Sponges are the most primitive macroinvertebrates living on North American west-coast shores. Intertidal forms tend to be low and encrusting, and are often colourful; subtidal forms are usually more erect, but often more drably coloured.
NOTE from the Old English sponge or spunge, derived from the Latin (L.) spongia, referring to the animal. There are three main Classes of sponges. Representatives of each live on the west coast, but largest and most visually obvious are the Class Demospongia, and these comprise about 95% of all sponges commonly seen in the intertidal and shallow subtidal regions. Glass sponges of Class Hexactinellida live mostly in deep water. They are included in the ODYSSEY because of interesting work being done on them in British Columbia and because of the presence of unique glass-sponge reefs in this same province. Calcareous Sponges of Class Calcarea are not so common nor so visually obvious