Do Fish Scales Grow Back? (Why + Can They Live Without Scales)

Image of fish scales

Fish scales do grow back. It’s common for most fish to lose their scales due to physical injury during breeding, bruises, infection, or attack from other aggressive fish. However, fish scales usually tend to grow back. The time needed for the scales to regrow depends on the breed of the fish.

We tend to compare animals with each other. So, many people think fish is similar to a snake when it comes to scale shedding. Snakes do shed their skin. However, fish are not similar. They do not shed their scales without reason. To understand this better, let’s talk about all the aspects of scale loss in a fish.

Why Do Fish Scales Grow Back?

Losing scales is not uncommon in fish. There are numerous reasons why your fish may lose its scales.

However, the good thing is that regrowth of scales is possible in most cases.

Scale regrowth may take some time, but it will happen eventually.

However, sometimes the scales may grow back smaller than the original.

There is nothing to worry about unless your fish is losing its scales due to a disease.

Most of the time, fish lose their scales if they get rubbed by the sharp objects in the aquarium.

Or, if you have an aggressive fish, it can cause the timid fish to shed their scales.

Once you remove the aggressive fish or the sharp objects from the aquarium, your problem should get solved.

In due course, the scales of your fish will grow back or repair themselves.

However, in certain cases, it is possible that the scales may not grow back.

This is true when your fish has already lost a lot of scales. The scales may then not regrow.

A lot of scale loss happens mainly due to the infectious protrusion disease among fish.

Proper medication is essential for your fish if it is suffering from any disease.

Once your fish becomes healthy again, most of the scales should grow back.

For that to happen, you need to ensure that your fish gets proper nutrition and care for its speedy recovery.

Can Fish Live Without Scales?

Fish have scales for the same reasons that we humans have skin.

Scales play an important role in keeping the fish hydrated by maintaining proper water balance in their body.

Secondly, scales help the fish to glide through the water smoothly.

Mostly, the fish scales are thin, lightweight, and flexible.

This allows them to swim efficiently without having to drag their body in the water.

Besides, scales provide a hydrodynamic purpose. They reduce water resistance when the fish are swimming.

Also, some scales of the fish reflect light. This helps them to camouflage underwater.

It acts as a shield of armor to protect them from predators in the wild.

Another advantage of scales is that they act as a barrier to protect the fish from harmful fungi, bacteria, or parasite infection.

Scales protect fish when they accidentally rub themselves against corals, rocks, or any sharp edges of the decoration in aquariums.

Fish don’t get severely injured due to the presence of scales.

Now that you know the importance of scales in fish, you must be wondering whether fish can survive without scales?

Technically, fish can survive their whole life without scales. However, they need to avoid threats in the water, like attacks from predators, bacterial infections, and sharp objects. Their scales help them to survive all these dangers underwater.

As long as your fish successfully avoid the threats mentioned above, they can live a long and healthy life without their scales.

Alright! Now that you know fish can survive without scales, let’s also gain insight into how long it takes fish to regrow their lost scales.

How Long Does It Take The Fish To Grow Back Their Scales?

The time it takes for scales to regrow depends on the fish breed.

For some fish, the scales may grow back as early as within few weeks.

In contrast, other fish may take as long as 3 to 4 months to grow back their scales.

The time required for fish scales to regrow also depends on the amount of damage.

If the damage is more, it will take more time for scales to grow back completely.

However, the good thing is that even if your fish loses a large number of its scales, it will regrow the scales sooner or later.

You will be surprised to know that certain fish species don’t have scales.

Most of these scaleless species are bottom dwellers, such as catfish and lamprey.

Even swordfish don’t require scales to survive.

Do All Fish Scales Grow Back?

All fish scales do grow back usually. The only difference is that for some fish, it takes longer than others.

If your fish loses its scales due to some injury or during spawning, which is common, they will grow back.

However, if fish scales fall due to some infection, they will not grow back naturally.

It would be best if you treat the underlying cause with proper medication. Then the scales should grow back.

Scales of fish do grow over time. However, you must now be wondering if fish shed their scales.

If yes, then under what circumstances?

Do Fish Shed Scales?

Fish don’t shed scales under normal circumstances.

However, there are certain instances when you may notice your fish shedding their scales.

But they don’t shed them as part of their normal growth. The fish scales grow back as they grow older.

Fish need scales to live a long life.

Actually, if nothing wrong happens in their environment, your fish will never shed their scales.

However, when they shed scales, there are multiple reasons for it.

Given below are some of the common reasons for fish to shed scales.

