Invertabrates are animals without a backbone. They are twenty times more invertebrate types of animals than their are vertebrate. Most are insects, with over a million described and cataloged, with several million more unidentified. Phyla that are classified as invertebrates include insects, jellyfish and sea anemones,hard-bodied crustaceans and spiders, segmented and unsegmented worms, starfish, sea urchins, slugs and snails, squid, and cuttlefish.