The following resources have proven very useful to me during the development of www.seawater.no:
Taxonomy and general species identification sites:
- Marine Species Identification Portal: A great site and a huge source of information on a very wide range of marine animals.
- WoRMS - World Register of Marine Species: My major reference on taxonomy.
- Encyclopedia of Marine Life of Britain and Ireland: A great site with a lot of images.
- Tree of Life: Covers the characteristics of land animals as well as the marine fauna.
Fish:
- FishBase: A Global Information System on Fishes
Mollusks:
- Sea Slug Forum: The worlds by far most extensive website about sea slugs, run by Australian Museum.
- Scottish Nudibranchs: An extensive list and beautiful images of nudibranchs.
Sponges:
- Sponges of Britain and Ireland: A huge collection of sponge descriptions and images.
Cnidarians:
- actiniaria.com: An extensive collection beautiful images of sea anemones from around the world.
Crustaceans:
- crustacea.net: Provides illustrated, interactive keys to worlds crustaceans.