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Can Harlequin Rasbora and Betta Fish Live Together?

Sarah Psaradelis

By Sarah Psaradelis

harlequin rasbora in aquarium

Both the harlequin rasbora and betta are beautiful freshwater fish that are quite popular as small, tropical pet fish. You may be delighted to know that both fish species do well when kept together. This makes an attractive pair of tankmates as the harlequin rasbora, and betta has stunning colors and finnage. Although they can be kept together, the success rate of this pairing depends on the tank condition and individual personality of each fish.

This article will help you determine the best way to keep these fish together and if the species are compatible.

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Understanding Both Species of Fish

Getting to know the species better and their requirements will help us narrow down if they are good tank mates for each other. By understanding what each fish needs will ultimately help

The Betta

dumbo halfmoon betta
Image Credit: panpilai paipa, Shutterstock

Commonly referred to as the Siamese fighting fish, bettas are beautiful specimens from the Gourami family. Bettas come in a wide variety of attractive colors ranging from red to white, with many different patterns and fin types. They grow to an adult size of 3 to 4 inches and the fins of the betta fish can sometimes be double to size of their body. The betta can live for 2 to 4 years and are notorious for their territorial and aggressive nature. An individual male betta should have a minimum sized tank of 5 gallons, whereas female bettas should have a minimum of 10 gallons. When keeping bettas with other fish, you want to ensure the tank sized is increased according to the number of tank mates you want to add.

The Harlequin Rasbora

This colorful fish is a beloved tropical fish that should be kept in shoals of at least 6 fish. A gender ratio of 2 males and 4 females will balance out any chasing for mates. Rasboras are strictly freshwater fish which makes them ideal to be kept with bettas as both fish have similar water condition requirements. A minimum tank size of 10 gallons will suffice for a small shoal of rasboras. They are not overly aggressive and should not attempt to bother other fish in the same tank. These fish live between 2 to 5 years and grow around 1.5 to 2 inches in size.

Harlequin rasbora in aquarium
Image Credit: InsectWorld, Shutterstock

Is It True That Rasboras and Betta Can Be Tank Mates?

Yes! It can be done if you get the process of introducing them right. You want to ensure both species of fish are kept in ideal conditions with adequate space. There is no guarantee there will not be any chasing or aggressive behaviors when they are adjusting to being kept together. Bettas who have previously been housed with other fish are more likely to cohabitate well with harlequin rasboras. You will need to closely watch them ensure one is not bullying the other. It is also important to check that the rasboras are not nipping at your betta’s long fins. Only one male betta should be kept with a shoal of rasboras, but females can be kept in sororities with the addition of harlequin rasboras.

betta splendens in aquarium
Image Credit: panpilai paipa, Shutterstock

Providing the Right Conditions

The tank size should be altered according to the number of rasboras you want to keep with a betta.

Tank size guidelines:
  • 1 male betta with 6 harlequin rasboras can be kept in a minimum of 10 gallons.
  • A sorority of female bettas and a shoal of 6 harlequin rasboras should be in a minimum tank size of 20 gallons.
  • If you plan to add more fish, the size should be increased by 5 gallons. This also helps to limit aggression since small tanks cause stress and the feeling of being cramped which can cause the fish to turn on each other.

Filter: A strong sponge filter is ideal for both species. Remember bettas do not like strong currents and sponge filters release bubbles from the top which aid in surface agitation.

The tank should be fully cycled before you place the fish inside. Make sure that the tank is heated around 75°F to 80°F since they are tropical fish.

man changing water in aquarium
Image Credit: hedgehog94, Shutterstock

Tips to Successfully Keep Bettas with Harlequin Rasboras

  • Keep the tank heavily planted with different live plants. Not only does this create a natural environment that both fish are used to in the wild, but it also helps aid in good water quality. Plants are loved by both rasboras and bettas. You may even notice your betta lays on flat leaves near the surface. Both species can hideaway amongst the plants if they feel threatened by one another.
  • Ensure each fish is fed a species-appropriate diet. Bettas may try to eat the rasboras food which can lead to digestion issues. You can combat this issue by feeding the fish on different sides of the tank so that their diets do not interfere.
  • If you notice any aggressive behaviors like constant chasing or fin-nipping, the fish should be separated immediately.
  • Keep the harlequin rasboras in a decent-sized shoal to prevent them from feeling aggressive and potentially attacking the betta fish.
rimless aquarium
Image credit: Africa Studio, Shutterstock

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Bettas and harlequin rasboras can make great tank mates. They are compatible and can get along well together. There is a higher success rate of bettas living with other fish from a young age than when they have been living alone most of their adult life.

We hope this article has helped inform you on how you can successfully pair the betta and harlequin rasbora together.

See More: Can an Otocinclus Catfish and a Betta Fish Live Together?

Featured Image Credit: Arunee Rodloy, Shutterstock

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