- Kingdom: Animalia
- Phylum: Mollusca
- Class: Gastropoda
- Subclass: Heterobranchia
- Order: Gymnosomata
- Family: Clionidae
- Scientific name: Clione limacina
- Norwegian: hvalåte
The transparent, cylinder shaped body of the common clione, also called the naked sea butterfly, may reach a length of 7-8 cm. The snail foot has developed into two small "wings", positioned close to the small head. There are some deep red pigmentation on the tip of the tail.
The common clione is usually found between the surface and a depth of 350 meters. Like plankton, it is a pelagic species. It is known to migrate vertically towards the surface in the night.
Traditionally, the common clione has been regarded as a bipolar species, but recent research suggests that the northern and a southern variants should be regarded as separate species.