Last update: November 28, 2023

15 Best Rainbow Shark Tank Mates

Rainbow sharks are beautiful bottom dwellers known for their semi-aggressive behavior. Because of their temperament, they can be challenging to build a community around.

But that doesn’t mean you can’t have a large aquarium with an extensive community if you want to care for these beauties. Here are the 15 most suitable rainbow shark tank companions.

Rainbow Shark Tank Mates – What You Need To Know

Rainbow Sharks aren’t too difficult to manage, but if you aren’t careful they can turn into territorial bullies toward your other fish. This is especially true if the other fish are smaller than the rainbow show or if they resemble it, like the red tail shark.

Just remember that you want other fish to give it space and not antagonize it. Rainbow sharks like lots of vegetation in a large tank. This gives them plenty of room to move around and plenty of hiding places for other fish.

Rainbow Shark Tank Mates

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1. Zebra Danios

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  • Scientific Name: Danio Rerio
  • Adult Size: 2 inches
  • Compatible With: Most Fish
  • Water Temperature: 64 to 74° F
  • Minimum Tank Size: 10 gallons
  • Care Level: Easy
  • Origin: South Asia

The ever-playful zebra danios are fantastic tankmates for rainbow sharks because they are dither fish. Dither fish are fish that swim out in the open. They are usually smaller schooling fish, and they can often make shy or aggressive fixed feel more relaxed in the tank.

Due to their playful nature and the fact that they move around the entire tank, zebra danios are great at calming aggressive fish, like the rainbow shark. If your rainbow shark is feeling more at ease, it’s less likely to cause trouble with all its other tankmates.

Zebra danios are schooling fish, so keep them in a group of five or so and watch out for fin-nipping! These critters are small, fast, and playful, so slow fish with shiny fins can get targeted. These fish love lots of vegetation in their tank. They’re omnivorous and not picky, so you can feed them whatever you like.

2. Harlequin Rasbora

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  • Scientific Name: Trigonostigma heteromorpha
  • Adult Size: 1.75 in
  • Compatible With: Non-Predatory Fish
  • Water Temperature: 73 to 82° F
  • Minimum Tank Size: 10 gallons
  • Care Level: Easy
  • Origin: Southeast Asia

The harlequin rasbora is a schooling fish, meaning you’ll want at least six of them in your aquarium to keep them healthy. Their metallic shine and quick movements add flair to any aquarium. Because they are so visually stimulating and easy to care for, harlequin rasboras are very popular fish. 

They make excellent tankmates with rainbow sharks because they are peaceful top-middle-dwellers, which means the rainbow shark will not feel intruded upon. Their size also protects them just in case your Rainbow Shark is having a bad day.

Make sure to give them a colorful tank with lots of plants and shiny stones. They are omnivores and will eat anything you give them, although they prefer live food if possible. Frozen pellets and dried flakes are also an option.

3. Black Skirt Tetras

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  • Scientific Name: Gymnocorymbus Ternetzi
  • Adult Size: 2.5 inches
  • Compatible With: Most Fish
  • Water Temperature: 78 to 82° F
  • Minimum Tank Size: 15 gallons
  • Care Level: Intermediate
  • Origin: South America

These black beauties can get a little finicky regarding temperature, but they make fantastic tank mates for rainbow sharks. 

Even though they themselves are mildly aggressive with long-finned fish, they have a reputation for getting along with most other semi-aggressive breeds.

On top of that, they live in the middle level. So each fish can have its space. They also like lots of vegetation and other hiding places, perfect for rainbow sharks.

4. Boesemani Rainbowfish

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  • Scientific Name: Melanotaenia boesemani
  • Adult Size: 4.5 inches
  • Compatible With: Most Fish
  • Water Temperature: 75 to 82° F
  • Minimum Tank Size: 30 gallons
  • Care Level: Easy
  • Origin: Indonesia

The ever-popular Boesemani rainbowfish is a delightful little pet with a bright blue head and rich red tail. These are one of the larger fish on the list, and they prefer to be in a school, so you will want to make sure you have a large enough tank to house at least six of them with your rainbow shark.

