A typical kreisel tank housing several moon jellyfish A kreisel tank (kreisel remaining German for "spinning top" or "gyroscope") is surely an aquarium shaped similar to a horizontal cylinder that's created to keep fragile animals for example jellyfish and new child seahorses. These aquariums give slow, round drinking water circulation http://www.islandmarket.biz/signal-hill/business/age-of-aquariums