A World of Unseen Colors

Aarav: Saanvi, check out this rainbow I drew! I used every single color I have. I was trying to imagine what it would be like to see even MORE colors than this. Do you think any animal can see more colors than we can?

Saanvi: That's a great question, Aarav! Not only is the answer yes, but the champion of color vision is a creature you might not expect. It’s a small, colorful crustacean called the mantis shrimp. It can see a world of colors that we can't even begin to imagine!

Aarav: A shrimp? No way! I thought shrimp were just pink and comma-shaped. How can a shrimp see more colors than I can?

Saanvi: It’s all about how our eyes are built. Think of it like this: inside our eyes, we have special cells called cones that detect color. Humans have three types of cones – one for red, one for green, and one for blue. By mixing the signals from these three cones, our brain can see all the colors of the rainbow, like mixing just three paint colors to make millions of shades.

Aarav: Okay, so we have a three-color paint box in our eyes. What about the mantis shrimp?

Saanvi: The mantis shrimp doesn't have a three-color paint box. It has a giant artist’s set! Instead of three types of color-seeing cones, they have between 12 and 16 types! Each one is tuned to a different, specific color of light.

Aarav: Sixteen?! That's incredible! So… what do those \textra colors look like? Is there a color between blue and green that we're missing?

Saanvi: That’s the mind-bending part – we literally can’t imagine them. It would be like trying to describe the color red to someone who has only ever seen black and white. They see colors in the ultraviolet spectrum, which is invisible to us. It’s a whole different reality of color. But their super-vision doesn't stop there. They have another secret power.

Aarav: Another one? What is it?

Saanvi: They can see something called polarized light. Have you ever used polarized sunglasses?

Aarav: Yeah, my dad has them! They make the glare from the road disappear. How does that work?

Saanvi: Light waves usually travel while vibrating in all directions, which creates glare. Polarized sunglasses have a special filter that only lets light vibrating in one direction pass through, like mail fitting through a narrow slot. This cuts the glare and makes things look clearer. Well, mantis shrimp don't need sunglasses. Their eyes have these filters built right in!

Aarav: So they see the world like they're always wearing super-sunglasses? Why is that a superpower?

Saanvi: Because in their underwater world, many things reflect polarized light differently. Some fish scales and crab shells, which might look camouflaged to us, shine brightly in polarized light to a mantis shrimp. It’s like having x-ray vision for finding hidden prey! And even better, they can use it to talk to each other.

Aarav: They talk using light?

Saanvi: Exactly! They have special patches on their bodies that reflect polarized light in complex patterns. They can flash these patterns at each other. To another animal, it looks like nothing is happening. But to another mantis shrimp, it’s a bright, secret message. It could be a warning to stay away or a signal to a potential mate. It's a secret communication channel that only they can see!

Aarav: Wow! So they see a world with way more colors, and they see secret light-messages that other animals can’t. That's one of the coolest things I’ve ever heard. Our rainbow looks kind of simple now!

Saanvi: Not at all! Our rainbow is still beautiful. It just reminds us that what we see isn't all there is to see. The world is filled with amazing things happening just outside our perception.

So, What Did We Learn Today?

Saanvi: Let’s recap the mantis shrimp’s amazing eyesight!

  • While humans have three types of color-detecting cone cells in their eyes, the mantis shrimp has between 12 and 16.
  • This allows them to see a huge range of colors, including ultraviolet light, that are completely invisible to us.
  • They can also see and control polarized light, which is light that vibrates in a single direction.
  • They use this ability to see camouflaged prey and to send secret messages to other mantis shrimp using special patterns on their bodies.

Aarav: So the mantis shrimp is basically an underwater superhero with color vision and secret-code vision! It makes you wonder what else is out there that we're not seeing.