What do you think of this fact?
It looks like a rainbow lobster from a video game, and it probably has the most dangerous fist in the ocean. Mantis shrimp are small predators from warm seas, and pretty much everything about them is extreme. Even their greatest talent comes with a surprising catch.
A punch with an aftershock
Some species have club-like limbs they use to smash snails, clams and crabs. These clubs shoot forward at 23 meters per second. That’s about 83 km/h, or 51 mph, underwater and from a standing start.
Because it happens so fast, the water behind the club can’t keep up. Tiny vapor bubbles form and instantly collapse. That’s called cavitation, and the collapsing bubbles pack a punch of their own. So the prey basically gets hit twice: once by the club, once by the bubbles.
Eyes with up to 16 color channels
Humans see color with 3 types of photoreceptors. Mantis shrimp have 12 or more, and some species have up to 16 types, including some for ultraviolet light. They can also detect polarized light, which is invisible to us.
Sounds like the ultimate color vision. Apparently, it isn’t.
Lots of sensors, little nuance
In 2014, researchers from the University of Queensland tested how well the animals could tell similar shades apart. The result: surprisingly poorly, even worse than humans. The study was published in the journal Science.
The researchers’ explanation: our brains compare signals from a few receptors and calculate super fine color differences. The shrimp seems to do it differently. It scans its surroundings with eye movements and recognizes a color by which of its many receptors fire. Kind of like a barcode scanner. It’s less precise but fast. On a coral reef, where every second decides between eating and being eaten, that’s a deal worth taking.
Their eyes sit on stalks, move independently of each other, and each single eye can perceive depth on its own.
So more hardware doesn’t automatically mean better pictures. Sometimes it just means faster decisions.