Good upkeep will give you the brightest colors, so feed them well. Putting some females in with the males will help, too as the males will try to show off for them.

The Boesemani rainbowfish make excellent tankmates with your rainbow shark due to their quick speed and healthy size. This will keep the rainbow shark from getting too aggressive. 

These fish are very peaceful and live in the middle area of the tank, so you won’t have to worry about them starting a fight either.

Keep your tank stocked with plenty of plants for these beauties. They are omnivores, so give them whatever you have on hand, and they’ll eat it right up!

5. Black Ruby Barb

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  • Scientific Name: Pethia nigrofasciata
  • Adult Size: 2 inches
  • Compatible With: Most Fish
  • Water Temperature: 72 to 79° F
  • Minimum Tank Size: 30 gallons
  • Care Level: Easy
  • Origin: Sri Lanka

With a name like black ruby, you know this fish will dazzle. Its body is just that, a deep ruby mixed with black fins.

Black ruby barbs make excellent tankmates for rainbow sharks because they are very peaceful. They do live in the bottom of the tank where the territorial rainbow shark also lives, but their friendly demeanor should keep them from causing a stir.

Other barbs, like the tiger barb, can get somewhat nippy. Luckily, these guys don’t have that problem. Just keep them together with eight to ten other black ruby barbs, as they are schooling fish.

Like many of the fish on this list, the black ruby barb likes a lot of plants in their tank. They are also bottom feeders, grabbing up whatever they can find among the rocks. They are omnivorous, but you should try to emphasize a vegetation-heavy diet for them.

6. Honey Gourami

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  • Scientific Name: Trichogaster Chuna
  • Adult Size: 3 inches
  • Compatible With: Peaceful Small Fish
  • Water Temperature: 71 to 82° F
  • Minimum Tank Size: 10 gallons
  • Care Level: Easy
  • Origin: India and Bangladesh

The shy but colorful honey gourami likes to hang out at the middle and top level of the fish tank, perfect for the bottom-dwelling rainbow shark to have some space.

These gouramis also like to live in a group. Four of them in a tank should keep them happy and feeling safe. By having vegetation in the tank, you can give the honey gourami plenty of hiding places. Rainbow sharks won’t attack fish that are hiding, and honey gourami prefer to stay out of sight.

They don’t get along with tiger barbs, so think twice before adding them both at once.

7. Dwarf Neon Rainbowfish

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  • Scientific Name: Melanotaenia praecox
  • Adult Size: 2.5 inches
  • Compatible With: Non-Predatory Fish
  • Water Temperature: 72 to 79° F
  • Minimum Tank Size: 20 gallons
  • Care Level: Intermediate
  • Origin: Indonesia

Like other schooling fish on this list, the dwarf neon rainbowfish likes to be in a group of at least six. These tiny, active fish love to be around other active breeds but can get along with almost any type.

While these fish are relatively easy to take care of, they don’t handle stress well. So it may be wise to get your other fish started and feeling settled before adding a school of them.

The dwarf neon rainbowfish make for excellent tankmates with rainbow sharks because they are relatively small and peaceful. They won’t antagonize the Rainbow Shark, and they aren’t territorial.

Lots of vegetation and plenty of room to swim around and exercise in will keep these little guys happy and colorful. Of course, they will eat almost anything you put in the tank, so there is no fuss there.

8. Bee Shrimp

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  • Scientific Name: Caridina Cantonensis
  • Adult Size: 1.25 inches
  • Compatible With: Most Fish
  • Water Temperature: 68 to 74° F
  • Minimum Tank Size: 10 gallons
  • Care Level: Intermediate to Advanced
  • Origin: Taiwan

Bee shrimp have become quite popular for the ability of aquarists to breed them into a seemingly infinite variety of colors. They are pretty small and demand a lot of attention, particularly when it comes to water quality, but they add a tropical flair to the tank.

