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Barred danio

Devario pathirana

Fishes › Carp, barbs, minnows, loaches (Cypriniformes) › Danionidae (Danios and rasboras)

The barred danio (Devario pathirana) is a species of freshwater ray-finned fish belonging to the family Danionidae.

Aquarium hobby
Experience: Easy
Barred danio
Photo: Rupert A. Collins, CC BY 3.0, via Wikimedia Commons
FamilyDanios and rasboras
Adult lengthup to 3.1 in
WaterFreshwater
HabitatLives in freshwater

Care at a glance

Species-specific aquarium care

  • Tank: At least 24 in long and 12 in front to back for one adult (adults commonly reach about 2.4 in / 6 cm).
  • Water: Freshwater.
  • Temperature: 72–77°F (range recorded for this species).
  • Layout: Uses both the bottom and open water: give open swimming space plus cover near the substrate.
  • Diet: A predator: feed meaty foods sized to its mouth (frozen fish, shrimp, worms); it will eat tankmates that fit in its mouth. FishBase classes it as a carnivore.

Calculated from this species' own FishBase record: tank size from its typical adult length and swimming zone, water values from its recorded ranges. The group guide below fills in general care.

Care guide

Species care notes

  • Tank: a base of at least 47 × 18 in (roughly 64 US gallons); space needed is rated “large tank”.
  • Water: a fairly wide range, from slightly acidic to slightly alkaline, 73–79 °F, pH 6–7.5, 1–8 dGH.
  • Behaviour: a shoaling fish best kept in a group of six or more; suited to a community tank.
  • Difficulty: Moderate (Seriously Fish rating).

Short excerpts from the species profile:

  • Setup: “Not difficult to keep in a well-maintained set-up, though we recommend aquascaping the tank to resemble a flowing stream or river with a substrate of variably-sized, water-worn rocks, sand, fine gravel and perhaps some small boulders.”
  • Diet: “Almost certain to prey chiefly on insects and their larvae in nature.”
  • Tankmates: “Not especially belligerent but can upset very slow-moving or shyer tankmates with its constant activity and vigorous feeding behaviour, and may nip trailing fins.”
  • Breeding: “Like most small cyprinids Devario spp.”

From the Seriously Fish profile for this species, which has the full habitat, maintenance, diet, behaviour and breeding write-up 167

Group care guide

Danios and rasboras

Applies to most species in this group. Habitat: These Asian fishes occupy habitats ranging from zebra-danio pools and rice paddies to shaded harlequin streams, rocky Devario streams and planted galaxy-rasbora wetlands. [fg159-zebra, fg159-harlequin, fg159-giant, fg159-galaxy]. Individual species can differ, so compare with the species numbers above and the linked sources.

Level 2 reflects common aquarium species. Water range is ONLY for zebra danios; harlequins use 69.8–82.4°F, galaxy rasboras 68–78.8°F and D. aequipinnatus 60.8–78.8°F. [fg159-zebra, fg159-harlequin, fg159-galaxy, fg159-giant] Avoid routine tannin-rich wood/leaf additions for galaxy rasboras. [fg159-galaxy] Giant danios are often misidentified as D. aequipinnatus. [fg159-giant] Obtain separate profiles for the listed Rasbora and T. espei before using these examples as a stocking prescription.

Housing & setup

  • Use at least 90 × 30 cm (36 × 12 in) for zebra danios.
  • Harlequins require at least 60 × 30 cm (24 × 12 in), shaded planted cover and subdued light.
  • Devario aequipinnatus needs at least 120 × 45 cm (48 × 18 in), oxygenated water, moderate flow and a tight lid.
  • Galaxy rasboras need dense planting and broken sight lines in at least 45 × 30 cm (18 × 12 in), with gentle sponge filtration.
  • Match chemistry: harlequins pH 5.0–7.5, 1–12 dGH; galaxy rasboras pH 6.5–7.5, 5–15 dGH.

Sources 877878879880

Climate & lighting

Water64.4–77°F

Sources 877878879880

Diet

  • Quality flakes or granules sized to the fish.
  • Live or frozen Daphnia and Artemia.
  • Bloodworms for zebra danios, harlequins and Devario.
  • Small sinking foods for galaxy rasboras, which rarely feed at the surface.

Sources 877878879880

Social life

  • Keep zebra danios and harlequins in groups of at least 8–10. Galaxy males spar: dense cover and larger groups distribute aggression. Active Devario can overwhelm timid feeders.

