The Mantis Shrimp Can See Colors Humans Cannot Even Imagine

A World Humans Cannot See

Imagine looking at a coral reef and suddenly discovering that almost everything around you has colors, patterns, and signals that your eyes were never designed to detect.

That is close to the problem faced by humans when trying to understand the visual world of the mantis shrimp.

These marine crustaceans are famous for their powerful front appendages, which some species use to smash or spear prey. But their eyes may be even more remarkable than their weapons.

A mantis shrimp does not simply have "better eyesight" than a human.

Its visual system is built differently.

Some species possess numerous types of photoreceptors and can detect ultraviolet light. They can also detect polarized light, a property of light that humans normally cannot perceive without special equipment.

The result is an animal experiencing visual information that is fundamentally different from our own.

When a human looks at a reef, we see one version of reality.

A mantis shrimp may be seeing another.

The Eyes Look Like They Belong on a Machine

The first thing you notice about a mantis shrimp is that its eyes look unusual.

They are mounted on stalks and can move independently.

Instead of being fixed permanently in one direction, the eyes can scan their surroundings while the animal remains relatively still.

This is extremely useful for a predator living among rocks, coral, sand, and other complicated underwater structures.

The independent movement gives the animal enormous flexibility.

One eye can examine part of the environment while the other is looking somewhere else.

That may sound strange to us because human eyes normally work together as a coordinated pair.

But mantis shrimp have evolved a very different solution to the problem of seeing the world.

Their eyes are not simply cameras attached to the body.

They are sophisticated biological sensors.

More Photoreceptors Does Not Simply Mean Better Vision

Mantis shrimp are often described as having an extraordinary number of photoreceptor types.

That fact can easily be misunderstood.

Humans have three main types of cone cells responsible for color vision.

Mantis shrimp can possess many more photoreceptor classes.

But that does not necessarily mean they see a much larger rainbow of colors in the way people sometimes imagine.

Their visual system appears to be optimized for rapidly detecting and processing particular types of information.

In other words, the advantage may not be "seeing every possible color."

It may be recognizing useful signals quickly.

That distinction is important.

Evolution doesn't build senses to win a technology competition.

It builds senses that help an animal survive.

Ultraviolet Light Changes the Picture

One of the most fascinating abilities found in mantis shrimp is sensitivity to ultraviolet wavelengths.

Humans cannot naturally see ultraviolet light.

Our visual system detects only a limited portion of the electromagnetic spectrum.

Ultraviolet radiation lies beyond that range.

For a mantis shrimp, however, parts of this invisible-to-us region can become useful visual information.

This could help the animal detect patterns or signals that are hidden from predators and prey that cannot perceive the same wavelengths.

The underwater environment is already visually complicated.

Add ultraviolet information to the picture, and the mantis shrimp's sensory world becomes even more difficult for us to imagine.

Polarized Light Is Another Secret Channel

The most unusual part may be the ability to detect polarized light.

Light can behave differently depending on the orientation of its electromagnetic waves.

Humans do not normally perceive this property directly.

Mantis shrimp can detect polarization information.

That gives them an additional visual channel that is almost completely absent from ordinary human experience.

Scientists have found that polarization can play roles in communication, detecting objects, and navigating complex underwater environments.

Some animals use polarization patterns produced by reflection from surfaces or by biological structures.

For a mantis shrimp, these patterns may provide information that ordinary color vision cannot.

It is like having an additional language written into the light itself.

Why Would an Animal Need This?

The obvious question is simple:

Why evolve such a complicated visual system?

The answer probably involves the environment in which mantis shrimp live.

Many species inhabit shallow marine habitats, including coral reefs and rocky environments.

These places contain enormous amounts of visual information.

There are predators.

There is prey.

There are hiding places.

There are reflections from surfaces.

There are shadows.

There are other members of the species.

Being able to distinguish useful signals from background information can make a major difference.

A visual system capable of detecting wavelengths and polarization patterns may provide information that ordinary color vision misses.

Their Eyes Can Move Independently

The unusual structure of the eyes is not limited to their position.

Each eye can move in several directions.

This allows the animal to scan its environment without moving its entire body.

For an ambush predator, that is extremely valuable.

Moving the body can reveal your position.

Moving an eye can provide information while leaving the rest of the animal hidden.

The mantis shrimp can therefore gather visual information while remaining close to its shelter.

The ocean floor becomes a surveillance system.

The shrimp watches.

The prey approaches.

And the predator can respond.

The Two Eyes Can Also Work Independently

Independent eye movement creates another unusual feature.

The two eyes can process visual information separately.

This means the animal does not rely on exactly the same visual strategy that humans use.

Human vision is strongly centered around combining information from both eyes to create depth and a unified visual field.

Mantis shrimp have evolved a different approach.

Their eyes can perform specialized tasks while moving independently.

The result is a visual system that is difficult to compare directly with ours.

It isn't simply superior or inferior.

It is specialized for a different lifestyle.

They May Use Polarization to Find What Color Cannot Reveal

One of the most interesting possibilities is that polarization can help mantis shrimp detect objects that would otherwise blend into their surroundings.

Underwater environments can contain enormous amounts of glare and reflection.

Ordinary visual contrast can sometimes become difficult to interpret.

Polarization provides another source of information.

An object that is hard to distinguish through brightness or color may have a different polarization signature.

That could give a predator another way to detect prey.

It could also help animals recognize members of their own species.

The important point is that polarization is not just a strange scientific curiosity.

It can become useful information.

Their Vision May Also Help With Communication

Mantis shrimp are not solitary machines that only hunt.

They interact with other animals of their own species.

Visual signals can therefore become important.

