Circle Hooks: How They Work, Circle vs J Hook, Sizes, and the Law

A circle hook has its point curved back toward the shank, so far that the gap between them is a near-circle, and it hooks a fish without the angler striking. A fish takes the bait, turns and swims off, and the line comes tight. The hook slides out of the throat and along the jaw to the corner of the mouth, where the curved point rotates and sets itself. The result is far fewer gut-hooked fish, and a growing list of waters where the law requires one.

Point the rod at the fish and reel. The hook does the rest. Strike, and you pull it straight out of the mouth.

How does a circle hook work?

Picture the hook inside a fish that has swallowed the bait. On a J hook the point faces up the throat, so the first pull drives it into whatever it touches: gullet, gill arch, the heart behind them. On a circle hook the point faces inward, toward its own shank, and a straight pull drags the hook flat along the throat without catching. It slides until the bend reaches the hinge of the jaw, the one place the line has to turn a corner. There the hook pivots around the jawbone, and the point swings in and locks through the corner of the mouth. That spot has bone, little blood and nothing vital.

That is also why striking defeats it. A snap of the rod at the first tap jerks the hook up the throat before it has reached the corner. The inward point finds nothing to bite on and comes out clean. Cooke and Suski’s 2004 review of the research notes that circle hooks work best on fish that turn after taking the bait, and worst on species that nibble while holding still.

Commercial longliners and trotliners used them long before anglers did, because a fish that swims off with a baited circle hook hooks itself and stays hooked. Early Japanese fishers tied pieces of reindeer horn into the same shape.

Circle hook vs J hook: which is better?

For a bait that a fish takes and swims off with, the circle hook: it hooks as many fish or more and deep-hooks far fewer. For a bait you watch and strike at, the J hook lands more. The difference is the point. A J hook’s point runs parallel to the shank and bites into whatever the pull drives it against, gullet included. A circle hook’s point faces the shank and only catches when it reaches the jaw.

So the choice follows how you fish. A rod in a holder, a fish that takes the bait and runs, a fish you mean to release: circle. A line in your hand, a fish that nibbles, a lure: J. One finding cuts across both. In the 2015 bluegill study, a worm left still under a bobber deep-hooked more fish on either hook, likely because the fish swallowed it before the angler saw the bite. The J hook page has the J hook’s side of the research, with the panfish and muskie studies where it wins.

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How do you fish a circle hook?

Maine’s instruction stands: “simply point the tip of the rod at the fish and slowly begin to reel in. The hook will set itself, usually in the corner of the mouth.”

1. Rig for a slow take. A softer rod and monofilament, which stretches, give the fish time to turn with the bait before the line comes tight; a fast rod and braid snatch the hook out. A slip-sinker rig helps for the same reason: the fish feels no weight when it picks up the bait.
2. Leave the rod in the holder, drag light or clicker on, so the fish can take the bait and move off.
3. Wait for the rod to load. The tip pulls down and stays down as the fish moves off; that is the fish hooking itself. A tap or a bounce is a fish mouthing the bait, not yet time.
4. Tighten the drag and reel. Steadily, rod pointed at the fish or held low and off to one side at about 45 degrees, never high, until the rod bends fully.
5. Then lift and fight. The hook is in the corner of the jaw.
6. A fish swimming at you is the hard case. The hook needs line angle to reach the corner; let it run to the side before the line comes tight.
7. Never set the hook. Tournament catfish angler John Jamison says even serious tournament anglers complain to him about missing fish on circle hooks. “With a little coaching, however, they get the hang of it pretty quick.”

In fresh water, circle hooks do most of their work on catfish, and the catfish rigs page has the slip-sinker and drift rigs built around one.

Hooks on the workbench. Photo: kvkirillov / Depositphotos.

How do you get a circle hook out?

