demosponge

noun

Etymology: From Ancient Greek δῆμος (dêmos, “common people”) + sponge, a partial calque of translingual Demospongiae.

1. A sponge of the class Demospongiae, having skeletons made of spongin fibers.

   “We know that at least some living calcified demosponges grow extremely slowly (0.2 mm/year Willems and Hartman 1985) and, since individuals can grow up to 1 m in diameter, are also very old (up to 5000 years).”

   “Demosponges have siliceous spicules and a network of fibrous protein, spongir, that is similar to collagen. The demosponges are the source of natural household sponges, which are made by soaking dead sponges in shallow water until all the cellular material has decayed, leaving the spongin network behind.”