There are few things as frustrating as watching a tarpon break off from a string of fish, coming up behind your fly, only to stare down your offering and refuse it at the last second. The aftermath leaves you confused and pondering everything. Was it the fly pattern, was it the size, or maybe the color? The countless heartbreaks tarpon have imposed on anglers can largely be attributed to their big, beady eyes. This eye, like tarpon in general, has been largely unchanged for the last 18 million years, and for good reason; it does its job exceptionally well. Understanding this eye, and how tarpon see color, may just change the way you think about fly selection.
The Everchanging Eye
Tarpon, part of the Elopiformes sub-order (along with bonefish, ladyfish, and eels), have what is known as leptochephalus larvae. These tiny, translucent larvae are born at sea after the annual spawning migration, then drift with ocean currents back to shallow-water estuaries. When they are first born, these larvae have only rods in their eyes. Rods are the part of the eye that detects black and white shades, whereas cones detect color. In the deep dark ocean, these rods are all a larval tarpon needs to see, but these requirements soon change as they head inshore.
Once the larvae reach shallow-water estuaries and mangroves, tarpon eyes begin to change dramatically. Tarpon are one of the few creatures that develop cones as they mature. Unlike humans, who are born with both rods and cones, tarpon retinas develop the cones only once they start to move shallow. These cones are better in bright light and can distinguish between different colors. As they continue to grow, they eventually develop five unique types of cones to see color, compared to the three types of cones in human eyes.
How Tarpon Eyes Work
The five types of cones in a tarpon’s eye result in a much wider range of color spectrums that they can see, with each cone specializing in a specific wavelength. Of these cones, the most prevalent are those that detect green and yellow wavelengths. This is followed by cones that detect UV wavelengths (which we can’t see). The third most prevalent are cones that detect blue wavelengths. So what does this mean for tarpon anglers?
In terms of tarpon flies, there are plenty of well-established and proven patterns. Flies like the tarpon toad, cockroach, and worm flies have all seen their fair share of fish, but the bigger question is what color flies should you throw and when. For starters, chartreuse and yellow flies work well in oceanside and backcountry fishing with relatively clear water. Black and purple are also proven colors for low-light conditions and stained water.
UV light comes into play when fishing in turbid or deeper water. Since UV light penetrates the deepest in low-visibility water, flies tied with UV materials are, in theory, more visible to these fish. Materials like EP fibers are available in UV versions, which can add another level of visibility to your flies in deep, dark water or when fishing at night.
What Can Anglers Do With This Knowledge?
Learning about how tarpon see color is an important piece of the puzzle when trying to catch the Silver King. It allows you to pair your color selection to specific conditions, which can ultimately improve your odds of hooking a fish. However, when it comes to tarpon fishing, how you present your fly often trumps color. Work on your casting, and know where to put the fly in relation to an oncoming fish. If you can get the fly in front of a fish and avoid spooking it, you’ll have a much better chance of hooking a fish.
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Rare Transformation of Tarpon from Nearly Blind to Super-seers Could Have Human Applications
