Understanding how crappie see things can help you make better lure selections and more effective presentations.
Reprinted with permission from In-Fisherman, the following excerpt about a crappie’s vision is taken from “Making Sense of Crappie Behavior,” an article written by Steve Quinn that appeared in the In-Fisherman 2015 Panfish Guide. We feel the timeless knowledge is a real eye-opener as to just how much crappie depend on sight for their feeding preferences, and therefore wanted to share the information again here.
(Text is exactly as it appears in the article. Photos courtesy of Bobby Garland Crappie Baits)
Making Sense of Crappie Behavior
Biological Keys to Triggering a Hot Bite
By Steve Quinn
Watching crappies move under water demonstrates their cautious deliberate style that makes, at times, for the fastest fishing imaginable. Other times they leave us baffled, wondering where they went or why they won’t bite.
When hungry crappie scull along, seemingly measuring the distance between their mouths and a preyfish. If prey is close enough, they may swoop in and vacuum the minnow, or else try to inch closer without causing it to flee.
In clear water, like in our giant In‐Fisherman aquarium and in many of the clear natural lakes of the North Country, where scuba observation and underwater cam‐ era viewing conditions are ideal, crappies use vision to find and catch prey. But at what range can crappies
see, and can they detect colors?
And what about the murky rivers and reservoirs that are also home to crappies? Where do a fish’s other four senses fit into the feeding strategy? A look at the way crappies sense their world provides clues to more effectively finding and catching them in all sorts of conditions.
The eyes of crappies are among the largest for their body size of all freshwater fish, a feature that alone suggests the importance of vision to both crappie species. For fish and other animals, what is not needed usually isn’t present. Occasionally, a feature is a throwback to an earlier ancestor and is obsolete. But for fish, intense predation pressure tends to shape a critter to fit its environment.
This assumption is helpful when describing the sensory world of the crappie, including its vision. Little research of the sensory systems of crappies has been done, surprising in that crappies tame quickly, live in confined quarters, and are easily handled. As a result, much of what we think we know about crappie vision and their other sensory systems is based on research with other species, usually trout and goldfish, but sometimes other members of the sunfish family. Crappies are closely related to sunfish and bass, and likely are similar in many sensory respects, but undoubtedly different in subtle ways we can only guess at.
Visual Range: As humans, it’s difficult for us to imagine vision in any way other than the way we see. Yet the watery medium is far different and puts serious limits on vision under water. Fish eyes are similar in form to ours, with a cornea, iris, lens, and retina. As with vision in air, underwater vision depends on the detection of light of different wavelengths.
These same wavelengths enter water but are absorbed, reflected, or scattered before traveling nearly as far as they do in air, a much purer medium. In an ultraclear lake, blue and violet penetrate deepest, beyond 50 feet. But in more typical water that’s stained by suspended particles and various, greens, yellows, or reds penetrate deeper. Yet the more algae and suspended particles, the shorter the field of view, both looking into the water and viewing from below.
The length of a fish’s visual field depends on water clarity and is generally similar to a Secchi disc reading, a simple water‐clarity test. The Secchi depth is the depth that the black‐white disc disappears when lowered into the depths during prime viewing conditions (bright sun, relative calm). So with a Secchi depth of 10 feet (considered clear), a fish’s visual field in the upper layer of water would extend about 10 feet in front of its snout. And field of view shrinks with depth.
Fish vision expert Dr. Don Quick has likened a fish’s vision to walking into a thick fog during daylight. Above, the sky looks white and white surrounds on all sides. It’s impossible to make out dark objects in front of you because the light entering your eyes is reflecting off fog droplets closer to you.
As you move closer to an object like a tree, it becomes dimly visible, growing more distinct as you near it. Standing just inches from the trunk, the tree looks as it would in clear conditions. But branches several feet above are still obscured by fog. Like a person in fog or in a smoky room, a crappie sees close objects clearly but more distant objects as though in a perpetual fog.
Crappies like to inspect objects closely, and this characteristic should be a guide to your crappie fishing. A crappie, interested in an item, either by vaguely spying its shape from several feet away (farther in clear water) or else detecting it with another sense, often closes in for a better look. If the object is moving fast like a crankbait, it’s likely already out of range. But if it’s nearly motionless, jiggling along, or slowly moving vertically, it may be fair game, being of the right size and with an appealing profile.
The forward and upward position of crappie eyes suggests the preferred direction for feeding—ahead and somewhat above the snout. A bait in this position attracts the attention of one or sometimes many crappies that rise to inspect it more closely, or some‐ times engulf it in a rush if they’ve put on the feed bag.
As fish approach a target, they focus their eyes with specialized muscles that move the lens of the eye forward and backward, a process called accommodation. The lens is retracted for scanning a distant background, then pushed forward to inspect a close target, like the zoom lens on a camera.
These physical and behavioral characteristics associated with vision suggest the use of a float for crappie fishing, to suspend lures or livebaits at a level slightly above the depth at which fish are holding. As crappies shift vertically, in response to light, baitfish, or other factors, float adjustment keeps the offering in the best position. Float fishing with small jigs or livebaits is a staple presentation for crappies throughout the year, though other options complement it.
Color Vision: Crappie eyes have multiple cones, light receptors used in bright light to differentiate wave‐ lengths of light that equate to colors, giving evidence of color vision.
Further evidence arises from tests with the closely related largemouth bass, bluegill, and green sunfish, whose color detection has been verified in lab tests. By studying the characteristics of the cones of a species, physiologists can make educated guesses about the colors the species is most sensitive to.
Human eyes have three sets of cones, each most sensitive to a particular color, and the cones compare the amount of stimulation from longer wavelengths (red, orange, yellow), intermediate wavelengths (yellow‐green, green and blue‐green), and short wavelengths (blue, and violet). Largemouth bass have two sets, thought to give more sensitivity to colors in the red‐orange range, with less sensitivity for yellows and grays. Bass and sunfish can, however, sense colors of the entire spectrum, to some extent.
Little study of bass vision has been done, and to my knowledge, no experiments have tested crappies. Color sensitivity is therefore purely speculative, and its effects on color choice in jigs is even more of a stretch. Suffice to say that in clear, shallow water, crappies probably can discriminate chartreuse from yellow or white, orange from red shad, or pink from nuclear chicken.
In murky rivers, stained impoundments, or fertile ponds, color vision is lost at depths around 10 to 15 feet, depending on clarity and light levels. Fish switch from reliance on color‐sensitive cones to rods, receptor cells that detect black and white and shades between. The last color to remain visible is one that matches the general water color of the lake.
Crappies apparently see well using their black‐white vision capability, for they feed extensively after dark during all seasons. Their large eyes may gather more available light than the eyes of small preyfish, placing crappies at an advantage. They also take advantage of the typical vertical migration of plankton, which move toward the surface after dark and recede at first light. Dense plankton draw preyfish, and crappies school below the plankton to feed heavily.