[4] As pelagic marine gastropods, Limacina swim by flapping their parapodia, inspiring the common name sea butterflies.

The shells of Limacina are well developed, sinistrally coiled, turret-like, and include an operculum.

Two large winglike parapodia, derived from foot tissue, propel these invertebrates through the water column to overcome negative buoyancy due to the animal's shell.

As diel vertical migrators, Limacina inhabit deeper waters during the day and travel to the surface at night to feed.

Large aggregations of Limacina migrating to the surface of the water attract predators such as Clione (family Clionidae, suborder Gymnosomata), baleen whales, various species of salmonids, herring,[5] and seabirds.