Well, there is a reason for that. There are many different kinds of fish and they all have different shaped mouths. When selecting a fishhook you should first consider the size and shape of the fish’s mouth that you plan to catch. If the hook is too large the fish can’t get it in his mouth, and if it is too small you will not get a good hook up.
Hook sizes are numbered according to size with number 22 being the smallest hook. Five or six No. 22 hooks would fit on your fingernail. No. 20/0 is the largest and one of these hooks is larger than your hand. Counting backwards from No. 22, No. 21, No. 20 the hook size gets larger as the hook number gets smaller with No. 1 being the largest of the small hooks.
Then comes the “0” numbers, No. 1/0, No. 2/0, No. 3/0, etc. all the way to No. 20/0. As these numbers get larger, so do the hooks.
The “J” type hook is the most common, but there are many variations and modifications of this hook. Long shank hooks are easier to remove if the fish swallows them. Short shank hooks are better for live bait or cut bait.
Hooks for soft plastic baits have special bends so they will keep the plastic bait straight while moving it through the water. If you change to a larger or smaller plastic bait it will usually be necessary to change the hook too. If the bait is too large for the hook, it will wad up on the hook and prevent the hook from penetrating.
A khale hook is another example of a custom hook. It is a long shank hook with a 45-degree bend halfway down the shank. This hook is used for fish that have protruding teeth like sheep head, flounder and drum.
Another specialty hook is the circle hook. As its name implies, it is bent almost in a complete circle. This hook was designed to hook the fish in the lip, causing minimal damage. Just looking at a circle hook you would think there was no way it could possibly hook a fish.
The idea is for the fish to swallow the bait on a slack line and when the fish swims away the circle hook is pulled out of his mouth and snags behind his lip. The fish can be released with no damage.
The best hook for catch and release would have to be a barbless one. This hook is smooth from the eye to the tip. It has a small “S” bend just below the point and this allows the hook to be removed with a small amount of pressure and no damage to the fish. I have used barbless hook in Canada and much to my surprise I lost very few fish. For some reason unknown to me the barbless hook just hasn’t caught on in the states.
I guess the fisherman is afraid he will lose a fish on the barbless hook that he is going to throw back anyway. Go figure.