Also known as Finger Sponge, Marine Sponge, Siliceous Sponge.
Found on walls with good current flow. Thick and lobe encrusted.
They feed on plankton.
Varies in colour from shades of yellow to orange.
Length - 20cm
Depth - 20-30m
This sponge is attached by a stalk to the reef and grows as a number of lopes, however in sheltered deeper waters the sponge can be fan or goblet shaped.
The apertures are transparent tubes distributed over the surface of the sponge.
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