Heliacus (Gastropoda: Architectonicidae) symbiotic with Zoanthiniaria (Coelenterata).
Eight species of Heliacus are obligate symbionts with Zoanthus and Palythoa, colonial zoanthid sea anemones. The gastropods live among Zoanthus polyps and under the edges of Palythoa incrustations, on which they feed and to which they and their egg masses are attached with sturdy but elastic mucous threads.
D000818:Animals; D003063:Cnidaria; D008974:Mollusca; D013559:Symbiosis