In the beginning, all one needs in fishing is a hook and a line. But today different fishing conditions require different tackle, and hook styles were invented in reply to fit them. Yet even so, many styles are multifunctional although developed for their own particular purposes. Therefore we shall discuss only the general styles though variations for each exist in the fishing industry.
Round hooks. These are the egg hooks and tuna circle hooks. The egg hook is a small short-shanked hook with a turned-out or turned-in eye almost exclusively used in river or lake fishing for trout using salmon egg as bait. Since salmon eggs bounce along the river bottom as they drift with the current, egg hooks are used so as not to impair this movement and impart an unnatural look to the bait eggs.
Tuna hooks are almost circular hooks with just holes in the shank-end for the eyes, and a curved-in point. Contrary to its name, these are not for tuna fishing but mostly used for deepwater bottom fishing. The circular configuration makes it difficult for the hooked fish to dislodge the hook once caught due to three barriers: the barb, the turned-in point and the shank end. Theoretically, circle hooks do not catch the fish in the gut or throat, but in the mouth, so that releasing them is easier.
Long shanked hooks. Mostly Limerick, Aberdeen and similar styles, keluaran hk are thin-wire hooks with long shanks and dark colors, from red to black. Some have small burrs at the back of the shank to hold the bait and may have turned-in or turned-out eye. Used primarily to catch soft-mouth fishes like river carp, but also effective for flounder and other flatfishes. This hook style is popular in Great Britain and European coarse fishing.
General purpose hooks. Exemplified by the round haddock, O’Shaughnessy and flatted hooks in their varied styles. Round haddock hooks have large eyes turned along the hook bend and point. Considered not as effective as others but almost perfect for multi-hook trolling flies, since the tinsel or fiber can be threaded through the large eye to hold them more securely. Still remains popular in many areas.
The O’Shaughnessy style is deemed the best all-purpose type, and many variations are available. This style has a small eye turned perpendicular to the bend and point, and with the shank bent a little forward. Variations include the baitholder, with the small points at the shank to hold the soft bait; and snelled hooks with turned-in or -out eyes, sold with short leaders already tied. Weedless hooks are those with a short piece of wire from the eye to the point, to ward off weeds and other water debris from lodging in the hook bend or point. Weedless hooks are mostly used in fishing water with thick vegetation, either with bait or as flyhook. Many hooks can be rigged weedless, though.
On the other hand, the flatted hooks have flat shank ends instead of eyes, the flat part to bar the snell knot from pulling out of the hook. Snelled flattened hooks are popular to light long-liner fishermen, but not to sportfishermen because the thin flattened end breaks rather easily. Also the flat end hurts one’s finger when removing the hook from the fish.