Jellyfish gyroscopes to orient the eyes skyward. Certain jellyfish look upward at the mangrove canopy while making a daily migration from mangrove swamps into the open lagoon, where they feed, and back again. Box jellyfish have more advanced vision than the other groups. Each individual has 24 eyes, two of which are capable of seeing colour, and four parallel information processing areas that act in competition, supposedly making them one of the few kinds of animal to have a 360-degree view of its environment. Jellyfish range from about one millimeter in bell height and diameter, to nearly in bell height and
Irukandji jellyfish by Hugo Flecker in 1952. They were named after the Irukandji people, whose country stretches along the coastal strip north of Cairns, Queensland. The first of these jellyfish, "Carukia barnesi", was identified in 1964 by Jack Barnes; to prove it was the cause of Irukandji syndrome, he captured the tiny jelly and allowed it to sting him, while his 9-year-old son and a lifeguard observed the symptoms (and then rushed him to ICU). Australian toxinologist Jamie Seymour made a documentary about the jellyfish called 'Killer Jellyfish'. In 2015, North Queensland researchers discovered evidence that Irukandji jellyfish actively hunt prey. The