Biology Walleye Senses Dan Johnson August 31st, 2017 | More From Dan Johnson Share0 Tweet Email Share on Facebook.Share on Twitter.Share on Google+ Consistently successful walleye fishing isn’t the result of black magic, flukes, or luck. It can be learned through a basic process that’s quantifiable and predictable. It’s also relatively simple, though it does take time and effort to master. In-Fisherman’s teaching system has held to these tenets for decades, and taught countless anglers how to catch more fish and have more fun. Unfortunately, the basis for sustained walleye fishing success often gets overlooked, overshadowed by the same factors that have made achieving such success difficult for generations of anglers. The problem is, too many anglers seek shortcuts to success—a magic lure, secret bait, deadly new color, or a breakthrough jigging motion walleyes can’t resist. Aiding and abetting such destructive desires are tournament winners who proclaim a special lure propelled them to victory, along with television hosts and YouTube tipsters touting silver-bullet solutions to far more complex scenarios. Temptations such as these distract us from the fact that hot lures, baits, and even reliable fishing patterns are at best only pieces of the overall puzzle. The foundation for putting together fish-catching presentations—then deploying them in the strike zone—is a solid understanding of the walleye’s basic nature. Vision Walleyes rely on eyesight to navigate and capture prey. Their daytime vision is stellar, but it truly shines after sunset. The walleye eye is amazing, blessing the predator with incredible night vision, second in freshwater only to its cousin, the sauger. The eye is large, allowing the pupil—the light-gathering part of the eye—to gather as much light as possible. No creature can see in total darkness, but even scant starlight provides enough illumination for walleyes to stalk their prey far below the surface. A reflective layer on the retina, called the tapetum lucidum, gives walleyes another advantage when the lights go out. A principal adaptation for night vision found in nocturnal animals including cats, deer, raccoons, and some other fish, this layer concentrates light when it enters the eye. Vision begins when light passes from the pupil opening through the cornea and then to the lens, which focuses the image. Light then reaches two types of light-sensitive cells in the retina, rods and cones. Cone cells detect color when exposed to daylight. Rod cells distinguish shades of gray and allow vision when sunlight isn’t present. Walleye and sauger eyes contain a larger proportion of rods than the eyes of perch, shiners, and other fish that are most active during the day. The tapetum lucidum is located in the lower portion of the retina’s deepest later. This physiology suggests that walleyes see lures and baits moving above them more clearly than objects moving below them. Likewise, fishing experiences suggest it’s best to position lures slightly above the sonar returns of fish. Still, there are times when quickly dropping a bait below eye level can trigger a reaction, such as when a walleye follows a jigging spoon upward in the water column but is hesitant to strike. Allowing the lure to plummet downward can cause an otherwise wary walleye to rush down and grab it. As a result of their night vision, walleyes often feed under the cover of darkness because they can see better than the prey they pursue. This explains why walleye fishing at night is productive year-round on clear lakes and reservoirs. Times when light levels change rapidly, such as around twilight, are also legendary for sparking walleye activity, as are waves or clouds that reduce light penetration. Longtime touring pro and In-Fisherman confidante Keith Kavajecz adds observations on these golden moments, as well as the relationship between forage, water conditions, and walleye behavior. “Prime-time bites are more pronounced where food is abundant and walleyes have the luxury of waiting for an easy meal,” he says. “If food is scarce or there are lots of walleyes, the fish are hungry and eat all day long, whenever they get the chance.” In a similar vein, he notes how low-vis conditions such as heavy algae blooms and tannic-stained water trigger daylight feeding forays. “Daytime activity increases where night vision is minimized due to poor light penetration,” he says. Walleyes also possess color vision, based on analysis of the structure of the light-sensitive cones. Scientists tell us walleyes should see red, orange, and yellow the best, followed by green. Theory also suggests walleyes see blue and violet less well, and these colors may even appear black. Kavajecz is a firm believer that color is a major piece of the walleye-catching puzzle. “They certainly key on colors,” he