British Jellyfish

Lion's Mane Jellyfish
Cyanea capillata

  Photograph by Wayne Curtis (Sunderland)

British distribution:

Common off the west coast of Scotland and in the northern North Sea. Every year they are stranded on the shore and against salmon cages off west Scotland. Off north-east England the occurrence on the shore is dependent on easterly winds, but they seem to occur in most years.
As you go further south their frequency decreases, but they occur off both the Welsh coast (west) and Yorkshire coast (east) regularly.

Do they occur in the Irish Sea?  Yes, at least one BMLSS record. Recorded as far south as Lundy (Bristol Channel).
Records in the English Channel are unusual. Do they occur, how often?


Books say the sting is powerful (Hayward & Ryland) but frequently the sting is innocuous. However, divers who have been stung in the face report it like a wasp sting, and a diver who got stung in the eye was treated for an abscess.

Specimen in Loch Fyne (External Site)

Cyanea lamarcki.
No common name: Norwegians call it Blue Jellyfish, or Bluefire

Photograph by Trevor McDonald  (Aberdeen)

British distribution:

It has the same distribution in British seas as Cyanea capillata but is not nearly as common. Both Cyanea jellyfish will occur together sometimes. Common off Scotland. Recorded as far south as Lundy (Bristol Channel) and around the southern coast of Cornwall.


Most reports say it is innocuous. Not enough information, but probably similar to Cyanea capillata.

We have at least one report of loose strands of tentacles of this jellyfish can sting sensitive sting (Peter Glanvill)

7 July 2014

Thousands of jellyfish were washed ashore at Polzeath, north Cornwall. Easily over a thousand Bluefire Jellyfish, Cyanea lamarckii; up to a hundred Moon Jellyfish, Aurelia aurita, and two juvenile Compass Jellyfish, Chrysaora hysoscella, were noted. A few of the Bluefire Jellyfish must have been about 35 cm diameter, but most were much smaller, with lots of very juvenile specimens.

Report & Photographs by David Fenwick Snr
on NE Atlantic Cnidaria facebook


3 September 2010
Three Bluefire Jellyfish, Cyanea lamarkii, were washed up at Eccles-on-sea, Norfolk.
Report and Photograph by Neil Bowman

8 July 2010
My dog jumped in a rock pool at Paignton by Tor Bay, Devon, and when I put my hands in to haul him out, I got stung by some small jellyfish. These were the Bluefire, Cyanea lamarkii, and they stung like a bee sting. I managed to get stung again on the ankle but rinsed it at home with cold water and now it feels like nettle stings!  They ranged in size from 3 cm in diameter to 25 cm and some of the larger ones were brownish and could be a different species.

Report and Photographs by Aaron Husain

3 July 2010
Whilst walking along the beach at Seasalter, Kent, there were a lot of seemingly dead Moon Jellies and beautiful purple flower like Cyanea lamarkii jellies washing up on the beach. Probably saw 100 or so along a quarter mile stretch of beach.  I just wondered what may have killed them?  The place I saw them is where the 'Swale'  meets the North Sea... They were almost certainly washed on to the shore with tides, currents and offshore winds.

Report by Leo Charles
June 2010
Bluefire, Cyanea lamarkii, Jellyfish are washed up annually on Par Beach, Cornwall, with both blue ones and brown coloured ones.
Report by David Fenwick on Facebook
June 2006
I spotted loads of jellyfish at a beach on the Lleyn Peninsula in north Wales. Mostly they were Moon Jellyfish, but there were also some as shown in the photograph on the left. The diameter of the bell was about 25 mm. These were probably Bluefire Jellyfish, Cyanea lamarckii.
Report and Photograph by David Meiklejohn

16 July 2005
A Bluefire Jellyfish, Cyanea lamarckii, was found in the shallows at Shoreham Beach, West Sussex.

Bluefire Jellyfish (Photograph by Carole O'Connor)
Report and Photograph by Carole O'Connor
This species has not been recorded recently off the Sussex coast although it has been discovered in the shallow seas around the rest of Britain. It is one of the lesser known jellyfish that frequent the seas around the British Isles, although there have been more than the usual number of reports from other shores this year.
Marine Life Reports for Sussex

Spring (probably June) 2005
This specimen of the Blue Jellyfish, Cyanea lamarckii, was washed ashore on the Isle of Man with half a dozen Moon Jellyfish, Aurelia aurita.

