Dendy, 1892
Definition: Massive, tubular, pear-shaped and branching growth forms, occuring as solitary sponges or in groups. A continous cortex, pierced by ostia and reinforced by asymmetrical triactine spicules with unequal angles, entirely covers the choanocyte chamber layer. Inarticulated or articulated tubular skeleton is characterised by a distinct subcortical zone formed by pseudosagittal triactines, but articulated choanosomal spicule skeleton may be present or absent. The cortical triactines are believed to have originated from the articulate chamber skeleton through reorientation of the spicules, so that one of the paired rays becomes the sagittal ray and the latter pairs up with the remaining ray. The asymmetry of the new paired rays and the angle of one of them is evidence of the rotation of the spicule as it has shifted from a position in the chamber skeleton to a cortical position. Choanocyte chambers are asconoid, elongate and radially arranged, or spherical and irregularly scattered in the choanosome (leuconoid).
Remarks: 6 genera are included in this family (of 8 generic names). Review: Borojevic et al., unpublished.
Source: Hooper's Internet Sponge Guide.
Genus represented in the area:
Heteropia Carter, 1886 (type species Aphroceras ramosa Carter in Higgin, 1886): ramose, sessile; surface even, non-hispid; oscules apical, terminal; firm texture; ectosomal skeleton with a tangential layer of small sagittal triactines and large ("colossal") longitudinally-placed oxeas; skeleton of chamber layer of sagittal triactines; choanosomal skeleton a tangential layer of small triactines and larger sagittal tetractines, the latter near the gastral cavity and oscule (Burton, 1963).
Species included:
Heteropia ramosa