Species, Cyprinids, Freshwater fish, Rasboras

Dwarf Rasbora: The Ideal Fish for Small Tanks

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by Jason Matthews



The Dwarf Rasbora is a species of pet fish popular among owners because of its attractive appearance and peaceful demeanor. Whether you are a beginner or an experienced pet fish owner, the Dwarf Rasbora is an excellent addition to your aquarium. 

In this article, we will explore the fascinating world of Dwarf Rasboras, including their origin, appearance, size, gender differences, behavior, ideal tank conditions, compatible tank mates, diet, breeding, and common diseases. Prepare to be amazed by this small gem of the underwater world.


Scientific Name: Boraras maculatus
Common Names: Dwarf rasbora, pygmy rasbora
Life Expectancy: Up to 5 years
Adult Size: Up to 0.75 inches (2 cm)


HabitatSmall, slow-moving streams and forest pools with dense vegetation
OriginThailand, Indonesia, Malaysia
Care LevelEasy
TemperamentPeaceful and social
Tank LevelMid to bottom
Minimum Tank Size5 gallons (20 liters)
Water pH6.0-7.5
Water Temperature73-82°F (23-28°C)
Water HardnessSoft to medium
LightingLow to moderate
Tank MatesPeaceful and small fish such as other rasboras, small tetras, and shrimp

Fun Fact Corner

This ability to change coloration is known as “physiological color change” and is a common trait among many fish species. However, the Dwarf Rasbora is particularly adept at this skill, which makes them fascinating to observe in an aquarium setting.


The Dwarf Rasbora, scientifically known as Boraras maculatus, originates from Southeast Asia’s clear, slow-moving streams and swamps, particularly in Indonesia and Malaysia. The name “Dwarf Rasbora” derives from its small size and classification within the Rasbora genus of fish. 

The scientific name of the species, Boraras maculatus, comes from the Greek word “boraras,” meaning “eater of small things,” which refers to its diet of tiny invertebrates and zooplankton, and “maculatus,” meaning “spotted,” which describes its colorful markings.

These fish are known to live in groups in their natural habitats and are typically found near vegetation, where they can find protection and food. Dwarf Rasboras have been widely introduced to other regions for use in aquariums, and their popularity as a pet fish species has only continued to grow. 

Appearance & Size

The Dwarf Rasbora is a visually stunning species with a vibrant and striking appearance. These fish have slender, cylindrical bodies with streamlined profiles, making them well-adapted for life in their native streams and swamps. They have a unique coloration that ranges from a deep red to a vibrant orange, with black spots dotting their bodies and fins. 

Some individuals may also have a metallic sheen, adding to their eye-catching appearance. The male Dwarf Rasbora is usually more brightly colored than the female, and during the breeding season, the male’s colors may become even more intense. 

The Dwarf Rasbora is a small fish species that typically grows up to 1 inch long. As such, they do not require a large aquarium and can thrive in a tank as small as 10 gallons. However, as with all fish, a larger aquarium is always better as it provides more swimming space and can support a larger fish population.


The Dwarf Rasbora is a species in which males and females can be easily distinguished by appearance. Generally, males are more brightly colored and have more intense markings than females. 

During the breeding season, the male’s colors may become vibrant and exhibit more territorial behavior. Females, conversely, are usually plumper and have a more rounded belly, indicating that they are carrying eggs. 

It can be challenging to differentiate male and female Dwarf Rasboras unless they are viewed side-by-side or during breeding behavior. However, observing their behavior during feeding and mating can also give some clues about their gender.


The Dwarf Rasbora is a peaceful and sociable fish best kept in a small school of 6–8 individuals. They are active swimmers and spend most of their time near the surface or mid-water level of the aquarium. 

These fish are naturally shy and prefer heavily planted environments that provide ample hiding places and security. Dwarf Rasboras also exhibit schooling behavior, which means they swim in coordinated groups, darting and weaving together for safety. This schooling behavior can also be seen when they compete for food during feeding time.


When it comes to choosing tank mates for Dwarf Rasboras, it is important to select species that have similar temperaments and water requirements. These fish are friendly and do best when kept with other non-aggressive species. 

Some good tank mates for Dwarf Rasboras include:

It is important to avoid keeping Dwarf Rasboras with any larger or aggressive fish as they may become stressed or injured. Additionally, fish that require different water parameters, such as higher pH levels, should not be kept together with Dwarf Rasboras as this can compromise their health and well-being.

Tank conditions

When creating an ideal environment for Dwarf Rasboras, there are a few key factors to consider. First, these fish need a spacious aquarium with plenty of swimming room. A 5 gallon tank or 10 gallon tank is the minimum recommended size for keeping a small group of these fish.

Second, Dwarf Rasboras prefer a well-planted aquarium with plenty of hiding places, such as caves and plants. This will help them feel more secure and enhance their overall display.

Water temperature is an important factor to consider when keeping Dwarf Rasboras. They prefer a temperature range of 75°F – 79°F (24°C – 26°C), which should be maintained using a reliable aquarium heater. Additionally, the pH level should be between 4.5 – 6.5. However, Dwarf Rasboras are adaptable fish that can tolerate various conditions. Maintaining good water quality and stable water parameters ensures their health and well-being.


In the wild, Dwarf Rasboras are known to be omnivores, feeding on small insects, crustaceans, and plant matter. In the aquarium, they will readily accept a variety of foods, including high-quality flakes, pellets, and frozen or live foods such as brine shrimp, daphnia, and bloodworms.

A mix of different foods is recommended to ensure a well-balanced diet, including both dry and live/frozen options. It is important to avoid overfeeding as Dwarf Rasboras are small fish and can easily become overweight. 

A good feeding routine is to offer small amounts of food 2-3 times daily and remove any uneaten food after a few minutes to maintain good water quality. 


Breeding Dwarf Rasboras is relatively easy and can be achieved in a well-maintained aquarium with the right conditions. It is recommended to keep a small group of 6-8 Dwarf Rasboras in a well-planted tank with plenty of hiding places, such as caves and dense vegetation, to encourage breeding. 

Provide a balanced diet to the fish, as healthy and well-fed fish are more likely to breed. When the conditions are suitable, the male Dwarf Rasboras will display their brightest colors and perform a courtship dance to attract the females. Once the female is ready to breed, she releases eggs, which the male will fertilize. The eggs will then stick to the plants or other objects in the aquarium.

Use a separate breeding tank with a sponge filter and an air stone to provide a gentle water flow to increase the breeding success rate. The temperature should be maintained between 77°F and 82°F (25°C and 28°C), and the pH between 5.0 and 6.5. Once the eggs have been laid, removing the adults from the breeding tank is important to prevent them from eating the eggs or fry.

The eggs will hatch after 24-36 hours, and the fry will become free-swimming after about five days. It is important to feed the fry small amounts of live or powdered fry food several times a day and to perform frequent water changes to maintain good water quality. The fry will multiply with proper care and can be introduced into the main aquarium after 2-3 weeks.


Dwarf Rasboras are generally hardy fish and are not particularly prone to disease. However, like all fish, they can be susceptible to certain diseases if the aquarium conditions are not properly maintained.

Maintaining good water quality and a well-balanced diet is essential to prevent these diseases. It is also recommended to quarantine any new fish before introducing them into the main aquarium to prevent the spread of disease. Regular water changes and stable water parameters can also help prevent diseases in Dwarf Rasboras.


Jason Matthews

My name is Jason Matthews, and welcome to my website. When other kids were bragging about how their dog could sit and roll over, I was bragging about my latest Betta Fish and the cool sea castle I just added to his aquarium. 

Jason aquariume

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