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  • Amelia

Know your jellyfish!

Summer is here & ocean swimming is on! With the giant jellyfish found off the coast of Cornwall, I'm sure for many of us the thought of what lies beneath is a little unnerving, especially if it could sting you! Here's the low down on the most common UK jellyfish.

1. Moon jellyfish (Aurelia aurita)

Up to 40cm in diameter, transparent and easily recognised by the 4 purple shaped rings in the bell. A mild sting, they are very common on UK beaches.

2. Compass jellyfish (Chrysaora hysoscella)

Upto 30cm in diameter, with a transparent bell and brown v shaped markings. The compass jellyfish has long, thin tentacles and unfortunately does sting!

3. Blue jellyfish (Cyanea lamarckii)

Upto 30cm in diameter, with a blue bell and blue line markings that can easily be seen, this jellyfish has a mild sting.

4. Lion's mane jellyfish (Cyanea capillata)

Reddish brown in colour and large, this jellyfish can reach upto 50cm. A large mass of thin, straggly tentacles, the lion's mane stings.

5. Barrel jellyfish (Rhizostoma octopus)

Pale pink/yellow, with a rubbery bell up to 1m in diameter, the Barrel jellyfish is very common in UK waters. With a very mild sting, it's long arms are pretty harmless.

6. By wind of the sailor (Velella velella)

Blue/purple in colour, by wind of the sailor is not a jellyfish, but a floating hydranth. Often found in big swarms, they have an upright sail and small tentacles and float along the ocean surface.

7. Portuguese Man of War (Physalia physalis)

By far the most dangerous, and again not a jellyfish, the Portuguese man of war is rarely seen off the UK coastline. With a purple/blue, airbag like body and very long blue tentacles, this floating colony of hydrozoans carries a dangerous sting. If found in large numbers, it should be reported to the local authorities.


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