What they are
Sponges
Morphology
Poriferas (Latin, porus, "channel" and ferre, "to carry") are tiny, multicellular animals. Poriferas, or sponges, are nothing more than a gathering of cells that secrete a shared porous skeleton. This skeleton is typically a cone or cylinder, which is lined with numerous pores and canals, in which the individual poriferas live. The sponge cells use a whip-like flagellum to create currents to both bring food and oxygen to the cells and remove waste from them. Poriferas are a unique phylum; being the only one in which their largest opening is for waste removal and not food or oxygen intake.
Ecology
Poriferas can make their home in just about any aquatic environment. They can inhabit all marine and freshwater areas, stretching from the poles to the equator. Approximately 4 out of 5 Porifera species live in shallow marine environments.
One of the key limiting factors as to where Poriferas are found is the presence of a firm substrate for them to attach to. Another limiting factor is turbidity. Poriferas prefer clear waters. If too much sediment is in the water, it can easily clog the individual cells of the colony.