Also known as Calcareous Sponge, Coral Killing Sponge, Encrusting Sponge, Marine Sponge, Purple Coral-eating Sponge, Siliceous Sponge.
Found on coral and rocky reefs where it spreads over living corals dissolving the tissue of the coral and takes over their living space.
Colour purple to magenta with fine white lines.
They feed on corals.
Length - as large as the corals
Sponges come in a range of sizes from minuscule encrusting species under rocks to massive sponges which can be up to one and half metres high.
They are able to filter many litres of sea water every few seconds.
Sponges can exude highly toxic chemicals and so have very few predators apart from nudibranchs, sea stars, sea urchins and umbrella shell.
Their colour can vary if growing in the light or when growing in the shade. (edit) Ref: x