Sponges feed, breath, reproduce, and excrete by means of pumping water through their body. Their size is correlated to ocean current velocity and other factors such as availability of space and inclination of the substrate. These traits are helpful in identifying the sponge species. The sizes are very diverse. Range and Habitat Most species are marine and are found at all depths.
Many animals use sponges for shelter.
Sponges are a source of food to other invertebrates such as nudibranchs , chitons, and sea stars, and to sea turtles and tropical fishes. Research on the biochemical products produced by sponges indicates its potential use as a source of pigments, steroids, and antibiotics.