spongin

(noun)

a horny, sulfur-containing protein related to keratin that forms the skeletal structure of certain classes of sponges

Related Terms

Examples of spongin in the following topics:

  • Phylum Porifera

    • The presence and composition of spicules and spongin are the differentiating characteristics between the classes of sponges .
    • Demosponges, which contain spongin and may or may not have spicules, constitute about 90% of all known sponge species, including all freshwater ones, and have the widest range of habitats.
    • They contain no spongin.
    • Many sponges have internal skeletons of spongin and/or spicules of calcium carbonate or silica.

  • Morphology of Sponges

    • Some of these more-specific cell types include collencytes and lophocytes, which produce the collagen-like protein to maintain the mesohyl; sclerocytes, which produce spicules in some sponges; and spongocytes, which produce the protein spongin in the majority of sponges.

  • Physiological Processes in Sponges

    • In gemmules, an inner layer of amoebocytes is surrounded by a layer of collagen (spongin) that may be reinforced by spicules.