The jellyfish has only been seen twice, and this is the first video of it.
A diver off the coast of Australia captured footage of a massive jellyfish swimming alongside them and posted it to their Facebook page. They said the jellyfish was about the size of a soccer ball and swam “quite fast.”
Four groups of striped tentacles trail behind the translucent jellyfish’s body, which is dotted with rings of varying sizes. A bright red organ inside the bell is most likely the animal’s gastrovascular cavity.
This jellyfish is so rare that only two sightings have ever been recorded. One of them is this video.
Chirodectes maculatus (from the Latin for “spotted”) is a very rare species of box jelly found off the coast of Queensland, Australia. Box jellies, so named because of their boxy shape, are frequently venomous to humans—some are even fatal. C. maculatus, on the other hand, is not.
“It is not possible to make out all of the characters of the species Chirodectes maculatus from the video (some are internal), but it certainly fits very well based on what can be observed,” Dr. Allen Collins, a zoologist and curator at the Smithsonian Institute National Museum of Natural History, told Motherboard in an email.
C. maculatus was discovered in 2005 by an Australian team led by Paul Cornelius. They had captured and preserved the specimen in 1997. They write in the paper that they were “reluctant” to dissect it, so they only made external observations. The scientists named the species Chiropsalmus at first. Another scientist, Lisa-Ann Gershwin, published comments on the organism’s classification a year later, and it was officially moved to the genus Chirodectes, where it was accepted.
Collins observed that the colour pattern on the organism’s bell in the video differed from that described by the original scientists. The jellyfish in the video had rings, whereas the one from 2005 had solid spots. “I suppose there is always the possibility that this specimen is from a closely related but unnamed species of Chirodectes, but I would lean toward C. maculatus,” he said.
Collins described the video as remarkable because, despite its size, it was only the second sighting of the jellyfish. “It’s quite surprising that something so large and conspicuous in appearance would only be seen twice,” he said. “However, a lot of diversity is rare.” It tells me that there is still a lot of exploration to be done.”