explains. “But there’s more to it than matching the forage base. There are so many variables that every time you put a formula together, you miss potentially productive color patterns because you’re not open-minded enough to try them.” He relies on experimentation to dial in the best colors at the moment. “I keep throwing colors at them,” he says. “Even when a pattern starts to take shape, I keep testing other colors to make sure I have the best combination for the conditions.” Walleye anglers have used phosphorescent, or glow, finishes for walleyes for decades. Glow finishes represent a form of luminescence—the process by which a material emits visible light when subjected to an energy source such as a camera flash. Kavajecz advises factoring glow into your strategies, but says to choose glow colors carefully. “Not all lures glow in the color you see on them in daylight,” he says. “The JJ Mac Muffin pattern of Moonshine Lures’ Shiver Minnow, for example, is purple, chartreuse, and white, with red dots, but from my observations, it glows blue in deep water. “Glow color makes a big difference on some lakes,” he says. “On Lake of the Woods, red glow is hot. On others, green glow is the deal. And on fisheries including Lake Erie and Sakakawea, I’ve seen blue glow baits outfish every other color. It’s not necessarily related to what they’re feeding on, either, because blue glow catches fish were walleyes are eating perch and silver-sided baitfish. So here, too, experimentation is key to consistent success.” Lures treated with UV finishes that fluoresce when struck by ultraviolet light are a relatively new trend on the walleye scene. While some fish can see UV light, science tells us that its short-wavelength rays fall outside the portion of the electromagnetic spectrum visible to humans and walleyes. Still, many astute and respected anglers report increased catches when using optically brightened UV baits, particularly in low-light and low-vis situations. Kavajecz isn’t one of them. “I’ve experimented with UV and it makes a big difference for salmon,” he says. “But I haven’t seen it for walleyes, even when trolling the same colors in UV and non-UV finishes side-by-side.” But he doesn’t rule out UV as a factor, either. “I’m a believer in the power of confidence,” he says. “If you have confidence in UV finishes, you probably catch more fish with them.” Hearing Sound waves in water and air are produced by particles rebounding after compression, imparting directional energy to neighboring particles. Because molecules in water are closer together than in air, directional energy is transferred from one to another nearly five times faster below the surface than above it, making sound a key component of the underwater world. Although sound waves pass through a fish’s body with little effect, because a fish’s density is nearly the same as water’s, they do cause vibrations in the calcium carbonate earbones, or otoliths, located on either side of the skull. Hence, fish recognize familiar patterns of frequencies as sounds, just as we hear airborne sound waves, and they use these sounds to detect the presence of predators and prey. Walleyes lack external and middle ears, but their inner ears are similar in structure and function to those found in humans. As a result, walleyes hear well under water, though not quite as keenly as species such as catfish and minnows. Science tells us walleyes hear underwater sound waves in the range of 100 to 2,000 hertz (Hz; cycles per second). Their hearing range includes most sound produced by rattling crankbaits and other relatively loud lures. High-pitched rattles are a novelty in the underwater world, and often arouse curiosity, compelling walleyes to test for identity and edibility by biting. “I absolutely believe in using rattles for walleyes, particularly in crankbaits,” Kavajecz says. “Having helped design lures like Berkley’s Flicker Shad and Flicker Minnow, I’ve been a party to extensive testing that convinced me rattles boost catch rates.” He notes that not all rattles are created equal, however. “The high-pitched rattle of several small glass or plastic beads is far more effective in most cases than the sound created by one large, clunky bead thumping around in a rattle chamber. Still, a low-pitch performance is better than no rattle.” He’s not as convinced about adding rattles to most other presentations, though he concedes that rattles could enhance the sonic attraction of spoons and jigs fished with active, consistent strokes during vertical jigging. Lateral-Line Hair cells inside the tiny neuromasts of the walleye’s lateral line detect low-frequency sound waves from 1 to 200 Hz (note the slight overlap with hearing) and sends those messages to the brain. To help fish pinpoint the vibrations’ source and location, some sensory cells are