Dolphins' octopus shake makes prey more palatable

Researchers in Australia have revealed new findings that show how Indo-Pacific bottlenose dolphins have learnt to eat large octopuses, an extremely rewarding but potentially lethal prey.

Dolphins do not chew their food, they simply swallow it whole or in large chunks. An octopus is a formidable challenge as it can latch its tentacles, which can be over three metres long in some species, on to the dolphin. One adult dolphin died from suffocation after trying to eat a whole octopus which it could not successfully swallow.

The dolphins get round this sticky problem by biting the head off the octopus and then either tossing the body through the air several times before eating the remains, or simply shaking the body vigorously on the surface. The tentacles have a reflex response which means they still pose a threat for a while even after being removed from the body.

The fact that the dolphins are prepared to take such risks indicates the octopus is probably an important prey for the dolphins, perhaps targeted when other easier food sources are less abundant.

Sprogis, K. R., Raudino, H. C., Hocking, D. and Bejder, L. (2017), Complex prey handling of octopus by bottlenose dolphins (Tursiops aduncus). Mar Mam Sci. doi:10.1111/mms.12405

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