Emerald Dwarf Rasboras: Care, Size, Breeding & Tank Mates

Scientific NameDanio Erythromicron, Celestichthys Erythromicron
Common NameEmerald Dwarf Rasbora
Temperature70F-75°F (21-24°C)
Water pH7.0-7.8
Adult Size1-1.5 inches

Emerald Dwarf Rasboras Facts:

  • Emerald Dwarf Rasboras are a shoaling  fish, this means that even though they live in groups, the males will tend to spar with one another.
  • The more Emerald Dwarf Rasbora you keep in your aquarium, the more interesting behaviors they will display.
  • Emerald Dwarf Rasboras produce a lot of waste, and it is important to provide them with a filter that can handle 4 to 5 times the volume of the tank to ensure that it filters out all of the ammonia and nitrates.
  • The scientific name Erythro is the Greek word for ‘red’, and Micron means ‘small’.

Emerald Dwarf Rasboras Care

Emerald Dwarf Rasboras are a very unique looking fish. Their bodies are a light pink to orangish shade, and they have bold stripes along their bodies that are a turquoise green color. Emerald Dwarf Rasboras also have a black spot on the end of their bodies towards their caudal fin.

The males are typically smaller than the females are, but the females usually have a duller coloration. Male Emerald Dwarf Rasboras have a reddish tint to their fins, and the females have more transparent colored fins.

 They are easier to tell apart when they are mature as the females will have more rounded bellies when they are full of eggs.

Emerald Dwarf Rasboras
Emerald Dwarf Rasboras

Tank Requirements

Emerald Dwarf Rasboras are a shoaling fish that thrives in a group rather than being a solitary fish. The minimum size tank that Emerald Dwarf Rasboras require is a 10 gallon. A 10 gallon tank can house up to 6 Emerald Dwarf Rasboras. They tend to fare better in a 20 gallon size tank so that a larger group can be kept together. They are a busy little fish, and the more Emerald Dwarf Rasboras that are housed together, the more active they will become in displaying all their natural behaviors.

A proper aquarium setup for Emerald Dwarf Rasboras has a water temperature of 70F to 75F, and a pH of 7.0 to 7.8. If you are planning on keeping your Emerald Dwarf Rasboras in a room that is below 75F, you will want to make sure that you have an aquarium heater for their tank as they can be sensitive to water changes.

Emerald Dwarf Rasboras are happiest when they have many places to hide. Their tank should be heavily planted, and have rocks or shelters. This will give them plenty of places to hide and destress. If you keep your Emerald Dwarf Rasboras in a tank that does not have enough places to hide, then you will see them behaving in a stressed manor, and this could lead to illness.

You will want to avoid placing driftwood in your tank as it can break down and release tannins into the water. Emerald Dwarf Rasboras come from clear waters, and tannins could negatively affect them. The more closely resembling their natural habitat their tank is, the more confident they will be to explore their tank.

When it comes to substrate,you will want to provide them with a fine sand opposed to rough gravel. Choosing a darker colored sand will help make their colors pop, and is a lot safer for them. Emerald Dwarf Rasboras are a fish that produce a lot of waste. It is important to purchase the right filtration system and it is recommended to use an aquarium filter that has a water flow that is 4 to 5 times the volume of the tank so that it filters out all the ammonia and nitrates.

Do Emerald Dwarf Rasboras Need a Heater?

If you are planning on keeping your Emerald Dwarf Rasboras in a room that has a temperature that is below 75F, then you will want to add an aquarium heater to their setup. They are small fish that are sensitive to water changes. It is important to monitor the temperature of their tank so that your Emerald Dwarf Rasboras are happy and healthy.

Food & Diet

Emerald Dwarf Rasboras are omnivorous, and they are opportunistic feeders in the wild. In captivity, they will accept dried foods like flakes or pellets. They will also readily eat freeze dried daphnia, bloodworms, brine shrimp, and tubifex. In the wild, they prefer to eat a mostly protein rich diet, and will eat a lot of insects. They will also eat what is available to them, including algae, zooplankton, and plant matter.

