INVERTEBRATE ZOOLOGY - H. I. Shcherbak - 2008

KINGDOM MULTICELLULAR ANIMALS (METAZOA)

SUBKINGDOM PRIMITIVE MULTICELLULAR ANIMALS (PROMETAZOA)

PHYLUM SPONGES (PORIFERA)

CLASS DEMOSPONGES (DEMOSPONGIA)

The most numerous Class of modern Sponges, comprising medium to large-sized organisms (up to 2 m). Both marine and freshwater species exist, predominantly colonial. Colonies exhibit diverse colors and shapes, such as encrusting, globose, branched, or cup-shaped. The structural Organization is exclusively leuconoid. The siliceous Skeleton consists of mono- or tetraxonal spicules. Spongin fibers are frequently present, forming the organic framework of the skeleton. Occasionally, the skeleton is entirely composed of spongin (for example, in the bath sponge Euspongia officinalis, Fig. 59, d).

Representatives of this class include various species of bath sponges, such as Euspongia officinalis and Spongia zimocca; Neptune's cup (Poterion neptuni), which has a body shape resembling a giant goblet (up to 1 m in height); and boring sponges (Cliona), capable of excavating channels in calcareous substrates (Fig. 65).

Fig. 65. Horny-siliceous sponges:

a - bath sponge (Spongia zimocca); b - Neptune's cup (Poterion neptuni) (adapted from Koltun); c - freshwater sponge (Spongilla lacustris) (adapted from Dogiel)

Freshwater sponges include several species of spongillids. Widely distributed in the Water bodies of Ukraine is Spongilla lacustris, which colonizes stones, snags, and submerged wood debris.