Angelfish and harlequin rasboras

In this post, we will learn about the relationship between Angelfish and Harlequin rasboras. We will also discuss some of their characteristics and tank requirements.

Angelfish and harlequin rasboras

Angelfish and Harlequin rasboras are widely raised by aquarists around the world. However, their compatibility is conditional to plenty of space for the two species to coexist. Here we will discuss a little of the general characteristics of these two ornamental fish. 

Harlequin rasboras 

Harlequin rasboras are small-sized metallic coloured fish. They are quite easy to take care of. They tend to be more colourful and active when kept in planted tanks with open areas for swimming. 

These fish are original from Southeast Asia and can grow up to 2 inches and live for around 6 years. 

Behaviour & Compatibility

Harlequin rasboras are gregarious species that can be kept in community aquariums with other small fish. It is important to keep a school with at least 10 individuals, so they can show their natural behaviours and brighter colours. Due to their small size, they are ideal for a well-planted and/or ornamental aquarium.

Although the Harlequin rasbora is a fish that lives very well in community aquariums, some less active fish are not able to tolerate the active fast swimming of this species. Additionally, as small fish, they can be easily eaten by larger fish. Cyprinids are a good choice of tank mates, so are tetras, guppies, platies, and swordfish.

This species can also coexist with numerous bottom-dweller fish, and even with dwarf cichlids. However, they will suffer in the company of large aggressive fish.


The Harlequin rasbora is omnivorous. In nature, for example, they feed on small insects, worms, crustaceans and zooplankton. In aquariums, however, they should get a diet consisting of an excellent flaked or pellet, supplemented with live foods such as brine shrimp and bloodworms. 

Although live foods are an important part of their diet, try not to overdo it as they may start to refuse prepared fish food. Also, it is recommended to add some lettuce or spinach to the Harlequin rasbora diet. These fish should be fed several times a day, but in small amounts that can be consumed within 3 minutes.

Habitat and Tank requirements

The Harlequin rasboras are native to South-eastern Asia. For this reason, they enjoy warmer water temperatures. Thus, temperatures should be between 73 and 82 degrees Fahrenheit and pH levels ranging between 6.0 and 7.5. Regarding tank size, at least a 10-gallon tank is necessary.


Angelfish are tropical freshwater fish species original from South American warm water bodies. They occupy slow-flow water bodies with lots of vegetation in the Amazon River basin.

These fish are very popular among aquarists. They are generally peaceful and give an amazing look to tanks. They can grow up to 6 inches and live for around 10-12 years in ideal care.

Behaviour & Compatibility

In general, Angelfish are peaceful fish. However, some aquarists classify them as semi-aggressive. They are somehow territorial fish, and thus, can become a bit aggressive regarding their territory, as well as during the breeding season, when they protect the eggs and, later, their offspring.

Additionally, as medium-bodied fish, Angelfish may chase and devour smaller fish. Thus, ideal tank mates should not be small enough to fit in their mouths. Some potential good tank mates are Corydoras, Rainbowfish, larger Tetras and Rasboras, and some peaceful Gouramis, as the Dwarf Gourami. 

However, there are some tips to reduce the chasing of smaller fish. Introducing the young Angelfish reduce the chances of chasing, as they would be smaller and see the tank mates as real mates and not prey.


Angelfish are omnivores. Thus, they can feed on almost anything that fits their mouth. In nature, these fish usually feed on small invertebrates, larvae, insects, and smaller fish. In a tank, they must be fed following a protein and fibre-rich diet. Some good items to offer them are live worms, fleas, and shrimp. They would also accept some pellets and flakes, and natural vegetables, such as spinach and zucchini. It is recommended to feed them twice a day.

Habitat and Tank requirements

As Angelfish are originally from the tropical areas, specifically the Amazon River Basin, in South America, they appreciate warm water temperatures. They also enjoy slow-moving well-vegetated environments. For this, the water temperatures in their tanks should be controlled using a heater and thermostat and be between 73 and 82 degrees Fahrenheit with a pH between 6.5 and 7.8.

A fine sandy substrate is ideal for them. As well as live plants as Anacharis, Amazon Sword, Java moss and Java fern.

Can angelfish and harlequin rasboras share the same aquarium?

Yes, Harlequin rasboras are very peaceful fish and can be housed with many other fish species. Angelfish and Harlequin rasboras share the same requirements of tanks, from the dimensions to the water quality and pH. 

However, when introducing Harlequin rasboras to Angelfish, it is important to observe the fish behaviour, as adult Angelfish could see the rasboras as prey and star chasing them. For this reason, we recommend introducing young angelfish to rasboras. The lower the size difference, the lesser the chances of chasing and bullying.


In this post, we will learn about the relationship between Angelfish and Harlequin rasboras. We will also discuss some of their characteristics and tank requirements.

If you have any thoughts or doubts, feel free to drop us in a comment below!

Frequently Asked Questions (FAQs): Angelfish and harlequin rasboras

Can Harlequin rasbora live with angelfish?

Yes, Angelfish and Harlequin rasboras can share a community tank. However, it is important to keep an eye open when first introducing them to avoid any aggressive chasing behaviour.

Would Harlequin rasboras nip Angelfish fins?

It is very uncommon, however, Harlequin rasboras could try to nip the Angelfish fins.

Are Harlequin rasboras social?

Yes, Harlequin rasboras are very social fish. They are schooling fish that swim actively around the tank. The larger the group, the brighter the colour and more natural behaviours.

What fish can live with Harlequin rasboras?

Many fish species can become tank mates to Harlequin rasboras due to their peaceful easy-going behaviour. Some species of tank mates are Cherry Barbs, Corydoras, Danios, Dwarf Gouramis, Mollies, Platies and Zebra Loaches. However, it is important to keep in mind that larger fish could see the Harlequin rasboras as prey and devour them.

Are Harlequin rasboras top dwellers?

Yes, Harlequin rasboras are classified as top to mid-dwelling fish. Thus, they can occupy the majority of the tank areas.

Can neon tetras live with Harlequin rasboras?

Yes, Neon tetras are great tank mates to harlequin rasboras. They have similar sizes and are peaceful fish. Thus, they would not bother or harm each other. They also require the same range of water parameters, making it easier to maintain adequate tank conditions for both.

Are Harlequin rasbora territorial?

Sort of, although they tend to establish territory, they do not fight for it nor become extremely aggressive when it is “invaded”.

Do rasboras breed in captivity?

Yes, Harlequin rasboras do breed in captivity. However, water conditions need to be stable during this process and they do not require specific assistance from the aquarist.


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Monkolprasit, S., S. Sontirat, S. Vimollohakarn and T. Songsirikul, 1997. Checklist of Fishes in Thailand. Office of Environmental Policy and Planning, Bangkok, Thailand.