Phylum: Porifera

 

Norwegian: svamper

(Storsteinan - The Trondheim fjord / 7.25.2001 / 19 meters)

Sponges do not have a mouth, a neural system or even any sensing organs. Still they have a variety of specialized cells, performing different tasks like pumping water, extracting and digesting particles from the water. A sponge may filter 10.000 - 20.000 times its own volume every day. Tiny hairs shimmer continuously to pump water through its internals. Sponges are responsible for the very important task of dissolving solid calcium and thereby enable mussels and others to reuse it to build their shells.

In general, both sexual and asexual reproduction occurs.

When classifying sponges three major classes are identified, the largest class Demospongiae, the glass sponges Hexactinellida (not represented on seawater.no yet) and finally the calcareous sponges, Calcarea.