Science Natural Science The Adorable Science Behind the “sea Bunny” By Margaret Badore Margaret Badore Facebook Twitter Senior Editor Columbia University Sarah Lawrence College Maggie Badore is an environmental reporter based in New York City. She started at Treehugger in 2013 and is now the Senior Commerce Editor. Learn about our editorial process Updated February 5, 2021 atopapa / a.collectionRF / Getty Images Share Twitter Pinterest Email Science Space Natural Science Technology Agriculture Energy Meet the cutest sea slug ever? It’s round, and fluffy and has wiggly little ears! Sort of. These little sea creatures, affectionately dubbed “sea bunnies” have recently become social media celebrities. They’re actually sea slugs, and belong to the wild group of mollusks called nudibranchs. The bunny slug species is Jorunna parva, and was first described by the renowned Japanese marine biologist Kikutaro Baba. The fluffy white sea bunnies are primarily found off the coast of Japan. Jorunna parva have also been found in the Indian Ocean and off the coasts of the the Philippines. As for the “ears”—over on Deep Sea News, Dr. Craig McClain explains that those are really rhinophores, organs that help the sea slug sense chemicals dissolved in the water and also detect changes in currents. “In the group of nudibranchs that contains the sea bunnies, the rhinophores are particularly 'fuzzy' allowing for more surface area for this reception to occur on.” All nudibranchs are hermaphrodites, which means they produce both sperm and eggs but cannot fertilize themselves. Jorunna parva have a number of different colorings, and are often yellow with black specks and rhinophores. Some can even be a bit greenish. McClain points out that there is some debate in the scientific community over whether or not the different color variations represent separate species. If there wasn’t enough reason to “aawwww” over sea bunnies, the fact that these creatures are incredibly tiny adds extra points to their adorableness score. Jorunna parva are less than an inch in length. Here's a video of one in action: And in case your day hasn't had enough bunny cuteness from Japan, check out this island full of (land) rabbits.