A Russian marine biologist who’s dedicated his life to studying the ocean has captured some remarkable images of a tiny species of slug known as the sea angel. Named for their winged appearance, these aquatic creatures’ natural habitat is the freezing-cold northern waters. With luminescent bodies, these mollusks are not just stunning to look at but also a source of fascination for the scientific community.
“My personal goal is to study underwater life through camera lenses and to boost people’s interest in marine biology,” he wrote in his Flickr profile. “I do this by sharing all my findings through social media and in real life through public lectures, movies, exhibitions, and media events.”
Back in 2017, Semenov captured an incredible video of the underwater angels, scientifically known as Clione limacina. These marine semi-transparent sea slugs have long translucent light-blue bodies, with orange-pink chests and wing-like appendages.
Semenov says that the sea angels are “protandrous hermaphrodites,” which means that they start out as males; however, as they reach adulthood, they start developing eggs.
Despite their tiny, delightful appearance, they are also feared predators. Specifically, they feed on a species of sea butterfly called Limacina helicina. Some sea angels use tiny little tentacles to capture and consume their prey.
What makes these little creatures even more fascinating is their mysterious lifespan.
According to Semenov, after reaching adulthood, and as soon as the water temperature rises to about 2–3 degrees Celsius (36–37 degrees Fahrenheit), the sea angels simply disappear—only to come back the following winter. Apparently, the one thing scientists have figured out for sure is that these beautiful sea slugs can actually survive for up to six months without food.
“So far,” the marine biologist added, “no one has figured out how to track the life of a tiny angel in the Arctic seas all year round to find out where they are going.”
