Ever wondered how fish truly perceive fluorocarbon, a line advocated for its invisible qualities? And how can panfish, trout, and other species dine on transparent prey like zooplankton if they can’t see them? Or can they?

When you examine fluorocarbon under water with an underwater camera or a dive mask, you might be surprised to see that it’s as visible and opaque as braid. But how do the fish perceive it? Does it matter?

The answers to these questions might change the way you approach fishing, or at the least, compel you to question lure selection and colors for certain species, particularly panfish.

A few years ago, I became intrigued by a particular brand of “invisible” fluorocarbon swivels. Beyond their apparent transparency, these clear, semi-soft accessories were said to be neutrally buoyant in water. I used them while livebait rigging for walleyes, and as a line-to-leader connector while ice fishing with jigging spoons and tiny panfish jigs. Immediately, I began detecting phantom bites, but failed to hook fish. On the ice, the mystery was revealed, as I observed fish on sonar and on an Aqua-Vu camera. Sunfish, crappies, walleyes, and bass sometimes ignored the lure or bait, and inhaled the little clear swivel instead.

Though the swivel looked transparent in hand, under water it appeared opaque and easily visible. I recalled what a fishing line expert had told me a few years before when I’d asked about the visibility of fluorocarbon. He’d said that because fluorocarbon line is round, it acts as a lens, gathering and reflecting light rather than allowing it to pass straight through. If fluorocarbon were flatter and made with square edges, he’d admitted, there would be less of a lens effect, and it would be much more transparent under water.

Surely the same dynamic applied to the clear swivels. Because they had corners, edges, and notches, these angular surfaces reflected light rather than absorbing it. But why were sunfish, crappies, and other fish responding more favorably to the clear swivel than the lure hanging below it?

Invisible or Obvious?
The answer likely resides within the hidden world of zooplankton, those miniscule, translucent critters that often compose a large part of wintertime panfish diets. Scientists have long assumed that slow-swimming zooplankton such as copepods and cladocerans (including Daphnia) have clear bodies to conceal themselves from predators. Others, such as mysis shrimp, are adept swimmers but also rely on a see-through shell as camouflage.

Daphnia, mysis, and Mesocyclops are relatively large zooplankters that often predominate panfish diets, particularly in open water. While these and other zooplankton species possess clear, translucent bodies, they also have small pigmented regions—eyes, organs, and egg sacs— that provide visual cues to tempt predation by nearsighted fish.

Ultraviolet (UV) rays can penetrate the upper layers of the water column, more so in some waters than others. The relationship of planktonic foraging by fish and UV light is a hot field of research at this time. Fish vision experts have generally found that while juvenile fish of several panfish species possess photoreceptors for UV light, they lose this ability prior to adulthood.

Sunfish, crappies, perch, and trout possess excellent close-range vision, capable of discerning diminutive details such as eyes, cilia, and other anatomical features. So while clear lures might be poor choices for attracting fish from a distance, these discrete presentations can excel for triggering bites from selective panfish hovering below your hole.

Further, since the visual acuity and contrast sensitivity of fish are in proportion to the amount of available light, we can assume that translucent animals such as Daphnia are most visible when viewed from below, rather than from above or from the side.

Continued after gallery…

 

 

A Case for Clear Baits
As a result, clear lures may be more effective at triggering bites than those decorated with gaudy colors. These past two ice seasons, I’ve been conducting experiments with clear softbaits and flies, fishing them alongside traditional patterns. The results have been rather dramatic.

I’ve found that sunfish, crappies, and yellow perch prefer clear, translucent baits over solid reds, yellows, pinks, or other hues whenever they’re focused on zooplankton, even in somewhat stained water. The 1-inch Domination Fry, offered by Micro Spoons & Jigs (microspoons.com), are zooplankton-like panfish lures. These little hand-poured beauties have tiny swatches of color within their crystalline bodies. Each lure is molded from select plastics by owners Keith and Jessica Pace, then placed on drying trays to maintain straight tails and uniform bodies. Their lures are delightfully detailed, yet simple to use.

