Invertebrates

There are several groups of invertebrates, including: coelenterates (pronounced "see-lent-er-rates") flatworms annelids molluscs echinoderms (pronounced "ee-kyno-durms") arthropods The table shows some of their key features. Remember they do not have backbones. Group Examples   Key features Coelenterates Jellyfish Sea anemone Hollow bodied Mouth is the only body opening Tentacles Flatworms Liver fluke Tapeworm Flat, thin bodies Digestive system has one opening Annelids Earthworm Leech Rounded bodies Bodies made of rings or segments Molluscs Snail Oyster Soft body in three continuous parts with head, foot and body mass May have one or two shells Echinoderms Sea urchin Starfish Spiny body in five parts Central mouth Arthropods Crab Spider Fly Centipede Hard body divided into segments Jointed legs