Some mantis shrimp have body patterns that can reflect specific wavelengths of light.

If another animal can see information that a predator cannot, that signal can become useful for communication.

This creates an intriguing possibility.

A pattern that looks ordinary to a human observer may contain additional information for another mantis shrimp.

We might photograph the animal and see a colorful crustacean.

Another mantis shrimp may see a much more complicated visual message.

The Famous Punch Is Still Extraordinary

Vision is not the only reason mantis shrimp are famous.

Certain species have highly specialized appendages capable of striking prey at extraordinary speeds.

These species are often called "smashers."

Their appendages accelerate rapidly enough to create powerful impacts.

Other species use spear-like appendages to capture prey.

So mantis shrimp are not one uniform type of predator.

Different species have evolved different hunting strategies.

The combination of unusual vision and specialized hunting equipment makes the group particularly fascinating.

One part of the body detects the target.

Another part delivers the attack.

A Predator Living in a Tiny Fortress

Many mantis shrimp spend much of their lives around burrows.

The burrow provides protection and gives the animal a place from which it can observe the surrounding environment.

This lifestyle fits their visual abilities surprisingly well.

A mantis shrimp doesn't have to constantly swim across open water searching for food.

It can remain hidden.

Its eyes scan.

Its body stays close to shelter.

When the right opportunity appears, it can react quickly.

The animal's entire lifestyle is built around information.

See the environment.

Detect movement.

Recognize the target.

Attack.

Return to safety.

Why Humans Struggle to Imagine Their Vision

The biggest problem is that we naturally describe vision using human experience.

We say an animal sees more colors.

We imagine a bigger rainbow.

But that may not accurately describe what is happening inside a mantis shrimp's nervous system.

Its visual receptors, eye movements, neural processing, and sensitivity to polarization all work together.

The result isn't necessarily a picture with millions of additional colors.

It is a different sensory system.

A mantis shrimp does not see the ocean the way a human diver sees it.

And humans have no direct way to experience exactly what that animal experiences.

We can measure wavelengths.

We can record neural activity.

We can study its photoreceptors.

But translating those measurements into the animal's subjective experience remains extremely difficult.

Evolution Built a Different Camera

The mantis shrimp is a reminder that evolution doesn't always improve an existing design.

Sometimes it takes an entirely different route.

The human eye is extremely sophisticated.

So is the eye of a mantis shrimp.

But they solve different problems.

Humans evolved visual systems suited to life on land.

Mantis shrimp evolved theirs in an underwater world filled with reflections, changing light, camouflage, and complex visual signals.

The result is a biological camera unlike anything most humans ever encounter.

Scientists Are Still Learning From Them

The mantis shrimp's visual system has attracted researchers interested in biology, neuroscience, optics, and engineering.

Its eyes demonstrate ways that biological systems can detect information humans normally ignore.

Polarization-sensitive vision has also inspired interest in technology.

Engineers can build sensors that detect polarization, but nature has already developed sophisticated biological systems for doing something similar.

Studying these animals can therefore reveal more than facts about crustaceans.

It can show how biological systems solve problems involving light and information.

The Ocean May Look Completely Different Through Their Eyes

A human can spend years studying coral reefs and still be limited by the capabilities of human vision.

A mantis shrimp lives in the same environment but has access to visual information that we cannot naturally perceive.

That is perhaps the strangest part of the story.

The reef is not changing.

The light is not changing.

The environment is the same.

Only the observer is different.

What appears to us as a simple pattern may contain information invisible to our eyes.

What looks like ordinary reflection may carry polarization information.

What appears to be a colorful animal may have signals that another mantis shrimp can detect in ways we cannot.

The world itself has not changed.

Our access to it has.

Frequently Asked Questions

Can mantis shrimp see ultraviolet light?

Some mantis shrimp species have photoreceptors sensitive to ultraviolet wavelengths that humans cannot naturally see.

Can humans see what a mantis shrimp sees?

Not directly. Scientists can measure aspects of the animal's visual system, but human subjective experience cannot simply be converted into the exact visual experience of another species.

Do mantis shrimp really have more color receptors than humans?

Many species have significantly more types of photoreceptors than humans, but this does not necessarily mean they experience proportionally more colors. Their visual systems appear specialized for rapid detection and processing of different visual signals.

Can mantis shrimp see polarized light?

Yes. Their visual systems can detect polarization information, giving them access to a property of light that humans normally cannot perceive.

Why do mantis shrimp have movable eyes?

Independent eye movement allows them to scan their surroundings while keeping their body relatively still, which can be useful for detecting prey and threats.

Are all mantis shrimp punchers?

No. Different species have different hunting appendages. Some are "smashers" that strike prey, while others are "spearers" that impale or grab prey.

Where do mantis shrimp live?

They are marine crustaceans commonly associated with shallow coastal environments such as coral reefs, rocky areas, and sandy or muddy seafloors.

We See an Animal. It Sees a Different World.

A mantis shrimp can sit on the seafloor looking almost ordinary.

Its body is small.

Its burrow may be hidden among rocks or sediment.

A human diver might look at it and see another strange crustacean.

But that simple observation misses the most remarkable part.

The animal is looking back.

And its eyes are detecting information that our own visual system cannot naturally access.

Ultraviolet wavelengths.

Polarization.

Complex patterns.

Rapid movement.

Its world is not simply more colorful than ours.

It is different.

That may be the most fascinating lesson of the mantis shrimp.

We often imagine that the world we see is the world that exists.

It isn't.

It is only the version of the world our senses allow us to experience.

On a coral reef, a mantis shrimp is living inside a visual universe that humans can measure but cannot truly see.

And somewhere beneath the waves, one of nature's strangest eyes is quietly watching.