The Shape of Life: Porifera
- Introduction to the phylum, including photographs, classification, and habitat.
- http://www.pbs.org/kcet/shapeoflife/animals/porifera.html

Introduction to Porifera
- A good start on the biology of sponges, including phylogeny, life history, and ecology.
- http://www.ucmp.berkeley.edu/porifera/porifera.html

Demospongiae (Sponges)
- Brief descriptions about sponges and their natural history.
- http://www.oceanoasis.org/fieldguide/sponges.html