One of the world's largest jellyfish species has been spotted along Scotland's coastline and beach-goers are being warned to keep their distance.

The magnificent Lion's Mane jellyfish, which can grow to around two metres in size, has a pretty powerful sting that can produce blisters, irritation and muscular cramp.

In extreme cases, it may even affect respiratory and heart function but in normal circumstances and healthy individuals their stings are not known to be fatal.

Several have been reported along the Scottish coast line this summer, with the warming seas prompting a jellyfish bloom.

Susie Raeburn and her 16-month-old grandson found one Lion's Mane washed up on Portobello beach in Edinburgh at the weekend.

"My husband had gone down to the water with my grandson, the whole beach was covered in jellyfish but this was the only red one," says Susie.

"There was another granddad there with his wee boy, and together they counted more than 200 small jellyfish in their small section alone."

Susie posted a picture of her jellyfish find online and was surprised by the number of people who said they had seen similar ones along Cramond and Musselburgh.

Dr Peter Richardson, head of ocean recovery at the Marine Conservation Society, confirmed Susie's jellyfish is the famous Lion's Mane.

"We run a national survey every year and the Lion's Mane is one of the jellyfish usually reported," he says.

"We tend to see them more in the north. It's our biggest jellyfish and the tentacles can have quite a powerful sting - they have long thin tentacles which can reach up to 30ft in length."

The Lion's Mane though, is a naturally passive resident of the sea and a sought-after sight among divers who appreciate its hypnotic dance through the currents.

Quite weak in body, they barely have enough strength to pulse themselves along and use their tentacles like a large net to catch small fish, plankton or even smaller moon jellyfish.

"Where you find moon jellyfish, you're likely to find a few Lion's chomping down on them," says Peter.

"Jellyfish have an incredibly successful design, they've been around for about 500 million years and are generally harmless."

With no brains, no heart and no blood, jellyfish are captivating creatures, known for drifting to and fro at the whim of ocean currents.

They've been residents of the seas for millions of years and more species are still being uncovered.

The golden jellyfish found in the Pacific nation of Palau spend much of their lives on the move during a daily migration that follows the sun's arc across the sky.

Before sunrise, the jellies cluster along Jellyfish Lake's western shore. Each morning, when the first rays of sun appear, they begin to swim toward the light.

Pumping water through their bells, they use a type of jet propulsion to follow the sunlight until they reach the other side of the shore.

In Scotland, we have a collection of regular jellyfish visitors, identifiable by their striking shapes and patterns.

If you spot any jellyfish in our coastal waters, you can report it to the Jellyfish Survey, run by the Marine Conservation Society.

"We started it in 2003 and hope to gather a long-term data set," says Dr Richardson.

"If you spot a jellyfish, look but don't touch as some species can sting."

You can download the Jellyfish ID Guide to help you figure out what kind of jellyfish you've found.

The Lion's Mane is fairly common and large - often growing to dustbin lid-sized proportions.

Some individuals even rival in size the blue whale, the largest animal in the world.

The largest recorded specimen found, washed up on the shore of Massachusetts Bay in 1870, had a bell with a diameter of 2.3m (7ft 6in) and tentacles 37m (121.4ft)-long.

They are umbrella-shaped and reddish brown in colour with long thin tentacles that can reach up to 30ft in length and produce a sting if touched.

The mouth of the jellyfish can be found under its bell-shaped body surrounded by tentacles that are divided into eight clusters of up to 150 tentacles each.

These tentacles contain poison that stuns prey when they are enveloped.

It also produces light, making it glow in dark waters.

Moon jellyfish wash up regularly on most beaches and are a scrumptious meal to the Lion's Mane.

They're umbrella-shaped and around 40cm in diameter with a transparent shaped bell edged with short hairlike tentacles.

They also have four pinky/purple spots on the top that are actually the creatures gonad rings.

Their stings are like minute harpoons fired by springs and are not powerful enough to pierce our thick skin, though you may feel a mild sting.

These are smaller than moon jellyfish, roughly the diameter of a ruler and are very distinct in colour.

They are usually found with a pale umbrella-shaped bell and brownish V-shaped markings which radiate out from a brown spot located in the centre of the body.

They have a variety of tentacles underneath - 32 marginal lobes, 24 long thin tentacles and four long thick frilled arms that will all sting if touched.

Barrel jellyfish can grow up to 1m in diameter and are robust creatures with a spherical, solid rubbery bell.

White or pale pink, they can also be blue or yellow and fringed with purple markings.

The bell lacks tentacles but eight thick, frilled arms hang from the manubrium which can give you a mild sting.

Also known as Bluefire jellyfish, these are similar in size to the compass jellyfish and also bell shaped but have a purplish/blue tinge to them.

Up to 30cm in length, if you look closely, you'll be able to see through the body and notice darker radial lines inside. Like other jellyfish, they will sting but it is very mild.

"Confusingly, they can sometimes appear yellow in colour," says Dr Richardson.

The above Bluefire was captured stranded on St Andrew's West Sands by Mike Pennington.

"The Portugese Man-o-War occasionally pops up around the south coast of Britain but we've not had a lethal case in the UK so far," says Dr Robinson.

"They are a genuine super-predator, with long trailing tentacles and a fierce venom."

The Man-o-War is not actually a single jellyfish at all but a fascinating colony of symbiotic hydrozoans, and big enough to be easily avoided by swimmers.

It lives at the surface of the ocean. The gas-filled bladder remains at the surface, while the remainder is submerged.

As the Portuguese Man-o-War has no means of propulsion, it moves according to the winds, currents, and tides.

Although it is most commonly found in the open ocean in tropical and subtropical regions, it has been found as far north as the Hebrides.

Detached tentacles and dead specimens (including those that wash up on shore) can sting just as painfully as the live organism in the water.

Remember, while some jellyfish are harmless or have a very mild sting, others have a painful and even dangerous sting. For your own safety, you should not touch jellyfish.

Check out the Marine Conservation Jellyfish Guide for other jellyfish to look out for.