Baitfish Imitation - Factors To Consider

Baitfish Imitation - Factors To Consider

Matt Klara | Sunday, 11 September 2016

Streamer fishing is one of the oldest versions of fly fishing, yet it also seems to be one of the fastest growing types of flyfishing today. I don’t know why that is the case, but streamer fishing is certainly an interesting, complex, and exciting way to angle. It also opens up new doors, and allows the fly angler to experience many “new” and exciting fisheries where insect imitation with dries and wets simply cannot and will not work.

You may have already guessed that I’m referring to fisheries where baitfish are the primary prey.  You’d be hard pressed to catch many of today’s popular gamefish on the usual mayfly or caddis imitations.  Saltwater species like striped bass, roosterfish, dorado/mahi mahi, tuna, queenfish, jacks, trevally, and billfish all eat other fish – and little else.  Even in freshwater, anglers will find situations where the fish they want to catch will only eat other fish.  I’m thinking of certain trout fishing situations, certainly, but also other targets like smallmouth bass, walleye, freshwater dorado, and more.

Of course, impressionistic patterns may be good enough in some instances, and when unpressured fish are acting aggressively.  But, more often than not, a good baitfish imitation on the line of a competent angler will win the day, and outfish other patterns. 

Baitfish fly patterns go way back in time.  Carrie Stevens’ Grey Ghost and other trolling streamers come to mind.  With their long shank or tandem hooks, flowing feathery lines, and eyes made of jungle cock nails, they share many features of modern baitfish imitations.  But the modern fly tier has access to a nearly infinite variety of materials that have made tying baitfish imitations into more than just an answer to a vexing fishing problem.  We can do so much more with the modern materials than we could with only fur and feathers.  Tying streamers – particularly baitfish imitations – has become as much a science as it is a craft.

So, what makes a good or great baitfish imitation? In the end, the fish will be the only relevant judge and jury.  There are hundreds of patterns out there available at your local fly shop.  Guides carry them too.  But there is also a joy in selecting your own or even crafting your own lure.  I’m less interested in telling you what flies to buy or tie than I am in getting you to think about this topic a bit more, maybe in a new way.  With the remainder of this piece I hope to at least call attention to a few factors that I believe are important to consider when sitting down at the vise with dreams of catching big fish that eat smaller fish.


Color is probably the first thing an angler notices about a fish, baitfish, or a fly pattern.  Tan over white.  Olive over white. Brown. Blue. Silver.  Tannish olive over white with flecks of blue and silver.  Baitfish come in loads of color combinations.  I really like how some of the modern synthetics come in complex colors.  I try to match the baitfish whenever I can. 

Have you considered how baitfish look alive vs dead?  A living minnow rarely looks the same as a dead one.  A baitfish that is alive but has been in the live well for 2 hours can look different than they do when freshly netted.  It can make a difference which color phase of the bait you are imitating, especially in fisheries where live baits or dead baits are used as teasers or chum.


The size of the size of the fly should approximate the size of the baitfish you are trying to match, similar to matching the size of a mayfly during a hatch.  While I have not experienced extreme selectivity to overall size, I try to get my fly as close to the expected size of the bait as possible.

Some fisheries are based on very fast growing prey species.  Early in the season, the predators may be used to seeing 3 inch long bait, but a few months later all the bait may have grown to 5 inches.  If possible, it’s good to do some research and be ready with the right size flies. 

What about a customizable pattern? Some flies can be trimmed on the water to make them smaller while they retain all the necessary fish catching qualities, but few can be made larger.


When I refer to profile, I mean the overall shape of the baitfish.  Some are long and thin, others short and fat, or somewhere in between.  Some baitfish have a circular cross section – with bodies as wide as they are tall (mullet or sand lance).  Some are laterally flattened – a fancy term for taller than they are wide (sardina  Others are dorsoventrally flattened – a really fancy term for wider than they are tall (sculpin

It goes without saying that fly pattern should address the overall shape of the bait being imitated.  Again, material choice plays a big role in this.  So does the technique used to attach materials to the hook and build the body.  It’s always good to make sure the fly keeps the proper profile when wet and retrieved in the desired manner.  More on that later!


Eyes may be the first thing that a predator fish notices about your fly, or it may be the last thing it notices when deciding to either refuse, or gobble your offering.  Many baitfish species have prominent eyes, or false eye spots.  On translucent baitfish, the eye can be just about all you see of them.  For that reason, I like eyes on most of my baitfish flies. 

On the other hand, a baitfish like a sculpin does not have prominent eyes, and therefore adding them to your pattern may be less important.


Some baitfish are flashy.  Some are not.  Simple, right?  Sort of. 

It seems to me that flash is often the absolute difference maker when it comes to how well a fly works.  I’ve noticed that in bright sunshine and clear water that flash is often a turn off for the fish I’m trying to catch, even when I perceive the live baitfish as quite flashy.  Maybe the modern flash materials are so reflective that it is easy to overdo it.  Maybe we perceive shininess differently than predator fish in some instances.

