The Mantis shrimp is best known for their incredibly fast punches – moving their arms so fast that they create pockets of seawater that vaporize in explosions of light and heat. However, scientists have set their eyes on another Mantis Shrimp feature – their eyes.
The Mantis shrimp punch is incredibly powerful – packing a 50 mph speed despite the shrimp only being 6 inches long. This is the most notable feature of the shrimp to the majority of researchers, but Biologist Ilse Daly at the University of Bristol in Britain has focused her research around their eyes rather than their quick punches.
The Peacock mantis shrimp eyes are located on the end of stalks, where they rotate independently in all directions. And despite the ability to move their eyes completely sideways and all around, the mantis shrimp still always has a sense of direction – at least according to research by Daly and colleagues that was recently published in the journal Proceedings of the Royal Society B.
Daly stated to the Washington Post that “their eyes are constantly in motion, up, down, side-to-side.” She feels that the wandering gaze gives the mantis shrimp an air of intelligence when compared with the dull behaviors of the rest of the crustacean family. She means this metaphorically, of course, as the mantis shrimp is likely not much more intelligent than the average crab – but the eyes are unique enough to be a topic of interest, setting this particular species of shrimp apart from the rest.
What makes the mantis shrimp eyes unique other than their ability to rotate wherever as the organism pleases is the fact that they have three “pseudo-pupils” that stack on top of each other – each with independent depth perception. These pupils allow them to see beyond what humans can perceive, dipping their toes into ultraviolet and infrared wavelength perception. There are trade offs, however, in that the mantis shrimp isn’t able to discern color in the same way that humans can.
The new report that was just published by Daly and her co-authors takes a look at the way the mantis shrimp receives a rotational world. In order to carry out the experiment, they constructed a tank with high-speed cameras that could record the mantis shrimp and their eye movements. As part of the experiment, the scientists subjected the mantis shrimp to various forms of movement – expecting that their eyes would adjust in order to remain stable as they moved.
It turns out that the hypothesis was incorrect, and that the mantis shrimp eyes didn’t seem to move as expected – sometimes moving in the complete opposite direction than what the scientific team expected. Unfortunately, we’re not yet sure what this means and it raises more questions than it answers. Daly suspects that the shrimp eyes are designed to be used while stationary and had trouble with the rapid movement, but it’s unclear as to whether this was intentional or the shrimp losing their orientation.
All in all, it’s another thing we have yet to uncover about this unique species. From lightning-fast punches to rotational eyes, it’s a topic of study that continues to intrigue Daly and her colleagues.