Beach-goers have been warned to be extra careful on Donegal’s beaches after a Portuguese Man O’War jellyfish washed up.
The creature was snapped lying on the sand on Derrybeg beach.
Experts have warned other beachgoers not to touch the creatures which are usually are covered in venom-filled nematocysts.
These are normally used to paralyse and kill fish but can cause a very nasty sting to humans.
They can be fatal for those who suffer a severe reaction.
Dr Donal Griffin, of Fair Seas Ireland, told BBC News NI that the public should leave the creatures “well alone”.
He said the photo of the creature shared online was probably a Man O’War and warned people to keep their distance.
Dr Griffin said: “You can see the gas filled bladder, the colours are right, the tentacles, the way they drape down, are right.
“They can be quite exciting to see because they are that little bit more unusual, little bit more exotic.
“And even when washed up on the beach, when they are dead or dying, their sting cells can still trigger”.
Dr Griffin urged anyone who sees another Portuguese Man O’War to report the sighting to the National Biodiversity Data Centre in the Republic of Ireland.