Photograph by Gary Lacey (Isle of Man)

Report and Photograph by Gary Lacey (Isle of Man)
7 June 2003
Hundreds of the Blue Jellyfish, Cyanea lamarckii, were seen whilst diving around the Lizard up to the Helford river in Cornwall. Also seen in the Helford river was a Lion's Mane Jellyfish, Cyanea capillata, and a Compass Jellyfish, Chrysaora hysoscella.
The staff at Porthkerris divers have recently seen vast numbers of By-the-Wind Sailors, Velella velella, which turned the beach blue!
Report by Paul Parsons
on the  Marine Wildlife of the North-east Atlantic Ocean Group
7 June 2003
Today Anne and David Williams found and photographed specimens of the Blue Jellyfish, Cyanea lamarckii, at Godrevy, St Ives Bay, Cornwall. There have been several other reports of this species in the past few weeks.
Report by Stella Turk MBE on the Cornish Mailing List

30 July 2002
Over the past  five weeks during shore surveys on the west coast of Scotland, two specimens of the Blue Jellyfish, Cyanea lamarcki were seen: in the Sound of Jura and near Loch Ewe in Wester Ross. Both were under 10 cm in diameter and a vivid blue. Today, a report reached me of a diver who was stung on the wrist off the island of Canna, probably by this species, and spent two and a half painful days in hospital. This species is much more unpleasant than the common reddish-brown Lion's Mane Jellyfish, Cyanea capillata, and seems to be much less common.

Report by Robert Harvey
BMLSS Jellyfish
Jellyfish Stings

Blue Jellyfish at Worm's head (Photograph by Roy Dale)26 June 2002
A jellyfish was discovered alive in a rockpool on Worm's Head, the "wurm"-shaped rock island connected at low tide by a causeway to the western end of the Gower peninsular at the southern end of Rhossili Bay in south Wales. By comparing the size of the periwinkle in the pool the viewer can see the size is about 100 mm in diameter. The jellyfish has been identified as the Blue Jellyfish, Cyanea lamarckii. Inverted the jellyfish was white underneath. It quickly righted itself.

Report by Roy Dale via UK Wildlife

BMLSS Cnidaria
Cnidarian Mailing List

Rhizostoma  pulmo
Common names not often used include:
Barrel Jellyfish, Football Jellyfish, Root-mouthed Jellyfish.

Sometimes known as the Barrel  jellyfish this specimen was 40cm  in diameter.  Accompanied by juvenile Scad.

Rhizostoma pulmo
Photograph by Paul Parsons

British distribution:

Rhizostoma Jellyfish washed at Beer, Devon on 7 May 2002 (Photograph by Ceri Jones)Particularly abundant in the Irish Sea. Occurs all around the British Isles, and is common off the west coasts, e.g. Cornwall.
Full distribution details not collated. On file somewhere.
Occurrence in eastern English Channel and southern North Sea may be infrequent as no reports are on file.


Reported not to sting at all. However, I may have one record, so like other innocuous animals and plants the sting can be felt through broken skin and will cause a rash in the sensitive.

Moon Jellyfish
 Aurelia aurita

Moon Jellyfish
Photograph by David Hall

This jellyfish is sometimes called the Common Jellyfish. This name could be misleading and be given to the jellyfish that are common in a particular area, so it would be best to discourage the use of this name.

