The popular tiny fish known as the Chili Rasbora or mosquito rasbora is scientifically called Boraras brigittae and is an incredibly popular choice for a nano tank. Their bright colors and tiny size make them irresistible and they are relatively easy to care for them.
Chili Rasbora has a peaceful demeanor and only grows to less than an inch long. These active fish don’t need much more than a five to 10-gallon aquarium loaded with live plants. They appreciate soft water, so unless your tap water is soft then you might need to use distilled water to keep your fish in good health.
If you keep fish or are thinking about it keep reading to learn all about this wonderful freshwater aquarium fish. I present to you the amazing Chili Rasbora!
Chili Rasbora Natural Habitat
Where is the Chili Rasbora From?
This nano fish is endemic to southwestern Borneo though little is known about exactly where it has and hasn’t been found.
The shy fish is found in blackwater streams, where the waters look like brewed tea from the tannin-rich waters.
This stained water lets little light in, and this is compounded by the fact that the water is densely filled with live plants that allow for ample hiding places.
Because of the tannins, the streams where Boraras brigittae are found usually have little to no hardness.
These waters are sometimes as acidic as 4.0 on the pH scale. That’s as acidic as tomato juice!
Threats to Their Habitat
Unfortunately, Chili Rasbora habitats are under threat from oil-palm plantations as well as other agricultural developments.
To create these plantations, native vegetation is completely clear-cut and hauled away.
This leads to excessive erosion and sediment is carried into streams where it can drastically alter the hydrology.
Once the plantation is up and running, large amounts of fertilizer and other pollutants enter the streams which can cause eutrophication and massive fish kills.
Chili Rasbora Appearance
The Mosquito Rasbora has a small size and vibrant color.
They have a black stripe that extends their ventral side surrounded by a bright red color that stands out against green plants and tannin-stained water.
These beautiful fish have fairly clear tail fins and a single black stripe on the anal fins and dorsal fins. Their bright color is aided by live foods such as baby brine shrimp and breeding.
As male specimens get ready to breed they become even brighter red as they try to court their female.
That being said, female Chili Rasboras are still wonderful and bright nano fish and it is unlikely you’ll even be able to tell a difference.
Both males and females will appear brighter with a dark substrate and live plants.
Chili Rasbora Lifespan
These tiny fish can live up to five years. A lifespan of between three and four years is average for the Chili Rasbora.
If you want to maximize your fish’s lives then it is important to feed them a healthy diet and to make sure their water quality stays pristine.
A larger tank and lighter stocking help to keep nitrogen levels lower and prevent dirty water.
Chili Rasbora Feeding Guide
How Often Do You Feed a Chili Rasbora?
You want to make sure you do not overfeed these tiny fish as that can harm them. But you do want to feed them small amounts on a daily basis
Strive to give them two or three small feedings a day.
What Do Chili Rasboras Eat?
There are many possible foods to feed your nano fish, and here I’ll go over a few of the possibilities. Live foods are always the best, but a varied diet is very important.
Frozen fish foods are also very good and healthy, with prepared foods working well too.
An important thing to remember is to keep the diet varied. Two different foods are better than one because one can help fill nutritional voids the other may have.
Prepared foods are the easiest t access and store since they can be kept at room temperature and in their own watertight containers.
One important thing to remember is prepared foods must be small enough to fit into the tiny fish mouths.
Tiny Mouths Need Tiny Food
Large pellets should be avoided and flake foods should be crushed between your fingers. Many commercially available fish foods will work well for the Chili Rasbora’s tiny mouths.
You may find the Mosquito Rasbora to be a picky eater, if that is the case then live or frozen foods may be better suited for you.
Frozen foods are magnificent, they offer most of the benefits of live foods but without the difficulty of sourcing or keeping them alive.
Although there are many different frozen foods available on the market, not all are suitable for this small fish.
As previously mentioned the Boraras brigittae has an exceptionally small mouth and so only a few frozen foods are able to be eaten.
These are mainly baby brine shrimp and daphnia. Sometimes they may be able to eat pieces of others, but they might not always go for larger food.
If you have the means and willpower, live food is a wonderful choice I will touch on in the next section.
Live foods can either be bought in stores or cultured yourself. There are many live food options, some of which can be found in the wild.
The main live wild food you will encounter is daphnia, there are many guides on finding and culturing your own daphnia population.
If you wish to buoy your start-up culture for life food there are many options:
- Baby brine shrimp
- Vinegar eels
- Tubifex worms
- Black worms
- Grindal Worms
- Banana worms
All of the above live foods are easy to culture yourself and will produce vibrant colors in your tiny fish. As an additional bonus, live foods also help condition your fish for breeding.
Chili Rasbora Tank Water Parameters
Hardness and pH Level
These fish are traditionally found in peat swamps with fairly soft water.
It is advisable to keep these fish in soft to moderate hardness and not to let the hardness increase above 200 ppm. Captive-bred fish will be more tolerant to harder water.
Traditionally, home aquarium keepers have used peat moss in their filters to reduce water hardness.
This practice has fallen out of favor though due to the adverse environmental impacts of peat mining.
