycle. Like all creatures on the reef, they are best viewed from a distance and left to mind their own business of cleaning up the sea floor.