Then, other times, maybe for a different predator, it seems like you can’t have too much flash.  For that reason alone it may make sense to tie a variety of patterns or the same pattern in a variety of flash combinations.  I like to think about how I might be able to alter a fly on the water as well.  Can I turn a flashy fly into one without flash with scissors or nippers?


Something I learned about many baitfish species is that they look very different in the water vs out of water.  In particular, many smaller baitfish are virtually invisible or at least highly translucent in the water.  Often, all you see of the prey is an eye, and a lateral line, or the digestive tract.

This is where the modern synthetic materials blow nearly all natural materials away.  Pick your material wisely and match the translucence of the live bait.  Don’t be afraid to go really sparse as well.  Test your flies in the water before you tie 50 of them!  If they look bad, make a modification.


Action and Tracking

I mentioned this briefly when discussing profile.  Here is a whole lot more.

Action is the way a fly moves in the water.  If your fly looks and acts wrong, you are probably out of luck, so I think this factor is worth a decent amount of discussion.  Part of a fly’s action is the motion that the fly angler imparts to the fly to make it look like a real fish, or at least to make it move (or not) in a way that elicits a take.  While the retrieve has a lot to do with the action of a fly in the water, the true action of a fly begins with material selection and construction at the vise.  In reality, the two must work together perfectly and the angler is well served to take both elements into account when selecting a fly.

Different materials move differently in the water.  If you have fished with me, or followed my old Frontpage rants on Sexyloops, you probably have heard me say that “nothing moves like rabbit”.  Well, that’s true.  Similarly, nothing moves like marabou, or EP fiber, or bucktail, or slinky fiber, or kinky fiber, or (name your favorite material).  Knowing the relative stiffness and wiggle of materials and purposefully experimenting with them in your baitfish patterns can really take your flies to the next level.

More than anything I would urge to you observe how the bait you are imitating acts in the water.  Do the baits dart quickly then dive for the bottom?  If so, maybe you need some weight up front to create a jigging action when stripped.  Do they swim continuously, without pauses, in a straight line?  Then consider stiffer materials that hold profile under constant tension in the water.  Do you want your fly to have motion even when it isn’t moving?  Softer materials will do that for you, but watch out for fouling.  Do the baitfish twitch and dart left and right and up when injured?  Time to get really creative with your tying and experiment with intentionally off balanced patterns.

Tracking is another part of fly action.  I consider tracking to be the way the fly moves through the water relative to its own vertical axis plane.  The concept is similar to tracking in fly casting.  Keep it in line for best results!  If a fly unintentionally “tips” off its vertical plane when retrieved, then I consider it to be tracking poorly.  Fouled streamers track poorly, and I feel like that is why they don’t work. Poorly designed flies also track poorly.  Baitfish (most of them at least, when they are healthy) swim effectively and remain “upright” even when moving at maximum speeds.  Predator fish are used to this behavior.  If a predator is following/chasing down your fly, and the fly happens to tip over on its side for even a split second, there is a chance that you will experience a fantastic refusal.  This is particularly true, in my experience, with roosterfish.  I started thinking really hard about this after seeing dozens of roosterfish refuse flies at extremely high speed and at very close range after the fly wobbled or tipped just slightly. 

Here in the Pacific Northwest, many conventional anglers “pull plugs” for salmon.  These guys know that the way the plugs run or track (straight and true) can make a big difference, and so they spend hours “tuning” their plugs to ride just right.  Why should it be different with flies?  I am now a huge believer in tank testing patterns.  Bathtubs, sinks, ponds, rivers, puddles, fountains, etc. have all been used as testing grounds.  Not just one of a pattern, either.  Every fly!  Sure it’s crazy, but it gives me confidence in every fly I have in my box. 


This last factor is one that I consider most abstract and difficult to test and understand.  For that reason it is a wildcard in my own mind.  Maybe the real reason that some flies out produce others for no apparent reason.

Water transmits sound and vibrations much better/faster than air, and fish are equipped with a lateral line that allows them to pick up on vibrations from other fish, predators, and prey.  We know that fish use feel to navigate, feed, and avoid danger.  Conventional anglers use vibration and the way their lures sound or feel much more than fly anglers.  Why should it be that way?  I’m not suggesting that we equip all of our flies with spinner blades and rattles, but it makes sense to consider the way a fly pushes or displaces water.  It may be more important than we fully understand.

Last Cast

Of course, there is much more that could be said.  But I think I’ve said enough for now.  It’s time to fish.  After all, there is no substitute for experience, gained through hours and days on the water.  So, get out there.  Fish.  Observe.  Learn.  Enjoy the day.

Thanks for reading. 

Take care, and Fish on!    -Matt