Pinacoderm

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The pinacoderm ( size : “pinax” = panel, “derma = skin”) is the outer covering layer of the sponges (Porifera). It is made up of two layers of cells from flat, mostly unlashed pinacocytes . They can break away from each other and form new bonds with other cells. In the pinacoderm are the ostia , small pores that serve to absorb water and lead the water through a canal system into the central cavity (gastral space, also spongocoel) of the sponges. The ostia are surrounded by ring-shaped cells that can contract. The pinacocytes also take in food. Sponges are Parazoa , so the pinacoderm is not an epithelium (tissue).

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  • Volker Storch, Ulrich Welsch: Systematic Zoology. Fischer, 1997, ISBN 3-437-25160-0 , p. 37.
  • Lexicon of Biology . Volume 6, Verlag Herder, Freiburg im Breisgau 1985, ISBN 3-451-19646-8 , p. 403.