During a mission to monitor marine fauna, some Australian biologists came across a surreal scene: a tiger shark had in fact regurgitated an entire echidna, a mammal that lays eggs, before their eyes. Such predation had never been documented before.
The tiger shark and the echidna just regurgitated. Credit: Nicolas Lubitz
It might sound absurd, but one tiger shark (Galeocerdo cuvier) has regurgitated awhole echidna – lifeless – before the surprised eyes of a group of Australian researchers. The event, the first ever documented of this kind, occurred off the coast of Orpheus Island (northern Queensland) in May 2022, but marine biologists from James Cook University have only reported it in recent days, two years away. The only document available is the photograph you see at the head of the article, taken by Dr. Nicolas Lubitz, who at the time was involved with some colleagues in monitoring the local fauna. More specifically, they were tagging with acoustic locators And satellite sharks, rays and other marine animals. Just as they were “working” on the tiger shark, the strange episode occurred.
“We were quite shocked by what we saw. We really didn’t know what was happening,” the scholar said in a university statement. “When he spat it out, I looked at him and said, ‘What the hell is that?’ I only managed to take one photo, but you can see the silhouette of the echidna in the water,” Lubitz commented. The animal was intact and with all its quills. The echidnas or tachyglossides I am mammals belonging to the primitive order of Monotremeswhich also includes platypuses. They are the only mammals in the world that they lay eggs instead of giving birth to live young, as well as having other unique and very specialized characteristics. Echidnas, of which there are four species, are also known as spiny anteaters precisely for their body bristling with spines, but they are not related to porcupines and hedgehogs. This is a case of evolutionary convergence. They are animals insectivorous which eat termites, ants and insect larvae, with different specializations based on the species (generally they have a long, narrow snout with a very long tongue).
Echidnas are clearly terrestrial animals, but with distinctive features swimming skills. According to experts, the tiger shark must have preyed on the unfortunate specimen as it moved from the island of Orpheus to a nearby one. Evidently he must have just captured her, given the integrity of her body. “It was a decent sized tiger shark but it wasn’t huge. It is very rare for them to vomit their food, but sometimes when they are stressed they can do so,” Dr Lubitz said, adding that the fish probably felt “a bit of a strange feeling in the throat” after vomiting it.
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However, it is not surprising for one prey so unusual; tiger sharks are in fact “good-mouthed” and eat everything, give them sea birds to turtles, unfortunately also ending up munching on human garbage. “I’ve seen videos of them eating a rock for no reason,” the scientist explained, noting that he once saw one regurgitate parts of a young dugong. It is clear that a “ball” full of hard, sharp spines can be quite difficult to swallow, even for a voracious predator and scavenger like a tiger shark.
