INVERTEBRATE ZOOLOGY - H. I. Shcherbak - 2008

KINGDOM MULTICELLULAR ANIMALS (METAZOA)

SUBKINGDOM PROMETAZOA (PROMETAZOA)

PHYLUM SPONGES (PORIFERA)

CLASS CALCAREOUS SPONGES (CALCISPONGIA)

Exclusively marine forms of small size (up to 10 cm in height), solitary or colonial, possessing a calcareous Skeleton. In solitary forms, the body is goblet-shaped, barrel-shaped, tubular, or sac-like, with a spiky surface and a fringe of long spicules surrounding the osculum (Fig. 64). Representatives of this Class exhibit all Three types of structural Organization: ascon, sycon, and leucon. The skeleton consists of spicules composed of CaCO3. The spicules may be monoaxonic, triaxonic, or tetraxonic. As a rule, they are small and embedded freely in the mesohyl without fusing together. Representative genera include Clathrina and Sycon.

Fig. 64. Calcareous Sponges:

a — colonial Leucosolenia bothryoides; b — solitary Leuconia aspera (adapted from Koltun)



Last update: 13/08/2026

Editorial and Educational Adaptation: This material has been compiled based on the primary/original source text. The project team performed an editorial review, corrected technical inaccuracies, structured sections, and adapted the content for an educational format.

What was processed:

  • elimination of formatting defects (OCR errors, structural breaks, corrupted characters);
  • editorial organization of content;
  • standardization of terminology in accordance with academic sources;
  • verification of factual statements against the original source text.

All mentions of the author, publication year, and origin of the primary text have been preserved in accordance with the source.