harlequin rasbora: Care, Lifespan, Feeding, Algae Eating, Size..

The harlequin rasbora is not only particularly beautiful to look at but also very peace-loving and robust. This is why it is an extremely recommendable fish, even for beginners. We have put together important tips for you on keeping and caring for the popular harlequin rasbora.

Care Level:	Easy
Temperament:	Peaceful
Color Form:	Silver Body with a Black Patch and Orange Fins
Lifespan:	5-8 Years
Size:	Up to 2 inches
Diet:	Omnivorous
Family:	Cyprinidae
Minimum Tank Size:	10 Gallons
Tank Set-Up:	Freshwater with Plants and Open Swimming Space
Compatibility:	Peaceful Community Aquarium

IN THIS ARTICLE show

Appearance: What are the external characteristics of the harlequin rasbora?

The harlequin rasbora is a small carp-like fish (Cypriniformes) from the Danionidae family. The beautiful ornamental fish owes its name to the dark, wedge-shaped markings that extend on the sides of the body, from the middle of the body over the caudal fin stalk to the caudal fin.

The scientific name of the harlequin rasbora is Trigonostigma heteromorpha. In English, the harlequin barb is called Harlequin rasbora or also Red rasbora.

The small, lively fish reach a body length of about four to five centimeters. The harlequin rasbora’s high-backed body has its widest point between the first rays of the dorsal and pelvic fins. The mouth of the carp-like fish is on top. In addition, the harlequin rasbora has relatively large, silvery, shiny scales.

The harlequin rasbora also has a beautiful basic color, ranging from a delicate rose to deep red copper. The head, back, tail fin stalk, and fins, in particular, are intensely colored – towards the belly, the color fades to a silvery-white shade.

Do you want to expand your fish population? In our Fish species, portraits tell you everything about keeping and caring for numerous salt and freshwater fish.

You may be interested: Rummy nose tetra: Care, Lifespan, Feeding, Algae Eating, Size..

How do you differentiate between males and females?

Know-how – then you can tell the sexes of the harlequin rasbora quite well. For one, the male is a bit slimmer than the female. On the other hand, the sexes show significant differences with regard to the wedge spot.

The male fish’s distinctive wedge spot runs as a dark trip through the middle of the caudal fin. Whereas in females, it ends in the base of the tail. In addition, the wedge’s front edge is slightly rounded down in the males; in the females, the front edge is straight.

You may be interested in: Cardinal tetra Care guide - Size, Life Span, Tank Mates, Breeding

In addition, the male is particularly bright orange around the wedge spot; the female is significantly paler.

Posture: What should you watch out for in posture?

Although the harlequin rasbora is one of the oldest ornamental fish species in the aquarium, the beautiful carp-like fish’s enthusiasm in the aquarium hobby persists. In their natural habitat the fish find many herbaceous plants, dark floors, and shady light conditions.

With the appropriate aquarium equipment, you can create a living space that is as appropriate to the species as possible for your protégés: with lots of delicate plants, fine dark sand or gravel as a substrate, and something Decoration made of roots and stones ensure a species-appropriate environment. In addition to dense vegetation, you should also ensure that there is a sufficiently large free-swimming area.

It is imperative that you adhere to the water values preferred by the harlequin rasbora: the harlequin rasbora needs a water temperature between 22 and 28 degrees Celsius and a water hardness of two to 15 degrees German hardness with a pH value of five to seven.

The harlequin rasbora likes to live in groups and have no problem with other conspecifics in the aquarium.

What size should the aquarium be?

If you want to keep a small group of eight to ten harlequin rasbora, the aquarium should have a capacity of 112 liters.

For a community tank with other fish species, choose a correspondingly larger tank – we recommend an aquarium with a capacity of 180 to 240 liters.

You may be interested: Swordtail Fish Care Guide: Lifespan, Feeding, Algae Eating, Size..

Diet: what do harlequin harlequin eat?

The harlequin rasbora is omnivores. Therefore, your fish prefer a combination of animal and plant-based diets. Feed your barbel alongside Flake food or Granules also include small live or frozen food in the form of mosquito larvae, brine shrimp (Artemia), or water fleas.

Large portions are not for the small fish. It is better to feed several times a day and keep a fasting day per week. If Trigonostigma heteromorpha are fed a varied and healthy diet, they can live up to six years.

Markings and Colors

Of the more than five dozen species of rasbora, the most common of all is arguably the harlequin. The body is sometimes referred to as a red rasbora, a reddish-copper hue accentuated by a striking black wedge covering the body’s rear half. Near the dorsal fin, the distinctive triangular patch starts and comes to a point near the base of the caudal fin. This species has a similar appearance to Rasbora espei and R. Hengeli.

Behavior: What are the characteristics of the harlequin rasbora?

