Marine Biodiversity » Marine Sponges » Calcarea » Calcarea Classification » Subclass Calcaronea

Definition: Massive, tubular, pear-shaped and branching growth forms, occuring as solitary sponges or in groups; continous cortex, pierced by ostia and reinforced by asymmetrical triradiate spicules with unequal angles, covers the entirely choanocyte chamber layer; inarticulated or articulated tubular skeleton characterised by a distinct subcortical zone formed by pseudosagittal triactines, but articulated choanosomal spicule skeleton may be present or absent; cortical triradiate spicules probably originate from 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; choanocyte chambers asconoid, elongate and radially arranged, or spherical and irregularly scattered in the choanosome (leuconoid).

Scope: Six genera are included in this family (of 8 generic names).

Reviews: Dendy (1893), Dendy & Row (1913), Hartman (1958), Burton (1963), Borojevic (1966), Borojevic, R. (1967).

Genera:
Sycettusa Haeckel, 1872 (type species: Leucaltis bathybia Haeckel, 1872) (syn. Djeddea Miklucho-Maclay in Haeckel, 1872; Sycothamnetta Haeckel, 1872) - tubular, substipitate; surface even, minutely hispid; apical oscule; firm texture; ectosomal skeleton a distinct tangential layer of sagittal triradiates, with oxeas projecting at right angles to surface; skeleton of chamber layer composed of centrifugally directed rays of sagittal triradiates and centipetally directed rays of subgastral pseudosagittal triradiates, supplemented or partially replaced by confused triradiates; choanosomal skeleton a tangential layer of sagittal tri- or quadriradiates (Burton, 1963).
Grantessa Lendenfeld, 1885 (type species: Grantessa sacca Lendenfeld, 1885) - sac shaped or cylindrical; surface even but bearing isolated tufts of oxeas; texture firm; ectosomal skeleton a sparse layer of tangential triradiates with unequal rays, paired rays of subectosomal pseudosagittal triradiates, and tufts of oxeas projecting from the surface; tubar skeleton of basal rays of subectosomal pseudosagittal and subgastral sagittal triradiates with numerous intermediate rows of subregular triradiates; choanosomal skeleton of paired rays of subgastral sagittal triradiates and several layers of choanosomal quadriradiates (Burton, 1963).
Grantilla Dendy & Row, 1913 (type species: Grantilla quadriradiata Row, 1909) - with syconoid organisation; the skeleton of the tubes are inarticulate and composed of subatrial triactines and subcortical pseudosagittal triactines and tetractines (Borojevic, Boury-Esnault & Vacelet, in prep.).
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 triradiates and large ("colossal") longitudinally-placed oxeas; skeleton of chamber layer of sagittal triradiates; choanosomal skeleton a tangential layer of small triradiates and larger sagittal quadriradiates, the latter near the gastral cavity and oscule (Burton, 1963).
Paraheteropia Borojevic, 1966 (type species: Paraheteropia ijimai (Hozawa, 1916) - with syconoid organisation and with cortical and atrial skeleton sustained by longitudinal diactines (Borojevic, Boury-Esnault & Vacelet, in prep.).
Vosmaeropsis Dendy, 1893 (type species: Heteropia macera Carter, 1886) - tubular to sacciform, compound; even hispid or non-hispid surface; apical oscules; firm texture; ectosomal skeleton of several layers of triradiates together with paired rays of subectosomal pseudosagittal triradiates and microxeas, with or without oxeas projecting at the surface; skeleton of the chamber layer of basal rays of subgastral and subchoanosomal triradiates; choanosomal skeleton of paired rays of sugastral triradiates and several layers of triradiates (Burton, 1963).