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How Big Does A Black Moor Goldfish Get? (With Weight Chart)

Sarah Psaradelis

By Sarah Psaradelis

Black Moor Goldfish up close

The Black Moor Goldfish is a type of fancy goldfish that makes an excellent pet for the right size aquariums. These goldfish are recognizable by their telescopic eyes, black velvety coloration, and medium to long flowing fins.

One question many Black Moor Goldfish keepers may ask is how big these fish can get. Understanding how big your goldfish can get is important when choosing the right-sized tank. It can also be helpful to know what size to expect your goldfish to get to, and how long it takes for them to reach this size. The average size of an adult Black Moor Goldfish is between 6 and 8 inches (15 to 20 centimeters).

Well, this article will help answer these questions.

Black Moor Goldfish Size & Growth Chart

Since they are fancy goldfish, they do not grow as large as Common or Comet goldfish. This size is achievable and standard in healthy Black Moor Goldfish that are cared for properly.

Black Moor Goldfish
Image Credit: JuanCarlosPalauDiaz, Shutterstock
Age Length Range
1 week 0.7 inches
3 months 2–2.5 inches
6 months 3–4 inches
12 months 4.5–5.5 inches
18 months 6–6.5 inches
3 years 7–7.5 inches
6 years 8 inches

When Does a Black Moor Goldfish Stop Growing?

Since goldfish have such lengthy lifespans, it does take them a while to grow and reach their full adult size. This can take anywhere from 3 to 6 years, and some Black Moors do not reach their adult size due to early deaths.

By the time a Black Moor Goldfish is around 2 years of age, they will be close to their final size. After this time, they will continue to grow until they reach 6 years if the living conditions allow it.

A Black Moor Goldfish’s growth will be the most noticeable when they are still young. Young Black Moor Goldfish can grow rapidly with the right environment and diet. You will notice their growth starting to slow down after the first 3 years, to which the goldfish will nearly be fully grown.

After the Black Moor Goldfish is fully grown, you may notice some changes in their weight and belly area depending on their diet and how often they are fed.

a couple of Black moor goldfish in a tank
Image Credit: Vlad Siaber, Shutterstock

The 4 Factors Affecting the Size of Black Moor Goldfish

The following factors can influence the size of your black moor goldfish:

1. Tank Size

The size of the tank heavily influences your Black Moor Goldfish growth. The larger the tank is, the more room they have to grow and maintain a steady growth pattern for the first few years of their life. A standard rectangular tank is recommended for these goldfish, with a starting size of 20 gallons for one Black Moor Goldfish.

Since they are social fish, your Black Moor Goldfish will benefit from another fancy goldfish companion. This means with the additional fish, a starting size of 30 gallons or more will be ideal. Bowls, vases, and other small aquaria are not recommended for goldfish due to their small size, even though Black Moor Goldfish are not the most active fish.

black moor
Image Credit: cherukuri rohith, Shutterstock

2. Water Quality

Good water quality means a happier and healthier goldfish. In the right-sized aquarium with a filter and aeration system, the water quality shouldn’t be difficult to manage. The tank should have undergone the nitrogen cycle before placing your Black Moor Goldfish inside. A filtration system without too much of a strong current can help prevent the water from becoming stagnant.

Once the cycling process is complete, you should keep up with gravel siphoning to remove the build-up of gunk, food, and leftover food that can pollute your black moor goldfish’s water.

3. Diet

A healthy diet provides your Black Moor Goldfish with all the nutrients they need to grow properly and maintain a healthy body weight. If their diet is lacking certain nutrients or they are fed low-quality foods throughout their primary growing years, then it can affect their growth.

black moor goldfish_leisuretime70_shutterstock
Image Credit: leisuretime70, Shutterstock

4. Overcrowded Conditions

A small tank that has too many goldfish in can affect the water quality and the amount of space each goldfish has to swim and grow properly. It is better to understock your goldfish tank than to overstock it—which can lead to crowding and water quality issues.


Ideal Diet for Maintaining a Healthy Weight

Like other fancy goldfish, the Black Moor Goldfish is an omnivore. This means that they eat both plant and animal-based proteins in their diet. Even when fed a healthy diet, your Black Moor still needs to be fed their food in appropriately sized portions. Overfeeding even the highest quality goldfish foods won’t be good for your fish and the aquarium’s water quality.

When it comes to feeding your Black Moor a healthy diet, you should feed high-quality commercial fish food. The food should be made from good ingredients with few fillers, colorants, and artificial ingredients.

Commercial goldfish food should be fed as a staple, while live or freeze-dried foods such as bloodworms and shrimp can be fed as a treat. Blanched peas and other green veggies can be used to supplement your goldfish diet a few times a week.

You can feed your Black Moor Goldfish every day or split one portion of food to be fed twice a day several hours apart.

Black moor goldfish on white background
Image Credit: Eric Isselee, Shutterstock

How to Measure Your Black Moor Goldfish

Measuring a goldfish can be quite tricky, and it is mainly used by goldfish breeders. Goldfish growth can usually be monitored by pictures for reference every month, and most growth will be noticeable in young goldfish.

You will need to place the Black Moor Goldfish in the palm of your hand should be a few inches out of the tank’s water. This whole process should go quite quickly, and shouldn’t last for more than a couple of seconds. Have a tape measure ready to line it up with the goldfish in your hand. Measure the Black Moor Goldfish from the eyes to the tip of their tail and record the length of the fish in a book for record purposes.

The measuring process needs to be done quickly before the fish has a chance to move around. Since it can be stressful for your goldfish, it should only be done occasionally.

The Facts About Black Moor Goldfish

  • The male Black Moor Goldfish is smaller than the female, with a slimmer appearance.
  • A good tank size for one Black Moor Goldfish is 20 gallons, and an additional 10 gallons per new goldfish can ensure that the tank size is large enough for all of the fish.
  • Other common names for the Black Moor Goldfish are the “Dragon Fish” or “Dragon Eyes” goldfish due to their protruding telescopic eyes.
  • Black Moor Goldfish are only available in one color, which is black. However, some Black Moor Goldfish can develop bronze discoloration on their body due to sunlight and temperature changes.
  • A Black Moor Goldfish is created by breeding a veil tail and a red telescope eye goldfish together.
  • Black Moor Goldfish are freshwater fish, which means that they do not live in water with a high salinity content.
  • As a temperate water fish that can live both with and without a heater, Black Moor Goldfish can adapt to various temperatures. As long as the temperature is not too hot or too cold.
  • The average lifespan of a Black Moor Goldfish is 10 to 15 years.




Black Moor Goldfish reach an adult size of 6 to 8 inches. This size can take up to 6 years for most black goldfish to reach, and factors such as diet, tank size, and aquarium conditions influence their growth. In some cases, a Black Moor Goldfish can exceed 8 inches in size. This might be rare, but it is not unheard of.

Overall, with the right living conditions and care, your Black Moor Goldfish can get quite large. This makes it necessary to keep them in an appropriately sized tank that provides them with enough space to grow and thrive.

Featured Image Credit: PicsWay, Shutterstock

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