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In what is believed to be the first such encounter witnessed by scientists, a tiger shark has been spotted vomiting up a dead echidna off the coast of an Australian island.
Echidnas, dome-shaped mammals covered in spines, are common in Australia.
Researchers from James Cook University in North Queensland observed the rare event while marking marine life off the region’s Orpheus Island in May 2022, according to a university press release on Thursday.
“We were quite shocked by what we saw. We really didn’t know what was happening,” marine biologist Nicolas Lubitz, a former doctoral student at the university and researcher at the Biopixel Oceans Foundation, said in the statement.
“When he spat it out, I looked at him and said, ‘What is that?’ “Someone told me to take a photo, so I rushed to get my phone,” he continued, adding: “I only managed to take one photo, but you can see the outline of the echidna in the water.”
The echidna was dead and “fully intact” with “all its spines and legs” when it was regurgitated by the three-meter-long (almost 10-foot) shark, according to Lubitz.
He added that it was “rare” for tiger sharks to vomit up their food, although they may do so when stressed. “In this case, I think the echidna must have felt a little strange in its throat.”
The shark was not injured during the encounter and was released into the water by the team after being fitted with an acoustic tracker, according to the release.
Another shark that the team captured and tagged also did a “surprising” regurgitation, vomiting up half of a dugong, according to the release. A dugong is a herbivorous marine animal most commonly found in Australia.
“He threw up a big chunk of fat and then a whole spine,” Lubitz said, thinking it was a dugong calf.
Tiger sharks have a gluttonous appetite, a scavenging habit and are known to eat humans. They eat other sharks, fish, sea turtles and seabirds, as well as waste including coal, tin cans, clothing and bones.
They have even been documented swallowing license plates, small television screens and tires, according to the release. “I’ve seen videos of them eating a rock for no reason,” Lubitz added.
Tiger sharks are found in warm oceans around the world. In May 2023, a kayaker fishing in the shallow waters off Windward Oahu, Hawaii, captured the frightening moment the animal slammed into his boat.