1. Physical injury.

Physical injury is the most common reason for scale shedding. This primarily happens during the breeding season.

While mating, both the male and female fish are very active.

During this time, they swim erratically and may brush against several objects in the aquarium.

Also, during mating, fish tend to rub their bodies against each other. This results in scale loss.

Another reason for scale loss is the aggressive behavior of some fish.

If you have an aggressive fish in the tank, it will try to bully the timid fish for showing its dominance.

The timid fish can constantly get hit by the aggressive fish, resulting in loss of scales.

The best way to avoid this is to keep peaceful and compatible tankmates together if you have a community aquarium.

2. Bruises.

Fish can get bruised by coming into contact with the hard objects in the aquarium.

Aquarists often decorate their tank with multiple objects.

While swimming, if your fish brush up against the objects’ sharp edges, they may lose their scales.

To avoid this, you need to ensure that your aquarium does not have any sharp objects.

More often than not, your fish will regrow their scales, and there is nothing to worry about unless they get severely injured.

3. Infection.

Infection is yet another primary reason that causes fish to lose their scales.

In home aquariums, fish are prone to many bacterial infections.

Scale shedding or infectious protrusion is a specific disease that results in heavy scale loss.

This disease is serious and needs immediate medical attention.

Or else, your fish can lose most of the scales, which can prove fatal if not treated on time.

Scale shedding or infectious protrusion disease is caused by bacteria such as Pseudomonas fluorescens and Aeromonas punctate.

This bacterium is found in nature. It can enter your aquarium from natural reservoirs.

Scale shedding disease can get introduced in your tank via water, plants, and gravel from infected tanks.

If an infected fish is introduced into your tank without quarantine, your healthy fish can get infected by transmission.

Besides, another common transmission method is from the fish tank equipment used in infected tanks.

Okay! Now that you know about the deadly scale shedding disease, let’s understand the underlying symptoms and its treatment.


The primary symptoms of the disease are:

  • Scale shedding, and
  • Scale raising.

In the early stage of this disease, you will find your fish healthy. But you can notice some protruding scales.

Later on, as the disease develops, it becomes fatal.

You can see the scales begin to stick up all over the body of the infected fish.

This is due to the formation of small bubbles that are full of serious fluids or pustules.

These pustules form under the skin of the fish where the scales are attached.

As a result, it leads to scale loss. The young infected fish may find it difficult to breathe due to the scale loss, formation of pustules, and scale protrusion.

At this stage, your fish will use dermal respiration instead of gills to exchange gases.

However, these symptoms don’t always hint towards this disease.

Sometimes, the scale protrusion is caused due to bacteria such as mycobacteriosis or ichthyosporidium.

If you need to be sure about the exact cause of scale shedding, you need to examine the tissue surrounding it and the scales.


You must diagnose the scale shedding disease at an early stage when the scales start to stick up in patches.

If you diagnose it later, after your fish has lost many scales, it cannot be cured.

It’s better that you do not keep the infected fish in the aquarium along with healthier fish.

Some of the things that you can use to treat the fish are:

  • Basic Violet K: You can use this to treat the fish in a separate tank.
  • Antibiotics: Sulfanilamide, Bicillim-5, and Biomycin can be used to treat the infected fish.

The infected fish that you cannot cure need to be disposed of.

Once you dispose of the infected fish, the aquarium, its equipment, and the fishing tackle need to be properly disinfected.

You can use 5% of Hydrochloric acid, Sulphuric acid, or Chloramine solution to clean the aquarium equipment.

While the plants can be treated with a Bicillin-5 solution. Also, the gravel should be tempered or boiled to disinfect it.

Related Questions

Do koi fish scales grow back? Yes, koi fish scales do grow back. Sometimes, it may happen that the scales will grow back in a different color than the original ones. However, they will grow back with time.

Do betta fish scales grow back? Yes, betta fish scales do grow back. However, it may sometimes take more time for the scales to regrow. If your betta fish loses its scales, you need to ensure that the tank water is clean. Since scale loss is not an open wound, there is not much to worry about. However, you need to keep an eye on the scale loss and check to see that it’s not caused due to an infection.

Do oscar fish scales grow back? Yes, oscar fish scales do grow back. However, it takes longer for them to regrow their scales compared to other fish species like goldfish. Also, the regrowth of scales depends on the injury. If the injury is severe and has affected the epidermis’ regenerative tissue, then there is a possibility that the scales may not regrow completely. In such cases, it’s better to take a veterinarian’s expert advice.

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