The Dwarf Rasbora, also known as boraras maculatus, is a wonderfully colorful, small schooling fish that does very well in smaller aquariums.
In the past two years, fish keeping has become very popular with those who are shut-in because of the global pandemic, and this is one of the best entry-level species.
Small tank fish keeping, in particular, is developing into its special category, and species such as the Dwarf Rasbora offers everything a small display aquarium needs.
They are friendly and attractive. Schools of them make a shimmering, glassy display that can be the centerpiece of a community or sole-species tank.
They are a delicate species, however, enough so that they can be difficult to transport and to obtain. As a result, they can be more costly than other small tropical fish species. This combines to make them a moderately challenging species to keep.
Read on to learn everything you need to know on how to care for, maintain, and breed your Dwarf Rasboras.
|Listed tank sizes are the minimum|
|Size:||Up to 1 inch (25.4mm) TL, Typically ¾ inch (19mm) TL|
|Tank:||At least 10 gallons|
|Strata:||All over but tend to stay in the middle of the tank.|
|PH:||pH recommendation 5.0 – 6.0|
|Hardness:||dH range: 5 – 12|
|Temperature:||Best kept between 75 F – 0 F (23 – 27 C)|
Dwarf Rasbora: Origin and Appearance
At less than three-quarters of an inch in length, the Dwarf Rasbora Boraras is considered a pygmy rasbora. It is also one of the most attractive, with a colorful glassy sheen.
The Dwarf Rasbora or micro rasbora is found widely from southern Malaysia into Thailand, Sumatra, Singapore, and Indonesia. It is very prolific, being found in streams, bogs, ponds, and ditches associated with forests and bogs.
Like many small schooling fishes worldwide, the Dwarf Rasbora’s natural habitat is slow-moving, tannin-stained, or dark waters with mud bottoms and plenty of leaf debris and plants.
This is a species that thrives in the company of its kind. You can easily keep schools of 10 or more in relatively small aquariums. Dwarf Rasbora are micropredators and feed on very small insects, worms, and zooplankton.
In appearance, these pygmy rasboras have a glossy red to orange patch behind their eyes and an overall red to pink body tone. This patch can be one of many shades.
Most fish have a prominent black spot at the midpoint of their body with smaller patches towards their anal fin and tail.
Male fish are usually more brightly colored, while the females are usually a little pinker. Male fish also tend to be slimmer in body shape.
Dwarf Rasbora: Proper Care and Upkeep
This is a species that does not respond well to fish medicine, so prevention in the way of a well-maintained aquarium is the best way to keep them healthy.
– Finding the Right Tank Size for Your Dwarf Rasbora
The Dwarf Rasbora species do well in a small tank. You can keep a school of 10 in a five-gallon aquarium. It is easier to house them in larger tanks, up to 20 gallons with tankmates and aquascaping.
– Water Quality and Conditions
Maintaining stable water conditions is very important to tropical fish and this species in particular. A good filtration system with an external canister is ideal. It will not clog with any debris from the substrate. A gentle water return is sufficient.
Letting water pH or hardness fall outside of the preferred range will cause the fish to weaken and die. Check water quality every few days and when something seems amiss in the aquarium.
Depending on your local climate, you will need an aquarium heater to help keep the water in the ideal temperature range of 76 to 84 F (24 – 29 C).
Maintaining their water in the proper pH, dH and temperature range is as important as keeping the water very clean. Weekly cleanings are a must with this species.
Dwarf Rasbora are susceptible to most of the common tropical freshwater fish ailments including Ich, skin parasites and swim bladder disease.
At the first sign of any disease you should remove the sick fish from your tank. Disease can spread very quickly among rasboras. You can try to treat them in a separate tank using common medications but this species does not always respond well. A little prevention goes a long way to keeping them healthy.
Adding Dwarf Rasbora to your aquarium can be tricky because they are easily shocked by changes in water quality. If you can, match the water quality of their transport water to that of your aquarium.
One way to do this is to mix some destination tank water with the transport water and let the fish acclimatize to it before adding them to the aquarium.
Standard aquarium sand or fine gravel is a good choice of substrate. A dark substrate mimics their native environment, and they will be at their most vivid color.
