In the world of little fish, the Chili Rasbora (Boraras Brigitte) is positively Lilliputian in size. Yes, your read that right, just like Gulliver’s Travels, except underwater.
Even with vibrant coloring, these tiny fish also go by the name of Mosquito Rasbora, which is yet another indicator of their diminutive proportions. They are one of the tiniest fish in the hobby for tropical freshwater aquarium fish.
Personable, highly active, and social, these fish are considered the ultimate nano-fish in the hobby and deservedly so.
They do, however, have sensitivity to water quality, so they are not best advised for complete newcomers to the hobby despite their size and tank size requirements.
These little omnivores hail from Borneo and Indonesia in areas teeming with mosquitos. Many think they get their nickname from their little size and zippy action in the tank like the flying insect, but it’s actually because their habitat is rife with them.
With sparkling personalities, these highly active schooling fish are super vibrant when properly cared for and make a giant impact in nano-tanks or otherwise. Expect these little guys to pack a real punch in all of the good ways you want a tropical freshwater fish to be.
Chili Rasbora Behavior
Chili Rasboras enjoy being in the upper half of your tank most of the time, but they are opportunists! If the community permits, they will often be seen venturing to the bottom layer of your water column to check out what’s going on and even grab a bite to eat.
These are tiny fish who like to school, there is always safety in numbers, and Chili Rasboras are no exception to this sentiment. Their standout coloring makes them easy to see even at a distance despite their size, and when schooling, these fish really come into their own.
Never predictable or boring to observe, they will often surprise their caretakers with active and engaging behaviors, which are always a treat to watch.
It’s ideal to keep these fish in as large a group as possible to maximize your enjoyment of this species, but also for their security and stress levels. Definitely, a case of the more, the merrier when it comes to Chilis and their gang.
As a minimum, we would recommend a group of at least 6 to get started.
As far as their temperament goes, these fish are peaceful all the way. Given their size, you wouldn’t expect them to be bullies in the tank, and thankfully they are not. They are ideal for mixing it up in community tanks for some flashy, colorful schooling action that won’t cause you any hassle.
Chili Rasbora Lifespan
If you cater to the needs of your Chili Rasboras, you could expect them to live for around 4 – 8 years. The quality of their tank conditions will impact their lifespan, as always, so you can expect a longer life if you meet their requirements meticulously.
Their lifespan can be hugely impacted by water conditions, so ensuring you have the best possible quality will mean they will endure for longer.
We will discuss more on tank requirements a little later in this article.
Chili Rasbora Appearance
These fish are one of the tiniest in the hobby, reaching 0.5 – 0.8 inches in length at full maturity.
They are torpedo-shaped with large expressive eyes, and their body is mostly reddish.
Along their lateral line is a dark black horizontal stripe which contrasts beautifully with a vibrant red stripe directly above and positioned alongside it.
Their fins as small, with a short length and height dorsal fin smack in the middle of their length. They have a classic mid-forked caudal fin, and a small anal fin positioned close to the center of their length also.
Males also possess bright red spots on their fins, and females are in general less vibrant with a duller appearance.
For the most part, the fins are transparent except for a few patches of black and red. These fish are from the ray-finned fish family.
They are extremely attractive and easy to see in tanks despite their tiny size. Like little darts actively occupying your tank, they are rewarding and make themselves well known to their caretaker.
You might think that such a small creature wouldn’t make much of an impact in community tanks, but having a large school and their bright red color allows them to have a high impact even in a tank with other species.
Most hobbyists who have enjoyed Chili Rasboras will tell you they wouldn’t be without them!
Chili Rasbora Habitat And Tank Requirements
We ideally want to achieve optimum health for fish we keep in captivity by closely mimicking their natural habitat. Their wild origins are the blackwater streams and pools or Borneo and surrounding areas.
Fond of heavy vegetation, soft water, and dim lighting conditions, these little fish are winners for those already in a blackwater setup.
Let’s look at some specifics that are needed to provide these fish with a great quality of life that best suits them for optimum health.
Tank Conditions
First things first, these fish need an abundance of vegetation to be happy in any tank.
They love densely planted tanks and enjoy a darker sandy or fine gravel substrate.
Depending on if you’re keeping them in a nano tank or a larger community environment, there are many options for providing them with great vegetation.
Adding in almond leaves can help reduce the pH as well as peat moss which release tannins into the water like their natural blackwater conditions.
Try planted and floating plants to keep these fish happy and secure. Floating plants create a habitat for plankton and worms that will feed these tiny mouths. There’s more on feeding these tiny things a little later in this article.
Java Fern, Anubias Nana, and Java Moss are all great additions.
They love roots and driftwood branches to mimic the wild habitat of their blackwater origins.
