Rainbow Shark Tank Mates: Best 8 Companions | Aquascape Addiction

Rainbow Shark Tank Mates: Best 8 Companions

We cover our 8 best Rainbow Shark tank mates suggestions, why we feel they make good companions and other helpful information.

Rainbow Shark Tank Mates: Best 8 Companions

Rainbow sharks are really unique and beautiful fish, but that being said, they can be pretty aggressive. If you are looking to build a community fish tank, you need to be sure to only keep the rainbow shark with species that it will get along with. Let’s look at what we feel are 8 of the best Rainbow Shark tank mates and why.

What Fish Should I Avoid Adding With Rainbow Sharks?

Generally speaking, you should not house any other of these shark types with a rainbow shark. If you do house a rainbow shark with any other “shark” species, make sure that you have at least a 100 gallon tank and lots of plants and decorations so they don’t see each other very much. Rainbow sharks will be very aggressive with other shark species.

Also, don’t house them with other bottom dwelling fish because they will be viewed as threats (with the exception of loaches and plecos). You should also not house a rainbow shark with long finned fish as they may nip at them. On the other hand, fin nippers should not be housed with rainbow sharks because rainbow sharks also have fairly long fins.

The 8 Best Rainbow Shark Tank Mates?

So, let’s talk about some of the different fish companions which you can house with a rainbow shark and have the best chances of them living in harmony.

What Fish Can Live With Rainbow Sharks?

1. Barbs

Barbs tend to be mid water fish or even top water fish, meaning that they like to dwell near the middle of the fish tank. This is a bonus when it comes to rainbow sharks because a rainbow shark likes the bottom, so it will not feel threatened because the barb tends to not be near the bottom. The barb is a schooling fish, which for some reason seems to do fine with rainbow sharks.

Rainbow sharks tend to get along with schooling fish because schooling fish tend to be peaceful and non-aggressive. Rainbow sharks have fairly small mouths, so they usually won’t be able to eat barbs, except for the really small species. The best kinds of barbs to get and house with a rainbow shark include the rosy barb, the gold barb, the denison barb, the tiger barb, and the zebra barb.

2. Loaches

Generally speaking, rainbow sharks are not too friendly with bottom dwellers because they tend to feel that their territory is threatened by them. However, rainbow sharks have been living with loaches in the wild for a long time now, so as far as bottom dwellers go, rainbow sharks usually tend to do the best with loaches.

Loaches are not all that big, but still big enough to avoid being eaten as they will not fit in the mouth of a rainbow shark. Different rainbow sharks do have varying temperaments, which means that they may attack a loach if it feels threatened somehow, but usually they get along just fine. The bigger the loach is the better it will do, because rainbow sharks like to pick on smaller fish, but is often weary of larger ones.

3. Rainbow Fish

The rainbow fish is another good tank mate for the rainbow shark, and it is not just because they both have the word “rainbow” in their name. One of the main reasons why these two fish get along quite well is because the rainbow fish is a middle and top dwelling fish.

This means that the rainbow shark will most often not see them as a threat to their territory. Moreover, the rainbow fish can grow to be up to 4.7 inches in length, or in other words, it is way too big for the rainbow shark to consider it as being food. The rainbow shark is also no pushover, which means that it will fight back against the rainbow shark if it gets any bright ideas.

4. Danios

Now, keep in mind that there are different types of danios, so you are going to want to get one like a zebra danio which can grow up to 3 inches in length. Most danios are big enough so that a rainbow shark will not see it as a source of food (we have covered our favorite foods for Saltwater Fish on this article).

Also, danios tend to be very peaceful and will avoid confrontation if possible. Moreover, danios tend to be schooling fish, and for some reason rainbow sharks are usually not threatened by schooling fish. These guys also like to live in the middle of the tank, not the bottom, so the rainbow shark will not see it as a threat to its territory.

5. Rasboras

Yet another fish that tends to do fairly well with the rainbow shark when living in the same tank is the harlequin rasbora. These are schooling fish and do best ingroupsof 4 or 6, which means that the rainbow shark will not really see it as a threat. The rainbow shark will also not see the rasbora as a threat because rasboras like to stay near the middle of tank, as opposed to a species that lives at the bottom and invades the space of the rainbow shark.

