Home Acknowledgments Conventions Glossary Maps References Links Articles Thumbnails Species list Order Next family	Aplustridae The family Aplustridae (also known as Hydatinidae) includes acteonoideans with thin, strongly inflated shells with low spires. Sometimes referred to as "bubble shells," they have large parapodia, lack an operculum and cannot withdraw completely into their shells. The genus Hydatina is nocturnal while Micromelo is diurnal. They feed on polychaete worms. There are at least four species in Hawaii in three genera (Aplustrum, Hydatina and Micromelo). Aplustrum amplustre Hydatina physis Hydatina zonata Micromelo scriptus
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