By Sandhya Sekar
Species: The collector sea urchin (Tripneustes gratilla) – also called the cake or Parson’s hat sea urchin
Habitat: Coral reefs, seagrass meadows and algae forests in the tropical seas of the Indo-Pacific
The collector sea urchin looks like a pretty pincushion lying on the ocean floor, going about its business of munching on algae and seaweed.
But when threatened, this sedate pincushion has a most extraordinary defence. It releases a cloud of semiautonomous weapons: hundreds of tiny jaws that are still capable of biting and releasing venom even when separated from the sea urchin’s body.
Sea urchins have a hard, chalky shell covered in long spikes. Nestled among the spikes are tubular stalks topped with biting jaws known as pedicellariae. One type of these appendages even has venom as well.
Continue reading by clicking the name of the source below.