Astrosclera willeyana is a sponge of the tropically warm seas, it does not form any, up to 2.5cm large bodies.
Sponges produce more body cells than they need for their own growth and release these excess cells into the sea or into the aquarium.
Other marine animals then feed on these cells.
Sponges are also interesting for scientists. From this sponge, substances can be extracted for medical purposes.
Astrosclera willeyana somehow uses its endobiotic bacterial community to form its highly calcified skeleton.
The host sponge actively degrades part of its bacterial community via an autophagy pathway and the prokaryotic organic remains are used as scaffolding on which the calcification of the sponge skeleton is initiated.