British distribution:

Abundant of all British coasts, more often seen on the west coast when in is blown inshore, but it will go through its life cycle in shallow water and even harbours. Most reports come in from the Bristol Channel and south Wales, but it may be so familiar elsewhere that it is not worth a mention.
In the eastern English Channel, there may be some years when it is not abundant. This may be just inshore waters. It was rarely seen from the shore off Sussex from 1980 to 1990 (e.g. not seen in 200 visits to the shore, and 60 dives). It is found in harbours and brackish water.


It has been long regarded as innocuous. However, there has been more than one report in British seas of this species causing a rash (from my records) and even pain (Paul Cornelius). Other reports are of itching and distinct reddening of the skin by skin divers swimming through a swarm.
9 July 2015
Thousands of Moon Jellyfish, Aurelia aurita, were washed ashore at Westward Ho! north Devon. And probably in other places on the rocky shore facing the Atlantic Oceans. It was a prelude to numerous strandings all around the British coasts, depending on which way the wind was blowing. 

Moon Jellyfish
Photograph by Thiago Bosque


Compass Jellyfish
Chrysaora hysoscella
The other name of Sea Nettle, I have never heard used and it is not so descriptive.

  Photograph by Steve Barker (Shoreham-by-Sea 1979)

British distribution:

All around the British Isles. Not in the large swarms of other jellyfish and often seen singly. It is uncommon, or rare, off the Scottish coast.

7 August 1998
Hundreds of Compass Jellyfish, Chrysaora hysoscella, were seen 3 miles off  Torbay.



Unknown from the BMLSS records. Otherwise reports are of it as a stinger and as harmless.
I am wary of using foreign records, because the Pacific reports may be of a similar looking but different species.


29 July 2001
There were a considerable number of Compass Jellyfish, Chrysaora hysoscella, off Hallsands Beach, south Devon. I counted well over a hundred. There was also a small (25 cm across) Cyanea which was bright blue, it could have been Cyanea lamarcki due to its size, colour and lack of sting (I brushed past it whilst swimming).

Report by Chris Davis (Devon WWT)
Richard Lord also reported Compass Jellyfish  from  L'Ancresse Beach, on the north coast of Guernsey.                Notes.
Original Marine Wildlife of the North-east Atlantic Ocean Group Report (Link)

4 August 2002
Quite a few largish Compass Jellyfish, Chrysaora hysoscella, around just now (15 cm diameter) seen close to my local pier (West Loch Roag) - I saw six actively swimming ones in an area about 100 metres square.

More interesting is the reported death and destruction wrought on Salmon farms on the east coast of Lewis by small jellyfish clogging the salmon gills. A fish farmer claims its a foreign species introduced by ballast water, but I need to try and confirm this. Apparently they are 'solid down to 15 metres' so there must be a lot of them; allegedly the mortality is so great that local facilities for disposal are overwhelmed and they have to take them to Shetland for disposal!
PS:  These are probably Mauve Stingers, Pelagia noctiluca.

Report by Paul Tyler

9-10 August 2003
Whilst travelling out from Littlehampton marina, West Sussex, on Friday night, we passed four very large Rhizostoma pulmo and counted 21 Compass Jellyfish, Chrysaora hysoscella, over a period of an hour.
On Saturday morning we went armed with cameras. Within 20 minutes we had found three Rhizostomas. The last two were close enough to see the juvenile fish? swimming alongside. We dived with the third Rhizostoma for about 30 minutes. It stayed within the top 3 metres of water.
We saw a third as we headed back to the marina on a different heading.
We also spotted 8 Compass Jellyfish.

Report by Paul Parsons on the Marine Wildlife of the North-east Atlantic Ocean Group

9 September 2006
Steve Trewhella and Julie Hatcher found about sixteen Compass Jellyfish, Chrysaora hysoscella, washed up on the beach at Sandymouth Bay, near Bude in north Cornwall.

Amphipod Hyperia galba on a Compass Jellyfish
from the Channel Islands
Photographs © by Richard Lord (Guernsey)

A number of these contained the symbiotic amphipod crustacean Hyperia galba alive inside them. These are remarkable little creatures with large green eyes, and as adults they are only found in jellyfish.

