Hooks Part II: Anatomy

So we know that the hook has served as a canvas for the fly tyer for at least 1800 years, and likely even longer.  Therefore we should be well familiar with them.  We will focus exclusively on hooks used in fly tying and to a large extent to those used in  freshwater pattern. We’ll begin by exploring the anatomy of the fly hook.
One may think of the hook as a bent sewing needle or pin, and in fact many hooks used as recently as 200 years ago were in fact made from pins.  I find that the easiest way to remember the names of the various parts of the hook is by association with a sewing needle.  Beginning with a needle, it is easy to identify 3 main parts; the eye, the point, and the shaft or shank.

If you then imagine the needle being bent into the shape of a hook, you need 3 more terms to describe it.  The aptly named “bend” which is simply the turn of the hook, the gap, the distance between the point and the shank, and the throat which is the distance from the bend to the point. I usually think of the gap as the width of the hook, and the throat as the depth to which a hook can embed.  A little though about these parameters will lead you to conclude that the ratio of throat to gap is critically important in determining how easily a hook will embed in the intended target.

The only other part of the hook that you need to know about is the barb.  The barb is the little second point that juts out of the hook near the point.  It is the thing that makes it so darn difficult to pull a hook out once it accidentally impales itself into your thumb, or earlobe, or worse.  Many believe that the barb lodges into the fish and improves the probability of landing the fish once it is hooked.  They are half correct.  Barbs create a one way hook that slips into and then lodges in flesh which causes a great deal of damage when the hook is removed.  I, along with thousands of other fisherman stopped using barbed hooks, and I can honestly say that I have never lost a fish because my hook was barbless.  If you are a catch and release fisherman (and you are, aren’t you?) then a barbless hook will greatly improve the chance of the fish recovering from his “bitter repast.”  Even if you choose to keep some of the fish you catch, you will appreciate a barbless hook the first time it winds up sticking in your thumb.  Buy barbless hooks, or simply use a small pair of needle nose pliers to crush the barb before tying.
Unfortunately, this simple description is only scratching the surface of a massively complex topic.  While the basic anatomy of the hook described above is a constant (unless you consider eyeless or snelled hooks), a mind boggling array of variations exist.  For example, a simple straight hook may be ideal for tying an adult mayfly, but curved shank may better imitate a pupal caddis.  There are many arcane terms that have been historically used to describe hook shape such as sproat, Limerick, and kerned.  I’ll describe some of this in a bit more detail when we come to the end of the hook discussion, but I will focus on just a few hooks that I think are the basic minimal hooks needed to successfully tie the majority of patterns.

Hooks Part I: A little history

While not all fishing is done with hooks (e.g. spear or net fishing) all fly fishing is, and the hook is the canvas of the fly tyer. Therefor it is worth while to spend some time getting acquainted with these seemingly simple materials.


The generic fish hook that we all know well is a relatively recent invention. In fact, Frederic M. Halford in his 1886 book “Floating Flies and How to Dress Them” spends nearly 3 pages discussing the merits of the “eyed hook” and predicts that “Before many years are past the old fashioned fly, dressed on a hook attached to a length of gut, will be practically obsolete...” So we have only had eyed fish hooks for about 125 years.


The earliest known hooks have been discovered in the middle east and are dated to approximately 7000 BC. The first hooks, were really not hooks at all, but devices called gouges. A gouge looks like a pointed stick and would be tied to the line in the middle of the shaft. Bait would be impaled on the gouge, and when the fish took the bait, pulling on the line would theoretically cause the gouge to wedge in the fish’s mouth or throat, although the probability of success was probably quite low in practice. Early hooks were fashioned from a variety of materials including wood, bone, shell, horn, and stone.


Now in terms of fly tying, the earliest record of someone tying something to a hook to imitate an insect comes from the famous passage from Aelian in his Nature of Animals written approximately 200 AD. I reproduce excerpts of the pertinent lines here, not because they are unknown or difficult to find, but because I am always struck by how little the endevour has changed in almost 2000 years:


“ I have heard of a Macedonian way of catching fish, and it is this...These fish feed upon a fly peculiar to the country, which hovers on the river....When then the fish observes a fly on the surface, it swims quietly up, afraid to stir the water above, lest it should scare away its prey; then coming up by its shadow, it opens its mouth gently and gulps down the fly...Now though the fishermen know this, they do not use these flies at all for bait for fish...but they have planned a snare for the fish...They fasten red (crimson red) wool around a hook, and fix onto the wool two feathers which grow under a cock’s wattles, and which in colour are like wax. Their rod is six feet long, and their line is the same length. Then they throw their snare, and the fish, attracted and maddened by the colour, comes straight at it, thinking from the pretty sight to gain a dainty mouthful; when, however, it opens its jaws, it is caught by the hook, and enjoys a bitter repast, a captive.”

Next: The anatomy of a fishing hook

Introduction: Why Scientific Fly Tying?

My earliest memory of thinking about what I wanted to be when I grew up, was that I wanted to be a scientist.  Now, as a gainfully employed neruophysiologist 40 some years later, I look back on what I thought a scientist was, and laugh.  But despite my childish notions of men in white coats pouring solutions back and forth between beakers, I stumbled into a lifelong love of science.  I am fascinate by how things work, and in particular how natural things function in what seems to be a perfect fashion.  
I always loved fishing, and spent many happy summers salt water bait fishing for flounder and bluefish.  Fresh water fishing seemed arcane and somewhat boring to me.  Years later, I became a fly tyer almost accidentally when my father-in-law gave me a fantastic collection of materials and tools from his own tying bench.  I quickly became fascinated with the materials and how they came together to form a fly.  The entomology aspect of tying fit well with my love of biology, and I quickly began to think about tying in scientific terms.  Oddly, I was a tying flys for years before I ever tried to fish them.  Fly fishing still seemed arcane and had the added negatives of being expensive and difficult to master.  I approached fly tying as an artistic endeavour, more interested in creating or re-creating patterns than in catching fish.  Of course, I eventually gave in and became addicted to the sport of fly fishing.  I can’t put into words the joy that all of this had brought into my life.  The winter evenings spent learning how to control thread tension and how hackle feathers best wind on the hook, the beautiful spring days starting in the predawn hours waiting for the hatch to commence, the crisp fall days hiking along small streams, and the thrill of the tug on the end of the line signalling that I had won a battle of the wits with an animal relying on a brain smaller than a pea.
These are things that all fly fisherman are fortunate to share with me.  However I have also had the good fortune to enjoy the study of fly tying.  Not just the standard study of patterns and insects, but a deep delving into the properties of the materials used in tying.  I believe that many take the beauty of these materials for granted, and who could blame them when engaged in a sport of so much beauty.  My goal here is to share some of what I have learned and continue to learn.  I can’t say that any of this has made me a better tyer, and I suppose it could be argued that my time would be better spent practicing.  However I believe that there are some that will appreciate a closer look at he commonplace to marvel at the natural design. I'll look forward to your comments to both make these articles more informative and to let me know if anyone else is interested in these details.