Sea sponges are bottom-dwelling, multi-cellular animals. Most sea sponges attach themselves to the ocean floor, other sea animals or rocks for the duration of their lives. A small number of sea sponges are mobile creatures that move along the ocean floor at the rate of 1 to 3 millimeters per day.
Officially called Porifera, which means "pore-bearing," sea sponges depend on continuously moving water currents to bring food within reach of the animal's Flagellae tentacles found along the bottom of their bodies. The tentacles move the water and the small food particles into the sea sponge's internal cavities, filtering out water and waste particles as the sponge digests its food. Sea sponges close all or part of their absorption pores when surrounding water gets too dirty or sandy.
Sea sponges eat plants and other animals, including tiny crustaceans, such as baby crabs or shrimp, that they catch using sticky spicules located on their bodies. Once they capture a crustacean, the sea sponges form new cells that secrete the chemicals necessary to help it hold onto and digest the crustacean.
Sea sponges can live for more than 200 years. There are more than 5,000 known species of them, mainly residing in saltwater oceans, lakes and rivers.