Plakortis simplex



Because Plakortis simplex is classified into the phylum Porifera, it is sessile or immobile during its adult stage.  This also implies that it has no true tissues.  However, P. simplex does have a layer of cells that forms most of the epidermis which is similar to a true tissue but still is not considered to be.  Plakortis simplex maintains support by a proteinacious substance called spongin which forms a strong fibrous system as well as spicules made from silica.  It does not have any sensory cells, but it does have ostia which are openings in the wall of the sponge.  It closes its ostia when there is too much matter in the water or if it is touched. 


For nutrition information on P. simplex click here.