Looking for a pet to keep your children entertained? A Damselfish might be the perfect solution. The gentle, colorful fish are very entertaining, but they’re also quite easy to care for, even for the most inexperienced aquarist.

Damselfish aren’t as flashy as clown fish; they don’t have big horns or elaborate patterns. They aren’t particularly big, and they tend to stay in the background. These little fish are a popular choice for many saltwater fish keepers because of their adaptability, their hardiness in captivity, and their tiny size. As a family pet, a damselfish is ideal for someone who wants a pet that is easy to care for and that won’t require a lot of attention.

Most people confuse the Damselfish with Cichlids as they look quite similar. Their colors are also amazing, ranging from bright blues and yellows to deep pinks and purples.

These tropical fish are hardy, fun for children, do not grow too large and are relatively easy to care for. Though they’re typically kept in tanks with only other Damselfish, they can be kept in a peaceful community tank with other small, non-aggressive fish, as long as they are given plenty of space to avoid being eaten.

Information about Damselfish

  • Average size: 2 to 7 inches depending on variety
  • Colors: Red, Yellow, Blue
  • Good Pet: Yes
  • Good with Other Damselfish: Yes
  • Good with Other fish species: Moderate
  • Suitable for First-Time fish Owners: Yes
  • Attention Needs: Low
  • Health Concerns: The fish is prone to Marine Ich and Fin rot
  • Average Life Span: 5 to 6 years

Physical Appearance of Damselfish

Damselfish vary in colors from red, yellow, and blue. The fish looks similar to Cichlid fish in appearance. The Damselfish has a fork-shaped tail just like the Cichlid and a round-shaped body. 

Here are some of the most common Damselfish.

Yellowtail Damselfish

The Yellowtail Damselfish has a blue body and a bright yellow tail. The fish grows to about 3 inches and is among the few peaceful Damselfish.

Blue Damselfish

This fish is blue in color but the males tend to have a yellow mouth and tail. It’s also interesting to note that when the Blue Damselfish is scared, it can turn totally black as a defense mechanism. The Blue Damselfish grows to a maximum length of about 3 inches.

Bicolor Damselfish

They originate from the Caribbean Ocean and are characterized by a black to dark gray color on the front side of its body while the rear part is pale and almost colorless. This particular Damselfish grows to about 4 inches in length.

Domino Damselfish

The Domino Damsel is also called the Three Spot because of its unique black body with white spots. The fish grows to about 5 inches in size.

Azure Damselfish

As you can likely guess by the name, this fish is blue in color. Blue on the top part and bright yellow on the lower part of the body near the stomach. The fish grows to about 3 inches in length and is also known as the Half-Blue Damselfish.


Temperament of Damselfish

Most Damselfish and especially the Domino Damsel are very aggressive fish. The fish also tends to become very territorial and will defend its space fiercely. Damselfish mainly attacks peaceful fish that don’t fight back. The fights may lead to the targeted fish becoming stressed or even sick.

Tank Conditions

Tank size

In their natural habitat, Damselfish live in coral reefs and it’s advisable to place them in a reef tank to mimic their natural home. The tank should hold a minimum of 30 gallons of water for the small sized Damselfish. 

If you want to have a school of 4 or more, then they should be put into a 100 gallon tank. For only 2 Damselfish in a tank, then a 50 gallon tank should be fine. Remember Damselfish can become more aggressive if they feel confined in a small space especially with other fish.

Water conditions

Damselfish can adapt to a wide range of water conditions because they’re very tolerant to fluctuations. The temperatures in the fish tank should be between 73°F to 81°F and the pH levels should remain between 8.1 to 8.4.


This fish likes to have a sand substrate because Damselfish enjoy burrowing in it especially at night. The fish also prefers to have plenty of hiding places such as caves and plants with large leaves, and other hollow spaces. With plenty of hiding places in the tank, territory wars are reduced significantly because the materials reduce contact with other fish in the tank.

Tank Maintenance

A weekly checkup on the filters should be performed to make sure they are functional. It’s also a good idea to check on the water temperatures daily by placing a thermometer at the end of the aquarium furthest from the water heater.

The water quality should be looked at each week. Use water testing kits to confirm that nitrate, nitrite, and ammonia levels remain close to zero. Also carry out 25 percent water changes every four weeks to maintain the water quality. 

