Predator-prey relationships are dynamic and complicated. They are a complex part of nature that keeps the food chain connected. Sometimes, it’s a lion stalking a gazelle, or a Great White performing a sneak-attack on an unsuspecting seal. In most cases, after a small struggle (the animal wants to live, after all), the prey is quite easy for the predator to take down.
In 2015, an adult male bottlenose dolphin was found dead on a beach in Bunbury, southwest Australia. It is not uncommon to find deceased marine life on the beach but there was a surprising twist in the case. Upon investigation of the dolphin, a long arm dotted with small suction cups poked through its mouth. A veterinary pathologist determined the otherwise healthy dolphin’s cause of death to be suffocation. The dolphin had choked to dᴇ.ᴀᴛʜ on its dinner – a large octopus.
According to a new study, the male Indo-Pacific bottlenose dolphin is the first documented cetacean to diᴇ from octopus asphyxiation.
According to research leader Nahiid Stephens, a pathologist at Murdoch University in Perth, Australia, he “seems to have been exceedingly hungry and decided, ‘You know what, I’m going to swallow it whole.’”
When the young male, discovered on a beach about two hours south of Perth, was delivered to Stephens’ lab for a post-m.or.te.m in August 2015, he still had parts of a Maori octopus hanging out of his mouth.
Other dolphins have been recorded k.i.lling and devouring octopi in the past, so Stephens performed a post-m.or.tem to determine what went wrong—especially because the animal, called Gilligan, was in excellent shape. First, she had to get rid of the octopus.
“It was a massive octopus, and I just kept pushing and pulling, thinking, ‘My gosh! It’s still on the way,’” According to Stephens, it had a tentacle span of 4.2 feet.
The au.topsy, which was documented in a recent paper published in the journal Marine Mammal Science, indicated that the issue occurred as Gilligan was swallowing his final meal.
Dolphins may widen their throats and swallow larger amounts of food by disengaging their epiglottis, a flap of tissue that links the larynx to the blowhole.
The 4.6-pound octopus appears to have gripped Gilligan’s larynx with a tentacle, preventing it from reconnecting to the dolphin’s breathing equipment and effectively choking him to de.ath, according to Stephens. “That octopus may have been de.ad in principle, but the sucker was still working,” Stephens says, adding that while no one wins in this circumstance, “the octopus gets a bit of a last hurrah.” According to Kate Sprogis, a research fellow at Murdoch University, an octopus is “not simple prey to just swallow.”
Sprogis watched dolphins tossing octopi in the air in an attempt to tenderize the invertebrates—breaking them up into tiny, more edible pieces—while monitoring the dolphin population near Bunbury, where Gilligan died.
According to Sprogis, who was not involved in the current study, a cetacean would frequently breach the surface and send the octopus soaring into the air. “It’s pretty energetically taxing for the dolphins,” she explains, adding that the dissatisfied cephalopods would cling to the dolphins’ heads. “We think the octopus is very nutritious because of the sheer effort involved.”
The dolphin generally bites off the octopus’ head after flinging it about, but the struggle is far from done because its limbs can remain active for some time.
“He probably didn’t toss it enough, and got a little smug and swallowed it,” Sprogis recalls of Gilligan.
While Gilligan’s unusual death may have been a first for scientists, it is likely to occur more frequently in nature.
Historic seamen recorded legends of sperm whales combating krakens, which Stephens believes were likely misinterpreted clashes between huge octopi and sperm whales.
“It’s an intriguing way of spotlighting the things that happen in our backyard all the time that we’re not really aware of,” adds Gilligan.
Not only that, but the dolphin’s tragic de.ath allows scientists to learn more about the creatures and their biology. Gilligan, as a young healthy male, provides a vital counterbalance to many of the sick, elderly biological samples that pathologists frequently see.
“These chances don’t come along very frequently,” Stephens adds, “so the more we can see these people after the awful, tragic occurrence of their de.ath, the better.”