Sea butterflies can have or not shells depending on their taxonomic Order. Thecosomata have shells and Gymnosomata do not. While I was on the field with Woods Hole Oceanographic Institution (MASS, USA) in the Northeast Pacific last year we collected plenty of these ‘cute’ (you can judge for yourself) guys.
Their common name is Sea Angel. The Japanese are huge fans of this specific species. They make pins, soft toys, posters, everything! They even a Pokemon designed after a Clione! This species is called Clione and is a particularly carnivorous one! They feed on other pteropods like crazy!
They are so cute…
Less cute now right..?
Not to worry though, they are harmless to humans. Only other pteropods interest them. Clione, like other pteropods can occur in swarms. They basically swam on swarms.. and especially abundance in polar seas where the local Limacina helcina are a delicacy!
Although Clione is not part of the organisms I work on (no shells so no calcification) they are still very cool to look at under the microscope… we caught a couple matting on camera – rated PG+18