One punch man of the ocean

by Abhaydeep Pinjala

The strongest punch in the anime world is backed by Sitama, who is the protagonist of the One Punch Man show. He has tremendous power to punch through anything in this world and the world beyond. Coming to reality there is one contender that can challenge Sitama in his punching skills. This is the one and only Peacock Mantis Shrimp (Species Name – Odontodactylus scyllarus).

Well, you might think it’s just a shrimp.  How harmful can a shrimp be? Toss it up with some garlic sauce and it would make for a good snack. But this is where you have underestimated their abilities. They have a raptorial appendage like a modified claw. When threatened it can whip out a punch at speeds of 23 m/sec (75ft/sec). That’s 50 times faster than the blink of an eye, or about the same as the trajectory of .22 caliber bullet, it holds a record for the fastest self -powered strike by an animal according to the Guinness Book of World Records

[https://www.guinnessworldrecords.com/news/2019/4/the-mantis-shrimp-packs-the-most-powerful-punch-in-the-animal-kingdom-567501/

 

 A: Raptorial appendage, B: The position before strike C: Moments before the impact D and E: Formation of the cavitation bubble, F and G: Collapsing of the cavitation bubble, H and I: Moments after the impact   [https://jeb.biologists.org/content/208/19/3655]

With such speeds, the shrimp punch generates an area of low pressure at the point of contact.  This forms a vapor bubble in a process called cavitation. When these vapor bubbles collapse, they release tremendous energy, oddly in the form of heat and light, at an incredible temperature of 4704.444˚c (Although no one has ever measured the temperature of a mantis shrimp strike, according to Patek and as to what was published in the Wired web site this was the predicted measurements of cavitation heat release and can be reliably applied to the punch [https://www.wired.com/story/funky-materials-give-the-mantis-shrimp-its-powerful-punch/]). This is the reason why it is difficult to keep the shrimp in an aquarium.

Mechanism behind these punches

You might be thinking how in the world does such a small creature pack such a powerful punch? There needs to be a way to store all that potential energy all at once. For the lethal punch that the shrimp delivers it was calculated that there was a minimum power requirement of 4.7105 watt per kilogram of muscle for a typical strike.  [http://ib.berkeley.edu/labs/patek/shrimpMechanics/Pateketal2004Nature.pdf]

A: The time bound movement of the appendage of the shrimp during a strike at 0,1,2,3 seconds, B: The internal structure of the muscle and the Saddle-like muscle for the quick retraction for the punch, C:  The mechanism of the contraction and retraction of the saddle-like muscle during the punch with the parabolic movement of the appendage. [http://ib.berkeley.edu/labs/patek/shrimpMechanics/Pateketal2004Nature.pdf]

Shrimp muscles are usually incapable of storing such a tremendous amount of potential energy. There are two very special muscles, the saddle and the meral-V in the mantis shrimp that do the job. During a lethal strike, the shrimp contracts its appendages which further contracts the saddle and meral-V muscles. This is when the potential energy is stored like a compressed spring waiting to be released. Here, we see that due to the usage of two muscles the potential energy adds up and aids to increase the strike force. The flexor muscles act like a latch that holds everything in position waiting to be released. Due to the relaxation of the flexor muscle, the latch is released further, discharging all the potential energy at once.  This makes the raptor-like appendages move with super-high velocity to deliver the strongest punch in the animal kingdom.  

The next time you see a mantis shrimp don’t mess around with it,. If you do, make sure to face the consequences of getting punched!

A, C and E show the different shrimp. B, D and F: Corresponding appendages, G: Working mechanism of the energy storage in the saddle and the Meral V for striking. [https://www.researchgate.net/publication/233915500_Comparative_spring_mechanics_in_mantis_shrimp]

References   

1. https://jeb.biologists.org/content/208/19/3655
2. https://www.guinnessworldrecords.com/news/2019/4/the-mantis-shrimp-packs-the-most-powerful-punch-in-the-animal-kingdom-567501/
3. https://link.springer.com/chapter/10.1007%2F978-94-015-9215-4_16
4. http://ib.berkeley.edu/labs/patek/shrimpMechanics/Pateketal2004Nature.pdf
5. https://www.youtube.com/watch?v=t2jam1x5ki4
6. https://www.researchgate.net/publication/233915500_Comparative_spring_mechanics_in_mantis_shrimp
7. https://www.wired.com/story/funky-materials-give-the-mantis-shrimp-its-powerful-punch/