Dwarf Rasboras thrive in peat-stained water, so adding peat bags or other peat supplements will help them do well. Some aquarium keepers will add aquarium-safe peat directly to the tank. Once it is waterlogged, the peat will sink to the bottom and biodegrade.
Dried leaves from trees such as beech or oak can also be added as part of the substrate. As they biodegrade, it creates microbes that provide a food source for Dwarf Rasbora fry.
Keeping them in stained water also helps bring out their best colors. If you skip this aspect of their care, you will end up with fish that are muted and monotone in color. Bright rasboras are happy rasboras.
– Tank Decoration and Setup
When setting up the aquarium, place plants at the back and sides to give your Dwarf Rasboras plenty of swimming room. Good choices are species such as guppy grass, both rooted and floating. Using floating plants will help curb the leaping tendency.
The species also like thickly matted plants like Java moss. Thick plants are important because they provide both food and shelter for Dwarf Rasbora fry.
Adding bottom structures like beach or oak driftwood sections will help recreate the look of their native habitat and support the tannic nature of the aquarium water.
Rocks and other structures can be added to support tank mates who need some shelter to be happy.
– The Dwarf Rasbora Diet
In their natural habitat, Dwarf Rasbora feed on small invertebrates, insect larvae, small worms, algae, and zooplankton. In captivity, they need to be fed a varied diet that consists of both plant-based and meaty foodstuffs.
And because of their micro size, they need to be fed with foods that are matched to them. Tiny food offerings include:
- Baby brine shrimp
- Tiny flakes or tablets
Foods with natural pigment enhancers benefit this fish a lot. Some good ingredients to look for in commercial foods are those that contain spirulina algae and carotenoids.
Dwarf Rasbora thrive best on a two or three times a day feeding schedule. Only put in enough food that the fish will consume it within three to five minutes.
This will prevent the accumulation of waste in the tank, which can quickly lead to unclean water and the illness or death of your fish.
– Tank Mates
Dwarf Rasboras are ideal tank mates for any species that does well in warm water or dark, tannic waters. A mix of schooling and bottom-dwelling species will make a great companion tank.
A good rule to follow for tank mates is to use peaceful species that are not so large that a Dwarf Rasbora can fit in their mouth.
A few good tank mate choices include:
Rosy Tetra: The Rosy Tetra, as well as many other species of Tetra, thrive in the same water conditions. They are peaceful but may engage in fin nipping when stressed or in overcrowded tanks.
Guppy: There are many varieties of guppy that make great tank mates. What they all have in common is that they are peaceful fish that are not too small and get along well with everything that will not eat them. Some of the more ornamental varieties will look great in your aquarium.
Plecos: Plecos are beautiful little bottom-dwellers that are popular for their ability to help keep an aquarium clean. They are omnivores and will make short work of sinking food. They are peaceful but solitary. Don’t put more than one in standard size aquariums.
Corydoras: Like Plecos, Corydoras are a variety of bottom-feeding catfish commonly placed in tropical freshwater aquariums. They grow up to 4 inches in size and are peaceful omnivores.
Cardinal Tetra: Cardinal Tetras make great neighbors with many kinds of similarly gentle species. A small school of Cardinal Tetra adds beauty to any aquarium. Always a great choice. Add them in groups of 10.
Neon Tetra: Another great tank mate choice. Adding them in groups of 10, same as Cardinal Tetra, per 20 gallon tanks will give you an ever-moving, shimmering display.
Green Neon Tetra: If you want to keep a brightly colored aquarium, the Green Neon Tetra is a good tank mate to consider. Similar in size and appearance to the Neon Tetra, the Green Neon Tetra, as its name implies, has a beautiful streak of neon green along its sides.
Shrimp: Several varieties of small freshwater shrimp make good tank mates for Dwarf Rasboras.
Snails: Snails are slow and peaceful and will help keep the aquarium clean.
Tank mates to avoid include:
Fish larger than two inches in length: These fish are large enough to feed or pick on the small, shy Dwarf Rasbora.
