Natures wonders: mantis shrimp repeatedly hammer to eat (Introduction)

by David Turell , Friday, June 15, 2018, 14:54 (2140 days ago) @ David Turell

It is amazing they pick the weakest area of the shell:

https://cosmosmagazine.com/biology/engineering-excellence-mantis-shrimps-register-shell...

"Mantis shrimps, from the genus Stomatopoda, are famed for the impact force of their tiny club-shaped claws. The speed with which the two halves of a claw come together is the fastest movement of any known animal. One might be forgiven, therefore, for thinking that the crustacean dispatches its mollusc prey with single super-powered strike to crack its shell.
But surprising new research on the hunting behaviour of the mantis shrimp reveals that far from utilising a brute strength one-punch attack, it hits prey shells repeatedly, tens to hundreds of times, targeting very specific locations depending on the species.

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"Crane and her colleagues were surprised to see the shrimps carefully manipulate prey into position, and then deliver as many as 460 blows on a specific spot on the shell.

"In round shells, the shrimps moved the snails so they could attack the opening. In helical shells, the target was the apex.

"To test which parts of the shell are vulnerable, the researchers created a tiny robot – known as the Ninjabot – that struck with the acceleration and force of a real mantis shrimp. Ninjabot testing revealed that the shrimps targeted the weakest point of the shell – meaning that, at present, the shrimps are slightly ahead in the evolutionary arms race between predator and prey."

Comment: What did shrimp eat before they discovered this approach? Did they know how to do this when they evolved, or did they have a different diet until they discovered this method?