Not furry, but we like them anyway.

Black Ruby Barb

Pethia nigrofasciata

Also called Purplehead barb

SpeciesShort profile

From Sri Lanka (endemic): shaded forest streams of the southwestern wet zone, from the Kelani to the Nilwala river basins, up to about 300 m elevation1 2 3

At a glance the quick version

Length5.5 to 6.7 cm1 2 3

Sizesmall

Seriously Fish gives 5.5 cm SL; FishBase gives 6.0 cm TL for males and 6.7 cm TL for females

Very peaceful

Stunning breeding colours

Active schooler

1 3

Looks how to spot one

Deep-bodied scaled cyprinid

A deep-bodied barb with three dark vertical bars on a yellowish-grey body. Males in breeding colour turn a deep ruby to purple-red at the front with a dark rear body and a black dorsal fin. Females stay paler and are larger and fuller than males.1 3 2

Coloursyellowish greyblack vertical barsruby red to purple (breeding males)black fins1 3

Personality what they are like

Very peaceful and sociable, it suits a community tank with other gentle fish.1

Daily activity how busy a day looks

A lively schooling swimmer that needs swimming room between planted areas.1 3

Grooming and care the hands-on bits

Keep the water clean and soft with regular partial changes. Leaf litter and shade bring out its colour.1

Home where they are happiest

A tank with a base of at least 80 x 30 cm (about 72 litres). Temperature 20-27 °C (FishBase 22-26 °C), pH 5.5-7.5 (FishBase 6.0-6.5), hardness 2-15 °H. Sand, leaf litter, wood and dense planting copy its forest streams.1 2

Food basics what goes in the bowl

Forages on algae, detritus and small invertebrates in the wild. Offer quality flakes or granules with algae content plus small live or frozen foods such as bloodworm, Daphnia and Artemia.1 2

Company who they like around

Keep a group of at least 6-10. Good tankmates include tetras, livebearers, rainbowfish, small catfish and loaches.1

The story where it all began

Albert Günther described the black ruby barb in 1868 from Sri Lanka. It has long been a popular aquarium fish that breeds well in captivity, and Sri Lanka no longer allows wild fish to be exported.2 1 3

Fun facts for the dinner table

1
Breeding males change from barred yellow-grey to a rich ruby and purple colour.3
2
Its eggs hatch in one to two days and the fry swim freely a day later.2
3
It lives only in Sri Lanka, in streams shaded by rainforest.2
4
Sri Lanka protects it by banning the export of wild fish.1

Recognised by the official bits

IUCN Red List: Assessed as Vulnerable (August 2019)2
FishBase: Described by Günther in 18682
Sri Lanka: Export of wild-caught specimens from Sri Lanka is prohibited1

The care rhythm Furry Diary remembers it for you

A typical home-care rhythm for a Black Ruby Barb. It is our own starting plan, not a vet's advice, and you can change every line in the app.

FeedingSmall amounts once or twice a dayevery day
Temperature checkevery day
Water changeAbout 25% of the waterevery week
Water testevery week
Glass cleanevery week
Filter rinseRinse in old tank water, never tap waterevery month

Start a free diary

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Where this comes from

Every breed page shows where each fact comes from. If we got something wrong, sorry, we are pet people, not a science magazine. Tell us at [email protected] and we will fix it.

Seriously Fish - Pethia nigrofasciata seriouslyfish.comused for origin, size, tank and water parameters, diet, behaviour, appearance, export ban
FishBase - Pethia nigrofasciata fishbase.seused for author/year, IUCN status, size, water parameters, habitat, spawning
Wikipedia - Black Ruby Barb en.wikipedia.orgused for other names, colours, size

Checked 2026-09-30. Text is written in our own words from these sources.