Think of a calm morning, when the mist is still on the surface of the water and you cast your line. The bait falls in, a colored gleam flickering away to the bottom. A few seconds later, a strong jerk indicates success. But what was it that made that fish bite at your hook or bait? Was it chance, or something more complex?
Anglers have tried to discover this secret over generations, with an intuitive sense that there is more to a strike than the human eye can see. The answer lies in the depths of the sensory world of the fish itself, a world that lives by quite different perceptions than our own.
This article explores the amazing science behind what fish actually see and feel, and answers why certain lures always work better than others, allowing anglers to fish smarter and not harder.
A Fish’s Sensory Arsenal: Beyond Human Perception
To really see how well a properly designed fishing lure will perform, one must first get into the watery world and realize the special sensory abilities that fish have. Fish have developed specialized organs and senses to suit their aquatic life, unlike the human beings whose major sense organs are adapted to life on land.
The Visual World: Color, Light, and Contrast
The old saying “match the hatch” usually means matching the color and shape of the natural prey of a fish, and there is a good reason why. Sight is an important sense for a wide variety of fish species, especially predatory fish hunting in bright environments. Nevertheless, the visual perception of a fish is much more complicated and sophisticated than the ability to see colors.
Fish eyes, as ours, have rods and cones. Rods are the ones that detect the intensity and movement of light, particularly when the light is low. Cones on the other hand are the ones that perceive color. The spectral sensitivity, the range of colors visible to each species, depends greatly upon the number and type of cones, and this differs greatly among species. Fish are dichromatic (seeing two primary colors), trichromatic (three like humans) and even tetrachromatic, with four types of cones, allowing them to see inside ultraviolet (UV) range.
The nature of water has a significant influence on the perception of light and, as such, the color of underwater conditions. Light moving through water is being absorbed and scattered. Red light is absorbed first and vanishes in a few feet, followed by orange, yellow, green, and lastly blue, which penetrates the farthest. That is, a bright red lure near the surface may be camouflaged at deeper levels to dull brown or even black, whereas blues and greens will remain visible much farther. The clarity of water, the turbidity (muddiness) and even time of day (at dawn, dusk, under bright sun) radically change the spectrum of available light and the perception of colors.
The most overlooked feature of fish vision is their ability to perceive ultraviolet light. Trout, salmon and bass are among many fish species with UV-sensitive cones. This implies that they can observe light which is not visible to the human eye.
The Lateral Line: Feeling the Vibrations
In addition to sight, fish have another amazing set of senses called the lateral line, which is arguably their most important asset to navigate, hunt and escape predators in the usually murky water. The lateral line is a collection of specialized sensory organs known as neuromasts, which are embedded in a series of canals which run down either side of the fish’s body, head to tail.
These neuromasts are very sensitive to even minor variations in water pressure and displacement. They sense low frequency vibrations, water currents, and pressure waves caused by moving bodies in the water, e.g. struggling prey, other fish, or even the slightest movement of an angling lure. This system functions as an underwater ear and touch sensor, enabling the fish to have a sense of the surroundings without touching or even sight. In dark water or at night, the lateral line comes to the forefront of the prey detection and a fish is able to identify the precise location and movement of its next meal.
Although the lateral line mainly picks up low frequency vibrations, fish have an inner ear system that enables them to have hearing capabilities. These sounds are usually amplified in the swim bladder, which is an air-filled organ, and sent to the inner ear. The frequency range of fish hearing is very species-specific, though many species have hearing in the very low frequencies (which overlap with lateral line responses) to the high frequencies. Prey, predators or even the slight clicks and rattles of a lure can create these sounds.
Crafting Deception: Lure Design Principles
With a better knowledge of fish senses, lure designers carefully produce baits that appeal to these senses, making the inanimate objects appear as irresistible temptations.
Lure Design Color Theory
Color is the most important thing when designing lures. The aim is usually to replicate the natural forage of the target species. This implies that one has to think about the common bait fish, insects, or crustaceans within a specific environment and pick the colors of lures that are as close as possible to these objects. An example is a silver or white lure that would be very effective in waters with many shad.
Nevertheless, it is not always the only goal to get the exact color. In some cases, contrast and silhouette are more critical, particularly during low-light or murky situations where color is less apparent. A black-colored lure in a clear-blue sky, or a clear-blue lure in a dark bottom can produce a deep outline that fish pick up with ease. Also, adding UV-reflective pigments to lures may provide them with a unique advantage so that they appear to fish with UV-sensitive eyes to be glowing even when visible colors are long-gone. Most of the modern soft baits are loaded with UV enhancers to take advantage of this frequently neglected part of fish vision.