Report by Doug Herdson (National Marine Aquarium at Plymouth)
on the Marine Wildlife of the North-east Atlantic Ocean Group
BMLSS Jellyfish-1
BMLSS Hyperia
Portuguese Man-o'War,
Physalia physalis

British distribution:

Off the west coast of Britain in some years. Unpredictably frequency. May occur for several years in a row then absent for some years, perhaps five, perhaps more. CBRU will have records. Channel Islands coast as well in 1999 and probably other years.
Careful with erroneous reports with this species.


Reported to be fierce, but not always. Certainly painful if the diver is caught in the face. Leaves a weal that fades after a few days. It has caused two deaths.

Cornish Report

Mid September 2017

Portuguese Man-o'-War
Photograph by Martin Cavell

Portuguese Man-o'-War, Physalia physalis, have been washed up on widespread western shores from the Isles of Scilly  to Scotland. Beware of the venomous tentacles that still produce a severe sting even when stranded ashore. Hundreds of this venomous siphonophore were washed up on the sandy beach at Sennen Cove, Cornwall.

Image Report by Martin Cavell
on British Marine Life Study Society  facebook


We were able to visit the upper part of Hannafore Beach, Looe, on Friday 10 January 1998 in the immediate aftermath of the storms, and to mange a couple of hours rockpooling further down the reef during during the low spring tide (which was not as low as predicted, probably due to the sustained winds).

Portuguese Man o'War
(Photograph by Jane Herbert, Editor of the Cornwall Wildlife Trust site)

Portuguese Men o'War: Further Information on the Cornwall Wildlife Trust site.

 The foreshore and strandline  were strewn with an extraordinary number of empty mollusc shells of many species, a rough count putting the density at several thousand per square metre. Large numbers (several hundred) of By-the-Wind Sailors, Velella velella, were cast up, both as complete dead specimens and as dried sails, together with a couple of Portuguese Man-o'War, Physalia physalis, which were badly damaged and without their stinging tentacles. A prolonged search did not reveal any specimens of the pelagic snail Janthina janthina which preys on these colonial hydroids (both Velella and Physalia are not true jellyfish).                                                                                                     Jon Makeham (Looe)

Other Siphonophores

String Jellyfish  Apolemia uvaria

Also known as the Pearl-chain Jellyfish, this species is increasingly seen by divers off the south-west of England, Wales and Ireland. It forms long strings that can be several metres long. This is a mid-water oceanic species seen near the coast in the proximity to deep water only. This species can sting sensitive human skin.

2 October 2011
A pelagic string, probably the Agalma elegans, was seen at Evie Bay, Orkney Islands, Scotland.

Report and Photograph by Penny Martin (Orkney) on flickr
September 2007
In the last three weeks we have been observing the fragile String Jellyfish, Apolemia uvaria, in areas of plankton over deep water in various places off Land's End, Cornwall.
Report by Rory Goodall (Elemental Tours)

By-the-Wind Sailor,
Velella velella

Velella (Photograph by Steve Trewhella)   Photograph by Steve Trewhella

British distribution:

Off the west coast of Britain in some, or most? years. Unpredictable frequency. Reports in almost all years, but the very large swarms (armada) washed up may occur perhaps twice a decade, on one occasion in successive years.


None, I have heard of.

Small Oceanic Medusae


Gonionemus murbachii
This one can attain a diameter of 20 mm.

Please consult specialised texts for more information on the small deep water medusae.