They make good tankmates with rainbow sharks because they are relatively peaceful and often pretty shy. They live on the bottom of the tank with the rainbow shark, but they won’t get territorial. Just make sure they are getting along.

Bee shrimp eat detritus off the floor of the tank and are vegetarian. Having lots of plants in your tank could do the trick, but if they aren’t getting enough food from the plants, make sure to give them a vegetarian supplement.

Although not a requirement, bee shrimp like being in a group, and the more of them there are, the happier they will be. Because they are timid, having a lot of them won’t make them aggressive, which is a plus.

9. Congo Tetra

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  • Scientific Name: Phenacogrammus interruptus
  • Adult Size: 3.4 inches
  • Compatible With: Fish That Don’t Nip
  • Water Temperature: 73 to 82° F
  • Minimum Tank Size: 40 gallons
  • Care Level: Intermediate
  • Origin: Congo River Basin

Not all fish like a crystal clear tank. The Congo tetra is from Africa and is used to dense vegetation in a silty river. 

They are schooling fish, so get them together in a group of six, so they feel comfortable. They have very bright fins, so keep them away from fin-nipping breeds.

The Congo tetra is a good tank mate for rainbow sharks due to its peaceful nature and timidity. They also stay in the middle and top of the tank, giving the rainbow shark plenty of room.

Put dense vegetation in your tank to keep these happy, and consider using a dark, sandy material for the bottom to replicate the muddy Congo River Basin. These fish are omnivores and not picky. They’ll eat live, dried, or frozen food.

10. Blue Gouramis

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  • Scientific Name: Trichogaster trichopterus
  • Adult Size: 5 inches
  • Compatible With: Peaceful Fish and Bottom Dwellers
  • Water Temperature: 74 to 82° F
  • Minimum Tank Size: 20 gallons
  • Care Level: Easy
  • Origin: Asia

The South East Asian-native blue gourami loves thick vegetation and lots of room, as it can get mildly aggressive towards other fish. These fantastic creatures change the color of their scales with their mood like a living mood ring! How neat is that?

These fish are great tankmates for a rainbow shark because, despite their mildly aggressive nature, they inhabit all tank levels so they can give other fish space if needed. 

And with the size of tank you will need for your rainbow shark, the blue gourami will have no problem finding room for itself.

Once again, make sure to include lots of plants for this one to swim in. Blue gouramis are low-maintenance and omnivorous, so whatever fish food you like to use will be fine.

11. Hillstream Loach

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  • Scientific Name: Sewellia lineolata
  • Adult Size: 2 – 3 inches
  • Compatible With: Most Fish
  • Water Temperature: 68 to 75° F
  • Minimum Tank Size: 55 gallons
  • Care Level: Advanced
  • Origin: Vietnam and Laos

The hillstream loach, also known as the reticulated hillstream loach, is a vibrant and visually stimulating addition to any aquarium. These fish live as long as eight years but can be challenging to care for due to their water purity needs.

The hillstream loach is a great tankmate for a rainbow shark, but be warned that your tank will need to be large enough to accommodate them both, as both are bottom-dwellers, and the hillstream loach can become territorial.

The Vietnamese hillstream loach can add a lot to your aquarium if the challenge doesn’t scare you away. It has the body and movement of a manta ray, with the colorings of a water snake. It’s beautiful creature to watch!

12. Tiger Barb

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  • Scientific Name: Puntius tetrazona
  • Adult Size: 2.8 inches
  • Compatible With: Other Tiger Barbs And Fast Swimmers
  • Water Temperature: 68 to 79° F
  • Minimum Tank Size: 15 gallons
  • Care Level: Easy
  • Origin: Indonesia

Although the tiger barb is easy to care for, it can be tricky to keep it from bothering other fish. They are notorious fin-nippers, and slower fish will probably be harassed. 

By keeping your tiger barbs in a group of six or more, you can mitigate any aggression these fish may have towards other tankmates. A larger tank will also keep them from being overly aggressive.

