A New, Potentially Deadly Species of Jellyfish Was Discovered Floating Around Australia

The new species’ sting can cause Irukandji syndrome, which sometimes leads to stroke and heart failure

A similar species of Irukandji jellyfish, but with the tentacles (and a fishy lunch inside). Photo: Jurgen Freund/Nature Picture Library/Corbis

Scientists officially announced the discovery of a new species of venomous jellyfish, discovered off the coast of Western Australia. The species is dubbed Keesingia gigas, after John Keesing, a marine biologist who captured one of the jellyfish last year, the Guardian writes

The new species belongs to a group called Irukandji jellyfish. Most of those animals are tiny and harmless, but as the Guardian explains, some 16 species cause Irukandji syndrome. This potentially deadly condition triggers vomiting, pain and, in extreme cases, a heart attack or stroke. Given the new species' large size, scientists believe it probably belongs to the syndrome-causing group. 

The new species, however, curiously does not have tentacles—at least none that the researchers have seen. All of the specimens they've collected and photographed are nothing more than arm-length blobs. Jellyfish, however, all have tentacles, the researchers told the Guardian, so they think explanation is probably a simple one: all of the new jellyfish specimens likely lost their arms in the hunt for prey or escape from predators.  

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