Semi-aggressive or aggressive species: Cichlids, danios, and similar species are very territorial and will prey on small fish such as Dwarf Rasboras.
Because dwarf rasbora can catch disease quite easily, it is a good practice to quarantine your tank mates for 10 days before adding them to your rasbora tank so you can catch and prevent the introduction of ill fish.
Dwarf rasbora are not the easiest fish to reproduce but it can be done. Like many members of its species, the Dwarf Rasbora is a continuous spawner that scatters its eggs. They do not parent their eggs.
If you are interested in breeding your fish, there is not much you will have to do to make it happen beyond having a mix of male and female fish in a well-maintained tank. Your odds of success become much higher if you set up a separate breeding aquarium where you can also raise the fry.
The problem with rasbora is that they forget they have laid eggs and will go back and eat them.
Breeding tanks for dwarf rasboras can be small, simple operations. A five-gallon aquarium with standard water filtration is sufficient. Add the necessary heating equipment to keep the water near the top of their comfort zone of 75 F to 80 F. The water itself should be of pH 5.0-6.5.
As with their home tank, add a dark substrate and tannins to stain the water to keep the tank dim.
To keep the fish from eating their eggs, it is a good idea to either have Java moss on the bottom or some kind of matting that the eggs can sink into without the adults reaching them. The product widely sold as grass matt or astroturf works well for this. Cover up to half the bottom of the tank.
Once the breeding tank is set up, you can introduce two or three pairs of dwarf rasbora. Observe the fish to see if they show any distress or shock.
Signs that your fish are reproducing will include flashing, territorial displays by male fish. You may also notice slight scatterings of eggs on the bottom or even the appearance of tiny fry in the tank.
If they acclimatize to their new surroundings, they should begin to reproduce in a day or two. Let them egg scatter for two to three days, then return them to their home tanks.
If they have laid fertilized eggs, the eggs should hatch in 24 hours from the initial spawning. The fry are very small and will live off their yolk sacs for about 24 hours.
Be prepared to feed them microscopic foods such as paramecium or green water.
After a week to 10 days, they should be large enough to accept larger foods such as brine shrimp nauplii and microworms. Additional fry should appear over the next few days.
Once all the fry have hatched, it is best to wait at least a week before performing gentle water changes, so you do not shock or damage the young fish.
The fry grow quickly and, in about a month, will approach their full size.
If you can successfully breed and keep healthy Dwarf Rasbora, you will likely find many fish keepers willing to buy or trade fish with you. Their sensitivity to water changes and being shipped makes them good choices for localized selling and transport.
- Dwarf Rasbora is a schooling species and is best kept in groups of 10 or more.
- You can keep a school of them in a tank as small as five gallons.
- This species is very sensitive to water temperature and quality. It is a good choice for intermediate and advanced fish keepers.
- Ill fish do not respond very well to medicines, so the best way to keep them healthy is to keep the aquarium healthy.
- Their native habitat is warm, tannin-stained waters, so the addition of dark water conditioners or peat bags will help them feel at home.
- A dark substrate and water will help your Dwarf Rasbora shine their best.
- They make great tank mates for any small, peaceful species such as tetras and guppies.
- Quarantine new tank mates for at least two weeks before introduction to ensure they do not carry neon tetra disease into your aquarium.
- Ill or dead fish should be removed from the aquarium quickly.
- Breeding will occur naturally in aquariums where the conditions are close to their natural environment.
- You can increase the viability of breeding by setting up separate breeding tanks that mimic their native environment.
- Use java moss or artificial turf to catch the eggs so that adult fish do not eat them.
- Dwarf Rasbora fry hatch about 24 hours after spawning.
- The fry can live for 24 hours on their egg sac. After that, they should be fed micro foods such as green water.
- Juvenile fish grow to adult size in about a month.
- Feed your Dwarf Rasbora a varied diet of small flakes, pellets, baby brine shrimp, microworms, and other live foods.
- Flakes and pellets with pigment enhancers will help you bring out the best colors in your fish.
If you are constrained in the space you have available for fish keeping, the small but beautiful Dwarf Rasbora is a species you should consider. They will test your aquarium maintenance skills and reward you with colorful, shimmering displays.
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