Description

 The growth form of Suberites carnosus is variable. Although typically spheroid and anchored to the substratum by a short stalk, rather like a fig, it may also be encrusting or massive (growth vertical and lateral but unequal) and lobed, up to 15 cm in height. It is yellow to brown in colour. In the fig-shaped form, there is usually a single, apical osculum (a large surface pore, through which water leaves the body cavity), in massive lobed forms there may be several oscules but usually all on the uppermost surface. Surface is smooth and even. Contraction of the sponge is substantial when disturbed, with a corresponding change in consistency from soft to firm.Skeleton
For examination, magnifications of x 100 to x 1000 are required. The skeleton consists of spicules, tylostyles, of two distinct sizes. The largest constitute the main structural megascleres, whereas the smaller are perpendicularly arranged plumose brushes at the surface. The structure is subradiate, the radial arrangement of the spicules being most apparent near the surface. Internally the skeleton is confused and almost 'halichondriod' (like that of the Family Halichondrida, where the spicules of the endosomal skeleton are in disarray). In the stalk region the spicules are condensed to form an axial skeleton (Moss & Ackers, 1982).
Other species
Suberites ficus is another common sponge. It is usually found on hard substrata where there are tidal currents and also on wreckage where it hangs down into the current. It has a similar growths form to Suberites carnosus but may also be cylindrical. Colours include white, grey marbled and green in addition to orange. Surface and endosomal skeleton differ. Differences between Suberites carnosus and Suberites ficus (as S. domuncula) are based on criteria communicated by S.M. Stone in Moss & Ackers (1982).