Two newly discovered irukandji jellyfish species found off WA coast

Another two species of potentially deadly irukandji jellyfish have been discovered off WA's northwest coast.

The first and smaller of the two, the Malo bella, was found near Exmouth, while the Keesingia gigas was caught in a fishing net near Shark Bay.

Until now, there were only two species of irukandji known to be found off WA.

The discovery of the Malo bella and Keesingia gigas, made by CSIRO scientist and director of Marine Stinger Advisory Services Lisa-Ann Gershwin, brought to nine the number of irukandji species found in Australian waters and at least 16 found globally.

Irukandji can deliver a painful and in some cases deadly sting, and tend to keep swimmers out of the ocean during the warmer months.

Dr Gershwin said the larger Keesingia gigas, whose existence has been known for a while although it had never officially classified, was a "whopper".

"[It] is absolutely humungous - the body is about 30 to 50 centimetres tall and that's not including the tentacles. It's an absolute whopper of a jellyfish," she said.

Dr Gershwin said it was only about a year ago that a good specimen of the Keesingia gigas was caught by the CSIRO and able to be studied in depth.

She said it had challenged what was known about the irukandji.

"The features it has put it in two quite distantly related families which is a great head scratcher," she said.

"But in this case we were able to work out with DNA what it actually is related to, so it had a really surprising aspect to."
No link between irukandji size and toxicity

Both newly discovered species are able to deliver the trade-mark painful sting irukandjis are known for, but it is unknown whether a larger species can do more damage.

"There doesn't appear to be a direct link between size and toxicity," she said.

Dr Gershwin named the Keesingia gigas jellyfish after her CSIRO colleague Dr John Keesing, who provided her with the specimen.

"He's just such an amazing scientist who's done so much. I think he was really chuffed - he certainly blushed," she said.

Specimens of the new species will be kept by the WA Museum.

Head of the museum's aquatic zoology department Dr Jane Fromont said the jellyfish discoveries could prove useful for beach users.

"Publishing this information means our beachgoers, fishers and surf lifesavers can be alerted about the fact that there's this really big jelly that looks kind of nice and you might want to touch, but maybe just leave that one alone," she said.

Dr Fromont said the museum would continue to study the specimens.

"This means they can be compared to other specimens in the future to see if they're more widely distributed than we currently know," she said.

Source: Here