Tiger sharks are voracious predators that will eat pretty much anything they can get their jaws around – but even they can’t stomach an echidna.
Scientists from James Cook University in Australia witnessed a bizarre animal interaction after seeing a tiger shark throw up an echidna, a small and spikey monotreme that is a cousin of the platypus.
The unlikely observation was made in May 2022 while the researchers were tagging marine life off the coast of Orpheus Island in north Queensland.
“We were quite shocked at what we saw. We really didn’t know what was going on,” Dr Nicolas Lubitz, a former PhD student at James Cook University who took a photograph of the incident, said in a recent statement.
“When it spat it out, I looked at it and remarked: “What the hell is that? I managed to only get one picture, but you can see the outline of the echidna in the water,” he added.
The tiger shark, alongside the echidna, shortly after its vomiting episode in May 2022.
Image credit: Nic Lubitz
Echidnas are an unusual family of egg-laying mammals that are typically found (on dry land) in Australia and New Guinea. Surprisingly, they can swim. Scientists have documented echidnas paddling along bodies of water, although its not clear why they take these aquatic excursions. It’s also believed their ancestors were semi-aquatic, a bit like platypuses, so it’s not a total surprise seeing them in a marine environment.
Nevertheless, it’s very unexpected to see them being ejected from the belly of a sea-dwelling predator.
The tiger shark had likely chomped down the echidna as it was swimming the shallow waters off the coast of a nearby island. Understandably, the animal’s protective spines meant the meal didn’t settle well and the shark had an unpleasant stomach upset.
“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,” continued Dr Lubitz.
“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,” he explained.
Luckily, the tiger shark was unharmed by its dubious meal choice and the researchers managed to fit it with an acoustic tracker before being released back into the water.
On the topic of strange meals, Greenland sharks in the Arctic are also known for their adventurous diet. In 2008, scientists discovered the jawbone of a polar bear in the guts of a Greenland shark. It remained unclear whether the shark attacked a live swimming bear or if it scavenged its dead body. Either way, it must have been one hell of a feast.