7 August 2002
An invasion of tiny (12-15 mm) jellyfish has killed about 900 thousand Salmon at two fish farms in Loch Erisort on the Isle of Lewis in the Outer Hebrides. The offending deadly organism travelling like large 15 metre deep clouds through the sea have been identified as the narcomedusan Solmaris corona, and also identified three other hydromedusans that were abundant in the blooms as Phialidium, Leuckartiara octona and Catablema vesicarium.
These oceanic species will not be listed in the popular guides. The Narcomedusae are gelatinous hydrozoans, abundant at depths between 100 and 1000 metres, an area known as the midwater. These rarely seen jellyfish are most easily recognized by the unique location of their primary tentacles. Unlike other jellyfish, the tentacles of the Narcomedusae originate well above the bell margin. These tentacles are often held in front of the jellyfish as it swims through the midwater. They feed on zooplankton.
They have been recorded in the north-eastern Atlantic Ocean but they are rarely mentioned.

Original Report by Claudia Mills via the Cnidaria Discussion List
and Paul Tyler

Crystal Jelly

The Crystal Jelly : Aequora vitrina is a mesmerising hydroid medusa, often found floating in the water column. It's incredibly fragile yet manages to survive the rough seas surrounding Cornwall and can be found quite often during summer months.

Crystal Jelly, (Photograph  by Penny Martin, Orkney)12 July 2011
A Crystal Jelly, Aequorea species was discovered in the surface waters around Birsay, Orkney Islands, Scotland.

Report & Photograph © by Penny Martin (Orkney)

The prevalence of this seldom recorded species of hydromedusan is not known.

Featured Species: Aequorea
Another Report

BMLSS Aequorea Notes
Cornish Report (Aphtomarine)

Stalked Jellyfish

These are sessile species without a medusae stage.


An online guide to the Stalked jellyfish (Stauromedusae) found 
around the coastal waters of the United Kingdom and Ireland. 
Includes notes on their identification, and where and how to find them.

Stauromedusae UK is an online resource dedicated to marine animals within the order Stauromedusae, species are commonly and collectively known as Stalked Jellyfish. The Stauromedusae is an Order within the phylum Cnidaria, a phylum which contains more well known animals such as jellyfish, sea anemones and corals. Stalked Jellyfish can be found on algae or rocks in shallow coastal waters and intertidally on shores around the United Kingdom and Ireland. Stalked Jellyfish are not that well known or recorded, they can be quite small and are often well camouflaged and have a tendency to seemingly appear and disappear from pools overnight.


Jellyfish swimming

When a medusa swims, how is the bell refilled with water after a contraction? Is the refilling done passively with the surrounding water pressure, or can the jellyfish do anything actively to hurry up the process?

Karin Nordström (Zoologiska Institutionen, Lunds Universitet, Helgonav. 3, 223 62 Lund, Sweden)
046-222 93 40
0739-822 408

The bell is passively refilled due to the ambient pressure of the water.
Terry L. Peard, Ph.D. (Indiana Univ. of PA)

For jellyfish that I am familiar with (the hydromedusa) refilling is passive in the sense that muscles are not directly involved. However during the contraction phase energy is stored in elastic fibres in the jelly of the bell which are stretched as the bell becomes thicker. Then when the swimming muscles relax this energy is released by the bell returning to its hemispherical shape and the jelly thinning.  This draws in water through the velar opening, thus the shortening elastic fibres create a negative pressure in the bell cavity during refilling.  This has been described by Bill Gladfelter for Polyorchis (sorry the ref is not at hand but I believe it was Biol. Bull about 1978).  Others have more recently worked on the inertial forces involved with masses of water being transported in the bell cavity and the vortices induced.
Andy Spencer (Bamfield Marine Station, Canada).

Hi Karin

The idea seems to be that the jelly layer in the middle is of different thicknesses and stiffnesses.  The stiff, thick stuff is in plates, separated by "hinges" of narrow bands of thinner, softer material.  This allows the animal to retain a shape while being deformed by the contraction of the swimming muscles.  Then when the muscles relax, the
elastic rebound of the jelly skeleton pulls the animal back into the more flattened, umbrella shape.  And this shape has a larger enclosed volume.
So the water is sucked back into the umbrella passively.

There's an old paper by William Gladfelter on this.  I can't remember where.

