Sea Angel

Clione limacina

The sea angel (Clione limacina) is a small pelagic sea slug in the family Clionidae. Adults reach about 3-5 cm with a gelatinous, translucent body completely lacking a shell. They swim using two wing-like extensions of their foot called pteropodia, which beat rhythmically like angel wings. Internal organs, including the pink to orange gonads, are visible through the transparent body. This species inhabits cold waters of the Arctic Ocean and North Atlantic at depths of 0-500 meters, drifting in the water column as part of the zooplankton. Sea angels are specialized predators that feed almost exclusively on sea butterflies of the genus Limacina, using tentacle-like structures called buccal cones to capture and extract their prey from its shell. Their ethereal, otherworldly appearance as they pulse through dark, cold waters creates one of the most magical encounters possible for cold-water divers. They are increasingly studied as indicators of ocean acidification impacts.