Swimmers have been warned to be wary of the Lion's Mane jellyfish after the Irish Coast Guard received reports of swimmers suffering painful jellyfish stings.

There are five native jellyfish species in Ireland: Barrel, Blue, Common (Moon), Compass and Lion’s Mane

According to the HSE: "The Lion’s Mane is the most serious jellyfish in Irish waters".

The sting from a Lion's Mane jellyfish is the worst of the native jellyfish.

According to the HSE, the Lion’s Mane jellyfish prefers the cooler waters of the Irish Sea and especially the waters off Dublin.

"Recently an increase has been seen in waters off the East Coast and some very large jellyfish have been observed on beaches in this area," the HSE states.

All jellyfish possess stinging cells, “stingers”, on their tentacles, HSE information outlines.

"Brushing against tentacles can cause the release of these stingers which contain venom (poison). Depending on the type of jellyfish, the stingers may not be sharp enough and long enough to pierce the skin and the skin forms a natural barrier to most stings. More delicate areas, such as the eyes and lips, might be more easily pierced.

"However, the Lion’s Mane stinging cells are much sharper and can pierce skin easily resulting in a painful sting. Jellyfish stings in Ireland are not usually life threatening and just require basic first aid and simple pain relief," the HSE says.

A sixth type (Pelagia noctiluca) occasionally makes an appearance in Irish coastal waters, the HSE also outlines.

"There have been rare reported sightings of the Portuguese Man O’War in Irish waters. The Portuguese Man O’War is not a true jellyfish but is closely related to the jellyfish family and can give a bad sting," according to the HSE.