They make great tankmates for rainbow sharks because they are quite active and move around a lot but prefer the middle layer of the tank. This should keep them from overcrowding the rainbow shark at the bottom.

Tiger barbs are some of the most popular fish for aquariums. They like some vegetation but do well in simple tanks and are very durable in lots of water conditions. They are omnivorous and will eat most foods you give them.

13. White Cloud Mountain Minnows

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  • Scientific Name: Tanichthys Albonubes
  • Adult Size: 1.5 inches
  • Compatible With: Non-predatory fish 
  • Water Temperature: 60 to 72° F
  • Minimum Tank Size: 10 gallons
  • Care Level: Easy
  • Origin:  China

The peaceful white cloud mountain minnow is another schooling fish. Try to keep six of them at a time, at least.

Providing them with lots of vegetation will remind them of their natural habitat in the white cloud mountains of China. It will also give them a place to hide, although they also like to swim around in open water.

Because of its small size, be aware that predatory fish will try to eat this little guy. It stays in the middle to top so the rainbow shark won’t mess with it much, but if it gets too close, it may get bullied.

Because of its speed and its tendency to stay in other areas of the tank with vegetation, it’s a great tank mate for rainbow sharks. With a large tank, it will have plenty of room to move around.

14. Scissortail Rasbora

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  • Scientific Name: Rasbora Trilineata
  • Adult Size: 3.5 inches
  • Compatible With: Most Fish
  • Water Temperature: 73 to 78° F
  • Minimum Tank Size: 20 gallons
  • Care Level: Easy
  • Origin: Southeast Asia

The sprightly scissortail rasbora loves a large tank. While comfortable in 20 gallons, the 55-gallon tank a rainbow shark requires means these fish will have more than enough room to spread their fins.

Scissortail rasboras make great tank mates with rainbow sharks because they stay in the middle and top of the tank. They are peaceful, active fish who won’t antagonize your rainbow shark below.

These fish are easy to take care of. They’ll eat almost anything, and they can live in a wide variety of tank styles. That said, they like to have some open space to swim in, so don’t overcrowd it.

15. Bristlenose Pleco

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  • Scientific Name: Ancistrus Cirrhosus
  • Adult Size: 8 inches
  • Compatible With: Most Fish
  • Water Temperature: 73 to 81° F
  • Minimum Tank Size: 40 gallons
  • Care Level: Easy to Intermediate
  • Origin: Amazon Basin

Given enough space, the bristlenose pleco can be a good fit for rainbow sharks. But be warned that when they mature, they can become territorial of the bottom layer, which could lead to conflict with your rainbow shark. Adding more caves and hiding spaces will help keep things calm.

They are nocturnal, so the two breeds may simply be territorial during their preferred time of day. Because of its size, the rainbow shark will also be less inclined to bully the bristlenose pleco.

They like to have driftwood and other objects on the bottom to snoop around. They also eat algae, helping you to keep your tank clean. How nice!


These 15 best rainbow shark tank mates will provide you with great joy. Each has something they will bring to the community.

Now you have to choose which one you want! You can’t go wrong, whether it’s the black skirt tetra or the blue gourami. 

Good luck!

Frequently Asked Questions

What fish can I keep with a rainbow shark?

Barbs and rainbowfish make excellent tank mates for rainbow sharks. Because they are territorial bottom dwellers, fish that live in other parts of the tank work best.

How big will a rainbow shark get?

Six inches.

Is Rainbow Shark aggressive?

It can become territorial, particularly towards fish that resemble it. Try introducing your rainbow shark last to minimize its territorial nature.

Ian Sterling

Ian Sterling, founder of, began his aquarium journey over 30 years ago, driven by a deep fascination for fish and their diverse personalities. His website,, is dedicated to making fishkeeping accessible and enjoyable, offering beginner-friendly guidance, expert insights, and a community for aquarists to connect and share experiences.

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