Three examples of sponges are the calcareous sponges, glass sponges and demospongiae. These all fall under the main category of porifera, the scientific name for sponges.
Calcareous sponges are the most primitive of all three types. There are approximately 400 species that live in the shallow water of temperature regions. They may be found on coral reefs in the tropics. These sponges are small and dull in color.
Glass sponges are also pale in color and are found in the deep waters in the Antarctic. Because they are located so far into the waters, there is less human interaction with these sponges that with other types.
The demospongiae are the largest of the sponge classes and account for 90 percent of all sponges in the world. These sponges are bright in color and are used in commercial products, such as bath sponges. When the word sponge is used, these sponges are usually what it references.
Sponges are one of the most primitive animals living on the planet. They lack organs, nerves, bones and muscles. They provides homes for plants and creatures and remain immobile. They are multicellular organisms with approximately 5,000 unique species, 150 being freshwater species, in all classifications.