A group of researchers found a unique pattern in the dactyl club that mantis shrimps use to hunt. When the scientists led by Dr. David Kisailus put the little crustacean under a very powerful microscope, they found a herringbone pattern formed by hardened fibers.
The researching team also found a fragile coat, and based on the evidence; they said it could help to distribute the stress evenly at the moment of the impact.
Back in 2012, Kisailus and his team started to investigate the properties of the mantis shrimp’s killing weapon. There are more than 400 species of it, but they all favor two hunting weapons, a dactyl spear or club. Back then, the researchers focused all their efforts on the blunt weapon because of its incredible characteristics.
The mantis shrimp, also known as stomatopod, is a 10 cm marine crustacean who lives under rocks, and favors holes and burrows. It is curious that it inspired armor based on super-strong composite materials because only the rear part of the head and the first four segments of its thorax are covered by a shell. However, its method of hunting is exceptionally useful and powerful. The crustacean uses a sharp weapon like extremities to either pierce through the flesh of fish, or a club to destroy the carapace of its victims. Scientists named them after their arms; spearers and smashers, respectively.
The mantis shrimp has the fastest punch of any animal (50 mph) & can break aquarium glass with a single strike! pic.twitter.com/0qVlI85Ylt
— Strange Animals (@Strange_Animals) May 15, 2016
Smashers are particularly impressive. They have raptorial claws with a blunt impact area. They can swing these things with an acceleration of 10,400g and reach speeds up to 23m/s from a stationary position, for contrast, a V8 Formula One engine’s maximum piston acceleration scores 8,600g. In other words, they hit hard which led Australians to nickname these creatures as “thumb splitters” because of what they can do to people when they handle them incorrectly. In fact, some reports say that adult stomatopods have broken aquarium glasses with just one strike.
But that is not all, the movement is so fast it creates bubbles between the claw and the victim, they are called cavitation bubbles. When water is put to dramatic changes of pressure, a void filled with vapor is generated, but they are still in the water, so they immediately implode creating a powerful shockwave. So in the case of the mantis shrimp misses, the shockwave will still stun or even kill its prey.
The Mantis Shrimp sure has plenty of features
Such a powerful striking ability in such a small creature baffled scientists. If a person could punch a similar surface with an equivalent force, his hand would be reduced to mush in the process which brings the question, how comes stomatopods can do it without even flinching?
“We knew from previous studies that the impact region allows the mantis shrimp to transfer incredible momentum to its prey while resisting fracture, but it was exciting to reveal through our research that the properties of this highly impact-resistant material are created by the novel herringbone structure,” The leader of the research team said.
The research team said that not only the pattern they found allows the crustacean to withstand enormous amounts of pressure, but it also gives its ‘punches’ much more power. The researchers haven been studying mantis shrimp’s dactyl club since 2014, and they already have already built prototypes composite materials based on their findings. They have used new 3D printing methods to simulate the herringbone pattern which could be applied to improve a lot of things we already use.
— Pablo Zavattieri (@PabloZavattieri) May 31, 2016