The harlequin rasbora is one of the most popular ornamental fish species worldwide. Their beautiful color and their peaceful nature make them extremely pleasant aquarium fish that can also be socialized with other aquarium inhabitants.

You may be interested in: Bubble-eyed fish: Care, Tank Mates, Breeding & More

The calm harlequin rasbora only feels comfortable if they don’t get in the way of their neighbors. Therefore, it is ideal for socializing with non-ferrous fish from the lower water region, such as thread fish, loaches, or armored catfish.

However, you should not keep your harlequin rasbora in the same tank with crabs. Because when the opportunity arises, they snap to enjoy the little danios.

If you want to keep the red-spotted barbel, it is best to buy a group of at least eight animals. They are not schooling fish, but they live together with their fellow species in a social network.

Then the curious ornamental fish swim around lively in the pool – always looking for something new. With a bunch of lively harlequin rasbora in your aquarium, you won’t get bored.

You may be interested: Glowlight Tetra: Care, Lifespan, Feeding, Algae Eating, Size..

Harlequin Rasbora Tank Mates

The harlequin rasbora is a shoaling fish; it should be kept in schools of eight to 10 people. Schools of much bigger numbers make for a wonderful presentation. You can keep harlequins with any fish as long it’s not enormous and savage. It won’t nip at or squabble with some other species. Some possibly great tankmates may incorporate cardinal tetras, bettas, small barbs, neon tetras, dwarf gouramis, danios, other small rasboras, and cory catfish.

Which water values does a harlequin rasbora prefer?

The habitat of the animals should be mimicked as closely as possible. This can also be seen in the following water parameters:

Aquarium: at least 60 liters
Water temperature: 22 ° C – 28 ° C
pH value: 5 – 7
Total hardness: 2 ° – 15 ° dGH

Warm, low-calcium water with a temperature of up to 28 ° C is particularly important for a harlequin rasbora. As long as the tap water is not calcareous, this quality is generally achieved in this way.

A sufficient supply of oxygen is particularly important. Therefore, if you want to keep Trigonostigma heteromorpha, you should always ensure there is enough oxygen in the aquarium, both during the day and at night.

With a pH of up to 7, the water should be slightly acidic. A harlequin rasbora is most likely to tolerate a water hardness between 2 ° and 15 ° dGH. If possible, this zone should not be exceeded. The harlequin rasbora originally lives in soft water, so the natural habitat should be modeled as closely as possible.

Breeding: How do harlequin rasbora reproduce?

For years the breeders desperately wanted to reproduce the harlequin rasbora because the fish need very soft and acidic water to reproduce.

Nowadays, the breeding of these ornamental fish is no longer a problem, and there are other breeding farms such as the blue or the golden harlequin barb.

The male takes on intense basic color and woos the female with jerky dance movements for reproduction. After some time, the females lay their eggs and stick the very small, almost transparent spawn to the underside of the leaves of aquarium plants, such as Cryptocoryne. After that, fertilization takes place by the male.

You may be interested in: Amano Shrimp: Care, Lifespan, Feeding, Algae Eating, Size, ...

If you want offspring, move the eggs together with the leaves to a darkened breeding aquarium—the young fish hatch after 24 hours.

You may be interested: Endler Guppy: Care, Lifespan, Feeding, Algae Eating, Size, …

Origin: where does the harlequin rasbora come from?

This type of bear has been swimming in our aquariums for over 100 years. The popular ornamental fish came to Europe as early as 1906. The harlequin rasbora was discovered in Southeast Asia, where it is at home in Thailand and in Indonesia on the island of Sumatra.

The harlequin rasbora prefers to inhabit shady waters that have very strong vegetation. These are mainly smaller rainforest streams with a lot of wood, leaves, and dark ground. These biotopes have very soft and slightly acidic water values - which is crucial for the reproduction of the harlequin rasbora.

Gender Differences

Male harlequins are slimmer than females and have a rounded extension covering the back of the fish at the bottom edge of the distinctive black wedge. For females, the black wedge is completely straight. Also, the female harlequin rasbora is bigger than the male.

Conclusion: Keeping the harlequin rasbora in the aquarium is easy

Keeping Southeast Asian fish is generally not a major challenge for most aquarists. As long as the aquarium is kept dark, enough places of retreat are created, the plants are sufficient, and the ideal water values are also available, the animals will feel particularly comfortable in their new home.

The animals are also not particularly difficult to keep when it comes to feeding. Whether animal or vegetable, flake food, or small live food, a harlequin rasbora is not picky.

The animals can be socialized with numerous other species of fish, provided they can also live with these water values.

Only the breeding turns out to be a little more complex since a lot of importance is attached to the correct water quality. In addition, breeding should only be done with individual pairs in species aquariums, as even parent animals tend to spawn robbery.