Cassiopea, more commonly known as upside-down jellyfish are rare and hard to come across, so the discovery of the newborns by displays supervisor Kico Iraola who was cleaning out the tank, was astonishing.

Kico explains: “We previously kept upside-down jellyfish in the same tank many years ago so we believe that some polyps, similar to a sea anemone, must have been dormant buried in the tank’s rocks for all these years. They can remain in the polyp stage for a number of years, feeding continuously using their tentacles to catch food drifting past and waiting for the right conditions for the next stage of development.

“This winter something must have triggered in the tank which caused the polyps to breed and produce the 65 tiny jellyfish newborns which we have discovered today. This process can go on for days so we may have double the jellyfish once the breeding has stopped.

“Currently the jellyfish are around 3mm in diameter and will swim around the tank until they find a suitable spot to settle upside-down and grow. That’s where they get their name from as they are mainly photosynthetic, which means they need to position themselves upside-down to capture the sunlight for them to grow.”

The rediscovered jellyfish are due to be moved into the park’s nursery where they will be given a tank to themselves once they are full-sized as they will require more space. Once moved, the jellyfish will then be on display to the public. Due to the large quantity of the newborn creatures, some will be housed at other SEA LIFE sites across the county.