Can you imagine a world without colors? No, right? With colors, our world becomes so enriched and vibrant. I think David Hockney puts it the best way – “I prefer living in color.”
Do you think our little friends in the ocean also see colors? The short answer is yes, but there is an amazing way it all works. A fish can see colors, and they can see colors human eyes can’t.
To learn more about how fish see the world, read ahead.
Can my Fish see colors?
A fish can see, I have talked about it in my other article. Sure, they can see, but this leads us to our next question, can a fish see colors? The short answer is yes, a fish sees color. They see a wide variety of colors; in fact, a fish can see more colors than the human eye.
Speaking of humans, did you know that a human eye contains cells called rods and cones? These cells not only give us our sight, but it also gives us the ability to detect different colors. Why am I telling you this? Well, this is to tell you that a fish also has the same rods and cone cells.
So what exactly are rods and cones? Rods and cells are photoreceptors, which refers to the cells in our eyes that respond to light. Cones are the photoreceptor cells that let a fish see during the day. On the flip side, you will find rod cells that a fish can use to see at night.
The way they see colors may change as you go deep into the water. Why? As you dive into the depths of the ocean, there is no light, which would affect the photoreceptor cells.
So, does this mean all fishes have the ability to see color? Not really. The deep trenches are the darkest place in the ocean, most of which are yet to be explored. At the bottom of the ocean, it is rumored that some fishes don’t even have the ability to see. Even if they did, it doesn’t matter because it is too dark to see anything.
Did you know more people have been to the moon, than the deep trenches of the ocean?
Are there any colors that my fish can’t see?
Some fish can see colors with the presence of light. While talking about it with a curious friend, I was questioned; is there a fish that can’t see specific colors? It got me thinking, and I started digging around to see if this is possible.
What did I learn? A fish can see the colors similar to how you and I see colors. In fact, a fish can detect colors a human eye can’t. To understand this, allow me to tell you how a human eye differentiates colors. Our human eyes can only detect colors in the spectrum of red, blue, and green. If you increase or decrease the spectrum, the colors you can see vary.
For instance, a dog can see colors on the spectrum of yellow and blue. What does this mean? It means your dog can’t see the color blue. So which colors can a fish see, that a human eye can’t? Ultraviolet light.
The spectrum of colors an animal or human can see depends on our cone cells. A human eye has three cones, as mentioned earlier, these are red, blue, and green. On the flip side, a fish has four cones, which comprise of red, blue, green, and ultraviolet.
The UV light, or in other words, ultraviolet light is the color that our human eyes can’t detect. Why? As the name suggests, the color goes beyond violet, which is where the human eye color spectrum ends.
Colors are found on a specific wavelength, and our human eyes can only see the colors which fall under our visible spectrum. What is that visible spectrum? The visible spectrum for a human eye is somewhere between 380 to 740 nm (read: nm is short for nanometers). The spectrum at which the UV light is found is beyond our visible spectrum.
The UV light is visible at the spectrum between 400 to 10 nm. A fish has a visible spectrum between 150 to 750 nm. However, this is just a theory because a fish’s visible spectrum changes as we go deeper into the ocean. This leads us to the next section.
How does Water Depth Affect Colors?
The oceans comprise of four levels that are divide as you go deeper into the water. What are the five levels of the ocean?
- Epipelagic (The Sunlight Zone) – surface to 656 feet
- Mesopelagic (The Twilight Zone) – 656 feet and 3,281 feet
- Bathypelagic (The Midnight Zone) – 3,281 feet and 12,124 feet
- Abyssopelagic (The Abyssal Zone) – 13,124 feet and 19,686 feet
- Hadalpalegic (The Deep Trenches) – 19,686 feet to 36,100 feet
As you go from the sunlight zone to the dark trenches of the ocean, the light continues to diminish, and the way a fish sees colors begins to change. Going deeper into the water, the wavelength decreases.
In case you were wondering why the wavelength decreases, allow me to clarify. The wavelength depends on the light, and when we go deeper into the water, light decreases. Because the light decreases, the wavelength also decreases.
Why does this all matter? It matters a lot because, as you already know, colors are found at a specific wavelength. When this wavelength decreases, some colors on our visible spectrum are no longer visible. By the time you reach 330 feet, the only color visible is dark blue, which ends at the first level of the ocean.
How do they see?
