Can some1 rephrase this so it doesn't sound too sophisticated???? so my teacher think's i've written it

Corals are actually tiny living creatures. They are related to creatures sucha jellyfish, hydras and sea anemones which all belong to a group known as cnidarians. Corals are do not move around and are fixed tomone place. These types of animals are called sessile animals and the feed by catching tiny prey such as plankton with their tentacles...... how am I doing?