Since they spend the majority of the time in the upper layers of the tank
You don’t need a strong filtration with a current because they prefer slow to non-moving water and aren’t used to strong currents. Because of their small size, a sponge filter or hang-on back filter is ideal for preventing any accidents with your little ones.
The temperature needs to be steady, so keep an eye on the temperature and use floating plants to avoid direct light heating the water. They can handle a range of temperatures, but not fluctuations.
Water changes need to be done weekly of at least 10 – 15% to keep optimum water quality.
Straight tap water should be avoided because of added chlorine and mineral being too high. Use a water softener to allow for the levels to be appropriate for these guys.
Water conditions should be noted and maintained as follows:
- pH of 4.0 – 7.0
- Water hardness between 3 – 12 dKH
- Temperature between 68 – 82ºF (20 – 28ºC)
- Lighting conditions should be dimmed as they don’t experience much direct sunlight in the murky river water
Tank Size
The minimum tank size for a small school of 6, which is the minimum you should have, is a 5-gallon nano tank.
For every extra gallon, you add you could house another two fish.
In a community tank, they love dense vegetation but also need plenty of swimming room, so factor that in if including into a much larger tank with other inhabitants.
Choosing Tank Mates For Chili Rasboras
When it comes to finding species appropriate for your Chili Rasboras, you need to consider things carefully, given their tiny size and the possibility of predation by tankmates.
Some excellent tank mate pairings that would work well include:
- Neon Tetras
- Otociniclus
- Dwarf Shrimp
- Celestial Pearl Danios
- Sparkling Gouramis
- Cory Catfish
- Cherry Shrimp
- Chocolate Gouramis
- Ghost Shrimp
- Amano Shrimp
- Other Dwarf Rasboras
- Bamboo Shrimp
Snails can be included to clean the tank, but avoid anything larger than the types of fish listed as they will inevitably find your Chilis rather enticing as a meal.
How To Feed Chili Rasboras
Given the size of these fish, you will need to use food sources that fit their little mouths. In some cases, it’s not unlike dealing with and feeding the fry of other larger fish!
In the wild, they consume foods that are microscopic, like plantain and micro worms. Things like baby brine shrimp, tiny worms, and micro pellets designed for this size of fish are ideal for mixing things up.
Other things such as tubifex, daphnia, and bloodworms that have been chopped into smaller pieces also work well for additional protein.
Typical flake foods are too large, but if you crumble them up, they can also be fed to your Chilis.
Insect larvae can also work very well too!
They should be fed twice a day which is also better for their digestion.
Chili Rasboras Common Diseases And Illness
Like most freshwater fish, Chili Rasboras are susceptible to things like Ich which is very common and all too familiar for those in the hobby.
This external parasite can be easily spotted if you begin to notice cottony white spots or growths on the gills or bodies of your fish.
You may spot your fish rubbing themselves up against plants or decor to rid themselves of the irritation.
By raising the tank temperature gradually (remember, we do not want a rapid flux in temperature!) to 82ºF for around three days and using an Ich water treatment, you should be able to eradicate this parasite.
Often this parasite can enter the tank because of a lack of thorough cleaning on new decor, substrate, or vegetation. It’s important to quarantine those things and ensure they are clear of pathogens before entering your tank.
Another typical disease seen with Chili Rasboras is Cotton Mouth Disease (formally knows as Columnaris).
This causes discoloration or falling off of the fish’s scales, lesions, or other abnormal patches. Treatment is possible with antibacterial medication and by quarantining the fish affected to avoid spread within the community.
How To Breed Chili Rasboras
For any hobbyist looking for an easy breeding project, look no further than the Chili Rasbora!
Unlike many other fish, Chilis don’t usually consume their fertilized eggs and usually leave them alone. So you may find fry in your main tank without even intending to have bred your fish.
As long as the fry have hiding places within the vegetation, many will survive spawning.
Chilis breed constantly. Eggs hatch around 36 – 72 hours after being fertilized and falling to the tank bottom. Another 2 days after that, they will be free-swimming and super tiny!
Typical fry food like infusoria or other commercial fry foods suitable for the 100 -150 micron size range will work for these little guys.
Are Chili Rasboras Something You Might Consider For Your Hobby?
They are worth a second look, even if you always thought you wanted something flashier like Cichlids after having some experience in the hobby.
For many, they are ideal as a secondary tank in the home, an accompaniment tank if you will. The smaller and less labor-intensive tank requirements can make Chili Rasboras an ideal prospect for another room in the house that would enjoy the calming presence of a school of fish to observe.
Peaceful, even-tempered, and brilliant to watch with lots of personalities, they make a brilliant option that won’t overload your tank maintenance regime.
Spice up your life with a group of Chilis that won’t have any sting in their tail!
