Black Moor Goldfish Care: Size, Lifespan, Diet, Breeding, and Tank Mates

black moor goldfish care

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Hundreds of years ago, the black moor goldfish was discovered in China. Due to its unique traits, this species of fancy goldfish gained massive popularity among aquarists all across the globe.

Their protruding eyes and ball-shaped bodies are what makes them distinct. The velvety black coloration on their bodies also makes them look fancy and stunning.

The black moor goldfish are known to be docile, peaceful, and quite easy to care for. They can make great tankmates with other slow-swimming fish with similar characteristics.

If you want to know more about the black moor goldfish, keep reading!

Species Overview

Scientific Name:Carassius auratus
Common Names:Black moor goldfish, Demekin,
Dragon Eyes, Telescope eyes
Care Level:Easy
Compatibility:Housed with other peaceful community fish
Color Form:Dark grey, velvety black
Size:4″-8″ on average, sometimes reach 10”
Life Expectancy:10-15 years (average)
Diet:Omnivores, high protein & fiber
Minimum Tank Size:20 gallons
Water Temperature:65-80°F (18-26°C)
Tank Setup:Plants, Smooth substrate, and decorations


The Black Moor Goldfish was discovered a long time ago in China. It is said that the black moor goldfish was first seen in the early 1700s. Some historical writings stated that the Chinese have been breeding the goldfish selectively since before 1000 AD.

Later, the goldfish was brought and introduced to Japan. There it is called Demekin, which means Dragon Fish or Dragon Eyes. Now, this fancy telescope eye goldfish is already distributed all around the world.


By their name, the black moors typically have solid black colors. However, the colors differ depending on their age.

There are some common names that the black moor goldfish have. They are called Demekin in Japan, Dragon Eyes, or Telescope eyes. Those nicknames weren’t given to them without any reason. The black moors’ eyes protrude on the sides of their head, and they grow bigger as they’re maturing. Ironically, their eyesight is poor.

Other than the eyes, this fish still got several distinct features. Their round, ball-shaped body is usually what attracts people to want them. This feature makes them a cute slow-swimmer.

The juveniles are usually a bit pale or dark bronze. As they mature, the black color will develop fully. But sometimes, the black moor goldfish has bright orange patches.

When they grow older, some discoloration can happen. You may see the black moor turn to gray and develop white color around their belly. Water temperature can also affect the fish’ color. In some cases, the black moors turn into bright orange.

Size and Lifespan

This round fish is a small to mid-sized fish. Normally, the size of this fish range between 4 inches and 8 inches. But in some extreme cases, they can grow up to 10 inches long.

Typically, the males are smaller than the females, but it’s pretty difficult to tell them apart. You might need to wait until spawning season. Around that time, you can see the males develop little white bumps on their pectoral fins.

Speaking about fins, the black moor goldfish have small to medium-length dorsal fins. The side and tail fins, however, are long and flowing. You can see some different tail shapes, such as the broad tail, ribbon tail, and butterfly tail.

As for their age, the black moors can live around 10 to 15 years. But they are sturdy fish, and so you can keep them even longer than that. With optimum care and a healthy environment, it’s expected for them to live for 25 years or more!

With all these interesting features they have, the black moor goldfish can be a great addition to your tank.

Temperament and Behavior

Besides its cute and captivating appearance, the black moor goldfish is also known for its calm behavior. They are a bit shy, so keeping them together with boisterous fish species is not ideal.

But since they are peaceful, you can put them in a community tank where there are other peaceful small fish. There is a chance for them to get along with other fish and be good tankmates.

You can also keep them in groups of their own kind, which they seem to prefer.

You will often see them swim in the mid-level of the tank, but sometimes they will also hide in decorations when they are stressed.

black moor goldfish care guide

Tank Setup

Although tank size varies depending on the fish size, it’s recommended to provide at least a 20-gallon tank for the black moors. If you wish to add more fish to the tank, you will need to give 10 gallons of water per additional fish.

Make sure you don’t overcrowd the aquarium, as it will influence your fish’ health and growth. This also allows them to have plenty of swimming space and thrive optimally.

As for the shape, the long, wide, and shallow aquarium will suit best for the black moors. It gives them a wide surface area that allows sufficient oxygen penetration.

Filter, Lighting, and Substrate

The black moors, just like any other goldfish, produce many bioloads. Therefore, water filtration is necessary to maintain water quality.

Despite their poor eyesight, the black moors are very sensitive to unnatural light. So providing them any additional light (other than from the tank) is not essential. They also need some time of darkness, usually around 8 to 12 hours a day.