Movement and Action: The Dance of Deception
In addition to color, movement and action of a lure play an imperative role in initiating a strike. Lure designers know that various actions imitate various prey behaviors, and it is essential to select the proper action for the situation.
- Wobble: Some crankbaits and diving lures wobble or swim side to side, displacing water and causing vibrations that are attractive to fish through their lateral line.
- Flash: Spoons and certain spinnerbaits are made to flash during motion and resemble the shine of scales of a fleeing or wounded baitfish. In clear, bright water, this visual indication can be very effective.
- Erratic Movement: The injured or struggling baitfish moves rather erratically and thus is easy prey. This vulnerable behavior can be simulated by lures such as jerkbait or soft plastic worms when retrieved with a twitching action, which will cause a predatory response.
- Hydrodynamics: The design and form of a lure determines its hydrodynamic characteristics, i.e. its motion in the water. A round-bodied crankbait will wobble looser than a flat-sided crankbait, and a streamlined jig will fall faster than a bulky jig. Being aware of these nuances will enable designers to design lures with certain, attractive behaviours.
Vibration and Sound: The Silent Call
The vibration and sound are important components of lure design because of the lateral line system of fish. Several lures are specially designed to produce these sensory cues.
Rattles: Most hard baits (crankbaits and some topwater lures) have internal rattles (BBs or beads that make an audible clicking or rattling sound when the lure is moved). This noise is transmitted in the water and draws the fish at a distance, especially in stained or murky water where the visibility is poor.
Blades: Spinnerbaits and chatterbaits have metal blades that spin or vibrate very fast, producing flash and a noticeable amount of water displacement. This gives a good hydroacoustic signature that can be sensed by the lateral line of fish and resembles the swimming baitfish or struggling insect vibrations.
The Material Advantage: Innovation in Lure Manufacturing
The development of fishing lures is closely connected with the progress in material science and production technologies. The material directly influences action, durability and general effectiveness of a lure.
The Evolution of Soft Baits
The innovation and perfection of soft plastic lures is one of the biggest revolutions in the fishing lure industry. In earlier times, soft baits were often stiff and unnatural, but today, advanced polymer chemistry has given rise to modern soft baits. A top company in the production of soft baits, spends a lot on research and development to come up with proprietary mixtures that provide maximum performance, durability, and scent retention. They are usually produced using different forms of plastic polymers, generally of PVC nature, combined with plasticizers to enable soft baits manufacturer to produce lures that are really lifelike in their feel and action of the natural prey.
These materials are quite flexible and thus enable very realistic movements, e.g. the waving tail of a worm or the slight twitching of a creature bait. The flexibility also implies that they are more inclined to convey the vibrations in a more natural way across the water, which adds to their attractiveness to the lateral line of a fish. In addition to texture and action, today’s soft baits can also have scent infusions. Such scents, which may resemble those of baitfish, crawfish, or other prey, may provoke a feeding response even when visual or vibrational signals are weak.
The emergence of online retailers and direct-to-consumer models has caused the need for bulk soft plastic baits. Now, anglers can buy large amounts of their preferred worms, creature baits or even swimbaits at a cheaper rate and have a stock of them at all times.
Fishing Smarter: Using the Science
The science behind fishing lures is not an academic exercise, but a practical manual for being a more successful angler. By using this knowledge, you would be able to make better decisions about the water.
- Matching Conditions: Consider the clarity of the water, depth, and the light conditions. In clear, bright water, concentrate on realistic colors and subtle actions, perhaps using UV-enhanced lures. When the water is murky or low light, use lures that have a lot of vibration, rattle and that have high contrast silhouette.
- Knowing Prey: Study the main food in the waters you are fishing. In the event of the fish feeding on small minnows, a thin swimbait may be more productive than a wide creature bait. When the crawfish are thick, a jig or soft plastic craw could be the ticket.
- Experimentation: Fishing is still an art despite the scientific knowledge. There is no harm in trying out various kinds of lures, various colors of lures and various speeds of retrieving lures, until you figure out what the fish are biting on on a particular day. Success is decided by the fish themselves.
Final words
The evolution of a mere hook and line to the advanced fishing lures of today is evidence of human creativity and our constant interest in nature. The combination of the complex fish biology of sensory perception and the strict laws of physics, and the tactical approach of angling has allowed the lure designers to make fishing into a genuinely scientific process. The effectiveness of every cast is determined by what fish actually see, feel and hear. To the keen angler, a greater knowledge of these submerged processes not only makes him successful in his work upon the water, but also creates a deep interest in the intricate, living, and frequently invisible world beneath his feet. Fishing smarter is all about honoring the science, being innovative, and always learning, by the ultimate teachers, the fish themselves.
