The Amazing Eyes of the Mantis Shrimp
Think you see pretty well?
At Precision Family Eye Care we strive to make all of our patients see their BEST with glasses and contact lenses.
Unfortunately the human eyes can’t even hold a candle to the insane visual capacity of the Mantis Shrimp.
Today on Eye to the Future, we will explore the MOST ADVANCED EYES on the PLANET!! Meet the Mantis Shrimp!!
The Mantis Shrimp’s name is really a misnomer as it is neither a Mantis, nor a Shrimp, but is actually a close relative of the lobster. However, it takes one look to see this name is a pretty apt description for this amazing creature.
The Peacock Mantis Shrimp is pictured above. They will typically grow up to 8 inches long. I’ve personally had two of these as pets, they’re characters…grumpy characters.
What’s So Special?
The mantis shrimp has two eyes, same as us, but that is where the similarities end.
First, the eye stalk is directional and capable of rotating each eye independently up to 70 degrees in any direction. This allows each eye the ability to view its entire surroundings, kind of like the periscope on a submarine.
Humans, and mammals in general, have two eyes with one pupil each to focus light. Put two eyes together and you have binocular vision which allows us to sense depth in our three dimensional world.
However, EACH eye of the mantis shrimp has THREE pupils (above)! This means that each of the mantis shrimp’s eyes is capable of Trinocular vision and thus sensing depth with each eye simultaneously. Focus both eyes on the same thing and you have Hexnocular vision!
Thermonuclear Bomb of Color
As you can see from the photo above and below, each eye of the mantis shrimp is separated into three zones.
What’s going on with that?
Here is where the eyes of the mantis shrimp get REALLY interesting.
The human eye has three types of photoreceptors (cells that sense light) for seeing color. We have Red, Green, and Blue. The combination of signals from these three cell types allow us to see all the colors in the visible color spectrum. Dogs have one less than us with two (no, dogs aren’t actually color blind) and butterflies actually have 5. To our three, the mantis shrimp has 16 different photoreceptors!! As one researcher put it, they see a Thermonuclear Bomb of Color! Here’s how…
The mantis shrimp’s eye is separated into three different sections. The upper and lower hemispheres are used mostly for sensing motion and forms. The central area is called the midband and contains 6 rows of specialized clumps of photoreceptors.
The first 4 rows contain the color sensing photoreceptors that allow mantis shrimp to see colors in hues we couldn’t imagine and even allows it to see near infrared and ultraviolet (UV) light. These rows also contain filters that the mantis shrimp can use to adjust their visual input – like putting on different pairs of colored sunglasses. And if that was not amazing enough, row 5 and 6 of the midband even allow the mantis shrimp to see various polarized light!
How does this all work together?
Say you have a mantis shrimp, it’s crawling around the ocean floor doing little mantis shrimp stuff.
The upper or lower areas of the Mantis Shrimp’s eyes detect movement, like, say, a potential meal. The mobile eye stalk then allows the shrimp to move the eye to use the midband, scanning the target with it’s incredible array of photoreceptors to glean additional information… AND, each eye can do this independently.
Here is a terrific video of a mantis shrimp scanning it’s surroundings to illustrate how this works!
In fact, the brain of the mantis shrimp is actually very, very small by comparison. Their eyes contain more nervous tissue and it’s thought may actually “control” things. Cool stuff.
So there you have it, the most advanced eyes on the planet… But, wait! There’s more!!
Mike Tyson of the Sea
Superlatives don’t stop there with these little critters!
Mantis shrimp are also the Guinness world record holders for the FASTEST attack in the animal kingdom. The mantis shrimp stores energy in highly specialized cartilage called the saddle at the base of the claw (right). When this pent up potential energy is released, the strike occurs with the same speed as a 22 caliber bullet!
They use this attack to break open clams, mussels, crabs, stun/kill fish, or just to take a whack at whatever looks at them funny.
Their strike is so fast that water literally boils as it moves out of the way. This causes a secondary shock wave that causes more damage to the prey and even creates light and heat.
This attack occurs faster than the human eye can detect it.
Here is a video with a very high speed camera showing the attack as well as the cavitation bubbles and light produced by the strike.. Amazing.
Their attacks are known to break aquarium glass…in addition to anything else that crosses it’s path. In the aquarium, fishing, and scuba diving world, mantis shrimp are commonly referred to as “Thumb Splitters.”
They are armed to the teeth and aren’t afraid to break a finger if you come to close!!
I hope you enjoyed this slightly off topic discussion. When it comes to animals, Mantis Shrimp are not particularly cute and are definitely not cuddly, but they are an apex predator with some incredibly specialized killing equipment.
Until next time!
Nick Wolf, OD
– AMAZING photography of the Mantis Shrimp credited to Michael Bok. Here’s is his website. Videos embedded where taken from Youtube.