Speaking of aquarium substrate for black moor goldfish, you have a free range of choices for substrates. This species doesn’t spend much time on the bottom of the tank, so either sand or gravel will do.

Plants and Decorations

The black moors like to nibble on plants, so placing some thick-leaved or floating plants is also a good idea. Why thick-leaved? These plants will be able to recover themselves after being nibbled on by the fish. On top of that, they can help to maintain the water clean, too.

If you are to put decorations for your black moors, make sure the surfaces are smooth. Rough-surfaced decor can easily harm the black moors’ eyes. Some decor recommendations would be caves or bogwoods. They provide nice hiding places for your fish.

Water Parameters

An ideal water temperature for the black moor goldfish range from 65° to 80°F with a pH of 6.5 until 7.5.

The black moors don’t necessarily need tropical temperature water nor a heater. You only need to make sure there is no sudden drop in the temperature.

Diet and Feeding

As omnivores, the black moors eat both meaty and plant-based food. Feeding them both types of foods will keep their diet balanced.

You can feed them flakes, pellets, or gel foods that contain high protein and vegetables. When picking up their foods, make sure it is high-quality. We don’t suggest goldfish color-enhancing food as it may lose the black coloration.

Other than quality store-bought foods, you can give them supplementary live foods. These include bloodworms, Daphnia, tubifex, and brine shrimp. However, we don’t recommend treating the black moor with live foods daily as they may contain bacteria.

You can also try to make homemade vegetable-based fish food. If so, pick vegetables that are high in fiber since it’s important for the black moors’ digestive system. Green veggies like lettuce, broccoli, and spinach will be suitable for them.


Breeding the black moor goldfish in a house tank is not at all difficult. The most common age for black moors to breed is around 1.5 or 2 years old. Around that age, they have fully matured.

To trigger their spawning, you need to mimic the condition of spring water. Water temperature should be kept around 60°F at first and raised by 3°F every day until they spawn. But you can just keep the water temperature when it hits 75°F. An increase in feeding and light will also trigger the black moors to start breeding.

When the spawning starts, you can see the male chasing or circling the female. This may last for several days before the female finally lays the eggs on the tank surfaces. Female black moor can deliver up to 10.000 eggs.

After that, you need to separate the adults from the eggs to avoid the potential fries getting eaten. It normally takes 4 to seven days for the eggs to hatch. Once the fries started to appear, you can feed them small foods that are high in iron. You can put them back with the parents when they reach around two months old.

Black Moore Goldfish Potential Diseases

There is no particular disease that only affects the black moor goldfish. But still, several common diseases may happen to your fish if not taken care of properly. These include:


Ich or also known as white spot disease is a very common skin disease to freshwater fish. The cause is a parasite called Ichthyophthirius multifiliis. Since the parasite lives in the water, the best way to get rid of it is by changing the tank water. You can also add medication in the water or raise the temperature to 80°F.


The cause of this disease is the flagellate protozoan parasite. It results in cloudiness on the fish’s skin. Some red lesions with white slime can also appear. The best way to treat this disease is with formalin. You can add 2cc of formalin for every 10 gallons of water with the filter bypassed. But it’s better to consult with an expert if your fish caught this disease.


Skin flukes are flatworms that embed themselves in the fish’ bodies. It’s fairly easy to cure the disease but may be fatal if left untreated. The best way to tackle flatworms is by using an over-the-counter drug as directed and correct the water parameters.

Black Moor Goldfish Tank Mates

Can the black moors be kept in a community tank? The simple answer to that is yes. This fish species is peaceful, and there’s a possibility for them to be good tankmates with other fish.

However, keeping them with fast swimmer and other fish with good eyesight would not be a good choice. The black moors will have difficulties competing with other fish to get food since they got poor eyesight.

Even so, you can still keep them with other species with similar traits. The most common would be Neon tetras, Glass catfish, or Cherry Barbs. To add more diversity to your tank, you can put Ghost shrimp, Mystery snails, and African dwarf frogs.

But the most ideal way to keep the black moors in groups is with their own kind. Other fancy goldfish like Orandas, Fantails, and Ryukin will also be compatible with the black moors.

Are Black Moor Goldfish suitable for you?

The black moors are special fancy goldfish that are easy to keep in captivity. They are peaceful and calm, making them suitable for beginner or advanced aquarists.

No special requirements are needed. You only need to understand what the black moors need. Do not underestimate tank size since the black moors fins might be larger than you think. Also, keeping their diet balanced will help them healthy and thrive optimally.

Besides, they look totally magnificent. The black moor will look amazing in your community tank or just by itself.

After reading all the information, do you think the black moors are suitable for you?

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