He was a world-renowned expert on coelenterates and elasmobranchs. These snails also prey on corals and other coelenterates. He was also a world authority on coelenterates. However, some genomic studies have found support for monophyletic coelenterates. Examples are the glass coelenterates of Leopold and Rudolf Blaschka. All coelenterates are aquatic, mostly marine. It is an important breeding and nursery ground for fish, crustaceans, and coelenterates. The group Ascothoracida contains about 100 species, all parasites of coelenterates and echinoderms. "N. leptocheles" feeds on coelenterates. Many oligochete annelids, acoelous turbellarians, echinoderm larvae and coelenterates reproduce by this method. Cnidaria and Ctenophora both exhibit radial symmetry and are collectively known as coelenterates. Jellyfish, Portuguese man of war and sea anemones are other coelenterates found here. Some examples of invertebrates are sponges, coelenterates, tunicates, echinoderms, corals, algae, molluscs and bryozoans. The North Atlantic topshell "Calliostoma occidentale" has been reported to feed on coelenterates. The nervous systems of coelenterates allow for sensation, contraction, locomotion, and hunting/feeding behaviors.