VISITORS to the Blue Planet Aquarium have been enjoying a ‘jolly jelly Christmas’.

Almost 100 mysterious stingers are on display at the Cheshire Oaks attraction, showcasing two species of the deadly ocean wanderers.

Visitors will be able to come face to face with hypnotic moon jellyfish as well as the aptly named upside-down jellyfish, which spend its adult life lying on its back.

Blue Planet assistant curator Andrea Swatman said: “We’ve got close to 100 jellyfish on display at the moment and there are many more developing behind the scenes.

“They’re truly fascinating creatures: extremely effective predators and capable of travelling great distances, despite the fact they have no brains, no bones and are made up of 95% water.”

Moon jellyfish get their name from the four purplish ‘half moons’ on top of their transparent ‘bell’.

The bell can reach up to 30cm across and has stinging tentacles and four frilly mouth tentacles hanging below.

Although deadly to their prey, the moon jellies’ tentacles are only slightly venomous to humans, usually causing mild pain and a burning sensation.

And upside-down jellyfish are so called because their tentacles and mouth face upwards.

Algae which live in the tissues of the tentacles are exposed to sunlight and can photosynthesise to produce food, some of which is passed to the jellyfish.

The upside down jellyfish gets much of its nutrients from photosynthesis but does possess stinging cells in its tentacles which it uses to catch and paralyse passing prey.

It also uses this weapon to deter would-be predators by releasing stinging cells into the water.