Best Harlequin Rasboras Tank Mates | Ultimate Guide

Harlequin Rasboras are peaceful fish, so finding suitable tank mates for them is easy. They are popular fish with aquarists, as they can be kept in a large school, or kept in lower numbers in a smaller community tank. These fish are native to Malaysia, Singapore, Sumatra, and Southern Thailand, but have become quite popular all over for their small size and docile nature.

Learn about Harlequin Rasboras care from our guide as well.

harlequin rasbora tank mates
Harlequin Rasbora (Trigonostigma heteromorpha)

Harlequin Rasboras Tank Mates

Harlequin rasboras are a fairly easy fish to find tank mates for, as they are small and peaceful fish. They aren’t likely to be a threat to the other fish in your tank, however, they can be susceptible to attacks from larger, more aggressive fish. This needs to be kept in mind before choosing any fish to place in their tank with them.

List of Compatible Tank Mates for Harlequin Rasboras

There are many great choices when it comes to selecting tank mates to add to your rasbora’s aquarium. Some of the most popular choices include:

  • Bettas
  • Guppies
  • Mollies
  • Platies
  • Neon Tetras
  • Cardinal Tetras
  • Black neon tetras
  • Silver tip tetras
  • Lemon tetras
  • Cherry Shrimps
  • Amano Shrimps
  • Bamboo shrimp
  • Blue velvet shrimp
  • Ghost shrimp
  • Honey gouramis
  • Dwarf gouramis
  • Cherry barbs
  • Zebra Danios
  • African Dwarf Frogs
  • Cory catfish
  • Zebra loaches
  • Hatchetfish
  • Shrimps
  • Snails

Compared to some other species of fish, finding compatible tank mates for your harlequin rasboras isn’t too difficult. They are generally peaceful fish, not known to nip at or quarrel with other fish, provided they are in ideal living conditions.


Betta Fish (Betta splendens)

Bettas and harlequin rasboras live peacefully in the same environments in the wild, with both originating in Southeast Asia, where both species live in rice paddies, river basins, and slow-moving water. This makes them a great choice for tankmates, as they require the same water parameters as well. This makes bettas one of the most common choices for tankmates for harlequin rasboras, when in ideal living conditions.

Bettas, especially males, are known to become aggressive without much warning, especially if there isn’t enough room in the tank. Ensure you have a large enough tank for both species to have their own space.


Guppy Fish, Poecilia Reticulata

Guppies are another fish that make great tank mates for harlequin rasboras. Both have a docile, peaceful nature, and even though they will both occupy the same area in their tank, there should be no aggression between the two species.

Since guppies come in many different color combinations, it is possible to create quite a stunning contrast between your guppies and rasboras.

Neon Tetras

Neon tetras are a common choice for tank mates with harlequin rasboras, as they require the same water parameters. Their vibrant colors offer a nice contrast when paired with rasboras. Both are schooling fish, so as long as they have enough of their own species to school with, they will most likely never bother each other. Although both species prefer to spend most of their time in the middle of the water column, as long as their tank is big enough it shouldn’t ever be an issue.

Cardinal Tetras

Cardinal tetras are another species of tetra that makes a great choice when choosing tank mates for your harlequin rasboras. Like neon tetras, they require very similar water parameters, so keeping them in a community tank is quite simple.

Cardinal tetras will also inhabit the same area of their tank as rasboras, but they are also a very docile species so there shouldn’t be any aggression issues.

Other Tetras

Black Neon Tetra (Hyphessobrycon Herbertaxelrodi)

Other species of tetras can be great community fish with your harlequin rasboras, but not all tetras. Black neon tetras, silver tip tetras, and lemon tetras are all safe choices, as they are not known to be aggressive towards other fish in their tanks.

Not all tetras are docile, however, so make sure you do your research first before making a purchase. Bucktooth tetras, white tetras, and emperor tetras are all known to show aggression towards other fish. That doesn’t mean they can’t be kept together, but their tank needs to be optimized to keep aggression to a minimum.

Cherry Shrimps

Red cherry shrimp

Cherry shrimp and harlequin rasboras require almost the same water parameters, so that alone makes them great tankmates. Although the rasboras will grow roughly twice the size of the cherry shrimp, they will allow the shrimp to live in peace. The one exception is if the shrimp breed, they will likely feed on the shrimp fry once they are born.

Amano Shrimps

Amano Shrimp (Caridina multidentata)

Amano shrimp are another great choice for a tank with harlequin rasboras. Both require the same water parameters, and the rasboras are peaceful enough that they won’t bother the shrimp. As with other shrimp, if they breed, the rasboras are likely to eat the fry.

Other Shrimps

Bamboo Shrimp

Bamboo shrimp, blue velvet shrimp, and ghost shrimp are all species with similar water requirements that should be able to thrive when living with harlequin rasboras. When adding any new species to an aquarium, pay special attention to the behavior of all the species while they are getting accustomed to each other. Temperaments can change depending on many variables in an aquarium.


Dwarf Gourami (Colisa lalia)

Gouramis and harlequin rasboras have very similar water requirements, which makes them suitable tankmates when it comes to water parameters. The species of gourami you are considering purchasing will affect whether they are compatible with rasboras or not. Honey gouramis and dwarf gouramis are popular choices as they are very peaceful fish that generally get along with everyone.

Larger species, such as kissing gouramis and giant gouramis are both too large and too aggressive to be paired with rasboras. Avoid the larger species of gouramis when selecting fish for your rasbora’s tank.


Platy Fish

Platys are a very popular choice as tankmates for harlequin rasboras, as they are very peaceful and mildly tempered. They also both require the same water parameters and both species prefer a tank with lots of plant cover.