Liz Francis

Detailed biomechanics of jellyfish medusa swimming 1991

Mauve Stinger
Pelagia noctiluca,
The common name is from the Mediterranean.

Early December 2007
Mauve Stingers, Pelagia noctiluca, have been reported around the Scottish isles of Eigg and Skye, but the numbers are not known.

Argyll News by Telephone

21 November 2007
A massive swarm of billions of jellyfish known as Mauve Stingers, Pelagia noctiluca, covering several square miles and to a depth of 11 metres, wiped out Northern Ireland's only Salmon farm, killing more than 100,000 fish at Northern Salmon Co. Ltd. The Salmon were kept in two large nets about a mile off the coast of the Glens of Antrim, north of Belfast.  The Salmon hatchery is on Glenarm River deep within the Castle Estate and the smolt are transferred by helicopter to pens in Glenarm Bay. The extent and size of the jellyfish swarm was unprecedented.

CNN International News Report
BBC (Northern Ireland) News Report

Pelagia is more typical of warmer waters but does regularly occur in County Cork, Irish waters during October-December when it is carried up here via the Jet Current (a current that runs up along the Bay of Biscay and off the west coast of Ireland). So its not unusual to see Pelagia in the late autumn. However, it is probably unusual to see such numbers and such widespread occurrence i.e. offshore, west + north coast of Ireland and now Scotland (do you know where in Scotland they are washing up?). How far they head north depends on the strength of the Jet current, which varies from year to year, and so is probably very strong this year. There are records of Pelagia washing up in large numbers off the coast of Ireland going back 100 years (Delap sisters), more recent reports off the west coast of Ireland (1998), and in the mid 1960s, enormous numbers were reported in the Irish Sea.

Report by Thomas Doyle (University College Cork) on the Cnidaria Forum

16 November 2007
I found a dead Triggerfish, Balistes capriscus, on Balnakeil Beach by Durness (north coast of Scotland) last week, washed up following recent gales. It came in with thousands of little jellyfish. These jellyfish were very small and blew away quickly on the wind.
These were Mauve Stingers, Pelagia noctiluca. (AH)

Report and Photographs from Donald Mitchell

3 November 2007
Whilst surfing we had to come in because a shoal of jellyfish engulfed us.  They were about an inch across with little on no hanging tentacles; they were purple/ blue in colour and numbered in their thousands. Surfing at Hornish Point, South Uist, Outer Hebrides, Scotland at 57-24N  07-24 W

Photographs of Pelagia noctiluca by Darrell Campbell

Their sting was a bit nippy but not as bad as the larger brown jellyfish we normally get and they made me come out in a raised rash on my hands and face which stung long after I was dry also the sting (thankfully) did not return when I showered later that day.
The next day there were a few washed in on the beach 57-40N  07-21W a considerable distance from where the shoal was, there were none in the water.
I have never seen this type of jellyfish in 15 years surfing in Uist, never mind the thousands that we saw that day.
These were Mauve Stingers, Pelagia noctiluca. (AH)

Report from Daniel Skivington

12 January 1995
A dead Triggerfish, Balistes capriscus, was found washed up at Harlyn Bay SW8775, Cornwall, together with a large number of small jellyfish which were identified as Pelagia noctiluca.
Cornish Marine Life Records (Ray Dennis) 1995


Photograph  by Richard Lord (Guernsey)7-8 April 2004
Beautiful but if a not deadly jellyfish, the Mauve Stinger, Pelagia noctiluca, can impart a nasty sting to the unlucky swimmer. They are now being seen around the Channel Islands. I found one stranded in a rock pool by Lithou Island on the east coast of Guernsey on 7 April, 2004 and another stranded in a rock pool on the east coast south of St. Peter Port on 8 April 2004. Strandings of this jellyfish seem to occur often in spring around these islands. They are not common around the rest of the British Isles but there are reports in some years off the south and west coasts, especially off Cornwall.

