New toxic jellyfish with no tentacles found in WA

By AAP with AG Staff 8 August 2014
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A new species of venomous jellyfish, a giant that causes Irukandji syndrome, has been found in WA

A GIANT AND extremely venomous jellyfish found off West Australia’s north-west coast has researchers stumped because it appears to have no tentacles.

The Keesingia gigas is one of two new species of Irukandji jellyfish recently discovered by Marine Stinger Advisory Services director, and jellyfish expert Lisa-Ann Gershwin.

While Irukandji jellyfish are normally only the size of a pinky fingernail, the Keesingia gigas species is the length of an arm and believed to cause the potentially-deadly Irukandji syndrome.

The condition can cause pain, nausea, vomiting and in extreme cases, stroke and heart failure.

Deadly jellyfish has no tentacles

CSIRO scientist and director of Marine Stinger Advisory Services Lisa-ann Gershwin said the Keesingia gigas was first photographed in the 1980s.

A specimen was only captured in 2013 near Shark Bay by marine scientist John Keesing, after whom the jellyfish is named.

Dr Gershwin said in all of the photos the jellyfish did not appear to have tentacles and that the specimen was also captured without them.

“Jellyfish always have tentacles … that’s how they catch their food,” she said. “The tentacles are where they concentrate their stinging cells.

“Some of the people working with it through the years actually got stung by it and experienced rather distressing Irukandji syndrome.”

Jellyfish may shed tentacles in defence

Lisa said the species could shed its tentacles as a means of defence, like some bioluminescence jellyfish who drop their glowing tentacles in order to distract predators, but there was no evidence that any Irukandji had that capability.

“I think more probably it does have tentacles but by random chance the specimens that we photographed and obtained don’t have them any more,” she said.

“I think it’s probably a fairly tame explanation – I just don’t know what it is.”

The two new species bring the total number of jellyfish believed to cause irukandji syndrome worldwide to 16 and the total from WA to four.

Irukandji jellyfish have been found as far north as Wales and as far south as Melbourne and Cape Town.

Lisa and colleagues recently discovered a way to predict the movement of the deadly Irukandji jellyfish.