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Although not the easiest aquarium fish to breed, Chilli Rasboras will breed in the home aquarium as long as the conditions are right. So, as long as you have both males and females in a suitable environment, you stand a good chance of increasing their number.
Chilli Rasboras are egg scatterers, which means the eggs are fertilized externally. The female scatters her eggs and the male releases his milt (semen) onto them. The eggs fall to the bottom of the tank, with some of them landing on plants and other items in the aquarium. The eggs then develop and hatch into Chilli Rasbora fry.
In an aquarium environment Chilli Rasboras will breed regularly. Whether you actively want to breed them, or you’re just happy to wait and see what happens, knowing what to look out for is a great help.
How Can I Tell If My Chilli Rasbora Is Male Or Female?
The main thing, when it comes to breeding Chilli Rasboras, is make sure that you have both sexes in your aquarium. I know this sounds obvious but with some freshwater fish it’s not always that easy to tell. And Chilli Rasboras are no exception to this.
Telling the difference between the males and the females can be a little tricky. But the main distinction is that the male Chilli Rasbora is generally slightly smaller, deeper in colour and more active than the female.
Although the differences between male and female Chilli Rasboras are not always easy to spot it does help to have a basic guide.
If you’re planning to actively breed your Chilli Rasboras it’s a good idea to ask for a mix of the sexes when you buy them. I appreciate that there’s no guarantee that the Pet Store or Aquatic dealer will be totally accurate in telling the difference. But at least you stand a better chance of having both males and females.
Also, by having a fair number of Chilli Rasboras in your tank you’ll have a higher chance that they will breed. Because they’re a schooling fish they need to live in groups of at least 6-8 anyway. So whether you’re planning to breed them or not it’s best to have a school of them if you want them to thrive.
How Will I Know That My Female Chilli Rasbora Is Ready To Breed?
When a female Chilli Rasbora is ready to breed she becomes plump with eggs. Even though this fish is tiny the difference in the size of the female’s abdomen is easy to see. Her tummy becomes fuller and more rounded because of the eggs she is carrying.
Because the Chilli Rasbora is an egg scatterer the eggs are unfertilized at this point. So you can’t describe a female Chilli Rasbora as being pregnant. You can only say that she is in breeding mode and ready to mate.
What Does Chilli Rasbora Breeding Behaviour Look Like?
Once your female Chilli Rasbora is carrying eggs and ready to breed you’ll notice the males competing for her attention. The males will also develop a deeper colouring which makes it easier to distinguish between the two. And when a female is ready to mate the males become extremely lively. They start to show off to each other in competition for the females attention. The male Chilli Rasbora can also become territorial about the tank and the females that are ready to mate.
The good news is that injury due to ‘posturing’ is unlikely.
The Chilli Rasboras mating display means that you’re likely to notice a lot more activity than normal in your aquarium. Which, from a fish keepers point of view, is fascinating to watch. Particularly if you’re hoping your Chilli Rasboras will breed.
Chilli Rasbora Spawning Behaviour
Spawning is the time when the female releases her eggs and the male fertilizes them as they fall through the water. This usually takes place in the more secluded areas of the tank such as the densely planted areas. Because Chilli Rasboras tend to spawn at first light it can be difficult to catch them spawning. If you do get a chance to see them spawn you will notice almost frenzied activity amongst the plants as the males chase and engage with the females.
What do Chilli Rasbora Eggs Look Like?
Chilli Rasbora eggs look like minute pearls. In fact they’re so tiny that you might need a magnifying glass to spot them. And because the Chilli Rasbora only scatterers a few eggs at a time, usually between approximately 2-4, rather than a large cluster, it makes them easy to miss. However, they do spawn daily so you can still end up with a fair number of eggs over a couple of days or so, depending on how many adult males/females you are keeping.
How Long Does It Take For Chilli Rasbora Eggs To Hatch?
The average hatch time of Chilli Rasbora eggs is 48 hours but it can take a little longer. Once the eggs hatch into tiny fry they will feed on their egg sac for the first 24 hours before looking for food.
Feeding Chilli Rasbora fry can be difficult because the food needs to be small enough for these extremely tiny fish to manage. First foods for the fry include: powdered fry food, liquid fry food, infusoria and other micro foods such as powdered down freeze-dried brine shrimp.
If you’d like to learn more about what to feed to your Chilli Rasboras, both the adults and the fry, read my article ‘What Do Chilli Rasbora Eat?’
Do Chilli Rasboras Eat Their Eggs/Fry?
Chilli Rasboras are not parental when it comes to their eggs and/or fry. So they will eat them as a source of food if they get the opportunity. One way to avoid this happening is to make sure that your adult Chilli Rasboras are well feed during the breeding process. Another way, and probably the best one if you want to actively breed them, is to set up a separate cycled breeding tank. By removing the adults after they have spawned you stand a better chance of saving as many Chilli Rasbora fry as possible.
When the fry are too big to be eaten you can then put them into the main tank with the adults.
If your Chilli Rasboras live in a community aquarium other fish, and even some types of shrimp and snails, are also likely to eat the eggs and/or fry too. So any serious attempt at breeding them is best done in a species only environment with the added precaution of using a separate breeding tank.
Although, if you have a densely planted community aquarium, with plenty of places for the fry to hide in, you may still find that you end up with some young Chilli Rasboras that grow too big for their tankmates to eat.
How To Encourage Your Chilli Rasboras To Breed
Now that you know how the Chilli Rasbora breeds is there anything that you can do to encourage them to reproduce?
Here’s a few things that you can do to encourage your Chilli Rasboras to breed successfully
- Planted Tank – Chilli Rasboras breed more freely in a heavily planted tank
- Water Temperature – Chilli Rasboras breed better in warmer water so upping the temperature to approximately 27 Degrees Celsius (80.6 Fahrenheit) helps
- Water Conditions – Clean softer water with a low PH is preferred
- Filter Flow – Keep the filter flow minimal and make sure the filter intake can’t suck in the fish or fry
- Feeding Up – You can condition your Chilli Rasboras for breeding by feeding them plenty of high protein ‘meaty’ foods. You can do this in the main aquarium or after putting the adults into the breeding tank
The YouTube video link below is by Marks Aquatics. It’s an interesting and informative video about breeding Chilli Rasboras. It’s worth watching if you would like your Chilli Rasboras to breed or even if you’re just interested in the process.
As I mentioned at the beginning Chilli Rasboras are not considered the easiest freshwater aquarium fish to breed. But if you create the right conditions, and take the appropriate precautions to save the eggs and fry, you’re likely to be successful. And a little extra effort is definitely worthwhile when it comes to keeping and breeding these colourful lively Nano fish.
If you’d like to learn more about setting up a tank for Chilli Rasboras read my article ‘Best Tank Setup For Chilli Rasboras’.