Bergquist, 1978
Definition: These sponges lack mineral spicules, typically fleshy and soft, with pigment that oxidizes to purple colouration; skeleton consists of large, widely spaced spongin fibres forming dendritic or reticulate structures, and fibres may be aggregated (fasciculated) into bundles; no differentiation of primary and secondary elements, and detritus is only rarely incorporated into fibres; fibres have a laminated cortical (bark) region and a distinct central pith (Aplysina aerophoba fibre) of fine spongin fibrils, but the cortex may be reduced or disappear entirely in some species. Mesohyl contains abundant collagenous fibrils. (Aplysina fulva) (Verongula rigida)
Remarks: Three families, Aplysinidae, Aplysinellidae and Ianthellidae are known, all of which are thought to be oviparous. Only one family, viz. Family Aplysinidae, is represented in the area. This has a reticulation of spongin fibres forming polygonal meshes.
Source: Bergquist, 1980.