Do Fish Shed Their Scales? What Does It Mean

Fish are known for their scales, but do they really shed them? Research suggests that fish may occasionally lose some of their scales, but this is not a common occurrence. Some fish may shed their scales due to environmental changes or as a result of parasites or diseases.

Fish do not shed their scales. This is not a natural part of their life cycle as it is not necessary for their bodies or their environment. The only reason a fish might shed its scales would be if something very negative happened within its environment, as it is unnatural; stress, incorrect pH levels, an absence of light, etc.

This might be concerning if your fish is in fact demonstrating signs of shedding. Any form of shedding or swelling of the fish’s body should receive immediate attention. Rest assured that there are treatments available if you’ve noticed this within the early stages. 

The following will be an overview of what circumstances fish might shed in, what might cause a fish to shed, and treatments. 

fish scales up close

What Are Scales and What Do They Do for A Fish?

Scales are a common feature of many fish and provide important protection for the fish. Fish need scales to survive in their aquatic environments and provide them with an effective means of defense against predators. Scales also play an important role in regulating body temperature.

Do Fish Scales Shed Like Hair or Nails?

Fish scales are made up of small, overlapping plates that can easily flake off. But, fish don’t normally shed their scales like hair or nails bit if something is wrong with your fish their scales might start to fall off.

Fish scales are made up of keratin, just like hair and nails. However, unlike hair and nails, fish scales do not grow back so easily. Its scales are a protection from the water. So when a fish sheds its scales, it is actually getting rid of the entire layer and it exposes skin and muscle underneath.

Why Would a Fish Shed Its Scales? Look at The Envionoment

Your fish might have experienced some sort of physical bodily damage recently. If your fish is sheddings its scales, it’s likely a result of its environment. The following should be evaluated so that your fish do not start or continue to shed their scales: 

  • Reckless Movement During Breeding Periods: 

In many cases, the fish might have been moving aggressively against the tanks, the individual fish, and other products within its environment, causing their scales to be bashed against repeatedly.

For further context, the male and female fish will move ecstatically in search of their proper mates. More often than not, the male fish will end up hitting the walls of the tank accidentally, repeatedly as the female fish produce pheromones indicating that they are ready to reproduce. 

  • Aggressive Tankmates: 

Speaking of other fish, the opposite case could be that there have been some disagreements among your tank life. Physical altercations can result in losing scales, as well as damaging other parts of the body. Be sure to separate the opposing individuals if this keeps happening.

  • Dangerous Objects: 

Your fish might be in an environment with rough, sharp, or angular objects. Without even realizing it, they swim by these products and hurt themselves greatly. Take a look at your tank and make sure that there are no pieces that might be dangerous or hazardous. 

Why Would a Fish Shed Its Scales? Let’s Look at The Physical Aspects

If this is not a result of the environment, your fish might have some sort of internal issues, like stress or illness. The following should be taken into consideration when your fish is shedding its scales:

Your Fish Can Have a Sickness:

Your fish could have some sort of illness or infection. Fish can get sick from other fish, improper water, lack of water filtration, fungus, incompatible plants, and others. The most common way that fish get infected or catch diseases is from bacteria that might have built up, or mutated through the aforementioned. The fish will then begin to shed its scales in a very unhealthy manner. Some symptoms include mucus and sudden raising of the flesh underneath where the scales are.

They might look like tiny lumps. This is very serious as any issues surrounding skin and scales affect the fish’s ability to breathe. If you find that your fish is showing any signs of shedding or bubbling of the skin, this should be met with immediate attention. If a drastic amount of scales have fallen, or large bubbles have formed, it’s likely too late for your fish. However, if you were to see the signs early on, It is best to consult a veterinarian.

There are other antibiotics that you could also use for this case, such as Bibillim-5, Biomycin, Sulfanilamide, and others. Regardless, you should proceed with the following: First, take your fish out of its tank and into a new one if there are other healthy creatures in the tank. You should then put the recommended amount of product into the tank. This will treat them over the stated amount of time on the bottle. 

Your Fish Has Some Instability in Their Environment: 

There might be a lack of stability within the life of your fish. Constant environmental changes and physical disputes among other fish are considerably unstable circumstances. Mishalding your fish can result in them being physically injured and susceptible to illness and scale loss in general. This ties back to the concept of instability, where a fish being moved from place to place too roughly can damage the scales, flesh, and body overall. 

What Are Some Basic Signs that Your Fish Is Sick?

Here are some general signs/symptoms that would indicate whether or not your fish might be sick:

  • Swollen Abdomen, Reddening of The Fins, Sores, and Affected Fins or Tail: These symptoms are typically aligned with the Bacterial infection known as Aeromonas. 
  • Fuzziness: Any form of fuzziness on the body of a fish might be an indication of a bacterial infection. This infection is called Flavobacterium. 
  • How to Treat in The Case of An Aeromonas or Flavobacterium Infection: The best course of action would be to separate the fish from the tank, and place antibiotics into a new tank, as well as feed them antibiotic food/medication food. Make sure the water is especially clean and to keep an eye out on whether or not your other tank animals are having any signs of illness as well. Lastly, be sure to empty the water of that tank in order to ensure that non of the disease remains active.
  • Bumpiness/Lumps: This might be a sign that your fish has Carp Pox. 
  • Small Raised Bumps/pimples: Any sort of white or light pimples on the body of a fish might be a sign that the fish has a Viral Infection known as Lymphocystis.
  • How to Treat in The Case of Bumps and Pimples: You should take the needed antibiotics or solutions and place the treatments on the infected areas. Keep the fish in a separate tank for the time being in new water and continue to treat them until they are visibility and physically better. 
  • Not Eating and Extreme/sudden Weight Loss: In the best-case scenario, your fish might just be bored of the food you’ve been giving them. It’s natural for any creature to want something else after months or years of eating the same thing. In severe cases, however, a fish’s lack of hunger could mean something is going on with the fish’s body. if your fish has a sudden loss of appetite or significant weight loss, it is very possible that your fish has some sort of infection or disease hindering its stomach from sending the right signals and so forth. 
  • Coming to The Top of The Tank for Air: if your fish is constantly going out of its way to get air from the surface, it’s time to make sure the filter is on and working. You either need to filter the water or replace the water altogether. 


After reading this article, you will be able to better understand the importance of seeing a fish shed. As it isn’t a normal part of the fish’s lifecycle, it is an indication something is wrong. The scales can fall off in response to changes in water temperature, light exposure, or pollution level. take a look at the variables mentioned in this article and if you can’t find the root cause of your fish shedding, seek out professional help, and consult a veterinarian.

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