Do fish interbreed? and Can they crossbreed?

Over the years, breeding has allowed farmers and breeders to discover exciting new things, especially exciting things about fishes.

Dogs bred together have brought us fluffy pets like Corgis and Pomsky. Even in cats, you’ll find some fascinating interbred and crossbred cats like the Tabby or a Siamese cat. One might wonder if our docile fish have famous crossbreeds and interbreeds. Are they even interbred?

This leads us to the question, can fish even breed? I looked around to find an answer. If you are wondering what I found, read ahead.

Can They Breed?

The short answer to this question is yes, a fish can breed. You can find some crossbred and interbred fishes – look up the electric blue, blood parrot cichlid, flowerhorn, etc. Were these fishes interbred or crossbred? Can a fish interbreed? Is a fish capable of crossbreeding? Keep reading for the answers.

However, what is interbreeding, and how does it differ from crossbreeding? Interbreeding refers to breeding within a specific community. On the other hand, crossbreeding, as the word suggests, is breeding within different breeds or species. Sounds familiar? You’re not wrong. Mixed breeds are bred between different breeds or species. There is a slight difference, though, we don’t know about the parents of a mixed bred animal.


So, can fish interbreed? Yes, a fish can interbreed as long as it lives in the same community. It isn’t a matter of concern for a fish to breed within its families. Unlike humans, it won’t grow up with any deformities. The weaker fry (baby fish) either die on their own or get eaten by another fry.


On the safer side of the breeding spectrum, we find crossbreeding in fishes. Do they crossbreed? The simple answer is yes, a fish can crossbreed. There is a little twist, it can only crossbreed experimentally, not naturally. For instance, flowerhorns are a result of 2 to 3 species. There are some species which will hybridize (read: different species of fishes bred with each other).

Crossbreeding in Livebearers (Video)

Which Fish Is Easy to Breed?

If all this talk of fish breeding has got you giddy to become a fish breeder, allow me to be the one that kicks you off on this journey with the best tips and tricks. First, let’s talk about the fish which are easy to breed.

  1. Anableps If you want to start big, I would recommend breeding Anableps. It can grow up to 12 inches, and it is easy to breed. It is a win-win situation. You’d find it interesting to know that an Anableps actually has four eyes. Two of them look at the view above waters, while the other two keep an eye out for any prey or predators below.
  2. Convict Cichlids The hovering parent of fish, Convict Cichlids, is over-protective of their fry. To breed them, give Convict Cichlids food and keep them in water. I would recommend letting them raise their fry in a separate tank. A Convict Cichlids are willing to go as far as killing another fish to protect the younglings.
  3. Guppies A guppy is probably the easiest fish to breed. Put a couple in a separate tank, and watch the magic happen. The female guppy is also known to reuse the sperm to fertilize for as long as eight months. So, if the father tragically dies, the female guppy will live on to create an army of little guppies.
  4. Killifish Breeding a killifish would require great patience from you. It will bury the eggs in the sand, which hatch in about 1 to 4 months. This is how a killifish breeds annually, the non-annual breeders are a bit easier to breed. It only breeds once and attaches the eggs to the mop.
  5. Mollies In the perfect conditions, these guys are the easiest to breed. If you keep an aquarium full of Mollies alone, it is more likely to create fry. Also, if the aquarium is properly maintained, it is possible that these fry will grow into adulthood with ease.
    Caution: Mollies are a bit difficult to breed, due to which, I won’t recommend starting with them. 
  6. Mosquitofish Mosquitofish is an easy species to breed because it can easily breed under normal conditions. The female Mosquitofish can start breeding after two months. An additional benefit of having this species in your tank is that it will eat up hundreds of mosquito larvae, and keep the tank clean.
  7. Platys The Platys are a fish species with vibrant colors. It won’t require any coaxing to breed with each other. Since male Platys are a bit aggressive, compared to others, I would advise keeping one male and two to three females. The males will be less aggressive, and the females a bit less stressed.
  8. Rosy barb It is relatively passive, which makes it easier to breed. Rosy barb takes about one to two days for the eggs to hatch. As parents, it could probably benefit from learning a couple of things. Rosy barbs have a habit of eating their own fry.
  9. Swordtails Did you know that Swordtails are actually relatives of Platys? Don’t worry, it isn’t aggressive. This little guy has eye-catching colors. It is a great choice to breed fishes. A female fish can breed every 28 days.
  10. Zebra danio A Zebra Danio is quite peaceful and easy to take care of, similar to the Rosy barb. Coincidentally, their eggs also take about one to two days to hatch. Once it is hatched, you have to be careful about the filters because the baby Zebra danios are transparent. You could easily lose sight of them.
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How do they breed?

Now that you know which fish to breed, let’s talk about how exactly a fish breeds. To put it simply, the process is quite similar to our birds and bees, if you know what I mean.

A male fish fertilizes the female fish’s egg, which later hatches. The majority of the fish species you will try to breed have two genders, male and female. Alternatively, you have a type of fish that are both male and female, which are called hermaphrodites – they have the organs of males and females. Some fishes have an organ called genital papilla. It is all a bit complicated, but as you read further, it will get clearer.

Let’s jump right in, shall we?

Egg Layer

As the heading suggests, these fishes will lay their eggs. The scientific name for egg layer fish is oviparity. Before this egg can hatch, a male fish has to fertilize it to create a fry. Now, some egg layer fish either bury its eggs in the sand till it hatches, or it leaves them on the surface, waiting for the eggs to hatch.

Some things that you should keep in mind with regards to an egg-laying fish is spawning season. At a particular time in the year, a season known as fecundity is when a fish is ready to spawn. However, you should know, not every fish waits for a season.

