Fish
Trahira
Hoplias malabaricus · also called wolf fish
Lying motionless among submerged debris, a trahira waits to lunge at passing prey, a hunting style and aggressive temperament that earned this South American fish its common nickname, the wolf fish.
Overview
The trahira, Hoplias malabaricus, is a Least Concern freshwater fish found across rivers, lakes, and swamps throughout tropical and subtropical South America. Its ambush hunting style, ability to breathe air directly, and tolerance for poor water conditions make it one of the most adaptable predatory fish found anywhere on the continent.
Built to survive where others cannot
A specialized respiratory structure lets the trahira gulp air at the surface, allowing it to persist in stagnant swamps and oxygen-depleted pools that would be uninhabitable for most other freshwater fish, a key reason for its wide distribution.
Status
Least Concern, remaining widespread and abundant across rivers, lakes, and swamps throughout its South American range.
Trahira: common questions
Why is the trahira called the wolf fish?
Its aggressive predatory behaviour, powerful jaws, and ambush hunting style earned it the common nickname wolf fish among anglers and researchers alike.
How can the trahira survive in low-oxygen water?
It has a specialized respiratory structure that lets it gulp air directly at the surface, allowing it to tolerate stagnant swamps and oxygen-depleted pools where many other fish would not survive.
How does the trahira hunt?
It is an ambush predator, lying motionless among vegetation or debris before lunging suddenly to seize fish, crustaceans, and other prey that come within range.
Is the trahira popular with anglers?
Yes, it is valued as a sport fish for its aggressive strikes and strong fighting ability once hooked.