Violet Sea Apple Pseudocolochirus violaceus

Looking more like a Christmas decoration than a marine animal, the Violet Sea Apple, also called Violaceous or Clown Sea Cucumber, is native to the ocean floor around reefs in the Indo-Pacific. It is usually roundish like an apple but can be elongated like its cucumber relatives. They can grow to 20cm long. The tentacles, used for filter feeding of plankton, can be retracted into the body.

The name cucumber relates to the shape of most of the family. Sea cucumbers have a very important job: they eat detritus and waste and poop it out clean, cleaning up the world's oceans.

Despite their soft bodies, they aren't defenceless to predators: they have two weapons. One is the ability to almost liquefy their body to squeeze through small places and to harden their body to a stiff, fibrous state. The other is to release a toxin that can kill most fish and other animals in the vicinity.