portrait

Description :

A living spumellarian radiolarian (Spongaster sp.) that secretes a quadrangular, siliceous, spongiose shell enclosing the central capsule. The greenish tint is caused by numerous algal symbionts enclosed by the peripheral cytoplasm. A halo of cytoplasmic strands (axopodia) radiates from the surface. The axopodia are used to capture food, usually small crustacea (e.g. copepods) or algae.