Photo: Silk Baron/Wikimedia Commons
In April 1998, a ferocious creature named Tyson smashed through the quarter-inch-thick glass wall of his tank. He didn’t get very far, however, as he was soon subdued by nervous attendants and moved to a more secure facility. Still, it was quite the feat considering that, unlike his heavyweight namesake, Tyson was only four inches long.
The daring escape attempt is all the more remarkable since the animal succeeded without claws. Instead, it used its powerful pair of what scientists call “raptorous appendages,” which end in either a brutal hammer or a series of vicious, pointy spines. These prey-catching arms closely resemble the front legs of a praying mantis, giving these creatures their name: mantis shrimp.
When UC Berkeley researcher Sheila Patek decided to study these heavyweights on video, she hit a snag. “None of our high-speed video systems were fast enough to accurately capture motion,” he said. “Luckily, a team from the BBC offered to rent us a super high speed camera as part of their ‘Animal Camera’ series.”
With top-notch equipment at hand, the scientist managed to capture footage of one of these animals striking, slowed down more than 800 times. Patek was mesmerized by what he saw. He found that with each hit, the edge of the club travels at about 50 mph, more than double the previously estimated speed.
“The strike is one of the fastest limb movements in the animal kingdom,” Patek explained. “It’s especially impressive considering the substantial resistance that the water imposes.”
Since water is so much denser than air, even the fastest martial artist would have considerable difficulty landing a substantial blow in it. But it’s not a problem for the mantis shrimp: it finishes a strike in less than three thousandths of a second, outperforming even its terrestrial namesake.
As it does? A simple locking ratchet mechanism on top of the forearm allows it to store energy and then fire it forward with impressive acceleration that exceeds that of a .22 caliber bullet, delivering a whopping 1500 Newtons of force.
And if that wasn’t enough, the shrimp moves its forearm so fast that the pressure of the water in front of it drops, causing it to boil! Then, with the normalization of the water pressure, bubbles are released that also release a large amount of energy, a phenomenon called cavitation.
So it’s no surprise, then, that if you get hit by one of these ferocious little creatures, it hurts. A lot. Just watch this. Oh.
According to some scientists, the mantis shrimp’s rather aggressive nature evolved because the crevices in the rocks it inhabits are fiercely contested. The intense competition in these locations has also made these animals more intelligent than the average shrimp. In fact, they are the only invertebrates that can recognize other individuals of their species and can remember the result of a fight against a rival for up to a month.
And there is more, still. Mantis shrimp have a way of seeing that is unique in the animal world. Their compound eyes, which look somewhat like those of a bee or a fly, are made up of 10,000 tiny photoreceptor units, some of which are arranged in a strip-like fashion across their eyes. As a result, they view the world by scanning this strip through their subject, a bit like a barcode scanner in a store works.
Photo: prilfish
This means that instead of relying on heavy brain processing to compare colors and determine what they are (as most vertebrates do), with the help of their photoreceptors, mantis shrimp interpret the information immediately.
Understanding how mantis shrimp and other animals view the world has led to the development of a variety of practical applications for the technologies and human medicine. Satellites, for example, use multiple spectral channels arranged in a swath to scan the world as they roam before sending the information back to Earth, a mechanism very similar to how mantis shrimp eyes work.
Truly amazing animals. One can only guess how many more amazing adaptations they have in stock that have yet to be discovered.
