Fish have an outstanding evolutionary history with many types of variances and anatomical distinctions. Development and progress revolve around one core fundamental concept, the ability to maximize food intake while minimizing the potential to get killed by a predator practicing the same principles. As you might expect, fish have become animals that inhabit their environmental niche perfectly, and have developed incredible mechanisms that take advantage of environmental cues and enhance their senses in very specific ways. All senses are the best they can be on all animals at this point in time. Sound travels five times faster in water than it does through the air, and as a result, fish have incredible hearing abilities due to an inner ear bone and a lateral line organ that detects vibration. In addition, fish have developed an acute olfactory system to cue on the chemical compounds that are incredibly abundant in many shapes and forms in lakes and rivers, resulting in a sense of smell that is one million times greater than ours. And finally, fish have developed an interesting mechanism to efficiently use available sunlight at low light times to maximize their ability to profile prey. Conversely however, there is no real evolutionary advantage for detecting color in any great detail, with minor exceptions, and fish do not have the ability to detect a wide range of colors. This makes the discussion of color among fisherman an interesting and controversial subject.
A collaboration of senses is important to obtain total efficiency. When discussing sight, it is important to note that fish do see very well, but have not developed a specific importance to register color information. The exceptional visual capabilities of fish can be attributed to a very specific anatomical advantage that many animals have (i.e. deer, cats, fish, etc.), an organ called the tapetum lucidum; which is responsible for the phenomenon of reflective eye-shine. Upon receiving light, the eye collects amounts of light that is absorbed by the retina, which is composed of rods and cones. The rods simply detect the presence of light, while the cones detect color; providing perfect vision for total efficiency for that particular animal’s survival. Fish, on average, typically exhibit around 5 rods per 1 (one) cone on each nerve cell, however, the ratio expands exponentially as water depth increases. There is always the potential for light to go unused by the retina, but the tapetum lucidum utilizes this remaining light and reflects it back outward so it passes the retina for a second time. Walleyes and muskies are a couple noteworthy species that have this mechanism, allowing for ultimate vision through turbulent water and during low light periods.
After sunlight reaches matter in the atmosphere it immediately responds to that matter’s molecular structure and consequent absorption rate, instantaneously responding to the movement happening between the electron and protons within the matter. Everything absorbs some amount of light, but the light that is not absorbed is refracted off the matter resulting in the color we see the object as. Every color that we see has a specific wavelength associated with it, with the color blue having the shortest visible wavelength and the color red exhibiting the longest wavelength. Because there is less energy associated with longer wavelengths (red), it is easier for matter to absorb it, and easier for it to refract shorter wavelengths (blue). So, longer wavelengths are absorbed fastest by things that are very dense, i.e. water. This means that red light is absorbed first when water is between a lure and a fish’s eye. With three feet of water between eue and lure, approximately 30% of the red light is absorbed in clear water, and at 10 feet, all the red light is absorbed. This process intensifies as the amount of nutrients in the water increases. The same concept applies to all colors as you move down the color chart, until all colors are absorbed and things appear totally blue, gray, and black. Also, keep in mind that these principles don’t only apply to vertical light, they also apply to horizontal light. So, red light is considerably absorbed at any direction with more than three feet of water between the fish and the object. If a fish is eyeing your lure from ten feet away, all of the longer wavelength colors in your lure will be gray, and the other shorter wavelength colors will not hold true color.
For anglers, realistic silhouettes and realistic movements are most critical and usually trump lure color when triggering initial responses from fish, but it is important to note that particular realistic patterns and variances in color create a more desirable appeal at the moment a fish decides to eat. Interestingly, the color black offers the most visual stimuli to most fish at greater distances, providing the most stand-out base color and decisive outline. Black is the newest craze, and I’m a little reluctant to share this with you.