Essential Guides To Breeding Rainbow Sharks – Check Before You Try!

Breeding fish is fun, but it’s only true if you raise friendly species. How about aggressive fish like rainbow sharks? How to breed them correctly?

Do not let this tricky task prevent you from keeping these beautiful fish. We will give you a complete guide to breeding rainbow sharks.

Please check to give your pets the best treatment! 

Breeding Rainbow Sharks 

You can try breeding rainbow sharks when they are around six inches long and physically mature. They are aggressive, so you must keep a close eye on them.

Step 1: Prepare the tank.

To breed rainbow sharks, you will need a tank that is much bigger than 55 gallons. So, 75 gallons is the absolute minimum required. You can also find a larger container. 

By cycling it afterward, ensure the parameters in the fish tank match those in the main tank. Despite how tough this species is, its ability to adapt to new environments still needs your attention. 

To eliminate any potentially harmful substances in the aquarium, you can use a dechlorinator. Then, set aside at least 48 hours to establish a hygienic, safe, and friendly space for your fish. 

Try maintaining the water temperature in your fish tank between 72 and 82°F. Make sure it doesn’t fluctuate a lot or abruptly.

You can put plants and aquarium decorations in strategic positions so they may act as hiding spots for your fish when they get angry with each other. Later on, they will protect the young against attacks by parents.

Set up a new tank for the breeding fish

Step 2: Introduce the fish

Carefully net the parents and move them to the new tank. Keep checking your fish for the first few days to see how they react. If you fight, you will need to remove some of them. 

Sometimes, a few weeks before breeding, a spawning tube forms on the male, and he fertilizes the eggs. 

At this stage, you must keep an eye on the breeding sharks. Then, you can tell if they are good parents. Some of them may eat their eggs instead of protecting them. 

Female rainbow sharks won’t get pregnant, but they will become gravid. A female fish is gravid for around one to two weeks, and you may tell by looking at her tummy.

Pay attention to every behavior of your pet

Step 3: Take care of the fry

The eggs will hatch within 36 to 48 hours of breeding. However, extreme cases may take up to three to four days.

Be aware that the eggs don’t hatch the same way as those from reptiles. Rather, until the wigglers reached their final shape, the eggs would change into particular body parts, such as eyes or tails.

Now, your 75-gallon tank becomes too large for those little creatures. They can’t find food in such a big tank. 

Moreover, the fry may get sucked into the 75-gallon aquarium filter you used. It is advisable to build up a 10-gallon container for the fry as a result. 

Here are some tips to take care of the fry:

  • Do not add substrates to the tank because they will block your fish’s way of hunting for food. 
  • Put some plants in the tank to act as their food sources and shelter. 
  • Install a sponge filter to adjust the temperature. 
  • Transfer the fry into a new container with a nylon net. 
  • The best food for the fry are microworms, brine shrimp, flakes, and infusoria. 

When the fish reach one inch, they are big enough. You can move them to their main aquarium because their tank mates won’t confuse the rainbow shark babies for their food. 

Move the fish back to the main aquarium when they are ready

Are Rainbow Sharks Hard To Breed?

Yes. The semi-aggressive behavior has made rainbow shark breeding extremely hard. If you put males and females in the same aquarium, they may not get along well and often fight one another.

Some fish species consume their own eggs, and it’s unclear if rainbow sharks will also eat their babies. If there is a possibility that the parents will eat the eggs, remove them right away and put them in a different tank.

Breeding this species is hard


1. How can you tell if a rainbow shark is male or female?

Male fish have slimmer bodies than females and feature black stripes running around their tail fins. They also have more vivid coloring. 

This video will show more differences between male and female rainbow sharks: 

2. How long does it take for rainbow sharks to grow?

Rainbow sharks are just specks when they first hatch from their eggs. Then, they will expand quickly.

The fish will reach a size of between 1/2 inch and one inch during the first four weeks. And it takes weeks or sometimes months to reach their mature size. 

3. How many rainbow sharks should be kept together?

The key is to avoid raising only a few rainbow sharks. Maintain a group of at least five, so the dominant one will have many rivals to hunt around. 

4. What does rainbow shark fry eat? 

Rainbow sharks can eat common fish foods, such as flakes, pellets, or algae. Since they are bottom feeders, ensure the food can sink to the tank base.  

5. How often should you feed a rainbow shark?

It would be best to feed your pets twice a week. Feed them with tiny crustaceans several times per week to give them bright colors.  


Breeding rainbow sharks is hard, but it’s still possible. Please do not abandon your fish because they may fight each other. The aggressiveness of this species requires a lot of attention. 

Hopefully, you will find this guide helpful. If you fail to breed rainbow sharks, let us know your problem. We are always ready to assist you.

Thank you for reading!