Report and Photograph © by Richard Lord (Guernsey)
on the Marine Wildlife of the North-east Atlantic Ocean Group
British distribution:

Rare. Swarms washed up about once a decade on the Cornish coast. CBRU have records. Not checked yet. One BMLSS record from Lundy (Bristol Channel).

23 June 2003
There was a mass stranding of 500+  Mauve Stingers (small jellyfish), Pelagia noctiluca, at Porthcothan, Cornwall. This is the most unusual of the British species of pelagic jellyfish to wash up, but large swarms occur in years of abundance.
Amongst the Sea Rocket, Orache etc, on the strandline, a Peanut Plant has taken root.

Report by Jane and Nick Darke via the Cornish Wildlife Mailing List
Sea Beans page

10-12 June 2003
Large numbers of pelagic scyphozoan Pelagia noctiluca, the Mauve Stinger (small jellyfish), were spotted all along the east coast of Lundy, Bristol Channel. I was participating in an English Nature drop-down video survey  and found dense shoals of this beautiful pelagic jellyfish. The density was probably in the region of 15 to 20 individuals per square metre at the surface.
NB: Swarms of this jellyfish are unusual in British seas.

Report by Ian Reach (Maritime Protected Areas Officer, English Nature)
on the  Marine Wildlife of the North-east Atlantic Ocean Group
By1 February 2003 the westerlies have blown plenty of By-the-Wind Sailor, Velella velella, and the Mauve Stinger, Pelagia noctiluca, on to Sennen Cove, Cornwall, above the high tide mark.
Report by Darren Smith on the Cornish Mailing List

28 January 2003
Exceptionally, between 100 and 200 of the small jellyfish called Pelagia noctiluca, the Mauve Stinger or 'Nightlight' jellyfish were also discovered. These swarms seems to occur about every five or ten years, and is easily recognised by the pustules that cover the small (rarely more that 75 mm across) dome or umbrella.

Report by Paul Gainey from Stella Turk MBE on the Cornish Mailing List
  • September - November 1998
  • Large numbers of jellyfish, Pelagia noctiluca, have been stranded over the period September to early November 1998 on the west coast of Ireland. This is an exceptional event and it is the first time they have been recorded in such numbers in Irish waters.

  • The recent event started off Co. Donegal in August and has spread to the west coast of Ireland where, during October, it has occurred in sufficiently large numbers to kill cultivated salmon.
    This jellyfish has a potent sting.
    Full Report


    Despite being a small jellyfish, it has a reputation as a stinger, in the Mediterranean.

    Reuters News Report  25 August 1999

    This is an extract I found as a News Report on the Reuters Environment site.

    But the snake-like venom of the Pelagia noctiluca - the jellyfish glows a purple yellow in the sea at night - can in rare cases cause life threatening allergic reactions such as anaphylactic shock.

    However, no such cases have been reported this summer and usually a quick dousing with alcohol or vinegar is enough to calm a sting from the jellyfish which commonly measures 10 cm (four inches) in diameter and has eight tentacles dangling below.

    Go to Treatment of Stings

    Vinegar is only useful, but very effective, for preventing further discharge and removing adherent tentacles after cubozoan stings (Williamson et al 1996). It may make other stings worse (Fenner and Fitzpatrick 1986, Fenner et al 1993) and should
    not be used.

    Sting Pain Index


    Avian, M. 1986. Temperature influence on in vitro reproduction and development
    of Pelagia noctiluca (Forskal). Bollettino di Zoologia 53: 385-391.

    Goy, J. 1984. Climatic fluctuations of the jellyfish Pelagia noctiluca
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    Goy, J., P. Morand, et al. 1989. Long-term fluctuations of Pelagia noctiluca
    (Cnidaria, Scyphomedusa) in the western Mediterranean Sea. Prediction by
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    (Forsskal, 1775). J. Exp. Mar. Biol. Ecol. 126: 259-270.

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    Pang, K. A. and M. S. Schwartz. 1993. Guillain-Barre syndrome following
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            In French

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    Lisa-ann Gershwin

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