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Home > Goldfish > Goldfish Losing Scales? Here’s What to Do

Goldfish Losing Scales? Here’s What to Do

goldfish ich

Goldfish are beautiful and colorful fish that come in a variety of different sizes, colors, and body shapes. It is not uncommon for goldfish to lose a few scales throughout their life; however, it is not a normal occurrence.

Goldfish do not shed or molt, so if you notice that there are pieces of scale missing from your goldfish then it may be a cause for concern, however, there are several different reasons that your goldfish could be missing scales—which we will explain in this article.


Why Is Your Goldfish Missing Scales?

It can be shocking to glance at your beautiful goldfish and see that they are missing patches of scales from their body, leaving a white undertone that is quite noticeable. It is easy to spot a missing scale on a goldfish in bright lighting, where the scales look luminescent—the areas without scales will look dull and gleam white. It is not unusual for goldfish to be missing one or two scales, but if you notice that they are missing a lot of scales in a specific area then it could be an indication that there is an underlying issue causing this to occur.

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These are the most common reasons for your goldfish to be missing scales:


Goldfish Losing Scales? 5 Things You Can Do to Help

1. Aggressive Tankmates

If your goldfish is in an aquarium with other fish or goldfish, then they are at risk of being bullied which can lead to their scales being torn off through nipping, or, in cases where tankmates, such as Plecostomus, suck off the slime coat of goldfish.

This is most common in situations where your goldfish is paired with incompatible tank mates that do not get along, or where other goldfish bully the weaker and more vulnerable goldfish in the aquarium. The bullying fish will then nip away the scales of the goldfish which can cause scale loss to occur.

Goldfish in an aquarium
Image Credit: Hans Braxmeier, Pixabay

2. Damage From the Environment

If you have rough decorations in your goldfish aquarium or small ornaments with holes that your goldfish can swim through, it might begin to rip off the goldfish’s scales. Sometimes the damage can be severe and lead to scrapes and wounds on your goldfish beyond the missing patch of scales.

3. Bad Water Quality

High levels of ammonia can cause the scales from your goldfish to be burned away. This happens in uncycled aquariums or if your goldfish are kept in a small body of water without a filter and frequent water changes. The water can become toxic and start to burn away at their slimy coat which then causes flashing (when goldfish itch against the aquarium or any decorations inside) which causes scales to fall out.

Electric Aquarium Vacuum Gravel Cleaners
Image Credit: M-Production, Shutterstock

4. Dropsy

Dropsy can occur if your goldfish has organ damage, which can occur from an internal disease. Your goldfish will have the appearance of loose scales because their scales poke out from their bodies and can easily be torn off if they lay against the substrate or scrape against a decoration in the aquarium.

5. Infections

Hemorrhagic septicemia is a bacterial infection that causes goldfish to lose their scales through large red ulcers that grow on the body of the goldfish. This bacterial infection can spread fast amongst fish and even be transferred on aquarium equipment into other aquariums that you may use in if the equipment has not been thoroughly cleaned.

sick goldfish
Image Credit: A-photographyy, Shutterstock


What to Do If Your Goldfish Is Missing Scales

After you have identified which problem could be causing this problem in your goldfish, you can start to look for possible solutions.

  • The first step is to ensure that your goldfish are kept in the right environment, as this will help prevent your goldfish from losing scales due to being bullied by other fish or being injured by rough decorations in the aquarium. It is best to keep goldfish in a species-only aquarium as some species of fish can start to bully and nip at your goldfish. By keeping a small group of goldfish together (similar in size and breed) there is a less likely chance for bullying to occur.
  • Ensure that there are no rough decorations in your goldfish tank where they can accidentally scrape some of the scales off. Avoid keeping ornaments with small or rough openings in their aquarium where they can swim in and out of, as this might be scraping their scales off too.
  • There are water testing kits that you can purchase from a pet store so that you can test the level of ammonia and nitrates in aquariums. These tests will give you an indication of the quality of the water and you will be able to determine if your goldfish are flashing from the high levels of ammonia in the aquarium. Using a cycled filter (that has undergone the nitrogen cycle) alongside regular water changes can help keep your goldfish to lose scales due to an irritation in the water.
  • If you suspect that your goldfish has been infected with either an internal or external infection, they should be isolated from the rest of the fish in the aquarium and treated with a broad-spectrum antibiotic until their symptoms have cleared.

Do Goldfish Scales Grow Back?

If you are worried that your goldfish’s appearance will be permanently affected by missing scales, you do not have to worry because their scales will be able to regrow, however, they might not be the same coloration as before. The new scales may look duller or white as they start to grow out which can stand out in some varieties of goldfish. In many cases, the scales grow back normally and it is difficult to see the area where there were previously no scales.

group of sick goldfish
Image By: Suphakornx, Shutterstock



If you notice that your goldfish is missing scales, you should keep them in a clean environment as the slime coat and missing scales are exposing their delicate skin membranes. Scales are used to protect the goldfish and work as a form of armor, so your goldfish is more vulnerable if they are missing a lot of scales.

It is rarely an issue if your goldfish is only missing one or two scales from their body, though, as this can happen naturally and will grow back eventually.

Featured Image Credit: Zay Nyi Nyi, Shutterstock

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