oriented in one direction, while others face the opposite way. While hard-wobbling crankbaits and churning spinner blades certainly produce plenty of vibrations, other seemingly silent lures such as jigs and flat spoons send out pressure waves detectable by the walleye’s sensitive lateral line. In murky water, at night, and in other low-visibility situations, a walleye may sense a lure’s presence before it sees it. “Even baits that attract attention by appealing to a walleye’s other senses need the right vibration to seal the deal with a strike,” Kavajecz adds. Dialing in vibration has and always will be critical with high-action lures like crankbaits, but he says it’s a major consideration when selecting softbait tippings, too. “The rise in options of actions tails including various paddle, ripple, and curl-tail choices allows us to fine-tune tail-beat vibrations like never before,” he says. “Don’t just look at tail size and shape; pay attention to plastic density and stiffness, too.” Smell and Taste Because they must detect molecules of substances dissolved in water, a walleye’s senses of smell and taste are more closely linked than humans. While this makes it hard for researchers to determine which stimuli they respond to, there’s little doubt scent and flavor play a role in feeding behavior. A fish’s chemoreception (including both smell and taste) is also critical for avoiding predators, locating fish of the same species, coordinating spawning time, and homing in to residence areas and spawning sites. Judging by the design of its olfactory organ, a walleyes’ sense of smell probably falls somewhere between channel catfish and members of the sunfish family, and walleyes are likely able to detect amino acids in a dilution of several parts per 10 million. Studies have shown walleyes respond favorably to various amino acids and salt solutions, while fish mucus, essences of walleye body parts, and other amino acids repel them. It’s no surprise that walleyes smell well, considering that livebait is often the only answer to a tough bite and finicky fish. Taste is likewise important, often spurring the decision whether to spit a bait or swallow it. “On scent and taste, I’m more concerned with not repulsing fish than I am triggering them to bite,” says Kavajecz. “A walleye is very quick about sucking things in and blowing them out. It’s important that a bait doesn’t taste bad when they take it in, so they’re willing to hold it in their mouth long enough for me to set the hook.” Berkley Gulp! and PowerBait softbaits offer his favorite scents and flavors. “I like PowerBait’s impregnated scent with faster-moving presentations, while the water-soluble solution in Gulp! excels at slower speeds,” he says, adding that he often adds a dollop of Gulp! Marinade to a bag of Gulp! and lets the concoction rest overnight to “jazz it up a little.” More than a few anglers marinate or otherwise treat hardbaits such as Jigging Rap and Shiver Minnnow-style swimming and gliding lures with Marinade and other scents. “It’s not as much of a factor for me with these types of lures, but it doesn’t hurt, and before the scent washes off, it can cause walleyes to hold onto a lure longer than untreated baits,” Kavajecz says. Putting It Together In the end, Kavajecz is convinced a sound understanding of walleye biology—and the ability to apply it to real-life fishing situations—helps put more fish in the boat. “One of the overlooked sensory factors I consider more of a ‘sixth sense’ is the walleye’s instinct to attack injured prey,” he adds. “This can be a big factor when deciding whether to match the hatch or offer fish something completely different than what they’re feeding on. For example, when baitfish are abundant and food is easy to come by, you can drag a ‘crawler or leech in front of their noses and they won’t touch it. But when something different comes by that’s obviously wounded, like an erratic crankbait or hopping, darting glidebait, they can’t resist.” Kavajecz reports countless cases of overfed ’eyes pouncing on easy pickings. “I’ve even seen it happen where you have 20-foot-thick bands of smelt on sonar and walleyes are literally stuffed to the gills, but they still crush a lure that mimics distressed prey, even with two or three baitfish sticking out of their mouths. That’s keying on something in the walleye’s psyche that goes way beyond the normal senses.” *Dan Johnson is a frequent contributor to In-Fisherman publications and director of All Creation Outdoor Media. Share on Facebook.Share on Twitter.Share on Google+ Share0 Tweet Email Load Comments ( ) Don’t forget to sign up! Get the Top Stories from In-Fisherman Delivered to Your Inbox Every Week To sign-up for our newsletter, check this box and submit your email address below. 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