Schönbrunn Zoo, which is the world's oldest zoo and is based in the Austrian capital of Vienna, notched up the success and revealed they have managed to breed the rare animal, which is now on show in the aquarium.
Rhizostoma luteum is so rare that despite claims of its existence based on sightings from hundreds of years ago, there was significant doubt that any were still left alive.
Zoo director Dagmar Schratter said: "The giant jellyfish was discovered in 1827 in the Western Mediterranean. But it is so rarely seen nowadays that some scientists had doubted its continued existence.
"The fact that specimens are still alive was only confirmed a few years ago when a few of the animals were stranded on beaches in Morocco and Spain."
This jellyfish currently measures just 4 centimetres (1.6 inches) in diameter but the Rhizostoma luteum can span up to 60 centimetres (24 inches) and can weigh up to 50 kilogrammes (110 pounds) when fully grown.
Video courtesy of Central European News
And it still remains a mystery in many ways. Schratter said: "Not a lot is known about the species. Oceanographic researchers from Jellyfish Research South Spain managed to catch a male specimen of the jellyfish off the coast of southern Spain. At the laboratory, she discovered that the jellyfish was sexually mature and collected planula larvae which she sent to us."
The zoo painstakingly raised 30 baby jellyfish from planula to polyp and finally to jellyfish.
The zoo has taken photos of all developmental stages and collected important data which will be forwarded to other parties for further collaborative research.
Despite its size, researchers believe that the sting of the Rhizostoma luteum is not dangerous to humans, and causes only minor irritation, although anyone encountering one of these monsters out in the water may have a bit of a shock.
Story courtesy of Central European News