Molded with a bulbous Daphnia-like head and delicate tail, the Domination Fry quivers in the water, imitating the cilia found on many zooplankton. Its internal shots of color also remind you of Daphnia anatomy, which exhibit shades of translucent red, blue, yellow, and an almost glowing white.

In response to demand, Pace recently released UV-coated versions of the Domination Fry. In the presence of UV light, UV coatings don’t reflect UV light that predators can detect. But they do reflect visible light, making lures brighter under water.

It’s tempting to think that these minute anatomical features couldn’t possibly be significant to panfish. Yet this assumption could cost you fish. Consider studies that In-Fisherman has reported on earlier, suggesting that crappies and sunfish select for the largest individual zooplankton. The difference between “large” and average-size Daphnia is like comparing the head of a needle to a grain of salt. But to panfish, that difference can be important.

Certainly it’s not necessary to imitate zooplankters to catch fish. But it’s often beneficial to attempt to replicate their anatomies. During the most challenging bites—when crappies, perch, and bluegills appear uninterested in plastic combos adorned with traditional patterns, I’ve compared clear baits to opaque offerings, sometimes catching 10 fish to one on the clear one.

One lure that’s proved itself in these scenarios is the Zoo Bug, likely the only Daphnia-specific option in existence. Last winter, I asked master fly and jig tier Jeff Wenger (jeffsjigs.com) to craft a clear, plankton-like critter. The result was better than anything I could have imagined. The Zoo Bug’s clear epoxy body is accented with colorful inserts. Wenger even added cilia, the feathery “feelers” that allow Daphnia to dart and swim. Tied with Arctic fox hair, Wenger makes these tiny appendages quake beautifully under water—not as dramatic as a plastic or marabou tail, but just enough motion to induce takes from tentative panfish.

Several variations of the Zoo Bug exist, with or without internal tungsten beads, and with various interior accents and eyes. Moreover, Wenger often is willing to customize your selections. I’ve suggested different glow threads as internal accents, as well as perhaps coating the epoxy with a clear UV finish, such as UV Blast by CS Coatings (csipaint.com). While I had been skeptical of UV-coated lures, I’ve become convinced that they can make a big difference for panfish and rainbow trout. Last winter, we doused several clear softbaits with UV Blast during trips to Nebraska’s Valentine National Wildlife Refuge and other bluegill waters closer to home. Some of our largest sunfish bit these patterns on the brightest, post-frontal days.

Double Zoo Bug Rig

Triple Zoo Bug Rig

Rigging Zooplankton Swarms
Other noteworthy experiments have involved using Wenger’s Zoo Bug for suspended crappies. Rigged in a 2- or 3-lure series, either dropper- or drop-shot style, you can offer fish a variety of plankton patterns, staggering them at various distances. During most trials, the best configuration has been to anchor the rig with a heavier (1/32- to 1/64-ounce) tungsten jig or lead split shot. Two Zoo Bugs are then tethered to the mainline using short pieces of 2- or 3-pound-test monofilament, which give the baits more lift and a slower swaying action on the fall. Wenger ties an unweighted version of the Zoo Bug that works wonderfully on dropper rigs. And it’s possible to catch two fish or more at a time.

For dropper rigging, a standard dropper loop provides a clean tether for adding an unweighted Zoo Bug or other nymph. You can also use an Alpine Butterfly Loop, which is easy to tie and provides a good connection for tying in a dropper line and fly. In either case, the dropper line should be a bit thinner than the mainline to give the fly more sway and action.

For less active fish, 6- to 8-inch droppers give flies an extended flutter that can help trigger a response. Or for more control and no flutter, attach each fly with a Palomar knot, drop-shot style, which pins it to the mainline. Tiny quivers of the rod tip or light strums on the line with your index finger near the reel impart movement to the lures below. You can, of course, do more dramatic jigging to attract fish. But once they approach, and you spot them on sonar or a camera, it’s best to keep lure pulsing barely perceptibly.

