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Maximum size : 3.5 cm

Butterfly Barb - Barbus hulstaerti : Complete Fish Profile & Care Guide

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The Butterfly Barb (Barbus hulstaerti) is a fascinating species of Barb that is rarely seen in the hobby due to decades of political unrest in its native Congo region. However, these fish are perfect for the dedicated hobbyist who is willing to put in the effort to keep and breed them. These Barbs are peaceful, active and attractive, and would be a great addition to a community aquarium if kept with similar sized and tempered species. However, it is important to note that they are shy and retiring fish, and may be outcompeted for food by larger, more boisterous tankmates. The Butterfly Barb is a shoaling species that thrives in groups of eight or more individuals, and they develop a distinct pecking order between males. Therefore, it is essential to maintain these fish in a tank that is spacious enough to allow weaker individuals to take refuge from more dominant fish. Decor that provides hiding places would be ideal. It is not recommended to keep these fish on their own, in a small group, or in a cramped aquarium, as they may become withdrawn and bullied by subdominant fish. This Barb species has a distinctive elongated pale body colouration and a blunt head. The male boasts bold blueish-black splotches of varying sizes and yellow shading in its dorsal, ventral and anal fins, and a translucent caudal fin.

Butterfly Barb Photos

Sexual Dimorphism

Male and female Butterfly Barbs can be differentiated with ease. During breeding, males exhibit a much more vibrant and eye-catching coloration, which is not seen in females. Conversely, females typically display a relatively dull coloration and lack the yellow hue present in the fins of males. Moreover, females possess a bulkier body when compared to males.

Quick Facts

Scientific NameBarbus hulstaerti
Year Described1945
Other NamesNone
OriginsDemocratic Republic of the Congo
Max Size3.5 cm
Aquarium LevelMiddle
DifficultyIntermediate - Advanced
Best kept asGroups 8+
Lifespan2 - 4 years

Water Parameters

Water TypeFreshwater
PH4.5 - 6.5
GH0 - 6
TDS18 - 90
62 - 75
16.7 - 23.9

Natural habitat

The Butterfly Barb, originally from the Democratic Republic of Congo, is a captivating fish species that require a specific environment to thrive. These Barbs make their homes in shallow, slow-moving streams and rainforest swamps that are densely populated with vegetation, fallen leaves, and twigs. The water in these habitats is typically cool, very soft, and acidic, giving it a unique brownish colour due to the release of tannins and other chemicals from decomposing plant material. These habitats are shaded by the rainforest canopy above, creating a dark, peaceful environment for the Butterfly Barb to flourish in.
 Congo River - Democratic Republic of the Congo
Democratic Republic of the Congo Flag

How to breed the Butterfly Barb

The Butterfly Barb is a seasonal spawner, with breeding activity occurring during two periods of the year, from March to June and September to November. Being egg-scattering and continuous spawners, they do not exhibit any parental care. If kept in good condition, and with the presence of both males and females, they will lay small numbers of eggs daily in a well-furnished aquarium. Hence, a small number of fry may appear without any human intervention. However, for those looking to increase their fry yield, a more controlled breeding approach is necessary. To do so, the adults should be conditioned together, and small containers should be set up for breeding. Maintaining a higher temperature during breeding has been shown to yield more males, while lower temperatures result in a more equal and desirable spread of genders. A simple aquarium setup with java moss or spawning mops for egg laying and a handful or two of peat fibre for maintaining the appropriate water conditions are recommended. Filtration is not essential, but a small air-powered filter containing peat and set to turn over slowly can be used. Adding almond, beech, or oak leaves to the tank can also be beneficial. Once the breeding container is prepared, a single pair of well-conditioned adult fish should be slowly introduced to it. Spawning should commence daily in the evening, and the female can seek refuge in the plants or spawning mops when needed. It is uncertain if the Barbs consume their eggs, but they do not seem to hunt for them actively. After the young hatch and consume their yolk sacs, they should be fed with paramecium or other microscopic foods, followed by microworm and artemia nauplii once they become free-swimming. Additional fry may appear from later spawning events over time. It is advisable to wait a week or two before performing small water changes to avoid unnecessarily shocking the young Barbs.

Diet & feeding

The Butterfly Barb is an omnivorous fish species that readily accepts a variety of high-quality dried foods of appropriate size. However, to optimize the health and vibrant colouration of these fish and stimulate breeding behaviour, it is highly recommended to supplement their diet with frequent small servings of live and frozen foods such as artemia and daphnia.

Frequently asked questions

Males will display brighter colouration and have a yellow tint in their fins, especially when they are in breeding condition. In contrast, the females are a duller colour and have stockier bodies.

Young Butterfly Barbs develop very fast and show their first large spot within a week. At two weeks old, the second spot becomes apparent, and by six weeks old, the young fish have reached their full size of up to 3.5 cm, where they swim alongside the adults.

Butterfly Barbs will accept dried foods such as flakes or granules of a fitting size; however, you should not feed them this solely. Daily meals of small live and frozen foods such as artemia, grindal worm, daphnia, and suchlike will result in the best colouration and health as well as help to encourage your fish to come into breeding condition.

Although Butterfly Barbs are sociable by nature, they are a shoaling fish rather than a schooling species. These Barbs develop a distinct pecking order between males. Therefore, you should ideally maintain this fish in groups of 8 or more individuals; however, the tank needs to be of sufficient size, allowing weaker individuals a break from dominant individuals and decorated in such a way that you have plenty of broken lines of sight. If you choose to keep these fish singly, they can become withdrawn in a tiny group or cramped conditions, and subdominant fish may be bullied regularly.

Butterfly Barbs are not really suitable for most community aquariums. They have a shy, retiring nature and can be intimidated or outcompeted for food by larger, more boisterous tankmates. Instead, it would be best to choose similarly-sized, peaceful African species such as Jae Barbs, Killifish and smaller Tetras, as well as small south American Characins. Corydoras Catfish and Otocinclus may also make good tankmates.

Butterfly Barbs are endemic to the Democratic Republic of Congo in central Africa, where they have been recorded in major parts of the Congo River drainage system within the great area of equatorial rainforest situated east and south of the main river channel. Butterfly Barbs inhabit slow-moving, shaded, shallow rainforest swamps and streams with dense vegetation. The water is typically stained a brown colour due to the release of chemicals and tannins released by decomposing plant matter, and the substrate is covered with fallen leaves, branches and twigs. These environments contain very soft, acidic, cool water and are often dimly lit due to the rainforest canopy overhead.

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