There are six groups that make up invertebrate species. Sponges, corals, sea urchins, and stars are just a few examples of this category. This area includes poriferans (sponges), cnidarians (sea jellies and coral) echinoderms (such as sea urchin or starfish), mollusks such as octopuses, snails, and clams; annelids: worms; arthropods which include insects like spiders or lobsters