Natures wonders: dolphin eats octopus (Introduction)

by David Turell , Monday, April 10, 2017, 15:47 (2567 days ago) @ David Turell

It can be quite a battle as this article describes. Each of the eight legs, which can be quite strong and enervated to be semi-independent battlers. the intelligent dolphins have worked out a battle plan:

https://cosmosmagazine.com/biology/tackling-the-kraken-unique-dolphin-strategy-delivers...

"In particular, a large octopus can be a risky prey for predators to tackle. This is especially so for marine mammals, such as dolphins, which don’t have hands to help them keep control of this clingy, eight-armed prey.

"Our new research highlights the development of complex behaviours that allow dolphins to eat octopus, thereby improving their ability to survive and reproduce.

"It’s another example of a strategy that helps to drive the success of dolphins in coastal environments around Australia.

"In 2015 an adult male bottlenose dolphin was found dead on a beach in Bunbury, southwest Australia.

"Wild dolphins face many threats in today’s oceans, yet it was a gruesome surprise when we found octopus arms hanging out of the stranded dolphin’s mouth.
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"An examination by a veterinary pathologist revealed that this otherwise healthy dolphin, known as “Gilligan” to the research team, had suffocated to death while trying to eat an octopus.

"As strange as it sounds, this is not the first recorded case of a dolphin choking to death on an octopus in southwest Australia. There have also been several observations from around the world of dolphins facing difficulties while tackling octopus.
So what is it that makes octopus so hard to handle?

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"During these events, dolphins were observed shaking and tossing octopus around at the water’s surface. In some instances, the prey was gripped in the teeth before being slapped down onto the water.

"This likely helped both to kill the octopus and to tear it into smaller, more digestible pieces. In other instances, the octopus was tossed across the surface of the water before being recaptured and tossed again.

"By tossing the octopus across the water, dolphins avoid letting the octopus latch onto their bodies. This behaviour also likely assists in wearing out the octopus’s reflex responses that make the suckered arms so dangerous to swallow.

"Once the prey has been battered and tenderised enough that the arms are unresponsive, it is then safe for the dolphins to proceed with swallowing their catch.

"It’s quite a process the dolphins have developed to deal with the octopus. They have a short, fused neck which means they have to arch their whole body to toss their prey out of the water.

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"When we looked closely at when these observations were made, we found that the dolphins were targeting octopus more frequently over winter and spring. These cooler times of year are also the octopus’s breeding time.

"Octopus are semelparous, which means they slowly become weaker and then die in the weeks after they finish breeding. It is possible that as they become weaker, they also become easier to catch, making them a relatively easy meal for any opportunistic dolphins swimming by.

"At the end of the day, octopus are just part of the broad diet eaten by wild bottlenose dolphins.

"Dolphins have also been found to use several other highly specialised feeding behaviours, including processing cuttlefish by popping out the cuttlebone, stranding themselves while hunting fish, and using a marine sponge as a tool to probe the seafloor while searching for buried fish hiding in the sediment.

"Octopus shaking and tossing is yet another example that illustrates how intelligent and adaptable these charismatic marine predators are."

Comment: Bigger brains can think and find solutions.