Bernatzik's baril

Opsarius bernatziki

Also known as Barilius bernatziki, Blue hillstream trout

FreshwaterFish

Bernatzik's baril (Opsarius bernatziki) — The Wet Spot Tropical Fish · Used with permission

Care at a glance

Temperature: 72–81°F (22–27°C)
pH: 6.5–7.5
Adult size: 4.3 in (11 cm)
Minimum tank: 42 gal (160 L)
Temperament: Mostly peaceful
Social behavior: Schooling
Swim level: Middle
Difficulty: Medium
Breeding: No record
Rarity: Rare
Origin: Malay Peninsula streams, Thailand and Myanmar
Family: Danionidae

Overview

This is the warmest-water baril in this group, which lets it slot into a tropical river community. Keep it as a school of five or more in a long tank with current, alongside large rasboras, danios, and loaches that can hold their own. It is an athletic, surface-oriented feeder that jumps, so keep a tight lid and open swimming length. Offer floating foods along with frozen and small live items such as bloodworm, mosquito larvae, and daphnia. A tank of around 160 liters gives a group room to move.

In the wild

Bernatzik's baril lives in streams of the Malay Peninsula and the Thai and Myanmar border country, in clear, flowing, well-oxygenated water. Recreate that with brisk current from powerheads or a strong filter return, a substrate of sand and rounded gravel, scattered wood, and open water above. Keep it at 22 to 27 degrees Celsius with a pH of 6.5 to 7.5.

Good to know

Opsarius bernatziki is a danio-family baril, Danionidae, reaching about 11 centimeters. Koumans described it in 1937 and named it for Hugo Bernatzik, the Austrian anthropologist and photographer who collected the first specimen on one of his expeditions. Its spawning is not documented in aquaria.

Did you know

It carries an anthropologist's name because the man who collected it, Hugo Bernatzik, was in Southeast Asia to study people, and the fish travelled home alongside his field notes.

Tank mates

Bernatzik's baril is a mostly peaceful, schooling species that keeps to the middle. These picks match on water type, temperature, pH, size and temperament.