Sources 877878879880

Health watch

  • Pseudoloma microsporidiosis in zebra danios.
  • Pleistophora infection and columnaris can produce similar white lesions in zebra danios.
  • Nipped fins among rival galaxy males.

Sources 877878879880

Understanding the animal

About this animal

About this animal

Originating in Sri Lanka, this fish grows to a maximum length of 2 inches (5.1 cm). In the wild, the barred danio is understood to be critically endangered, but is freely available from captive-bred stock.

Quoted from the Wikipedia article “Barred danio” (CC BY-SA 4.0) 174

In the wild

In the wild

From this species’ own FishBase record (habitat, bottom type, water and breeding data), not its family. Good care copies these conditions.1

Where it livesLives in freshwater, in rivers and streams, lakes. Uses both the bottom and open water. Occurs in still pools to swift flowing streams with pebble or boulder substrates, seldom over sand. Has not been found in silted rivulets flowing into mainstream. More sedentary than D. malabaricus. Forms groups of 3-5 individuals slowly moving near the surface. Probably feeds on insects. Aquarium fish exporters voluntarily refrained from collecting this species until it was better understood and bred commercially. Collected in moderate numbers.
Water it lives inFreshwater, 72–77 °F (22–25 °C).
ClimateTropical climate.
Wild dietHunting macrofauna (predator).

What this means for care

  • Keep water within its wild range, 72–77 °F.
  1. FishBase species summary: Devario pathirana
From the sources

From the sources

Quoted from the matching sections of reputable sources for this exact species. Specialist databases are used first; Wikipedia (community-edited, CC BY-SA 4.0) only fills gaps. Other sources are short credited quotes.

OverviewThe barred danio (Devario pathirana) is a species of freshwater ray-finned fish belonging to the family Danionidae. Originating in Sri Lanka, this fish grows to a maximum length of 2 in. In the wild, the barred danio is understood to be critically endangered, but is freely available from captive-bred stock. Typically, the fish prefer water with a 6.0-8.0 pH, a water hardness of 5.0-19.0 dGH, and an ideal temperature range of 69–79 F. Its diet consists of annelid worms, small crustaceans, and insects. — Wikipedia (community-edited)
Where it livesHome ranges Population dynamics Growth parameters Max. ages / sizes Length-weight rel. Length-frequencies Mass conversion Recruitment Abundance Life cycle Reproduction Maturity Maturity/Gills rel. — FishBase
BiologyOccurs in still pools to swift flowing streams with pebble or boulder substrates, seldom over sand. Has not been found in silted rivulets flowing into mainstream. More sedentary than D. malabaricus. — FishBase

Data and studies

The numbers

The numbers

Each bar is what one source reports. Where several sources weigh in, the dashed gold band marks their average.

Adult length

Average of sources2.8in
FishBase 1642.4
Seriously Fish species profiles 1673.1

Maximum recorded length. Measured as standard length (snout to the base of the tail, not counting the tail fin). Fish in home aquariums often stay smaller than wild records.

Water temperature

Average of sources72.5–78°F
FishBase 16472–77
Seriously Fish species profiles 16773–79

Range the species tolerates in nature; aim for the middle.

pH

Reported6–7.5
Seriously Fish species profiles 1676–7.5

Water hardness

Reported1–8dGH
Seriously Fish species profiles 1671–8

Minimum tank footprint

Reported47in
Seriously Fish species profiles 16747

Seriously Fish recommends a tank base of at least 47 × 18 in (about 64 US gallons).

Sources for this sheet

  1. FishBase (Froese & Pauly, eds.), version 24.07 Peer-reviewed researchThe global scientific database on fishes, maintained by a consortium of research institutions; every value is referenced.
  2. Seriously Fish species profiles Experienced keeper or breederLong-running aquarium reference written and peer-checked by experienced fishkeepers and ichthyologists; each profile covers habitat, tank size, water, diet, behaviour and breeding.
  3. Seriously Fish: Zebra danio (Danio / Brachydanio rerio) Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
  4. Seriously Fish: Trigonostigma heteromorpha Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
  5. Seriously Fish: Devario aequipinnatus Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
  6. Seriously Fish: Danio / Celestichthys margaritatus Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
  7. Wikipedia (species article) Community referenceFree encyclopedia; useful overviews with their own citations. Intro text is quoted under CC BY-SA 4.0.
  8. iNaturalist (captive observations) Community referenceCommunity observation platform run by the California Academy of Sciences and National Geographic; observations marked captive show animals living in homes, zoos and aquariums.