Sponges are colonial animals that grow attached to rocks or living things. They obtain their food by pumping water through their bodies and filtering out the particles of plankton and detritus from the water. Sponges are very efficient and pump up to five times there own volume through their bodies each minute.
Many sponges are brightly coloured and their presence on reefs, particularly deep reefs and beneath ledges, gives a lot of Victoria's underwater environments their spectacular colour.