Aquarist Atlas
Barbs · Indian & Sri Lankan barbs

Opsarius bernatziki

(Koumans, 1937)

Full synonymy (1)
  • Barilius bernatziki Koumans 1937 · original combination

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

IUCNLEAST CONCERN · 2011
CARESNOT LISTED
Type localityKapa, northwestern peninsular Thailandper Catalog of Fishes
Scientific size3.5 in9.1 cm standard length
Depth—not recorded
DietNot described
BreedingNot recorded
Sexual dimorphismNot documentedNot recorded in available sources
PhotographsSee photosGoogle Images →

Opsarius bernatziki is a small danionid from the Malay Peninsula, described from Kapa in northwestern peninsular Thailand. FishBase gives a maximum of 3.5 in SL.

What's in the name

Opsarius bernatziki — op-SAR-ee-us ber-NAT-zik-ee

Opsarius
  • opsarosGreek — delicate, dainty
bernatziki
  • bernatzikiNew Latin (patronym) — honouring Bernatzik

Taxonomy & naming

Koumans described the species in 1937 from Kapa, northwestern peninsular Thailand. It now sits in Opsarius, and the authority is in parentheses because it was first described in another genus. The family is Danionidae, the danios and their relatives.

Morphology

A slim, small-mouthed minnow reaching 3.5 in SL according to FishBase. Colour pattern is not described in the sources the atlas uses.

Habitat

FishBase lists the species as freshwater and benthopelagic in tropical water, from the Malay Peninsula. Water parameters are not recorded.

Feeding

The diet is not described in the sources the atlas uses.

Mating

Mating behaviour is not described in the sources the atlas uses.

Breeding

Breeding is not described in the sources the atlas uses.

In the aquarium

No aquarium notes exist in FishBase. Related Opsarius are hillstream fish that do best in cool to moderate, well-oxygenated water with current and a tight lid, in groups.

Conservation

FishBase lists the species as Least Concern on the IUCN Red List, assessed 16 November 2011.

Common questions

Opsarius bernatziki: how big does it get?
Up to 3.5 in standard length (SL).
Opsarius bernatziki: where does it come from?
It is recorded from Thailand and Myanmar.

Related species compared · Opsarius

SpeciesAdult sizeTemperaturepHHardnessIUCN
Opsarius bernatzikithis species3.5 in SL———LC
Malabar barilOpsarius malabaricus3.5 in SL———NE
Opsarius ardens3.5 in SL———DD
Opsarius pulchellus4.5 in SL———LC
Opsarius shacra5.5 in TL———LC
Opsarius bakeri6 in TL———LC
Opsarius barna6 in TL68–79 °FpH 6.8–889–357 ppmLC

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 Malay Peninsula

Sources

  1. FishBase — Opsarius bernatziki
  2. Eschmeyer's Catalog of Fishes — Opsarius bernatziki (Koumans, 1937)
  3. IUCN Red List — Opsarius bernatziki

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

Last reviewed 2026-10-05.

How to cite

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

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Where it has been recorded

3 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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