Platys are also schooling fish and generally stick to the bottom third of the tank, below the level your rasboras are most comfortable at. This means there likely won’t be much interaction between the two schools of fish.


Cherry Barb (Puntius Titteya)

There are many species of barbs available, and many of them are simply too aggressive to be placed in a tank with harlequin rasboras. Species such as tiger barbs and rosy barbs are known to be aggressive fin nippers and are not recommended for a tank with rasboras.

Cherry barbs, however, make a great choice for being paired with rasboras. They are known to be the least aggressive of all the barbs and are a great choice for a community tank. Cherry barbs also live in the center of the water column, as do the rasboras, so the tank needs to be large enough, and have enough cover, for both schools to have their own space. 


Zebra Danio (Danio Rerio)

Danios, such as Zebra Danios, are very peaceful and non-aggressive fish, and are highly unlikely to cause any trouble when paired with harlequin rasboras, as long as both have adequate space. Both species have similar water requirements, and both prefer a heavily planted tank so they have lots of cover.

Like rasboras, danios are schooling fish that also prefer the middle of the water column. Provided they have enough room and cover in the tank, they are very unlikely to bother the rasboras.

African Dwarf Frogs

If you are looking for something a little different to add to your harlequin rasboras tank, consider looking for an African dwarf frog. These tropical frogs require the same water conditions and are also very docile by nature. Having said this, they do sometimes consider small fish to be food, so keep this in mind before adding one to your aquarium.

Another thing to watch for if pairing these two species is that they eat the same diet. Since the rasboras are faster than the frogs, they can often get most or all the food, leaving your frog malnourished.

Cory Catfish

Emerald Cory Catfish (Corydoras splendens)

Cory catfish are a great choice as tankmates for your rasboras for a few reasons; they are peaceful and non-aggressive, and live at the bottom of the tank, well out of the way of other fish. The ideal tank setup for rasboras is also perfect for catfish, and they will help clean the bottom of the tank of the messes left by other fish.

Cory catfish also like to be kept in schools of six or more, so make sure your tank is large enough for both schools of fish.

Zebra Loaches

Zebra Loach (Botia striata)

Zebra loaches are another popular bottom feeder that is compatible with harlequin rasboras. Although they can grow to be larger than the rasboras (up to 3.5”) they are one of the most peaceful loaches available. Both species of fish have the same water requirements, and both prefer a heavily planted tank.


Mystery Snail (Pomacea bridgesii)

Snails, such as Mystery Snails, are a great choice if you are looking for something to help clean up your tank while ensuring your harlequin rasboras will be left alone. Snails will not bother any of the fish in your tank, and rasboras won’t even look at them twice.

List of Incompatible Tank Mates for Harlequin Rasboras

Harlequin rasboras should only be kept in tanks with smaller, peaceful fish. Although rasboras are fast-moving fish, any type of large predatory fish will be incompatible with them as they’ll likely be viewed as a snack, not a tank mate. Some of the tank mates they should not be kept with include:

  • Angelfish
  • Most species of Cichlids (There are a handful of non-aggressive cichlids)
  • Dwarf Pea Puffer
  • Tiger Barb
  • Bucktooth Tetras
  • Afer Knife
  • Black Wolf Fish
  • Severums
  • Rainbow Shark
  • Red Tail Shark
  • Bichirs
  • Silver Arowana
  • Oscars
  • Jack Dempsey
  • Kissing gouramis
  • Giant gouramis


Freshwater Angelfish (Pterophyllum Scalare)

Since angelfish are known to be both aggressive and opportunistic eaters, they are not recommended as tank mates for harlequin rasboras. Rasboras’ relatively small size compared to most angelfish puts them at a disadvantage, and are likely to be seen as food to a larger angelfish.

However, some aquarists have had success keeping these two species together in one tank. The rasboras need to have adequate cover and enough room in the tank to be able to stay out of the way of the angelfish. No matter how perfect your tank is set up, there will always be a risk to the rasboras.

Harlequin Rasbora Behavior

Harlequin rasbora are shoaling fish, moving around their environment in groups more often than moving around alone. They are timid and peaceful fish who prefer to live in the mid-level of the tank.

Rasboras will hide amongst plants and caves when they are stressed, or if they feel threatened. For this reason, lots of cover should be provided, especially in tanks with multiple species.

If kept alone or in schools that are too small, these fish may become shy and reclusive, although they still aren’t likely to get aggressive as other fish would under the same circumstances.

Are Harlequin Rasbora Aggressive?

Harlequin rasbora is a peaceful community fish, known for its peacefulness and lack of aggression, towards other species or their own. They are not known at all to be fin nippers and are more likely to be the target of aggression, rather than the instigator.

Are Harlequin Rasbora Suitable for Community Tanks?

As long as you pay attention to the number of fish you have in regards to the size of the tank, harlequin rasboras make a great choice for a community tank. These beautiful fish will move around the mid-level of the tank in schools, creating a lot of movement in your aquarium.

How Many Harlequin Rasboras Should Be Kept Together?

Harlequin rasboras are happiest when kept in schools of at least 8 to 10 fish. If you have the room in your tank, even larger schools of rasboras can be kept together. If you have a school of less than 4 or 5, it can start to affect the behavior of the fish.

Will Harlequin Rasboras School With Other Fish?

While it can be uncommon, harlequin rasboras have been known to school with other fish. Most often they will school with other species of rasboras, but they have also been known to school with other peaceful fish, such as neon tetras.

Leave a Comment

Your email address will not be published. Required fields are marked *