Size & Lifespan

Emerald Dwarf Rasboras can grow anywhere from 1 inch up to 1.5 inches at full maturity. They have an average lifespan of 3 to 5 years if kept in the proper setup. This is roughly the same average lifespan of other Rasboras.

Tank Mates for Emerald Dwarf Rasboras

Emerald Dwarf Rasbora are described as a peaceful fish that can be housed with other peaceful fish easily. They prefer to live in a grouping of a minimum of 6 Emerald Dwarf Rasboras, but if you keep more together, then you will see their true personalities come out. They are lively, and sometimes the males will spar with one another. It is not uncommon to notice some fin nipping. Adding more Emerald Dwarf Rasboras to your tank will help spread out these behaviors to more of the group, and it will become less noticeable.

Emerald Dwarf Rasboras and Bettas – Are They Compatible?

Rasboras and Bettas coexist in the wild, and this means that they share the same water parameters and the same dietary needs. If you are planning on housing these two fish together, it is a good idea to provide them with a larger tank so that they have plenty of places to hide and get away from each other if they want to.

Emerald Dwarf Rasboras and Shrimp –  Are They Compatible?

Emerald Dwarf Rasboras are a peaceful enough fish that they can be safely kept with shrimp.

Emerald Dwarf Rasboras and Celestial Pearl Danios – Are they Compatible?

Emerald Dwarf Rasboras and Celestial Pearl Danios both have roughly the same temperament and can be housed together safely.

Emerald Dwarf Rasboras vs Celestial Pearl Danios

Emerald Dwarf Rasboras and Celestial Pearl Danios are both very beautiful fish that each have their own distinctive markings. Both fish come from Myanmar, and therefore enjoy many of the same things. They both enjoy roughly the same water parameters, temperament, and diet, and they are both peaceful fish that can be housed together fairly easily.

Celestial Pearl Danios are egg layers, and will lay about the same amount of eggs as a Emerald Dwarf Rasbora, but they will lay their eggs together opposed to scattering them. Both fish will eat their own young, and if breeding them they should be housed separately from the fry so that the fry do not get eaten.

Celestial Pearl Danios prefer more shallow waters than Emerald Dwarf Rasboras do, so it would be best to house these two fish together in an aquarium that is longer opposed to tall. This will give them more room to spread out and interact with each other.

Emerald Dwarf Rasboras Breeding

Emerald Dwarf Rasboras are an egg scattering fish, and if you are looking to breed them it is a good idea to set up a dedicated breeding tank for the fry. When the female is ready, she will scatter around 30 eggs, and the male will come along to fertilize them. Emerald Dwarf Rasboras do not provide any parental care for their eggs, and after they are done spawning, you will want to remove the parent fish from the breeding tank so that they do not eat their own eggs or fry.

If you find that your Emerald Dwarf Rasboras are not wanting to breed, you can help by conditioning them with a high quality protein diet. They can also be conditioned with more frequent water changes, as they prefer clear waters.

The eggs will hatch into fry in three days, and the egg sacks will provide all the nutrition that the fry will need for four days after they hatch. After they hatch, the Emerald Dwarf Fry will become free swimming.

Emerald Dwarf Rasboras could still scatter eggs in their aquarium, and if you have a more densely planted setup, the more likely the chance you will have some fry grow big enough to make it into the group.

Are Emerald Dwarf Rasboras Hardy?

Emerald Dwarf Rasboras are a hardy fish, but they can be susceptible to the same common diseases and illnesses that other freshwater fish are. Diseases are more likely to occur if the fish are stressed, or they are in an unclean environment. As with all problems, it is better to prevent them from happening than it is to solve them once they occur. It is a good idea to monitor your aquarium and perform small weekly water changes to keep the tank in good shape.