Hermit Crab Sponges - An article by Floyd Sandford about the sponges that are carried around by hermit crabs.

Introduction to Porifera - A good start on the biology of sponges, including phylogeny, life history, and ecology.

Khoyatan Sponge Page - Sponges of The Northeast Pacific - Photographs of four Classes of sponges in the Khoyatan Marine Laboratory.

Porifera Biology on the WWW - A central clearinghouse for sponge researchers, including a porifera listserver bulletin board and who's who in sponge research.

The Sponges of British Columbia - Descriptions of sponges by Curt Smecher.

Underwater Field Guide to Sponges of Ross Island & McMurdo Sound, Antarctica - Beautiful annotated photographs of sponges (Porifera) of Antarctica.

Phylum Porifera - Pore-bearing animals - Description of the phylum, including descriptions of its constituent taxonomic classes, with photos of a few representative species.