A circle hook usually sits in the corner of the jaw, easy to reach. That does not always make it easy to remove: in the eight studies of Cooke and Suski’s review that rated it, circle hooks were more often the harder hook to get out, though for largemouth bass the octopus hook was. Leave the fish in the water and remove the hook with needle-nose pliers or a dehooker. If the fish must come out, NOAA’s ideal is under 60 seconds in the air, with wet hands. Cut a deep hook off rather than pull it.

How do you rig the bait so the hook can turn?

A circle hook can only rotate if its point is clear and its gap is open. So the rigging rule is the opposite of the J-hook habit of hiding the hook in the bait. Push the point through and out the other side; a point buried in a bunker chunk or a ball of chicken liver has nothing to catch with when it reaches the jaw. Hook a bait once, through a thin part: cut bait through the skin at a corner, a live shad or shiner through the nostrils or behind the dorsal fin, an eel through the lips. Soft baits that fish nip at, such as clams in the surf or a ball of bloodworms, are tied down on the hook with elastic thread so they stay on. Choose the hook for the bait, not the fish: the whole hook has to disappear into the mouth with the gap still open.

Attach the hook with a snell knot or a knot that cinches on the eye, so the hook lies flat along the leader and the pull comes straight down the shank. On a loop knot the hook swings, and a swinging hook turns late or not at all.

Circle hook size chart: what size for each fish?

Go one or two sizes bigger than the J hook you would have used, because with a circle hook the gap is what matters. There is no industry standard for circle hooks, so a 5/0 from one maker can differ in shape and size from another’s. The table gives the range by fish and bait.

For catfish, the catfish hook size follows the bait more than the fish. The hook size chart explains the numbering, and why a 2/0 circle hook gapes less than a #4 octopus hook.

Inline or offset: which one, and why does the law care?

Inline. North Carolina’s regulators define a circle hook as one “with the point pointed perpendicularly back toward the shank”, with the point and barb in the same plane as the shank. That plane is what “inline” or “non-offset” means: lay the hook on a table and the whole hook lies flat. An offset hook has the point bent to one side, by a few degrees on a minor offset and about 15 degrees on a severe one.

The offset hooks faster and, in Jamison’s experience, more solidly, which is why he prefers it for catfish. It also hooks deeper, because the point now sticks out sideways and can catch in the throat on the way up. In a sailfish study cited in Cooke and Suski’s review, Atlantic sailfish on severely offset circle hooks were deep-hooked 44 percent of the time. That is about the same as Pacific sailfish on J hooks, at 46 percent, while inline and minor-offset hooks mostly took fish in the jaw.

Every regulation that requires a circle hook for conservation therefore says non-offset. That covers the Atlantic striped bass rule, Florida’s reef fish rule and the federal billfish-tournament rule, which forbids “a J-hook or an offset circle hook in combination with natural bait.” The federal Gulf reef fish rule asks only for “non-stainless steel circle hooks,” and that part follows a different logic. A hook left in a fish that broke off rusts away in weeks; a stainless one does not. Buy inline, non-stainless circle hooks for bait, and every rule in the law table below is satisfied at once.

Which circle hook should you buy?

An inline one, in a wire weight that suits the fish, sized to the bait. Cooke and Suski’s review advises anglers to avoid circle hooks offset more than 5 degrees, and every bait rule in the law table asks for inline. Past that, the patterns differ in wire, point and finish, and three common inline hooks show the range.

Light wire gives a live bait a livelier action and penetrates easily on light line; the 4X hook is built, in Gamakatsu’s words, “for the toughest battles in the deep sea.” None of the three makers’ pages names the metal, so where a rule asks for non-stainless hooks, read the package before you buy.

Where are circle hooks the law?

On the Atlantic coast for striped bass fished with bait, in Gulf and South Atlantic reef fishing, in federal billfish tournaments and in federal shark fishing. The table has the rule and the date for each.

The striped bass rule is the one most anglers meet, and New Jersey’s agency puts the reason for it plainly. About 90 percent of the striped bass caught on the coast are released, and an estimated 9 percent of those die. That adds up to nearly half of all the striped bass that die at human hands each year, commercial harvest included. Every rule in the table changes; the state’s current regulation page is the authority. The striped bass hub carries the season and size rules the circle hook sits inside.

