Cosuatis barb

Oreichthys cosuatis

Also known as High-fin barb, Hi-fin headstander barb

FreshwaterFish

Cosuatis barb (Oreichthys cosuatis) — The Wet Spot Tropical Fish · Used with permission

Care at a glance

Temperature: 68–79°F (20–26°C)
pH: 6.0–7.5
Adult size: 3.1 in (8 cm)
Minimum tank: 20 gal (75 L)
Temperament: Peaceful
Social behavior: Schooling
Swim level: Middle
Difficulty: Medium
Breeding: Medium
Rarity: Rare
Origin: India, Bangladesh and Thailand
Family: Cyprinidae

Overview

Keep this peaceful, slightly shy barb as a group of six or more so the males display instead of hiding. It swims in the middle water and suits a calm community of other small, gentle fish. Feed small, varied foods, fine flake and micro-pellet with regular frozen or live daphnia, bloodworm and brine shrimp to bring on condition and the males' sail-fin show. Provide around 75 liters, well planted and softly lit, with gentle flow. Give the fish time to settle in before expecting its best color.

In the wild

The cosuatis barb lives in quiet, often weedy fresh waters across South and Southeast Asia, from India east to Thailand. Recreate that with a densely planted, gently filtered tank, a dark substrate and subdued light. It prefers the cooler tropical band, around 20 to 26 degrees Celsius, at pH 6.0 to 7.5, with clean, stable water and little current.

Good to know

Oreichthys cosuatis is a barb of the family Cyprinidae described by Hamilton in 1822, reaching about 8 centimeters, though tank fish are often smaller. Mature males raise a tall, sail-like dorsal fin edged in dark and gold, which they flare in quiet lateral displays to rivals and females. Spawning it is a middling challenge; the fish scatters eggs and gives no parental care.

Did you know

The males settle their rivalries with pageantry rather than fighting, circling each other with their tall dorsal sails raised and spread, a silent posturing contest that rarely does any harm.