| Lion's mane jellyfish |
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| Conservation status |
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Scientific classification |
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| Kingdom: | Animalia |
| Phylum: | Cnidaria |
| Class: | Scyphozoa |
| Order: | Semaeostomeae |
| Family: | Cyaneidae |
| Genus: | Cyanea |
| Species: | C. capillata |
| Binomial name |
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Cyanea capillata
(Linnaeus, 1758)The lion's mane jellyfish (Cyanea capillata), also known as hair jelly,[1] is the largest known species of jellyfish. Its range is confined to cold, boreal waters of the Arctic, northern Atlantic, and northern Pacific Oceans. It is common in the English channel, Irish Sea, North Sea and in western Scandinavian waters south to Kattegat and Øresund. It may also drift in to the south-western part of the Baltic Sea (where it cannot breed due to the low salinity). 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.[2] 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.[3] |
Taxonomy[edit]
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.
Description
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,
[4] 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.
[2] 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.
Ecology
As coldwater species, this jellyfish cannot cope with warmer waters. The jellyfish are
pelagic for most of their lives but tend to settle in shallow, sheltered bays towards the end of their one-year lifespan. In the open ocean, lion's mane jellyfish act as floating
oases for certain species, such as
shrimp,
medusafish,
butterfish,
harvestfish, and juvenile
prowfish, providing both a reliable source of food and protection from predators
[citation needed].
Behavior and reproduction
Small, dead lion's mane jelly washing up on the beach
Lion's mane jellyfish remain mostly very near the surface at no more than 20 m depth, their slow pulsations weakly driving them forwards; they depend on ocean currents whereby they travel great distances. The jellyfish are most often spotted during the late summer and autumn, when they have grown to a large size and the currents begin to sweep them closer to shore.
Like other jellyfish, Lions manes are capable of both
sexual reproduction in the
medusa stage and
asexual reproduction in the
polypstage.
[5] Lion's mane jellyfish have four different stages in their year-long life span: a larval stage, a polyp stage, an ephyrae stage, and the medusa stage.
[5] The female jellyfish carries its fertilized eggs in its tentacle where the eggs grow into larva. When the larva are old enough, the female deposits them on a hard surface where the larva soon grow into
polyps. The polyps begin to reproduce asexually, creating stacks of small creatures called ephyraes.
[8] The individual ephyraes break off the stacks, where they eventually grow into the medusa stage and become full grown jellyfish.
[9]
Sting and human contact
Most encounters cause temporary pain and localized redness.
[10] In normal circumstances, and in healthy individuals, their stings are not known to be fatal. Historical remedies have included: vinegar,
isopropyl alcohol, and
meat tenderizer.
[11] However, none of these remedies are proven as first aid for jellyfish stings, and as such none are recommended for any jellyfish sting treatment. However, severe body contact with the lion's mane jellyfish, such as swimming straight through a huge one, may be deadly.
[12]
On July 21, 2010, around 150 people are thought to have been stung by the remains of a lion's mane jellyfish that had broken up into countless pieces in
Rye,
New Hampshire, in the United States. Considering the size of the species, it is possible that this mass incident was caused by a single specimen.
[13]
In popular culture
The lion's mane jellyfish appears in the
Sherlock Holmes short story "
The Adventure of the Lion's Mane" published in
The Case-Book of Sherlock Holmes. Holmes discovers at the end of the story that the true killer of a school professor who died shortly after going swimming (shouting "the lion's mane" before he succumbed) was actually this jellyfish. Suspicion was originally laid upon the professor's rival in love, until the latter was similarly attacked (he survived, although badly stung). In the context of the story, it is only because the school professor has a weak heart that he succumbs, as is confirmed by the survival of the second victim.
On the popular television program
QI the show claimed that the longest animal in the world was the lion's mane jellyfish, but this was later corrected - as the longest in the world is actually the
bootlace worm.