Before we move ahead, let’s talk a bit more about how the male actually uses their sperm on the egg.

  1. Buriers – After the eggs are buried, the male swims in to fertilize them
  2. Depositors – a female fish will the lay eggs in an area, where a male fish would spray on them
  3. Mouthbrooders – carrying the eggs in the mouth
  4. Nest Builders – females leave the eggs in a nest, where the male later fertilizes them
  5. Scatterers – these are sticky eggs laid somewhere under cover, after which, males will swim by or spray their sperm


There are two types of livebearing fishes, which are known as ovoviviparity and viviparity. There is a difference between the two, which we will explain a bit later.

First, let me tell you how a livebearing fish is different from the egg-laying fish. Simply put, a female fish wouldn’t have to lay an egg, because the male will fertilize them directly. In this case, a male fish uses the gonopodium organ, the anal fin, to fertilize the female fish.

Now, once the deed is done, there are two ways an egg gets its nutrition. The fish that receives its food from the egg’s yolk are called ovoviviparous. Alternatively, the eggs lucky enough to receive nutrition from their mother are viviparous. And, so, you have the two types of livebearing fishes, ovoviviparity and viviparity.

Solo Birth and Single Parenting

So these types of fishes are mostly females, they don’t need a male to give birth or parent. The ruling queens of the oceans are a solo fish. The gender of the fish that it breeds are mostly females too. This doesn’t mean a female fish of this kind won’t mate with a male, because they will. But, they just don’t need the sperm for reproduction.

A somewhat similar kind of fish are hermaphrodites, remember them? Yeah, you already know one hermaphrodite, take a wild guess – straight from your screen, it’s the famous clownfish, Nemo. A hermaphrodite fish has both male and female reproductive organs.

Here is an interesting fact; as they grow older, a hermaphrodite may change their gender. 

A male fish that later switches to a female is known as protandrous hermaphrodites. On the flip side, a female fish that become a male is called a protogynous hermaphrodite. Unlike the solo unisex, female fish, a hermaphrodite would still need the opposite gender to reproduce. Normally, there is one male and one female fish with a bunch of smaller male fishes. When the female fish leaves, the male fish turns into a female, and one of the smaller male fishes gets promoted.

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Breeding in a Fish Tank

You’re all caught up on how a fish breeds and which species are easy to breed, I can talk about where you can start breeding a fish. For your convenience, considering you are a starter, I’m going to talk about breeding in a fish tank. Yes, it’s possible, but it’s the how you gotta worry about.

The Right fish

For the perfect result, we will need the perfect ingredients. To get the breed you want, it is important to pick the right fish. So, when you are selecting a fish to breed, I want you to begin with a fish’s sexuality. There are two types – dimorphic and isomorphic.

The gender of a dimorphic fish is easy to identify, and you can identify the gender by their reproductive organs, which are shaped differently. Their size, shape, and color are all unique, so you can easily tell them apart. There is one simple difference between the male and female; the males are larger and more vibrant.

The isomorphic fish’s gender is a bit difficult to identify because they look alike. But, never say never. There is a way to tell the difference. You can tell the difference between the male and female fishes by keeping a close eye on their organs during spawning. The shape of the organ would help you easily identify which is which.

Before you go on a spending spree to pick a fish for breeding, you can remember this to identify you got each of the sexes.


Once you have the fish picked out, it is time to see if your fish tank is ready for breeding, regardless of crossbreeding or interbreeding. You can use the checklist below to make sure the conditions are met;

  • Surface
  • Surrounding
  • Lighting
  • Diet
  • Water pH levels
  • Temperature at 10 F

Additionally, I would recommend keeping the fish tank with sand and some soft rocks. I suggest keeping a soft base because it would encourage fish to mate. Harder surfaces could hurt the fish and the eggs.

You should also consider the environment required to raise a fry. Most people use a sponge to create the right type of current for raising a fry.

Moreover, I would recommend keeping the breeding tank in a shaded area. Bright lights could discourage or disrupt the mating.

I would advise feeding your fishes protein-rich food because it will make them healthier in the days to come. A healthier spawn of fishes can increase the chances of successful breeding. Continue feeding them for 3 to 5 days because it will give them enough time to gain their strength.

Lastly, you have to maintain water quality. This means maintaining pH levels, temperature, etc. Keep the water tank at a temperature that is good for crossbreeding or interbreeding.

While you are going through the checklist, research about your fish. Every species requires different conditions to crossbreed and interbreed.

Bonus tip: Keep the males and females separate because it increases the male’s urge to breed. This can lead to quicker breeding.


Can fish crossbreed?

Yes, a fish can be crossbred, but with one condition. The fish being crossbred need to be closely related. The fishes born out of this are called hybrids.

Can a female fish have babies without a male?

Yes! Some female fish can give birth to a young, and healthy fry. Alternatively, the other bunch of fish relies on one mating session to produce several babies even after the male is gone. Basically, it keeps the sperm and reuses it over a span of 8 months to give birth to several fry.

What two fish make a Flowerhorn?

The year was 1994, and one red devil cichlids fell in love with a trimac cichlids. One thing leads to another, and the two were bred to give birth to flowerhorn. Fun fact, the trimac came all the way from Central America, while the blood parrot cichlid, red devil, was flown in from Taiwan.

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Nadine Oraby

My name is Nadine; I am a passionate writer and a pet lover. People usually call me by the nickname “Joy” because they think that I am a positive and joyful person who is a child at heart. My love for animals triggered me to create this blog. Articles are written by vets, pet experts, and me. Thanks for visiting. Your friend, Nadine!

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