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

Definition: Tubular, spherical, flask-shaped, ovoid and branching growth forms, either solitary or in groups; ectosomal cortex is continous and strengthened by tangential spicules, but these do not cover the choanocyte chamber layer; choanosomal spicules, supporting choanocyte chambers, have an articulated arrangement of overlapping sagittal triradiates, with the angle between the paired rays larger than the angles between each paired ray and the long, unpaired ray; sagittal triradiates have the longest ray pointing to the exterior of the sponge, and form a layer beneath the spongocoele lining (referred to as the subgastral position); choanocytes usually confined to the radial chambers in the adult, and probably always with apical nuclei; choanocyte chambers asconoid, arranged radially around a central cavity (spongocoele), with ends of chambers projecting into ectosomal surface.

Scope: There are only four valid genera included in this family although there are approximately 60 other generic names included in synonymy with these

Reviews: Dendy (1893), Dendy & Row (1913), Tanita (1943), Hartman (1958), Burton (1963), Borojevic (1967).

Genera:
Sycandra Haeckel, 1870 (type species: Sycandra utriculus Haeckel, 1872) - with an atrial cavity partially obstructed by a column sustained by parallel diactines (Borojevic, Boury-Esnault & Vacelet, in prep.).
Sycetta Haeckel, 1872 (type species: Sycetta primitiva Haeckel, 1872) (syn. Sycyssarium Haeckel, 1872; Sycissa Lendenfeld, 1886) - tubular, stipitate; surface minutely papillate, non-hispid; oscule simple, apical; texture soft; tubar and choanosomal skeletons composed of regular triradiates; species lack tufts of oxeas at the distal ends of the radial chambers, and the radial chambers are always completely separate from one another, otherwise similar to Sycon (Burton, 1963).
Sycodorus Haeckel, 1872 (type species: Sycandra (Sycodorus) hystrix Haeckel, 1872) (syn. Sycodorussa Haeckel, 1892; Utella Dendy, 1892) - tubular, sessile; even surface prominently hispid; apical oscule with fringed margin; firm texture; ectosomal skeleton of several tangential layers of regular triradiates, with oxeas of two sizes projecting beyond the surface; tubar skeleton with several rows of sagittal triradiates and sagittal quadriradiates and basal rays of subgastral sagittal triradiates and sagittal quadriradiates; choanosomal skeleton of paired rays of subgastral sagittal triradiates, with longitudinal oxeas and a tangential layer of sagittal triradiates and sagittal quadriradiates (Burton, 1963).
Sycon Risso, 1826 (type species: Spongia ciliata Fabricius, 1780) (syn. Scypha Gray, 1821; Calcispongia Blainville, 1830; Calcepongia Lamarck, 1836; Dunstervillia Bowerbank, 1845; Coniasterium Ehrenberg, 1861; Artynes Gray, 1867; Syconella Schmidt, 1868; Sycum Haeckel, 1870; Artynella Haeckel, 1870; Sycarium Haeckel, 1870; Artynas Haeckel, 1870; Sycodendrum Haeckel, 1870; Sycidium Haeckel, 1870; Artynium Haeckel, 1870; Sycocystis Haeckel, 1870; Artynophyllum Haeckel, 1870; Sycophyllum Haeckel, 1870; Sycometra Haeckel, 1870; Sycettopa Haeckel, 1870; Sycettaga Haeckel, 1870; Sycurus Haeckel, 1870; Sycaltaga Haeckel, 1870; Sycuraltis Haeckel, 1870; Sycocarpus Haeckel, 1870; Sycocerus Haeckel, 1870; Sycocubus Haeckel, 1870; Sycostrobus Haeckel, 1870; Sycodorilla Haeckel, 1870; Sycodoranna Haeckel, 1870; Leukartea Miklucho-Maclay in Haeckel, 1872; Leucandropa Haeckel, 1872; Sycuretta Haeckel, 1872; Sycuranda Haeckel, 1872; Sycurortis Haeckel, 1872; Syconellortis Haeckel, 1872; Sycortarium Haeckel, 1872; Sycandrarium Haeckel, 1872; Syconellandra Haeckel, 1872; Syconcystandra Haeckel, 1872; Sycocystortis Haeckel, 1872; Sycothamnandra Haeckel, 1872; Sycodenandrum Haeckel, 1872; Sycinulandra Haeckel, 1872; Sycandrophyllum Haeckel, 1872; Leucandrometra Haeckel, 1872; Sycandrometra Haeckel, 1872; Sphenophorus Breitfuss, 1898; Sphenophorina Breitfuss, 1898; Hozawaia de Laubenfels, 1936; Homoderma Lendenfeld, 1885; Sycantha Lendenfeld, 1891; Hypodictyon Jenkin, 1908; Streptoconus Jenkin, 1908; Tenthrenodes Jenkin, 1908) - tubular, spherical to elongate and cylindrical; surfaec minutely papillate and hispid; apical oscule with ot without fringe; texture soft to firm; tubar skeleton of basal rays of subgastral sagittal triradiates and several rows of tubar sagittal or subregular triradiates, and ectosomal surface with distal cones ornamented with oxeas; choanosomal skeleton of paired rays of subgastral sagittal triradiates and choanosomal sagittal or subregular triradiates and quadriradiates; skeleton of chamber layer typically articulate and showing no marked differences in size between radiates of ectosome, chamber layer and choanosome except where tubar skeleton is reduced to sagittal subgastral radiates (Burton, 1963).