green finger sponge - Iotrochota birotulata

Sponges are characterized by the possession of a feeding system unique among animals, and the green finger sponge is no exception. Sponges don't have mouths; instead, they have tiny pores in their outer walls through which water is drawn. Cells in the sponge walls filter nutrients or food from the water as the water is pumped through the body and out other larger openings. The flow of water through the sponge is unidirectional, driven by the beating of flagella which line the surface of chambers connected by a series of canals. All sponges perform this same digestive process which is actually closely linked to their respiratory systems.