Opsarius barna: what water temperature does it need?

The atlas records 20–26 °C for this species.

Opsarius barna: what water chemistry suits it?

pH 6.8–8, general hardness (GH) 5–20 °dH.

Opsarius barna: where does it come from?

It is recorded from India, Nepal, Bangladesh and Myanmar.

Barbs · Indian & Sri Lankan barbs

Opsarius barna

(Hamilton, 1822)

Full synonymy (8)

Barilius barna (Hamilton 1822) · earlier combination
Barilius jayarami Barman 1985 · junior synonym
Cyprinus balibhola Hamilton in McClelland 1839 · junior synonym
Cyprinus balibola Hamilton in McClelland 1839 · junior synonym
Cyprinus barna Hamilton 1822 · original combination
Opsarius acanthopterus McClelland 1839 · junior synonym
Opsarius fasciatus McClelland 1839 · junior synonym
Opsarius latipinnatus McClelland 1839 · junior synonym

Source: Eschmeyer's Catalog of Fishes (Fricke, Eschmeyer & Van der Laan, eds.), California Academy of Sciences.

3 cited sourcesName checked against Eschmeyer’s Catalog of Fishes, update of 21 Sep 2026

IUCNLEAST CONCERN · 2011

EXEWCRENVUNTLC

CARESNOT LISTED

EWCRENVUNTnot on the priority list

Type localityBrahmaputra River, at Gualpara [Goalpara], Assam, Indiaper Catalog of Fishes

Scientific size6 in15 cm total length

Temperature68–79 °F20–26 °C

pH6.8–8alkaline

Hardness (GH)89–357 ppm

Depth—not recorded

DietNot described in the FishBase summary.

BreedingNot recorded

Sexual dimorphismNot documentedNot recorded in available sources

PhotographsSee photosGoogle Images →

Opsarius barna is a hill-stream danionid of the Brahmaputra region that reaches 6 in TL according to FishBase. Hamilton described it in 1822 from the Brahmaputra at Goalpara in Assam.

What's in the name

barna

barnaBengali vernacular — a local name, taken by Hamilton from the region where he worked, not a Latin or Greek word

Taxonomy & naming

Francis Hamilton described the species in 1822 in his account of the fishes of the Ganges, from the Brahmaputra River at Goalpara, Assam. It was first placed in another genus, so the authority is in parentheses under Opsarius. Opsarius is in the family Danionidae. No widely used English common name is recorded.

Morphology

A slender stream danionid. FishBase gives a maximum of 6 in TL for males and unsexed fish.

Habitat

FishBase lists India, Nepal, Bangladesh and Myanmar, with a report from the Mekong basin. Adults live in hill streams and large rivers, and are found in clear hill streams with a gravel bottom.

Feeding

Diet is not described in the FishBase summary. Related Opsarius species take insects and insect larvae.

Mating

Mating behaviour is not described.

Breeding

Reproduction is not described, and no captive spawning has been documented.

In the aquarium

FishBase gives 68–79 °F, pH 6.8 to 8.0 and hardness of 5 to 20 dH. Those figures suit a cool, clean, oxygenated tank with strong flow over gravel, kept in a group with a tight lid.

Conservation

The IUCN Red List category is Least Concern, assessed on 19 March 2011. Specific threats are not described.

Common questions

Opsarius barna: how big does it get?: Up to 6 in total length (TL).
Opsarius barna: what water temperature does it need?: The atlas records 68–79 °F for this species.
Opsarius barna: what water chemistry suits it?: pH 6.8–8, general hardness (GH) 5–20 °dH.
Opsarius barna: where does it come from?: It is recorded from India, Nepal, Bangladesh and Myanmar.

Biotope tank mates

Atlas fish recorded from the same waters, whose recorded temperature and pH ranges overlap this one’s and whose adults are within twice its size. A shortlist to research, not a stocking plan: temperament, territory and diet are not checked. Other genera only; this genus is compared below.

Aborichthys kempi
Shares Brahmaputra basin · ranges overlap 68–79 °F, pH 6.8–7.6 · adults 3 in SL
Mottled loachCobitis turio
Shares Brahmaputra basin · ranges overlap 70–79 °F, pH 6.8–7.5 · adults 6 in TL
Spearfin loachAcanthocobitis pavonacea
Shares Brahmaputra basin · ranges overlap 68–77 °F, pH 6.8–7.5 · adults 6 in SL
Zona loachParacanthocobitis zonalternans
Shares Brahmaputra basin · ranges overlap 68–77 °F, pH 6.8–7.5 · adults 3 in SL

Related species compared · Opsarius

Species	Adult size	Temperature	pH	Hardness	IUCN
Opsarius barnathis species	6 in TL	68–79 °F	pH 6.8–8	89–357 ppm	LC
Opsarius bakeri	6 in TL	—	—	—	LC
Opsarius shacra	5.5 in TL	—	—	—	LC
Opsarius pulchellus	4.5 in SL	—	—	—	LC
Opsarius bernatziki	3.5 in SL	—	—	—	LC
Malabar barilOpsarius malabaricus	3.5 in SL	—	—	—	NE
Opsarius ardens	3.5 in SL	—	—	—	DD

Recorded ranges from each species’ own page; hardness is the tolerance its sources give, not a measurement of the water it lives in.

Also from the Brahmaputra basin

Sources

Naming authority: Opsarius barna in Eschmeyer’s Catalog of Fishes ↗

Last reviewed 2026-10-05.

How to cite

Aquarist Atlas (2026). Opsarius barna. Aquarist Atlas.https://www.aquaristatlas.com/barbs/opsarius-barna/

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Where it has been recorded

64 georeferenced records (GBIF). Each point is a field observation or museum specimen — pan and zoom to explore where this species turns up. The coordinates come straight from GBIF and are often rounded or tied to the nearest town or river landing, so a dot can sit just beside the actual water rather than in it.

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