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Marine SpongesCalcarea Introduction

Calcarea Classification

Definition Class Calcarea

With exclusively calcitic spicules ranging from discrete monactinal, diactinal, triactinal or tetractinal spicules, to reticulate skeletons composed of fused crystalline calcite spicules; megascleres and microscleres are not differentiated; skeleton and aquiferous system occurs in three grades of construction: asconoid, with simple tubular construction (olynthus), without folding of the body wall, with thin walls pierced externally by ostia, leading to tubular water canals (porocyte canals) opening onto a central choanocyte-line cavity (choanoderm), connected to the exterior, at the apex of the sponge, by a single osculum; syconoid construction produced by folding of both the exterior (pinacoderm) and interior (choanoderm) walls, producing choanocyte chambers to lie within the body wall rather than only lining the central atrium as in more simple asconoid structures, but these chambers open directly onto the atrium; leuconoid, found in most sponges (including the Demospongiae), with complex folding and in which the choanocyte chambers are oval and isolated in a maze of canals within the body wall, with chambers opening onto branching and complex excurrent canals; sexual reproduction in Calcarea is exclusively viviparous.

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Subclass Calcinea

Subclass Calcaronea

REVIEWS: Dendy & Row (1913), Hartman (1958), Burton (1963), Borojevic (1966, 1968, 1977), Vacelet (1970, 1981, 1991), Borojevic & Boury-Esnault (1986), Borojevic, Boury-Esnault & Vacelet (1990). Borojevic, Boury -Esnault & Vacelet (2000).

taken from 'Sponguide' by J.N.A. Hooper (Queensland Museum, Brisbane)

PDF version of Sponguide Calcarea Chapter

Australian Faunal Directory: Checklist for PORIFERA

Supra-specific classification of Class Calcaronea has recently been revised in Hooper JNA & Van Soest RWM (2002): Systema Porifera. Guide to the Supraspecific Classification of Sponges and Spongiomorphs (Porifera). Plenum, New York, pp 1708, which contains some slight alterations to the one presented here from the Sponguide.

Due to copyright restrictions I am not able to reproduce those chapters here. Contact your local library or librarian.

An online version of the Systema Porifera is planned for the future.

However, classification of Calcarea in the Systema Porifera is not based on a thorough phylogenetic analysis and will certainly change in the near future. Therefore, the slightly older classification from the "Sponguide" provides an as good insight into these fascinating animals.