If you need to decree your hardness, consider an RO system or buying RO water from your local fish store, or LFS.
Many stores that have saltwater sections will have RO water. You can mix this with tap water to create an optimal amount of hardness.
Mildly to moderately acidic pH is good for Chili Rasboras, but luckily they are not picky.
Filtration and Flow
Because these peaceful fish come from slow-moving waters in swaps, powerful filtration is not a good idea, but you still certainly need a filter.
Chili Rasboras do not tolerate dirty water and need near pristine quality in their tank.
A slow flow ate sponge filter is perfect as these do not create a lot of flow, and additionally, they pose no danger of possibly sucking your fish into them.
Another good alternative is a low-flow hang-on-the-back filter with a sponge prefilter to prevent accidental fish deaths or injuries.
Chili Rasbora Tank Size
Although small, these fish are mighty! You can get away with a standard 5-gallon aquarium, but it is not the best solution.
Ideally, you should have more water volume and a longer tank. There are some dimensions of tanks, such as “bookshelf” tanks that are long and narrow.
These work well for Chili Rasboras because these tiny fish like to dart around and move quickly, so these longer tanks allow them to swim free and fast.
Do Chili Rasbora Like Live Plants?
Live plants are a wonderful addition to any freshwater aquarium, and doubly so for Chili Rasboras. Live plants not only make your tank look better, but they also help to naturally filter your water.
Additionally, plants also act as hiding places for your Boraras and will help them be less stressed and more colorful.
Below are some good options for live plants in your home aquarium:
- Java fern
- Java Moss
- Rotala species
- Ludwigia species
- Amazon sword
Floating plants such as frogbit can be especially useful if you wish to provide overhead cover.
Chili Rasbora Breeding
Chili Rasboras are an egg-scattering species which means they exhibit no parental care. They even may eat their own eggs!
For this reason, if you are serious about breeding your Boraras brigitae then it is worth setting up a separate breeding tank which I will detail below.
Breeding Tank Size
A 5-gallon tank is an ideal breeding size for mosquito rasboras as you can have a few of them and it gives them plenty of space to exist.
A breeding tank should have some leaf litter, such as almond leaves, in order to reduce pH and give the water tannins.
This will make the fish feel more secure and it will also help prevent egg fungus.
Your breeding tank should also have a spawning mop, basically a bunch of synthetic yarn which the eggs can stick to.
Once the fish have bred, you can remove them or the mop from the tank to separate the eggs and parents.
How to Care for Baby Chili Rasbora Fish
As small as adult Boraras brigitae mouths are, the babies are even smaller. The first food for these new babies will be their yolk sac but that does not last very long.
After that is used up you can either feed them paramecium, infusoria, or powdered fry food. Powdered fry food is the easiest by far, but the babies can sometimes be picky eaters.
Paramecium and infusoria are somewhat easy to culture, but they can be stinky and are also slow to get going to full breeding potential, but once they are there they are easily maintained.
Related Chili Rasbora Questions
Are Chili Rasbora good for beginners?
This tropical freshwater pet fish is actually fairly easy to take care of so it makes a good fish for beginners in my opinion.
Keep in mind, you still need to learn about how to properly care for them and give them the attention they need if they are going to survive long.
How many Chili Rasboras can you fit in a 5-gallon aquarium?
The standard rule is one inch per gallon, and in this case, it is actually a pretty accurate guide. You can fit about four to six Chili Rasboras in a 5-gallon tank.
But really, if you want to truly see these tiny fish shine you should put them in a longer tank for optimal vibrant colors.
Are Chili Rasbora Schooling Fish?
Yes, they are schooling fish and enjoy large groups which make these shy fish more comfortable and healthier overall. They will thrive with eight to ten other Chili Rasbora in the tank.
Do Chili Rasbora Eat Algae?
It is thought that the Chili Rasbora does not eat algae in the wild so they probably won’t be eating algae in your aquarium either.
Make sure to ask the pet store or breeder that you buy your fish from what is the best food they recommend for your tiny fish!
Where can I buy Chili Rasboras?
Because of their increasing popularity, Chili Rasboras can be found in many local fish stores. Even some big box pet stores carry them.
If none of these options are available to you, then you can order them from many breeders and suppliers online.
How much does a Chili Rasbora cost?
Of course, it depends on where you purchase them but expect to pay between $25 and $50 per fish.
Can I have a Chili Rasbora shipped to me?
Yes, there are many online fish retailers and breeders that will ship them to you using FedEx or UPS.
Are Chili Rasbora the smallest fish?
No, actually they are not. Although they are some of the smallest fish, and the genus has some of the smallest fish kept in the hobby, they are not the smallest fish on the planet.
The smallest freshwater fish known is in the Paedocypris genus.
Chili Rasboras Make Wonderful Aquarium Fish
Chili Rasboras, aka mosquito rasboras, aka Boraras brigitae, aka some of the cutest and most vibrantly colored fish is a relatively peaceful fish with a shy temperament.
They bring a pop of color to home aquariums and are a worthwhile addition. As long as you give them moderately soft water and moderately acidic water they will be perfectly happy.
If you want to breed them they aren’t too difficult if you give them the attention they deserve.