They are very peaceful fish, so they won’t get into confrontations with a rainbow shark. Also, most rasboras grow to be around 2 inches in length, which means that a rainbow shark will not be able to eat them. There are some rasboras which are exceptionally small and may be seen as a meal, but that usually does not occur. One problem with rasboras is that they may nip at the fins of a rainbow shark, but generally speaking the rainbow shark is more than enough to keep them at bay.

6. Gouramis

Gouramis, for the most part tend to be pretty peaceful with other species of fish, except other gouramis funny enough. There are several gourami species which are too small to house with the rainbow shark because they may get attacked and/or eaten.

There are some gouramis including the blue gourami, pearl gourami, and moonlight gourami which are all over 4 inches long, and therefore will not be eaten by a rainbow shark. Gouramis don’t really tend to be near the bottom of the tank, so rainbow sharks generally will not view them as a threat.

7. Plecos

Plecos make for good tank mates for the rainbow shark for one main reason, they are big. An average pleco can grow to be around 2 feet long, which is definitely much bigger than any rainbow shark could manage to fit in its mouth.

Plecos are bottom feeders, which usually don’t get along with rainbow sharks, but bottom feeder or not, the pleco is just way too big for the rainbow shark to be any kind of threat. Also, plecos are very peaceful suckerfish if you look after them right, that just scour the bottom for food. A pleco will not pose any threat to a rainbow shark.

8. Snails

You can always house some snails or something like that with a rainbow shark. Rainbow sharks generally don’t care about snails as they are not seen as a threat. Moreover, the hard shell of any snail will make it impossible for a rainbow shark to eat. We have covered aquarium snails in a lot of detail here.

About Rainbow Sharks: Size, Housing & Lifespan


The rainbow shark may sound like a pretty vicious fish, seeing as shark is in the name, but that is not quite so. Sure, rainbow sharks are not the most peaceful fish around, even maybe a little more aggressive than they ought to be, but generally speaking they are alright. Most people would classify the rainbow shark as being a semi-aggressive type of fish.

Color, Size and Lifespan

The rainbow shark usually has an elongated black or dark blue body, and can sometimes also be bright blue in color. They have pointed snouts with a flat abdominal area and usually have reddish black, or even orange fins. Males usually have thinner bodies and a brighter coloration than females.

How Big Do Rainbow Sharks Grow?

The average rainbow shark can grow to be 6 inches long and live anywhere from 4 to 6 years.

General Information

Generally speaking, in the wild they tend to be fairly peaceful with other rainbow sharks, but in tanks, due to it being an enclosed space, rainbow sharks can be aggressive towards one another. In terms of fighting, a rainbow shark will bite, head butt, and tail whip another smaller rainbow shark or other smaller fish if it feels threatened by them.

The rainbow shark is actually more closely related to the goldfish than any species of shark out there. The rainbow shark is a fresh water fish found primarily in South East Asia and in bordering areas. This fish is a part of the Cyprinidae species of fish and is also an actinopterygiian, which means that it is a “ray fined fish”.

The rainbow shark likes to live in waters that have sandy bottoms and tends to migrate to flooded areas when they can, especially when it is breeding season. The rainbow shark likes to feed on algae and plankton, but because they are a little aggressive they have been known to attack other fish. When you have a rainbow shark in an aquarium, they like to live in the middle and especially on the bottom.


They are bottom dwellers for the most part. They like to clean the glass, surfaces, and the bottom of the fish tank and love to eat algae and uneaten fish food. In the aquarium, they like to have lots of rocks, caves, plants, and other hiding places where they can relax and get cover.

Housing/Tank Size

One single adult rainbow shark is going to need a tank of at least 30 gallons in size and a length of 48 inches at the very minimum. If you house them in an aquarium any smaller than this, they will chase, harass, and possible kill other smaller fish which it sees as a threat. They can handle water temperatures from 75 to 81 degrees Fahrenheit, they need a pH level between 6.0 and 8.0, and a water hardness level between 5 and 11 dH.

We have covered a detailed Saltwater aquarium beginners guide here that you might find helpful.


Just remember our tips, what kinds of fish are good to house with the rainbow shark, and which fish to avoid putting together with them. As long as follow these general guidelines, your community tank will do just fine.

You might also like our post on Protein skimmers which you can find here.