The lion's mane jellyfish (Cyanea capillata)

While most jellyfish such as the moon jelly have a circular bell, the bell of the Lion's Mane is divided into eight lobes that resembles an eight-pointed star, each lobe contains about 70 to 150 tentacles,[5][6] arranged in four fairly distinct rows. Along the bell margin is a balance organ at each of the eight indentations between the lobes – the rhopalium – which helps the jellyfish orient itself. From the central mouth extend broad frilly oral arms with many stinging cells.[7] Closer to its mouth, its total number of tentacles is around 1,200.[8]

The long, thin tentacles which emanate from the bell's subumbrella have been characterised as “extremely sticky”; they also have stinging cells. The tentacles of larger specimens may trail as long as 30 m (100 ft) or more, with the tentacles of the longest known specimen measured at 36.6 m (120 ft) in length, although it has been suggested that this specimen may actually have belonged to a different Cyanea species.[9] This unusual length – longer than a blue whale – has earned it the status of one of the longest known animals in the world.[10]