Does A Fish’s Mouth Heal After Being Hooked?

Any responsible catch-and-release angler knows that removing a hook from a fish’s mouth must be done carefully. But sometimes removing a hook can cause more damage to a fish than intended. This leads to a common question that a lot of beginner anglers has … Can a Fish’s mouth heal?

Does A Fish’s Mouth Heal After Being Hooked? Fish that are classified as ‘Bony Fish‘ which is the majority of fish have the ability to heal from wounds. The damaged caused to a fish when hooked will heal over time.

Why is this such a concern?

An injured mouth for any animal should result in difficulty feeding as the wound heals. Anglers who participate in Catch-and-Release fishing want to increase the chances for a fish to survive once released.

Below are 6 helpful tips that you can use today to reduce damage caused to a fish’s mouth after being hooked.

NOTE: Check out “The Extraordinary Healing Abilities Of Fish” section in this post to learn more about the extent of a fish’s healing abilities.

6 Tips To Reduce Damage To A Fish’s Mouth

J-Hooks: These hooks are the most traditional and versatile hooks around. When a hook is set properly it can minimize damage to a fish’s mouth. Making it suitable for catch-and-release. There must be a reason why a lot of catch-and-release anglers use this type of hook.

Picture of a J-Hook

Circle Hooks: Generally considered to be better than J-hooks in terms of minimizing damage to a fish. These hooks are designed to hook the corner of the fish’s mouth. There is no hook set required by the angler. The hook sets itself which reduces the overall damage. If a fish swallows the hook it is designed to come out of the fish’s stomach with causing damage and can still hook the corner of the fish’s mouth.

Picture of a circle hook

Barbless or De-Barb Hooks: The barb on the hook is designed to lock the hook in place. To de-barb a hook, use pliers and press down on the barb to flatten the barb down. Alternatively, you can purchase a barbless hook. Both of these options will result in reducing the damage to a fish by allowing the hook to be removed easily.

Long Needle Nose Pliers: An essential tool to achieve a strong grip on the hook and provides lots of control to easily remove the hook out of the fish’s mouth.

De-hooker Tool: A tool designed to remove hooks quickly and safely in a single motion. Known to help with reducing damage to a fish’s mouth.

AVOID USING Treble Hooks: These hooks will cause the MOST damage to a fish because they are difficult to remove. Pre-installed lures with treble hooks can be removed. Treble hooks are attached to lures by a split ring, the same ring used for your car keys. By using split ring pliers these treble hooks can be removed and replaced with one of the recommended hooks above.

Picture of a Treble Hook

What To Do When I Deep Hook A Fish?

Deep Hooking a fish is when an angler hooks a fish in the throat and presents a tough choice for anglers. Should you remove the hook or leave the hook in place and just cut the line.

Most people would say to remove the hook and you would be right … removing the hook make a lot of sense. How can a fish eat with a hook in its throat?

A 2009 study was conducted to evaluate if fish that were deep hooked would it be better off if the hook was removed or left in place.

The study measured the effects on the fish if the hook was removed or kept in place. The fish’s performance indicators measured in the study were:

  • Swimming;
  • Physiological conditions;
  • Injury level;
  • Feeding;
  • Morality;

The study found there was no difference in the fish’s ability to swim or feed between the two groups. However, notably short term physiological changes and bleeding was observed when the hook is removed.

Both groups showed changes in feeding patterns. The group with the hook removed consumed 55% less than the controlled group (Control Group were hooked in the mouth and removed with little injury to the fish). The hook left in place group consumed 45% less than the controlled group.

Leaving the hook in place resulted in 10% more food consumed than the group with the hook removed.

Ultimately the mortality rate was significantly higher with the hook removed group compared to the group where the hook is left in place. The mortality rates were measured after 48 hours and after 10 days. Below summarizes these mortality rate findings from the study.

  • Controlled Group: 0% After 48 hours | 4% After 10 Days
  • Line Cut Treatment: 8% After 48 hours | 12.5% After 10 Days
  • Hook Removed Treatment: 33% After 48 hours | 44% After 10 Days

The study found that the group with the hook removed had a large death rate compared to the group where the hook is left in place. Removing the hook increased the chance of a fish dying by 25% after 48 hours. This increases to 31.5% after 10 days after the hook is removed.

This means that an Angler should leave the hook in place to give the fish the best chance to survive after being released.

An interesting fact was that the study found that fish with the line cut treatment had 45.5% of fish that expelled the hook from their throat after 48 hours and after 10 days this increased to 71.4%.

If you found that you deep hooked a fish, always cut the line as close as possible to the hook and leave the hook in place to give the fish the best chance of survival.

The Extraordinary Healing Abilities Of Fish

Fish generally fall into two different categories:

  • Cartilaginous Fish (Sharks, Rays, etc)
  • Bony Fish (Practically every fish that has a bony skeleton)

According to Britannica, an online encyclopedia states that virtually all bony fishes can regenerate most of their body parts. This regeneration ability ranges from plucked scales, an amputated gill filament, all the way to regrowing a complete fin. Their regeneration abilities can even regenerate the original coloured strips or spots on newly reconstructed fins.

Cartilaginous fish are not so lucky. Just like humans, cartilaginous fish are able to heal the immediate injured area resulting in scar tissue. Unlike the bony fish if cartilaginous fish were to lose a fin they will not be able to regenerate a new one.

With bony fish having the ability to regenerate completely new fins and gill filaments, it is not surprising that these fish can easily heal an injured mouth given proper hook removal techniques mentioned above.

Related Questions

Will A Fishing Hook Dissolve In Water?

Fishing hooks, just like any other metal in contact with water, will rust become weaker over time. This will result in the hook eventually breaking free from the fish. The rate of corrosion of the hook will depend on how thick the hook was, salt content in the water, the hook’s coating, and the coating thickness. Studies have shown that even barbed hooks will eventually break off from a fish within a few days due to the fish’s activities.

What is Foul Hooking?

Also known as “Snagging a Fish” occurs when the hook catches the fish other than the mouth region such as the gill plate, cheek, etc. This usually occurs by accident when the angler sets the hook when the hook is not completely in the fish’s mouth. To purposely attempt to foul hook a fish is illegal in most places.

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