Jellyfish are popular attractions at aquariums, with their see-through bodies and floating lifestyle. Keeping hungry jellyfish fed, however, can be a challenge. Fish and shrimp-based protein sources can be expensive, inconvenient, and may ultimately be unsustainable. That’s why P. Zelda Montoya and Barrett L. Christie, two aquarists from the Dallas Zoo and Children’s Aquarium, decided to try something a little different: peanut butter. A test group of around 250 young jellyfish were fed creamy peanut butter, free of corn syrup or preservatives. They ate the peanut butter twice a day for five weeks. The first notable observation was that the jellies turned a bit brown after imbibing. The aquarists say the growth of the jellyfish seemed to be on par with those fed more standard diets.