Researchers on Thursday said they were shocked to observe a Tiger shark throw up an echidna while tagging marine life near Orpheus Island off the north-east coast of Australia.
A team of researchers from Australia's James Cook University observed a medium sized Tiger shark regurgitate a still whole, dead echidna in May 2022 which the university believes to be "a world-first discovery."
"We were quite shocked at what we saw. We really didn't know what was going on," marine biologist Nicolas Lubitz said in a university press release.
Lubitz said he managed to get one picture as the shark spat out the echidna in which the monotreme's outline can be seen in the water.
The researcher said that he could only assume the 3-metre shark had grabbed the echidna as it swam in shallow waters off the island, since it was still whole when the shark regurgitated it.
"It was a fully intact echidna with all its spines and its legs," he said. "It was a decent-sized Tiger shark but it wasn't massive. It's very rare that they throw up their food but sometimes when they get stressed they can."
"In this case, I think the echidna must have just felt a bit funny in its throat," Lubitz said.
Tiger sharks are scavengers known to eat a wide range of prey and even indigestible objects. According to JCU they have been documented swallowing items including tyres, licence plates and even a small TV screen.
"It's known that Tiger sharks will eat anything. They're just a scavenger. I've seen videos of them eating a rock for no reason," Lubitz said.
The researchers said the Tiger shark in question survived the episode unharmed and was fitted with an acoustic tracker before being released back into the water as part of the project carried out by the JCU team.
The researchers have so far tagged 812 animals with trackers to gather data on marine life inhabiting the area from Australia's Gold Coast up to the Torres Strait.
The university said that the full data was set to be made available later this year, which will allow researchers to analyse the migratory patterns of various marine species.