Fish, Tanks and Ponds

A comprehensive guide to fish

Hoplias malabaricus

Wolf fish

Wolf fish, Hoplias malabaricus

General Notes:

Large specimens of H. malabaricus need very careful handling because they have strong teeth, very powerful jaws and they are highly aggressive. A bite from one could inflict a serious injury. Despite their size H. malabaricus doesn't as much space as most other similar sized fish because it is a fairly inactive species which doesn't require a lot of open swimming space.
H. malabaricus is a highly aggressive species which can't normally be kept with other fish as it gets older. In a huge aquarium fish which are to big to eat and are larger than H. malabaricus may be kept together in a large community but the tank would have to be vast for this to work. Young fish are compatible but they will eventually need separating or cannibalism may occur.
H. malabaricus is otherwise quite unfussy about its surroundings, it is a wide spread species and comes from a variety of habitats which demonstrates its natural adaptibility.

Feeding

Wild adults prey on other fish which are eaten whole, juveniles prey on insects, crustaceans and worms. In captivity feed them with a mixture of shell fish, prawns, earthworms, whole frozen fish such as lancefish, sardines, whitebait. Use a variety of food to ensure a healthy diet.

Sexing

When adult females are said to be larger and have more rounded abdomens.

Breeding

Breeding has been achieved by hobbyists but it is extremely difficult to maintain a pair of adult fish in the same aquarium. The pair will spawn in a prepared pit and post spawning the male will guard the eggs and he will continue to guard the brood for some time after the eggs have hatched.

Wild status

The wild population of H. malabaricus has not been evaluated but the species is very widespread and facing no immediate threats across its entire range. All specimens of H. malabaricus offered for sale will have come from the wild.

Additional information

There are eight other known species of Hoplias but  H. malabaricus is the most likely one to be seen in the aquatic trade.

Information at a glance

pH: 6 - 8
dGH: 4 - 25
Temperature: 22 - 28°C (72 - 82°F)
Diet: Carnivore
Size: 50cm (20in)
Min tank size: 675 litres+
Difficulty level: Intermediate
Aquarium type: Specimen
Swimming level: Bottom

Distribution and habitat

distribution map for Wolf fish, Hoplias malabaricus

Origin: Central and South America: Costa Rica to Argentina in most rivers basins.

Habitat: Occurs in diverse habitats from free flowing clear water streams, well up into the valleys, to slow turbid waters, water courses, irrigation and drainage ditches, and ponds on the plains

Classification

Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Characiformes
Family: Erythrinidae
Genus: Hoplias
Species: H. malabaricus (Bloch, 1794)

Other common names:
Wolf tetra, Tiger fish, Trahira

Synonyms: Esox malabaricus, Macrodon malabaricus, Synodus tareira, Synodus palustris, Erythrinus trahira, Erythrinus macrodon, Macrodon tareira, Macrodon ferox, Esox tararira