1. Sponges (Porifera)
2. Comb jellies (Ctenophora)
3. Hydras, jellyfishes, sea anemones, and corals (Cnidaria)
4. Starfishes, sea urchins, sea cucumbers (Echinodermata)
5. Flatworms (Platyhelminthes)
6. Round or threadworms (Nematoda)
7. Earthworms and leeches (Annelida)
8. Insects and arachnids (Arthropoda)
9. Snails, and octopuses (Mollusca)