Nonindigenous Aquatic Species: Sponges - Species list from the USGS on the nonindigenous sponges found in US waters, with factsheets and collection details.
Phylum Porifera (Sponges) - Description of the sponges and their taxonomy, from the Animal Diversity Web.
Porifera - Exercise from Invertebrate Anatomy OnLine covering the sponges, including Leucosolenia, Sycon, Spongilla, Cliona and Euplectella, in detail.
Porifera Biology on the WWW - A central clearinghouse for sponge researchers, including a porifera listserver bulletin board and who's who in sponge research.
Porifera List - Links to a number of sponge-related sites.
Sponge City - Article by William Amos on sponges and their general biology, and the pistol shrimp and other creatures that live inside their chambers.