Third, there was a balance between sediment coming into the area and sponge survival and growth, allowing the reef to persist and develop over geologic time. In a process similar to sand and silt dropping out of river water in lower velocity backeddies and off-channel areas, sediment deposits out of sea water as it travels into lower velocity eddies created by the rough surface of the reef. The Building Blocks Sponges of all kaleidoscopic shapes, sizes and colours belong to the Phylum Porifera. Over 10,000 species are known worldwide, from the equator to the poles, from shallow tidepools to deep ocean trenches. Aphrocallistes vastus, Chonelasma calyx and Farrea occa.
Sponges are distinct, having the most simple body structure of all multi-cellular animals.
Lining the walls of the labyrinth, millions of flagellated cells beat vigorously to sweep water through the sponge body, simultaneously trapping food particles for energy. Much like blood in our circulatory system, water also transports oxygen to internal cells while removing cellular waste products. At this rate, a basketball-sized sponge would process several thousand litres of water each day. Construction Individual sponge mounds, which initially look symmetrical and circular, develop irregular shapes as suspended sediment settles on the mounds through slowing of tidally-driven currents. As sediment accumulates, individual and coalescing mounds develop and tend to elongate in the direction of prevailing seabed currents.