A fish has worse eye-sight than a bat roaming around in the night. From the fish’s point of view, the world isn’t what we see in Finding Nemo. Maybe, from our point of view, but not for a fish. In reality, a fish can not see too far because it is nearsighted.
You’ve already learned that a fish sees using their rods and cone cells to see. But, what you didn’t learn is that for a fish to see anything clearly, the light has to hit their retinas at the right angle. A fish can see, just not all that well.
Can they see in the dark?
If you were down at the bottom of the ocean, it’d be impossible to see the person standing a foot away from you. A fish can’t see colors, plants, other fishes, or anything else.
But, wait, I did say a fish has rod cells, which gives it the ability to see in the pitch-black darkness. It is a bit confusing right now, let me explain. The fish that can’t theoretically see anything in the deep oceanic trenches is a surface-level fish. The fish that reside in those deep trenches, a deep-sea fish, can probably see the things more clearly down there.
Some scientists believe that the fishes at the bottom of the ocean have undeveloped cone cells (the photoreceptors for vision in brighter areas). As a result, the rod cells are more advanced compared to the fishes in the sunlight zone. Thanks to these advanced rod cells, a fish that lives in the bottom of the ocean can see other fishes, plants, etc.
NOTE: This is just a theory; it is yet to be proved.
There is another theory, which is more believable because we have proof. Some fish that live at the bottom of the ocean don’t have the ability to see. So, they rely on something called lateral lines. What in the ocean is that? Lateral Line is an organ which allows a fish to detect pressure, vibrations, and movements in their surrounding. Using this organ, they can make their way around the dark blue trenches.
In the end, to answer your question, I will leave the answer up to you; can they see in darkness with the help of heightened rod cells, or do they rely on lateral lines. What do you think a fish relies on? Let me know in the comments section.
How important is Light for a Fish to see Colors?
Underwater, light plays a big role in how you see things. The intensity of light, it’s density, etc. are all some factors that are vital to how we see. What happens when light enters the water? After it enters the water, light scatters into the water like one big fog that can only reach so far. By the time you enter the twilight zone, there is little to no light.
Where light is available, a fish uses its rods and cones to see it. Similar to how our eyes react to light, the light rays received by the fish’s retina process it into an image. This image, based on the rods and cones, is also given colors.
This doesn’t really matter much, though, because a fish, in general, has poor vision. You can learn all about it in our article about how a fish sees the world. The gist of it is that fishes are nearsighted. What does that mean? It means that a fish can see things very well only if they are really near. Consequently, they normally have a blurry picture of the world.
A light that reflects of a surface is called polarized light. If there is a light bulb in your house, let’s suppose the light rays from the bulb hits your watch. When you move it around, you notice a small circle of light on the opposite wall. This light reflecting from your watch to the wall is polarized light. What is the light coming out of the bulb called then? The light coming directly from the source is simply called unpolarized light.
Why are we talking about this? Polarized light is very important for a fish to see anything, whether it is colors or objects. Unlike humans, a fish can more easily sense these polarized lights. Mainly, a fish uses it to either run from their predators or to find their prey. A Fish has a reflective skin like you might have noticed, so the light shining off their skin helps fish see one another more vividly. Remember, a fish has a blurry vision, so polarized light is often helpful for them to see things.
Recent research indicates that a fish has gone through an evolutionary phase. It has started using polarized light to camouflage into the background to avoid their predators.
Surface Dwellers vs. The Trenches
The world above is rich with color, just take a gander at the Great Barrier reef in Australia. The vibrant colors are hard to look away from. Now, imagine the bottom of the ocean, where you can’t even tell if there is some fish in front of you.
How does this affect a fish? If you take a fish from the barrier reef and swoop out another fish from the twilight zone. The one from the surface will be more capable of detecting colors. This is because it is exposed to a wide variety of colors compared to the fish in the deeper levels of the water.
It is rumored that a deep-sea fish may not even see colors at all. Instead, they see the world in shades of grey. Research supports this claim, but it is difficult to be certain. Why? The way a fish acts in open water is vastly different compared to the contained environment in a lab. Plus, like animals on the land, not all fishes are the same. So, if a couple of them see in shades of grey, we can’t say that all deep-sea fishes can’t see colors.
The Color Of A Fish
From the eye-catching mandarin fish to the gorgeous peacock bass fish, the color of such surface fish is simply breath-taking. However, not all fish have a skin of striking vibrant colors. Yeah, there are some other fish like a clownfish or a goldfish that have one color but are still a treat to see in an aquarium. What about the deep-sea fish?
