An active, schooling cyprinid endemic to the shaded forest streams of Sri Lanka. They are peaceful but highly energetic, making excellent community fish for cooler tropical setups. Unlike the notorious Tiger Barb, Black Rubies are generally peaceful and rarely nip fins, provided they are kept in a proper shoal of at least 6. Their deep colors emerge best in heavily planted, slightly dim environments.
Black Ruby Barb At a Glance
Black Ruby Barb Tank Requirements
Will Black Ruby Barb fit in your tank?
Care guides tell you what Black Ruby Barb needs, the next question is whether your tank can safely provide it. Test Black Ruby Barb against your tank size, maintenance needs, and the fish you already keep before you buy.
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Black Ruby Barb Water Parameters
Water care products
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Black Ruby Barb Temperament & Compatibility
Black Ruby Barb Varieties
Each variety inherits the species defaults above. Only differences are highlighted.
Male
Males undergo a dramatic color transformation as they mature or enter breeding condition, developing a stunning dark ruby-red head and purplish-black body.
Differs in 2 traits from base species
Also known as: Male Ruby Barb, Show Color
Female
Females are plumper and slightly larger than males. They lack the deep ruby wash, maintaining a yellowish-silver body crossed with distinct black vertical bands.
Differs in 2 traits from base species
Also known as: Female Ruby Barb, Wild Type
Black Ruby Barb Care Guide Summary
The Black Ruby Barb, scientifically known as Pethia nigrofasciata, belongs to the Cyprinids family group. Adults reach a maximum size of approximately 6.5 cm and have a compressed body shape with a moderate growth rate. Classified as mostly peaceful, this species primarily occupies the mid-level and bottom zones of the aquarium and produces a low level of biological waste.
To thrive, the Black Ruby Barb requires a freshwater only aquarium with a minimum volume of 80 litres and a tank length of at least 80 cm. Water temperature should be maintained between 20°C and 26°C, with a pH range of 5.5–7.5 and a general hardness of 2–15 dGH. A moderate water flow is preferred.
Due to its specialist needs, the Black Ruby Barb is best suited for fishkeepers who can provide a carefully planned setup. This species is available in 2 varieties: Male and Female. Each may differ slightly in size, temperament, or care needs, so it is worth checking the specific requirements of the variety you plan to keep.
Black Ruby Barb Habitat Setup
When setting up an aquarium for the Black Ruby Barb, a moderate water flow best suits their natural preferences. Because this species occupies the mid-level and bottom zones, the aquarium layout should prioritise open swimming space in the centre of the tank for free movement and sufficient floor space with hiding spots among rocks, wood, or dense planting. Useful additions include driftwood, which can serve as both a hiding place and a dietary supplement, leaf litter or blackwater tannins to replicate their natural soft-water habitat, and dense planting to provide cover, break sightlines, and reduce stress.
Black Ruby Barb Compatibility Notes
Classified as mostly peaceful, the Black Ruby Barb is a schooling species that feels most secure in a sizeable group, where natural shoaling behaviour reduces stress and brings out their best colours. When choosing tankmates, shy or slow-feeding tankmates may be outcompeted at feeding time and their energetic swimming style may stress more sedentary or timid species. Selecting tankmates that favour different water layers from the mid-level and bottom zones can help reduce competition and territorial overlap.
Black Ruby Barb Recommended Tank Sizes
Standard aquarium sizes that meet the minimum volume and length requirements for Black Ruby Barb.
30 Gallon Breeder
40 Gallon Breeder
55 Gallon Standard
60 Gallon Breeder
75 Gallon Standard
90 Gallon Standard
Show 12 more tank sizes
Black Ruby Barb Feeding & Diet Considerations
The Black Ruby Barb will eat fry, so breeding efforts in the same tank are unlikely to succeed and is an aggressive eater that may prevent timid tankmates from getting enough food, so target feeding or simultaneous feeding at opposite ends of the tank can help.
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Frequently Asked Questions About Black Ruby Barb
How big does Black Ruby Barb get?
Black Ruby Barb (Pethia nigrofasciata) typically reaches a maximum adult size of approximately 6.5 cm. They have a compressed body shape and a moderate growth rate.
What tank size does Black Ruby Barb need?
A minimum aquarium volume of 80 litres and a tank length of at least 80 cm are recommended for Black Ruby Barb. This ensures enough swimming space and helps maintain stable water conditions.
