Cyanea capillata gonads 2 by Alexander Semenov on Flickr.
The lion’s mane jellyfish (Cyanea capillata), also known as hair jelly, is the largest known species of jellyfish. Its range is confined to cold, boreal waters of the Arctic, northern Atlantic, and northern Pacific Oceans. Similar jellyfish, which may be the same species, are known to inhabit seas near Australia and New Zealand. The largest recorded specimen found, washed up on the shore of Massachusetts Bay in 1870, had a bell (body) with a diameter of 2.3 metres (7 ft 6 in) and tentacles 37 m (120 ft) long. Lion’s mane jellyfish have been observed below 42°N latitude for some time—specifically in the larger bays of the east coast of the United States.
While the lion’s mane jellyfish generally use their stinging tentacles to capture prey, sea anemones can capture their tentacles, which then become tangled, torn apart and consumed.
The taxonomy of the Cyanea species is not fully agreed upon; some zoologists have suggested that all species within the genus should be treated as one. Two distinct taxa, however, occur together in at least the eastern North Atlantic, with the blue jellyfish (Cyanea lamarckii Péron & Lesueur, 1810) differing in blue (not red) color and smaller size (10–20 cm diameter, rarely 35 cm). Populations in the western Pacific around Japan are sometimes distinguished as Cyanea nozakii Kisinouye, 1891, or as a race, Cyanea capillata nozakii.
Although capable of attaining a bell diameter of over 2 metres (6 ft 7 in), these jellyfish can vary greatly in size; those found in lower latitudes are much smaller than their far northern counterparts with bell about 50 centimetres (20 in) in diameter. The tentacles of larger specimens may trail as long as 30 m (100 ft) or more. These extremely sticky tentacles are grouped into eight clusters, each cluster containing over 100 tentacles, arranged in a series of rows.
At 37 m (120 ft) in length, the largest known specimen was longer than a blue whale and is considered one of the longest known animals in the world. This title, however, may be contested: in 1864, a bootlace worm (Lineus longissimus) was found washed up on a Scottish shore that was 55 m (180 ft) long. But because bootlace worms can easily stretch to several times their natural length, it is possible the worm did not actually grow to be that length.
The bell is divided into eight lobes. An ostentatiously tangled arrangement of colorful arms emanates from the centre of the bell, much shorter than the silvery, thin tentacles which emanate from the bell’s subumbrella.
Size also dictates coloration – larger specimens are a vivid crimson to dark purple while smaller specimens grade to a lighter orange or tan. These jellyfish are named for their showy, trailing tentacles reminiscent of a lion’s mane.
(From Wikipedia, the free encyclopedia)