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.