Crambione cooki

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Then in the summer of 1999/2000, Puk Scivyer photographed a jellyfish on a beach near Mooloolaba, on Australia’s Sunshine Coast. Scivyer, an aquarist at the Underwater World aquarium in Queensland, suspected that this was no ordinary find. She sent her photo to Lisa-Ann Gershwin, an expert on Australian jellyfish. Gershwin compared Scivyer’s photo and remarks to Mayor’s original description. She confirmed that, remarkably, Scivyer had rediscovered the species Mayor had described a hundred years earlier.

Fourteen years passed, and the story repeated itself. Scivyer was releasing a sea turtle about an hour off the coast of Mooloolaba, and a couple of jellyfish caught her eye. One was about 50 cm in diameter and weighed about 20 kg, the other was smaller. Both had round, milky bells and frilly pinkish-brown tentacles. Scivyer was working on a jellyfish exhibit for the aquarium at the time, and she knew that these two jellies didn’t belong to any of the species usually seen in the area. She captured them and took them back to the aquarium. She also filmed them, and sent the video to Gershwin, suggesting that perhaps she had once again found Mayor’s Crambione cookii, also known as the corrugated jellyfish. At the time, Gershwin could hardly believe it. “I looked at it and went, ‘Oh my God. You’ve got to be kidding. What are the odds?’” she later told Scientific American. It would soon become apparent that the odds of the same person stumbling upon this species twice were greater than one might expect.

When news of Scivyer’s find spread through newspapers, televisions and websites, it set off a ripple of reactions. People started contacting Underwater World to report their own sightings of corrugated jellyfish, and to send in photos. These reports showed that the species had been in the region all along; it just hadn’t been spotted by anyone with the knowledge to identify it. The reports also gave scientists important clues about where the species lives, and when its numbers soar. Jellyfish populations often go through cycles of relative scarcity followed by ‘blooms’ when they can – briefly – be found in large numbers. Most of the encounters Scivyer and colleagues were told about seemed to happen in December, which could indicate that this is when the corrugated jellyfish bloom. On the other hand, it could also just be that December, being the height of Australian summer, is when more people are in the water, in a position to spot the jellies.

Over the years, sightings have continued. In December 2016, the Sunshine Coast Daily reported that, on a beach just north of where Scivyer made her first find, joggers encountered some jellies that could belong to the species. The jellyfish had most likely been washed ashore by strong winds that had blown towards shore that week. Thanks to the public’s enthusiastic response, scientists have learned that the species occurs along a longer stretch of coast than they initially thought. Rather than being confined to the area around Cooktown and the Great Barrier Reef, the jellyfish have now been spotted all along the 2,000 km of water down to Mooloolaba and the Golden Coast.

So, the corrugated jellyfish is alive and swimming all along the coast. And – to scientists’ surprise – it isn’t alone. When Scivyer took the jellyfish back to the aquarium, she noticed nine fish swimming amongst the big jelly’s tentacles. Over the course of the next few days, Scivyer and colleagues kept counting more and more fish. The final count was 76 fish nestling in the jelly’s tentacles. Scivyer and colleagues speculate that the fish could be feeding on crustacean parasites that attach themselves to the jelly’s tentacles. Their meal almost certainly comes with a price: the fish must get stung. The corrugated jellyfish’s sting is described as powerful but not deadly (to humans) and it can be felt in the water around the jelly. The fish that Scivyer found in the jelly’s tentacles weren’t known to come this close to any jellyfish, and scientists still don’t know much about this joint living arrangement.

 

Overall, most of the corrugated jellyfish’s life is still a mystery. Although it is clearly doing a lot better than you’d expect for a species that went unrecorded for 100 years, we don’t know how threatened it is, or even how long it lives. Scientists think that the largest of the two-corrugated jellyfish that Scivyer caught in 2013 was probably quite old, judging by its size and what they know about other jellyfish species. That large jelly died shortly after capture, and is now preserved in the Queensland Museum, in Brisbane. The smaller specimen was reportedly alive and well at the aquarium in 2013. Both they and their kin out in the ocean still have a lot to teach us.

For now, the story of the corrugated jellyfish and its rediscovery highlights that scientific knowledge often relies on the right person being in the right place at the right time. Between Mayor’s and Scivyer’s trips, hundreds of people probably saw these frilly, pinkish-brown-tentacled jellyfish swimming in the ocean or washed up on beaches. But those people couldn’t guess that they were looking at something out of the ordinary. As Scivyer told Scientific American, “[…] it’s not like it’s the last single jelly in the world, it’s just that nobody had really been in a position to find it when they knew that it was something unusual”. Nobody, that is, until Scivyer came along.

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