''Rhizostoma pulmo'', commonly known as the barrel jellyfish, the dustbin-lid jellyfish or the frilly-mouthed jellyfish, is a scyphomedusa in the family

Rhizostomatidae Rhizostomatidae is a family of cnidarians in the class Scyphozoa. Genera and species According to the World Register of Marine Species, 11 extant species are in four extant genera within this family: *Genus ''Eupilema'' **'' Eupilema inexpect ...

. It is found in the northeast

Atlantic The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe an ...

, and in the

Adriatic The Adriatic Sea () is a body of water separating the Italian Peninsula from the Balkans, Balkan Peninsula. The Adriatic is the northernmost arm of the Mediterranean Sea, extending from the Strait of Otranto (where it connects to the Ionian Sea) ...

Mediterranean Sea The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the ea ...

Black Sea The Black Sea is a marginal mediterranean sea of the Atlantic Ocean lying between Europe and Asia, east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. It is bounded by Bulgaria, Georgia, Roma ...

and

Sea of Azov The Sea of Azov ( Crimean Tatar: ''Azaq deñizi''; russian: Азовское море, Azovskoye more; uk, Азовське море, Azovs'ke more) is a sea in Eastern Europe connected to the Black Sea by the narrow (about ) Strait of Kerch, ...

. It is also known from the southern

off the western South African coast and into

False Bay False Bay (Afrikaans ''Valsbaai'') is a body of water in the Atlantic Ocean between the mountainous Cape Peninsula and the Hottentots Holland Mountains in the extreme south-west of South Africa. The mouth of the bay faces south and is demarcat ...

.Branch, G.M., Branch, M.L, Griffiths, C.L. and Beckley, L.E. 2010. ''Two Oceans: a guide to the marine life of southern Africa'' It is common in the

Irish Sea The Irish Sea or , gv, Y Keayn Yernagh, sco, Erse Sie, gd, Muir Èireann , Ulster-Scots: ''Airish Sea'', cy, Môr Iwerddon . is an extensive body of water that separates the islands of Ireland and Great Britain. It is linked to the Ce ...

. It typically is up to in diameter, but can exceptionally reach or larger, making it the largest jellyfish in British and Irish waters (''

Cyanea capillata The lion's mane jellyfish (''Cyanea capillata''), also known as the giant jellyfish, arctic red jellyfish, or the hair jelly, is one of the largest known species of jellyfish. Its range is confined to cold, boreal waters of the Arctic, northern ...

'' reaches an even larger size, but is generally smaller in Britain). On 13 July 2019, wildlife biologist Lizzie Daly dived off the coast of

Cornwall Cornwall (; kw, Kernow ) is a historic county and ceremonial county in South West England. It is recognised as one of the Celtic nations, and is the homeland of the Cornish people. Cornwall is bordered to the north and west by the Atlantic ...

in the United Kingdom, along with the underwater cinematographer Dan Abbott. The two divers shared their encounter with a human-sized barrel jellyfish, ''Rhizostoma pulmo''. The species could typically grow up to one meter (3.2 feet) and weigh up to 25 kilograms (55 lbs). However, they are not larger than the

lion's mane jellyfish The lion's mane jellyfish (''Cyanea capillata''), also known as the giant jellyfish, arctic red jellyfish, or the hair jelly, is one of the largest known species of jellyfish. Its range is confined to cold, boreal waters of the Arctic, northern ...

. ''Rhizostoma pulmo'' is moderately venomous but not as deadly as other species. Effects include a burning sensation on the skin, dermatitis, and ulcers which confirms it is toxic to humans. However, it does not pose a serious threat to humans. It is a favourite food of the

leatherback turtle The leatherback sea turtle (''Dermochelys coriacea''), sometimes called the lute turtle or leathery turtle or simply the luth, is the largest of all living turtles and the heaviest non-crocodilian reptile, reaching lengths of up to and weights ...

In Asia, they are a source of bioactive compounds used in traditional food and medicine. One study indicates that washing in aqueous solutions and the separation of high molecular weight proteins from the extract, e.g., by membrane filtration, could be a way to remove possible toxic compounds from jellyfish extracts and to concentrate potentially bioactive soluble compounds. The potentially active soluble components may have uses as nutraceutical and cosmeceutical ingredients.

References

External links

* *
''Giant jellyfish the size of a human spotted by divers off English coast''
(video)
Barrel Jellyfish
article at

Atlas Obscura ''Atlas Obscura'' is an American-based online magazine and travel company. It was founded in 2009 by author Joshua Foer and documentary filmmaker/author Dylan Thuras. It catalogs unusual and obscure travel destinations via user-generated content ...

, August 9, 2021 Rhizostomatidae Animals described in 1778 {{Scyphozoa-stub