Marine Biodiversity » Marine Sponges » Calcarea » Calcarea Classification » Subclass Calcinea

Definition: Solid body; aquiferous system always leuconoid; choanoskeleton well-developed forming regular network composed of triradiates and/or quadriradiates; cortex thin and composed of spicules similar to those in the choanoskeleton.

Scope: The family includes six generic names, of which two are valid genera and one incertae sedis.

Reviews: Borojevic (1968), Borojevic et al. (1990).

Genera:
Leucetta Haeckel, 1872 (type species: Leucetta primigenia Haeckel, 1872) (syn. Sycothamnus Haeckel, 1869; Leucetta Haeckel, 1872; Teichonella Carter, 1878) - a homogeneous organisation of the wall and a typical leuconoid aquiferous system; there is no clear distinction between the cortex and the choanoskeleton, nor the presence of a distinct layer of subcortical inhalant cavities; the atrium is frequently reduced to a system of exhalant channels that open directly into the osculum (Borojevic et al., 1990); solitary or compound, tubular, clathrate with tubular oscules, or lobate; surface even, harsh; oscules apical; firm texture; skeleton of regular to subregular triradiates arranged tangentially in ectosomal and choanosomal region, irregularly arranged in chamber layer (Burton, 1963). GBR species: Leucetta chagosensis, Leucetta microraphis Haeckel, 1872, Leucetta villosa Wörheide & Hooper 1999.
Pericharax Poléjaeff, 1884 (type species: Pericharax heterorhaphis Poléjaeff, 1884) - with a large central cavity, probably a pseudogaster, surrounded by a thick wall; the wall is divided into a choanoderm and a thin subcortical layer of inhalant cavities supported by a peculiar skeleton partially composed of the centripetal rays of the special cortical triradiates (Borojevic et al., 1990); solitary or compound, cup-shaped, subspherical or massive lobose; surface even, smooth, harsh often thrown into irregular folds in places; apical oscule, with or without margin; firm texture; ectosomal skeleton a tangential layer of subregular triradiates; skeleton of chamber layer of large and small regular triradiates irregularly scattered; choanosomal skeleton a tangential layer of regular quadriradiates (Burton, 1963). GBR species: Pericharax heteroraphis Poléjaeff, 1884.
Leucomalthe Haeckel, 1872 (incertae sedis) (type species: Leucomalthe bomba Haeckel, 1872) - with a solid body and a large central cavity; choanocyte chambers greatly elongated, tubular and copiously branched; skeleton consists of regular triradiates and microbiradiates in the cortical skeleton, regular triradiates in the choanoskeleton and sagittal quadriradiates both in the atrial skeleton and in the exhalant channels; large longitudinal biradiates present throughout the body (Borojevic et al., 1990); solitary, spherical; surface even; apical oscule with well developed fringe; texture firm; ectosomal skeleton of tangential layers of microxeas and regular triradiates; skeleton of chamber layer of regular triradiates and longitudinally placed oxeas, with larger canals lined with subregular quadriradiates; choanosomal skeleton a tangential layer of sagittal quadriradiates (Burton, 1963).