With two Zoo Bugs rigged drop-shot style, I can impart just enough nervous energy to keep the hook and Arctic fox antennae scarcely quaking. As you do this, often it’s effective to slightly raise the rod tip, making the lures rise ever so slowly, imitating zooplankton rising in the water column, as they do in response to light. It’s easier to master these moves when you can watch them on the screen of an underwater camera. It’s also fascinating to watch the tiny critters swim, by searching for “swimming Daphnia” on YouTube.

Wenger often tips Zoo Bugs with maggots or a single waxworm. While beneficial, it may not always be necessary, other than for giving fish incentive to hold the bait longer. And when sight-fishing, a waxworm provides visibility; when it disappears, set the hook. But when using a soft plastic imitation, such as the Domination Fry, livebait is usually unnecessary.

Plankton Rigging Plastics
Heavy yet tiny tungsten jigheads are great for thumping and bringing softbaits and natural fibers to life. I prefer plain metallic tungsten heads, as opposed to colored ones, to fix the attention of fish on the tail and hook portion of the bait rather than the head. The exceptions are faceted metallic “disco-ball” style heads. Disco balls reflect and scatter light in all directions. They almost seem to dissolve under water, and deliver an elusive target that’s suggestive of translucent prey.

Jigheads such as the silver and gold disco ball Tungsten Round Ball Jig by Kodiak Sporting Goods (kodiaksg.com) in 4- and 5-mm sizes pair well with the Domination Fry. The Round Ball rides with the hook hanging slightly, keeping the tail pointed toward the bottom at about a 45-degree angle. This configuration works well for both crappies and suspended sunfish, and I think it does a better job of hooking sniffing fish than the more common perfectly horizontal approach. Sometimes it helps to slightly shorten the head of the Fry, cutting the nose up to the eyeballs.

The same quivering movements that work with a dropper rig apply to single presentations. Keep the tail constantly quivering, punctuated by slow 6-inch upward rises. Then, once the jig rises above where fish follow, drop it back into the fish zone on a semi-slack line, watching for fish to intercept it on the way down.

One other hooking configuration I tried last winter was “reverse rigging”—positioning the bait so the tail was at the top of the jighead. This little trick worked well with both the GoJo by J and S Custom Jigs and the Double Trouble by Micro Spoons & Jigs. Reverse tail rigging produces an odd but strangely compelling action. It closely mimics swimming action of Daphnia and other tiny crustaceans that seem to swim backward, using appendages positioned on their forehead. For crappies and perch that engulf the bait, this has been an interesting and effective bit project that I will resume at first ice.

I enjoy these ongoing experiments—conducting them for fun and to encourage myself to reconsider my views of presentations for panfish and other species. Folks like the Pace family at Micro Spoons & Jigs and Jeff Wenger do a service by nudging us beyond our comfort zones. It’s surprising that so few have attempted to imitate the little creatures that fuel every fishery on the planet. Or maybe it’s not surprising, given that they’ve have gone unnoticed by everyone except the fish and a handful of scientists.

Bioluminescence on Ice?
Though largely absent from freshwater, bioluminescent creatures live on land and in the sea. Chemical reactions produce light energy in fireflies, squid, and algae, such as dinoflagellates. The purpose of bioluminescence is manifold, including distraction from predators, communication and warnings, and illumination.

Many fish seem to react positively to lures that emanate light, or fluoresce. Perhaps even freshwater fish recognize glow patterns as the signals of potential prey. Regardless, several effective options for crappies and other panfish at night include tiny soft plastic baits that fluoresce under the ice.

Several companies offer glow plastics. Notable are clear options from Micro Spoons & Jigs, including their glowing Domination Fry. Other top phosphorescent patterns are the IceMite Jr. and GoJo from J and S Custom Jigs, Finesse Plastics from Custom Jigs & Spins, and Ballzy from Big Bite Baits.

*In-Fisherman Field Editor Cory Schmidt, Brainerd, Minnesota, is an avid ice angler who enjoys working with the latest lures.

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