The Giant Jellyfish, Rhizostoma luteum, has a bell diameter of up to 60 cm (2 ft) and can reach a max weight of 40 kg (88 lb).
Zoo Vienna has now successfully bred this rare sea dweller for the first time in captivity. The baby jellyfish are about 4 centimeter tall and are now on exhibit in the Zoo’s Aquarium.
“The Giant Jellyfish was first discovered in the Western Mediterranean Sea in 1827. It is such a rare species that some scientists even doubted its existence. During the last couple of years, some specimens were stranded on the beaches of Morocco and Spain, and it could finally be proven that Rhizostoma luteum does indeed exist,” said Dagmar Schratter, director of Zoo Vienna.
The story behind this breeding success is as spectacular as the jellyfish itself. Schratter continued, “The marine researcher Karen Kienberger from Jellyfish Research, South Spain, collected an adult Giant Jellyfish in the coastal waters of South Spain for her scientific research. At the laboratory, she discovered that the jellyfish was sexually mature and collected planula larvae which she sent to Zoo Vienna.”
Almost nothing is known about this jellyfish. It was a real challenge even for the jellyfish experts at Zoo Vienna to successfully breed this species. But they were successful and raised 30 baby jellyfish from the planula to the polyp--- and finally to the jellyfish.
The Zoo successfully took photos of all developmental stages and collected important data, which will be forwarded to Kienberger for further collaborative research.
French naturalists, Quoy and Gaimard, first described the Giant Jellyfish, Rhizostoma luteum, in 1827. Since its discovery, it has only been mentioned in scientific literature six times due to its rarity. Some researchers even doubted its existence until the recent discovery of specimens off the coast of Southern Spain.