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Dwarf Barb

Pethia phutunio

Cyprinidae

FishDifficulty: ●●●○○Data: well-established

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About

The dwarf barb is the Pethia nobody orders on purpose. Seriously Fish calls it a "frequently misidentified species" that is "quite rare in the aquarium trade", and even the shops that stock it are unsure what to call it: Maidenhead Aquatics runs the page under the heading Dwarf Barb, then calls the same fish Dwarf Silver Barbs in its own care text. It is genuinely tiny. Seriously Fish gives 25–30 mm standard length, FishBase 3.9 cm total length, and Aquarium Glaser says the wild animal "only grows to 2-3 cm in size in nature" — Maidenhead's 5 cm is the outlier, and four centimetres is the number to plan around. Two vertically oriented black blotches mark the flank, one just behind the gill cover and one on the caudal peduncle; mature males are slimmer and more intensely coloured than females, with reddish ventral fins where hers are yellow. The distribution printed on most shop cards is inherited error — Seriously Fish places the species in the lower Ganges and Brahmaputra basins of Bangladesh and the neighbouring Indian states, assigns the Myanmar records to Pethia didi, and says occurrences in Pakistan and Nepal "would also appear to be cases of misidentification". The interesting part is temperature. Aquarium Glaser's history notes that "the dwarf barb has delighted aquarium enthusiasts since it was first imported from India in 1906", partly because "since it lives at temperatures between 14 and 30°C, not even an aquarium heating was necessary in heated dwellings yet" — and then argues that modern equipment is exactly why the fish now has a reputation for being delicate: "Control heaters prevent temperature fluctuations and there is no debris left in the clean aquariums. Debris, i.e. dead plant remains, faeces and food remains, are an important food component of these and many other barbs." Maidenhead agrees it belongs at the cooler end, giving 15–24 °C, asking for tankmates that "share the same preference for slightly cooler temperatures", and warning that "water quality is of utmost importance, as these fish can be a little more demanding to keep than some of the other members of the Pethia genus". A rare, shy, four-centimetre barb that wants cool, heavily planted, mature water is not what most people expect from a bag labelled dwarf barb.

Care

A shoal of at least eight — Seriously Fish says 8–10, Maidenhead sets the floor at six "in order to feel secure" — in a heavily planted tank with a base of at least 60 × 30 cm and a dark substrate; 60 L is the working minimum. Unusually for a nano barb it likes moving water: Seriously Fish says it "does seem to appreciate a degree of water movement and will also do well in a hill stream-type set-up". Aim for 20–24 °C. The sources spread widely — FishBase 22–24, Seriously Fish 21–26, Maidenhead 15–24, and Aquarium Glaser 14–30 in the wild — so the overlap rather than anyone's ceiling is the target, and this is one of the few barbs genuinely happy in an unheated room. Soft to medium water, pH 6.0–7.0, up to about 12 °dGH, kept clean and stable. Small, peaceful tankmates only: Seriously Fish calls it "very peaceful but does not make an ideal community fish due to its small size and rather timid nature" and names Microdevario, Trigonostigma, smaller Danio, Lepidocephalichthys and Caridina or Neocaridina shrimp. Maidenhead's compatibility line reads "Community with no long-finned fish", but no source records this fish nipping anything, and with a shy 4 cm barb the likelier risk runs the other way: it is the one that gets out-competed.

Diet

Micropredator on small insects, worms, crustaceans and zooplankton, with plant matter in the wild diet as well. Daily small live or frozen daphnia and Artemia, plus flake, green flake and micropellets sized for a very small mouth.

Tankmate compatibility

Gets along with (184)

