Box jellyfish box-like bell, from which its name is derived. From each of the four lower corners of this hangs a short pedalium or stalk which bears one or more long, slender, hollow tentacles. The rim of the bell is folded inwards to form a shelf known as a velarium which restricts the bell's aperture and creates a powerful jet when the bell pulsates. As a result, box jellyfish can move more rapidly than other jellyfish; speeds of up to per minute have been recorded. In the center of the underside of the bell is a mobile appendage called the manubrium which
Blue jellyfish Blue jellyfish Cyanea lamarckii, also known as the blue jellyfish or bluefire jellyfish, is a species of jellyfish in the family Cyaneidae. Populations in the western Pacific around Japan are sometimes distinguished as "Cyanea nozakii" or "Cyanea capillata nozakii". This species is found in the pelagic zone off the west coast of Scotland, the North Sea and the Irish Sea, sometimes with the more common Lion's Mane Jellyfish, ("Cyanea capillata"). "C. lamarckii" has a blue or yellow tone and grows to approximately 10 to 20 cm across, but specimens can grow to 30 cm. In Scandinavian seas this species rarely