Super Black Fishes
The majority of deep-sea fishes, if not all of them, are black in color with a red belly. Take the viperfish; for example; it is blacker than the color black. This isn’t the only fish to evolve in this way.
Why would they do that? It is simply because they are evolving in this way for survival. Isn’t that what every animal wants – including humans? Going super black can help a fish camouflage in the depths of the ocean. It absorbs whatever little light is in its surroundings to become blacker than the surroundings.
From what I can only assume is that the pitch-black trenches of the ocean are bound to be a dangerous place for some fishes. But, the question is, where does the light come from? As dory states,
“Trench. Through it, not over.”
The light comes from a fluorescent fish, or in other words, our neon-colored marine life. There are believed to be 180 fish species that can put on a light show in the dark trenches.
Bio-fluorescence is commonly found in numerous fishes and animals on the land. Ironically, we can’t really see these neon fishes from our eyes. A fish reacts with a chemical and absorbs the light to create the bio-fluorescence skin.
For instance, there is a chemical reaction in the ocean, and now the fish will absorb the light in its surroundings. Then, it will convert that absorbed light into a different color. Followed by which, the fish simply releases this bio-fluorescent light.
You can find some neon fishes that aren’t invisible. A company genetically engineered fluorescent fish and offered to sell them. These fish are called GloFish. You can find a fish glowing with all sorts of colors from red to purple. Where can you find them? Just visit your local pet store.
How does this help me, a Fisherman?
The colors of your bait and line can make a huge difference in the number of fishes you catch on a brisk Sunday morning. Why? From what you’ve learned in this article, you can judge how a fish reacts to colors at different levels of the sea.
If you use a blue bait, it has a higher chance of getting detected by fishes that reside in the deep sea. Using darker colored baits could be helpful in catching a fish from the bottom. Alternatively, when you are trying to catch a fish at the surface, you can experiment with other colors like red or yellow because they are more prominent.
Ultraviolet light could be a game-changer. You can use ultraviolet light baits and lures to attract a fish. Since a fish has a higher sensitivity to UV lights, it is possible that a UV light lure could help you catch more fishes compared to other colors.
Are You Sure?
Considering the way a fish perceive colors, it is impossible to say all fishes, in general, will act the way we think they act. For starters, let me remind you, most of the research findings are based on the experiments done in labs. And, it is uncertain if the fish will act the same way in the ocean, as it did in the lab.
Why is that so? In a lab, the environment is controlled by humans to stimulate a fish into a reaction. We fiddle around with the light, the water pressure, etc. to see how a fish reacts. Aside from this fiddling, we know for a fact that one fish is different from another.
What about the same species fishes? Interestingly, research indicates that some fish’s eye receptors also change over time. For instance, a fish with 4 cones in its youth, may not have all 4 functioning cones in its old age. A chinook salmon has blue and green receptors in its entire lifetime. As it grows older, the chinook salmon moves to the surface and has a red receptor instead of the blue and green.
In conclusion, you should know that I can’t be certain that every fish will react the same way we want it to. But, with what you’ve learned above, there is a better chance of catching more fishes. Good luck, fellow readers, and happy fishing!
Can fish see different colors?
A fish’s eye is made of cells called rod and cone. You can also find these cells in a human eye. Why are we talking about this? Well, the rod and cone cells are used to see color. So, if a fish has them, to answer your question, a fish can see colors. In addition to this, unlike humans, a fish can see the ultraviolet light. This is proof that a fish can identify between the colors through the color spectrum. Simply put, it means that a fish can see different colors.
Are fishes color blind?
No. Yes. The answer is a bit complicated. Most fishers believe fishes are color blind, but at the same time, they believe a fish can detect the lures of different colors. A fish can sense the difference in colors. Moreover, an important part of their survival is to detect light. The light in the water helps some fish find food and prey. Alternatively, they also use it to escape the fishes that rank higher on the food chain. To find out for yourself, grab a couple of different colored lures, and see how the fish reacts.
Do fish see red light?
Here is the thing, the way a fish sees color depends on the color spectrum. As we go deeper into the ocean, the light begins to disappear. Why does that matter? Well, without getting into too many details, let’s just say light plays a crucial role in the color spectrum. So, when we go into the depths of the ocean where there is little light, the only colors visible at that point are black and blue. Other colors like red, green, blue, yellow, etc. are not easily visible.