Do circle hooks really save fish?

In most of the research, yes. Cooke and Suski’s review covered 43 studies on 25 species, 28 of the studies in salt water, with striped bass the most-studied fish. Mortality on circle hooks ran from 0 to 33.8 percent and on J hooks from 0 to 46 percent, with circle hooks lower in most paired comparisons. They also meant more jaw hooking, less gut hooking and less bleeding, and the review puts the overall drop in hooking mortality at about 50 percent. The catch and release page carries the survival figures for everything else that decides whether a released fish lives.

Three caveats come with the table. Red drum in the North Carolina study died more often on circle hooks, 9 percent against 3, even though far fewer were gut-hooked. For largemouth bass, Cooke and Suski’s review finds only a “minimal conservation benefit”, and Cooke’s 2003 study half the catch rate of an octopus hook, so the case for it is weakest where most American anglers fish. For bluegill the injury was worse, not better: a hook too big for the mouth catches the eye instead of the jaw. The later bluegill study tested five sizes from 1/0 down to 14. It concluded that “circle hooks function most effectively when the entire hook can fit in the mouth of the fish.”

The treble hook is the other hook the rules single out, and barbless hooks are the other conservation choice.

What are the disadvantages of circle hooks?

Fewer fish landed on some species, and little use on a lure. The review rated circle hooks lower than J hooks for capture efficiency overall, and these are the places where they are the wrong tool.

• Lures. A lure is struck, not swallowed, and a J hook or treble sets on the strike while a circle hook mostly does not. The one exception is the coon-pop, a tarpon jig with a circle hook through its eye that the review credits with a large drop in Texas and Louisiana tarpon mortality.
• Soft plastics. A Texas-rigged worm is fished with a hookset, and the plastic itself fills the gap; use the worm hook the rig was designed for. The types of hooks page sets the circle beside the octopus, Kahle, worm and J hooks it gets confused with.
• Fish that nibble in place. Bluegill, perch and trout pick at a worm without moving off, so the hook never travels to the corner; a small Aberdeen or bait hook hooks more and, for bluegill, hurts less.
• Big baits that plug the gap. A whole bluegill on a 5/0 or a fist of liver on a 2/0 stops the hook turning; size up or hook the bait thinner.
• Anglers who cannot stop striking. A Kahle hook, halfway between J and circle, forgives both styles.

Treble hooks. Photo: shutterbug68 / Depositphotos.

Which mistakes cost fish?

Striking is the first. The rest follow from the same misunderstanding, that a circle hook is a J hook with a bent point.

• Burying the point in the bait. At the jaw it has nothing to catch with; push it through and out.
• Holding the rod high. Point it at the fish, or hold it low and off to one side.
• Tying on with a loop knot. The hook swings and turns late or not at all; snell it or cinch the knot on the eye.
• Picking the hook by the fish rather than the bait. A bluegill gets a 1/0 in the eye, or a big cat spits a 2/0 with the gap plugged.
• Pulling at a fish that has swallowed the hook anyway. When a circle hook does end up in the gut, Virginia’s marine agency says to “cut the leader as close as you can to the hook and leave it in the fish”. A corroding hook left in place kills far fewer fish than one torn out.

The hooks hub covers the ten hook types.

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Stop guessing hook sizes. Lay any hook on this page and read it

A jar of loose hooks and no packet in sight. Guess wrong and you find out with a fish on.

The True-Size Hook Chart. Print it at actual size, lay a hook on the outlines, and the one its bend fills is its size. One sheet, front and back, for the tackle box.

• 14 hooks from 9/0 to #8 at true size, plus a ladder from #32 to 12/0
• The size for 17 fish and 16 baits, from bluegill to tuna
• A 2/0 circle that gapes less than a #4: why a 2/0 is not always a 2/0

Every outline drawn from Mustad's published dimensions; every size from the 25 sources on the page, Maryland DNR and Idaho Fish and Game among them.

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