Redtail wolf fish

Hoplerythrinus unitaeniatus

Also known as Aimara, Jeju, One-lined wolf fish, Redtail trahira

FreshwaterFish

Redtail wolf fish (Hoplerythrinus unitaeniatus) — Célio Moura Neto · CC BY 4.0

Care at a glance

Temperature: 73–82°F (23–28°C)
pH: 5.5–7.5
Adult size: 11 in (28 cm)
Minimum tank: 66 gal (250 L)
Temperament: Aggressive
Social behavior: Solitary
Swim level: Bottom
Difficulty: Medium
Breeding: No record
Rarity: Very rare
Origin: Widespread across much of tropical South America east of the Andes.
Family: Erythrinidae

Overview

Keep this predator on its own, since it will eat tankmates small enough to swallow and can be rough with its own kind. A single fish needs a tank of at least 250 liters with a secure lid and plenty of cover. It is hardy and tolerant of poor water, but its predatory nature and jumping ability call for a careful setup.

In the wild

Lives in slow and still waters including swamps, ponds, and quiet stream margins, often where oxygen runs low. It is a bottom oriented predator that lurks among cover and ambushes prey. It can breathe air to survive in stagnant pools.

Good to know

Hoplerythrinus unitaeniatus is a wolf fish relative reaching around 28 cm, more slender than the common trahira and marked with a reddish tail and a dark shoulder spot. It can use its swim bladder to breathe air. It belongs to the family Erythrinidae.