What water parameters does Black Ruby Barb need?
Black Ruby Barb thrives in freshwater only conditions with a temperature range of 20–26°C, a pH between 5.5 and 7.5, and a general hardness of 2–15 dGH. A moderate water flow is preferred.
Is Black Ruby Barb peaceful or aggressive?
Black Ruby Barb is classified as mostly peaceful with an aggression score of 3 out of 10. They are generally well-suited to peaceful community tanks.
How many Black Ruby Barb should be kept together?
Black Ruby Barb is a schooling species and should be kept in groups of at least 6. Larger groups help distribute aggression and encourage natural schooling behaviour.
Does Black Ruby Barb have any special tank requirements?
Yes. Black Ruby Barb benefits from plants - densely covered, leaf litter/blackwater, and driftwood (digestion/hiding) in the aquarium. These features help replicate their natural habitat and promote overall health and well-being.
Top Tank Mates for Black Ruby Barb
These fish are strong compatibility matches for Black Ruby Barb based on water preferences, temperament, adult size, and tank behavior.
Celebes Halfbeak
Nomorhamphus liemi
Ideal Tank MatesWrestling Halfbeak
Dermogenys pusilla
Ideal Tank MatesJapanese Ricefish (Medaka)
Oryzias latipes
Ideal Tank MatesMacCulloch's Rainbowfish (Dwarf Rainbowfish)
Melanotaenia maccullochi
Ideal Tank MatesExquisite Rainbowfish
Melanotaenia exquisita
Ideal Tank MatesEastern Rainbowfish
Melanotaenia splendida
Ideal Tank MatesPlants That Suit Black Ruby Barb
These plants pair well with Black Ruby Barb based on shared water preferences, layout fit, and how likely they are to hold up in the same aquarium.
Afzel's Anubias
Anubias afzelii
Amazon Sword
Echinodorus amazonicus
Anacharis
Egeria densa
Anubias Barteri
Anubias barteri
Baby Tears
Lindernia rotundifolia
Balansae
Cryptocoryne crispatula
Fish Similar to Black Ruby Barb
Cherry Barb
Puntius titteya
A peaceful, schooling cyprinid endemic to the shaded streams of Sri Lanka. Unlike many of its barb cousins, the Cherry Barb is not a fin-nipper and makes an excellent community fish. They thrive in heavily planted aquariums with subdued lighting and leaf litter. Males display a striking cherry-red color, especially during spawning.
Tiger Barb
Puntigrus tetrazona
A highly active, schooling cyprinid famous for its striking black stripes and infamous reputation as a fin-nipper. They are boisterous and must be kept in larger groups (6+) to keep their pecking order internal. They should never be housed with slow-moving or long-finned tankmates like Bettas, Guppies, or Angelfish.
Chinese Barb (Green Barb)
Puntius semifasciolatus
A hardy, active, and peaceful schooling cyprinid originally from the Red River basin in Asia. While the wild form is a metallic green/silver, a highly popular selectively bred yellow morph (the 'Gold Barb') dominates the aquarium trade. They are distinctly subtropical and thrive in unheated or cooler water setups.
Brilliant Rasbora
Rasbora einthovenii
The Brilliant Rasbora is a peaceful, highly active schooling fish native to the forest streams and peat swamps of Southeast Asia. Known for its shimmering silver body and distinct dark lateral stripe, they thrive in gently flowing, heavily planted blackwater setups with subdued lighting. They are known jumpers, requiring a tight-fitting lid.
Denison Barb (Roseline Shark)
Sahyadria denisonii
An endangered, stunningly colored cyprinid endemic to the fast-flowing streams of the Western Ghats in India. Characterized by a torpedo-shaped body with a striking red line and black stripe. They are highly active, fast swimmers that require highly oxygenated water, strong flow, and cooler tropical temperatures. They are strictly shoaling fish and can be skittish if kept in small numbers.
Cigar Shark (Mad Barb)
Leptobarbus hoevenii
A massive, incredibly active schooling fish native to Southeast Asian rivers. Despite the 'shark' moniker, it is a giant cyprinid (carp). It grows exceptionally large and fast, requiring massive aquariums or heated ponds. Known as the 'Mad Barb' due to its erratic swimming and tendency to jump when startled. They are omnivorous and will eat anything that fits in their mouth, including smaller fish and plants.