Adolfo's CoryAfrican Butterfly CichlidAgassiz's CoryAgassiz's Dwarf CichlidAllen's RainbowfishAmano ShrimpAmapá TetraAssassin SnailBadisBamboo ShrimpBandit CoryBanjo CatfishBlack Neon TetraBlack Phantom TetraBlackline RasboraBlackwing HatchetfishBladder SnailBleeding Heart TetraBloodfin TetraBlue Neon GobyBlue Neon RasboraBlue Panda Dwarf CichlidBlue Tiger ShrimpBlue Velvet ShrimpBlueberry TetraBluefin NothoBolivian RamBorneo SuckerBristlenose PlecoBroad Stripe CoryBronze CorydorasBumblebee GobyButterfly Hillstream LoachCandy Stripe PlecoCardinal TetraCelebes RainbowfishCelestial Pearl DanioCheckered BarbCherry BarbCherry ShrimpChili RasboraChinese Hillstream LoachClown KillifishClown PlecoCochu's Blue TetraCongo TetraCroaking GouramiCrystal Red ShrimpDaisy's RicefishDawn TetraDenison BarbDiamond TetraDoctor FishDwarf Chain LoachDwarf Flag CichlidDwarf GouramiDwarf Neon RainbowfishDwarf Orange CrayfishDwarf RasboraElegant CoryEmber TetraEmerald CoryEmerald Green LampeyeEmperor TetraEuropean BitterlingFairy CoryFalse Black TetraFireline DanioFive-Banded BarbFlame TetraForktail RainbowfishFreshwater ClamGhost ShrimpGiant DanioGlass Bloodfin TetraGlass CatfishGlowlight DanioGlowlight TetraGold BarbGolden Dwarf BarbGolden Dwarf CichlidGolden PencilfishGolden TetraGreen Laser CoryGreen Neon RasboraGuppyHarlequin RasboraHead-and-Tail-Light TetraHengel's RasboraHighfin Dwarf CichlidHoney GouramiHorned Nerite SnailHorseman's CoryHovering Zebra LoachIndian GlassfishJapanese Trapdoor SnailJulii CoryKeyhole CichlidKribensisKuhli LoachLake Kurumoi RainbowfishLambchop RasboraLeast KillifishLemon TetraLeopard DanioLittle CorydorasLoreto CoryLyretail KillifishMacmasteri Dwarf CichlidMalaysian Trumpet SnailMarble HatchetfishMcCulloch's RainbowfishMedaka RicefishMelon BarbMystery SnailNeon TetraNerite SnailNorman's LampeyeOdessa BarbOpal Dwarf CichlidOrnate TetraOtocinclusPagoda SnailPanda CorydorasPanda Dwarf CichlidPearl DanioPenguin TetraPeppered CorydorasPinocchio ShrimpPurple Emperor TetraPurple TetraPygmy CorydorasPygmy SwordtailRainbow ShinerRainbow StiphodonRamshorn SnailRed Edge Dwarf CichlidRed Phantom TetraRed Whiptail CatfishRed White Fin GobyRed-eye TetraReticulated Hillstream LoachRosy LoachRosy Red MinnowRosy TetraRubber Lip PlecoRummynose TetraSalt and Pepper CoryScarlet BadisScarlet GobyScissortail RasboraSiamese Algae EaterSilver Tip TetraSixray CorydorasSkunk CorySlate CorySmudge Spot CorySparkling GouramiSpotted HeadstanderSterbai CorydorasStrawberry RasboraStriped KribensisTail-Spot Pygmy CoryThai Micro CrabThick-lipped GouramiThreadfin RainbowfishThree-striped Dwarf CichlidTiger Stiphodon GobyTiger TeddyTwig CatfishUmbrella Dwarf CichlidUpside-down CatfishVampire CrabVampire ShrimpVeilfin TetraVenezuelan CoryVirginia CoryWhite Cheek GobyWhite Cloud Mountain MinnowWrestling HalfbeakX-ray TetraYellow Phantom TetraZebra DanioZebra Nerite Snail

Possible with care (181)

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Avoid (53)

Computed by the AquaSage engine for a spacious reference tank — always check the full verdict for your exact setup in the calculator.

Telling males from females

What works for this species, most reliable first.

  • Colour and patternA hint only · from about 6 months, and only on a settled fish

    In rainbowfish, killifish and several barbs the male carries the colour — deeper and more saturated, intensifying further when he displays.

  • Extended finsA hint only · from about 8 months, and later in a suppressed male

    On many cichlids and killifish the male's dorsal and anal fins draw out into trailing points as he matures, while the female's stay rounded.

  • Belly depthA hint only · only on well-fed adults, and only as a comparison

    For most tetras, barbs and rasboras this is all there is: a conditioned female is deeper through the belly than a male of the same length.

All the methods, with diagrams

Also in these lists

Similar species

Same category and the closest water parameters — if this species isn't quite it, start here.

Sold in Lithuania

These Lithuanian shops listed this species in their public catalogue (checked August 8, 2026). Stock moves — ask before you travel.

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Frequently asked questions

What tank size does a Dwarf Barb need?
A Dwarf Barb needs an aquarium of at least 60 litres (15.9 US gallons) with a footprint at least 60 cm (23.6 in) long — for this species, swimming length matters as much as raw volume.
What water parameters does a Dwarf Barb need?
Dwarf Barb does best at 16–26 °C (60.8–78.8 °F), pH 6–7.5 and a general hardness of 3–12 °dGH.
What group size does a Dwarf Barb need?
Dwarf Barb is a social species — keep a group of at least 8 so natural behaviour emerges and stress stays low.
Is the Dwarf Barb suitable for beginners?
Dwarf Barb sits in the middle of the difficulty scale — manageable for a careful beginner who has done the reading, but it has specific needs worth researching first.

Sources

Water & tank

Temperature16–26°C
Optimal temp.20–24°C
pH6–7.5
Hardness (GH)3–12°d
OriginGanges–Brahmaputra basin · soft, acidic water (natural range)
Adult size4 cm
Min. volume≥ 60 L
Min. tank length≥ 60 cm
Group size≥ 8
Swimming zoneMid
TemperamentTimid
Water typeFreshwater
FlowModerate
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