Featured Image Credit: John Symons, Murdoch University via New Scientist
In Western Australia, a bottlenose dolphin was recently found dead with octopus arms hanging out of the side of its mouth. Turns out, the dolphin tried to eat a large octopus but it got stuck in the dolphins airway, causing the cetacean to suffocate.
“Gilligan” the Indo-Pacific bottlenose dolphin, who was quite popular among researchers in that area, was found dead on Stratham Beach near the port city of Bunbury back in 2015.
A post-mortem examination revealed that one of the octopuses tentacles was lodged down the esophagus of the dolphin, while the other several tentacles were stuck to its throat. The tentacle suckers were gripping the throat walls and blocking the dolphins airway. Unfortunately, Gilligan died from suffocation.
The tentacles belonged to a Maori octopus, which is one of the largest species of octopus found in Australian waters and the third largest in the world.
It is not unusual for bottlenose dolphins to feed on octopuses, but they normally break the body and tentacles into smaller pieces first using a “shake-and-toss” method. First, the dolphin shakes the octopus to kill it and tear it apart, while tossing prevents it from latching on and also weakens the suckers on the tentacles.
Nahiid Stephens at Murdoch University in Perth, Western Australia, who performed the post-mortem said “Gilligan’s downfall was trying to swallow the 2.1-kilogram octopus whole without proper preparation. We assume it simply wasn’t broken up adequately.”
Stephens says Gilligan is not the first to make this mistake. Park rangers along the coast of Western Australia have described similar octopus-related deaths in dolphins and sea lions, she says.
Even though hunting octopuses is risky business, there are plenty of benefits for dolphins to reap. Large, muscular octopuses provide a hearty meal packed with protein. They are also easier to catch than fish, because they tire quickly during pursuit, especially after they’ve finished breeding.