the science behind uv & tarpon
using science to help you
catch more fish
Karankawa Lure Co.
The idea behind reinventing how we paint tarpon lures came to us almost two years ago. Our friend, Michael Larkin, Ph.D. wrote an article for Saltwater Sportsman Magazine, entitled, "The Science Behind Tarpon" (click). Within the article was a great discussion of tarpon eyesight. After doing a little more research on the subject, we began testing our paint theory in 2015. We were pleased with the success and became convinced that the UV paint and color selections based on the science behind tarpon vision really did make a difference. As Dr. Larkin explains,
"First of all, fish eyes are very different from ours. [Fish] eyes... change as the fish move into different habitats and potentially opt for different food sources... As an example, the colors that juvenile tarpon see are different from those seen by adults... When tarpon become adults,... their vision in the shorter wavelengths, such as purples and blues, increases. They also develop cells to detect ultraviolet light... It is unknown why tarpon see UV light, but there are a couple of possibilities. One is since some fish reflect UV light for communication, tarpon may use the ability to detect prey. Another is, with UV light so abundant in the shallow waters they inhabit, they may use this light to create a background, allowing them to detect the silhouettes of prey that would otherwise be camouflaged."
This article sparked out interest. We did some more digging and found a few scientific journal articles examining the properties of the cells that make up tarpon eyes. Here is what we found:
What Can Science Tell Us? As we all know, light is made up of different wave lengths of light. Shine a light through a prism and the wave lengths are separated. It is the same thing that causes a rainbow. Each wavelength is a different color. As humans, there are some colors and wave lengths of light that we can see and some we can't.
The back of our eyes and tarpon eyes also are made up of different types of cells. Two of those types are called rods and cones. Each has a different function. Cone cells detect color and are better in bright light. Humans have three types of cone cells, enabling us to see a million different colors. In contrast, adult tarpon eyes have at least five different kinds of cone cells. As a consequence, tarpon may be able to detect up to 100 million different colors.
Young tarpon have a high concentration of cells in their eyes that help them see in low light and identify bait in brackish water, where they grow up. As tarpon get older and move into clear water environments, they develop more cells in their eyes that help them see more color. In fact, an adult tarpon's eyes are hypersensitive to certain wavelengths of light. Adult tarpon have the largest number of cells in their eyes that react to wavelengths of green and yellow light – a little more on the green side. The second most common cells in an adult tarpon's eye have a peak sensitivity for wavelengths of light in the ultraviolet (UV) spectrum. The third most numerous cell's peak sensitivity is in the blue light wavelength. Just based on the number of cells in a their eyes, tarpon have a higher sensitivity to green, UV and blue wavelengths of light.
So what does all this mean? You might be thinking, well if a tarpon sees a lot of green and swims in green water, isn't that like shining a flashlight in their eyes, blinding them? Probably not. We might think of it this way - If a fish has increased sensitivity in its eyes to the color of water it swims in, then it may be easier for that fish to detect differences or changes in its environment including bait or predators, thereby making its eyes more sensitive to everything around it.
So why are UV lures better? To answer that question, we need to remember some things about light in water. First, the color of light that fades fastest to gray in water is red, being the longest wave length of light. The longer wave length has less energy to penetrate through the water. The scale then goes as follows, orange, yellow, green, blue and violet. Violet penetrates the deepest of human visible colors, because of its shorter wave length. The murkier the water or the more plankton in the water, the shallower all colors and wave lengths of light will penetrate. What this tells us is yellow, green and blue are easier for tarpon to see and see in deeper water. Since UV light penetrates even deeper, lures reflecting UV may be even more visible to tarpon at deeper depths. So, if your lures are UV reflective and fall within colors that tarpon can see easily, your UV lure should be easier for a tarpon to spot. Add to this equation the fact that some bait fish may reflect UV light. A UV reflective bait may, therefore, look even more natural to a tarpon. Either way, our experience has shown that UV baits seem to disappear out of our tackle bags more quickly. We think they will do the same for you.
See - The tarpon's rare transformation from nearly blind to super-seers could have human applications.