Damselfish aren’t messy fish compared to other fish which is the reason why monthly water changes are needed, and not weekly. The Damselfish even forages on any algae growing in the tank helping to maintain clean water. If you have other fish in the tank you may need more frequent water changes.


Health Issues

Damselfish rarely become ill unless exposed to poor water conditions or overcrowded tanks causing stress. Here are general signs of a sick Damselfish.

  • Damaged fins
  • Cloudy eyes and slimy body
  • Abnormal swimming patterns
  • Hiding most of the time
  • Not eating
  • Weight loss

Here are some of the most common illnesses that attack Damselfish.

Marine Ich

Also known as Marine White Spot Disease, this illness is common among most saltwater fish including the Damselfish. The main cause of Marine Ich is poor water quality.You can easily tell a fish suffering from this disease because it develops white spots that appear like specs of salt on the skin. 

These spots are usually parasites attached on the skin of the fish and in an attempt to detach them and to relieve the discomfort; the fish tends to scratch against objects.  As the illness progresses, the fish may lack appetite and lose weight. It’s also possible to find a sick fish swimming as though it’s darting.

Putting copper in the water has been known to kill the parasites. Consult with your vet to get the dosage right because excess copper can kill your fish. Because the illness is highly contagious, it is recommended to first remove the affected fish and place them in a quarantine tank.

Then carry out tank cleaning and water replacement to remove the parasites from the water. This will help the fish recover fast and to prevent spread of the disease.

Fin Rot

Fin rot is common among Damselfish and mostly occurs due to drastic water changes in water quality and requirements. A sick fish has damaged fins that seem slimy due to excessive mucus production. 

The best treatment for a sick fish is improving the water quality by correcting any mistakes in temperature and pH levels. Improving the diet of your fish can also help it to recover from the disease faster.

Best Tank mates for Damselfish

By now you already know that the fish is very aggressive. The fish has even been known to bite the hands of caregivers during feeding. Choosing tank mates should be done wisely to avoid paring this fish with others that it may bully.

The general rule of thumb for Damselfish is that only similar varieties can live together. This means that Domino Damselfish can only be placed with Domino Damselfish. Blue Damselfish should not be kept together with a Yellowtail Damselfish or they could fight to death. Remember Damselfish are protective of their territory.

You can also have Damselfish living with other fish species but avoid placing the timid ones  with them or they could become stressed from the bullying. Here are some fish species that make good tank mates for the Damselfish.

Since the Damselfish is more aggressive compared to all the above listed fish, always place them into the tank last. By placing Damselfish last, it reduces the level of aggressiveness because the fish learns to share the space from the beginning.

fish flakes

Feeding Damselfish

Most Damselfish are omnivores and can eat commercial fish flakes, vegetables, live, or frozen foods. Some Damselfish are herbivores and it’s wise to consult the breeder or pet store owner before which type you are buying. Here are some of the best foods for your omnivorous Damselfish.

  • Brine shrimp
  • Copepods
  • Worms
  • Small fish
  • Worms
  • Shrimp
  • Finely shredded vegetables such as spinach, carrots, peas

If you have a community tank, you’ll realize that the bigger Damselfish eat from near the surface of the aquarium while the smaller ones eat from the bottom of the tank. The behavior likely has to do with the territorial nature of the fish.

Feed your fish 1 to 3 times a day and only give enough to avoid having leftovers that can quickly contaminate the water in the tank. If you are feeding them frozen foods, it is better to thaw them first before feeding your Damselfish. If you find that your Damselfish are a bit aggressive you might want to feed them more. Fish that are well fed are less aggressive compared to the hungry ones. 

Related Questions:

Is it possible to breed Damselfish in an aquarium?

The answer is yes. They can breed in the aquarium if placed in pairs. This can be hard because you cannot really differentiate between male and female Damselfish because they look similar in appearance. One of the bigger problems is that you can put two of the same sex together and not even know.

A male Damselfish usually prepares a nesting site whenever it wants to spawn and which attracts the females. After spawning, the male protects the eggs from predators until they hatch which happens after 4 to 5 days. 

After hatching, the fries grow fast and can survive in a tank as long as optimal water conditions are maintained.

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