For terrestrial and marine predators alike, spiky meals can be problematic ... to put it mildly.
"The last supper" Washed up on a beach in the #Maldives (photo Lauren Arthur). A lesson to us all not to bite off more than we can chew... pic.twitter.com/GiL6m3oknC
— Bryce Stewart (@BD_Stew) May 9, 2017
This lemon shark's* "last supper" was immortalised by marine biologist Lauren Arthur on a beach in the Maldives.
"[It was a] super interesting find. I have been working in the Maldives for over five years, and have never came across anything like this before," she says. "I received a call just before sunset ... saying there is a shark very close to the shore thrashing around. By the time I got there, it had died and was washed ashore."
As we've explained before, sharks can't "choke" in the way humans can because their breathing has nothing to do with the throat. In order for one of these animals to suffocate, food has to stop water from reaching the gills for an extended period of time – and that actually happens only rarely. In fact, most shark species can evert their stomachs to expel problematic prey.
Implementing that fail-safe, however, becomes more challenging when you try to swallow a pincushion. Enter the porcupinefish, a puffer-like fish in the family Diodontidae. Like true puffers, diodants have the ability to inflate like a balloon by quickly pulling water into a cavity near the stomach. But while their close kin are covered in thin prickles, these fishes sport thick, hard spines.
When a porcupinefish is in a resting position, the barbs are rear-facing, and in the case of our unfortunate shark, it looks like they got embedded as the predator tried to spit them out.
"It was very difficult to see inside the mouth, but from what I could observe, the porcupine had inflated whilst in the shark's mouth ... and completely blocked all the gills," recalls Arthur.
With the inflated fish stuck in place, water ceased to flow through the shark's gill chamber, and both animals eventually suffocated. "Cause of death was immediately obvious and I felt incredibly sad. A wrong judgement call by the shark caused the death of two beautiful animals," Arthur adds. "We did try to remove the fish; however, there were far too many sharp teeth and spines to risk it."
This particular incident may have ended in fatal acupuncture, but porcupinefish meals don't always play out that way. After seeing the photo on Twitter, marine ecologist Johann Mourier recalled watching a similar attempt. "I have seen a blacktip reef shark completely eating a porcupine fish that inflated too. "The shark won," he said.
Tiger sharks are also known to scarf this formidable prey, and large fish like tuna and grouper regularly gobble juveniles.
Want more fish-in-fish action? Don't worry, we've got you covered:
Editor's note: We previously misidentified this shark as a spinner shark (Carcharhinus brevipinna). This post has also been updated with additional details about the encounter.
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Top header image:Klaus Stiefel/Flickr
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