The Wolf Pack

Scientific Name:  Hoplias malabaricus - Common Wolf fish

Known Common or Trade Names: Wolf fish, Common Wolf fish.It is important to understand that common names can be applied to many individual species and does not guarantee the correct identification of the fish in question

Original Description:  Bloch 1794, Holotype - Suriname

Distribution and environment: A very widespread species encompassing many parts of the South American continent, Central America through to Argentina. Malabaricus lives in a range of habitats. Black water and white water streams and pools, usually round the edges of these environments also flooded forest floors. Small juveniles are often found in muddy puddles left by the drained forests waiting for the floods to reappear enabling them to move on.

Description:  The A-typical wolf fish in shape and colouring although this pattern and colour can vary greatly depending on location, and mood, usually uniformly grey brown colouring with a dark connected blotched pattern along it’s flanks. Hoplias malabaricus gallery

A good way to identify if the fish is a Malabaricus is to view the underside of the jaw. The lines of the inside of the jaw will meet at the front forming a V shape rather than running parallel forming a U shape displayed by lacerdae group and Hoplias aimara. See below image. Some lacerdae species i.e. australis have under jaw characteristics very similar to malabaricus so sometimes it can be hard to tell but this usually is an issue identifying australis as a lacerdae wolf as the physical appearance of australis shows it is not malabaricus.

Size: A max size of 50cm – 20 inches. Captive sizes are usually smaller reaching 40-45cm – 16-18 inches. There are larger individuals but these have usually been caught at the larger size.

Juvenile Description: The juveniles have a much slimmer profile than adults but generally look similar in patterning and appearance.

Sexual Differences: Females are thought to be heavier in build.

Water parameters: Generally unfussy as long as extremes are avoided. Anywhere between a PH of 6.5 and 8 will be fine. Tropical temperatures of 23c – 30c.

Tank Size: As a medium sized Hoplias species this fish should be kept in a medium to large setup. 120cm x 60cm x 60cm – 48” x 24” x 24” and upwards will be good for this fish. Hoplias malabaricus is a sedentary fish so does not require a huge amount of space. A large aquarium offers the opportunity to add additional fish to bring the tank to life.

Tank Setup:   A place to call home should be provided, a large pipe or peace of bog wood should be provided. A structured aquascape will help to make the wolf feel at home. Malabaricus tend to like dim lighting and tend to be more active at dusk and night time so cover will help to bring them out. Floating plants may help achieve this.

Some very good images of juveniles in there natural environment can be seen here. Aquatic experts images

Compatibility: Juveniles can be kept together with little issue although if there is a substantial difference in size cannibalism can occur. As they mature things change. Generally multiplies can’t be kept together but it can be achieved in larger setups. In larger setups there is also the possibility to add other larger fish too big to be eaten but these need to be fish that present no territorial threat. Open water swimmers like dollar species or brycon and other large characins would work well. As with all Hoplias species each individual has it’s own personality and tolerances to other fish and there will always be a risk that things might not work out.

There is a risk with fish that will present a territorial threat like aggressive cichlids species as this will cause conflicts with the wolf and substantial damage can occur with the wolves damaging teeth.

Preferred diet: malabaricus are not fussy eaters and will except most meaty foods, shrimps, mussel, crayfish, and fish meats are all accepted and variety will help ensure good health.

Breeding: Breeding has been achieved in captivity where a pair has formed. A pit will be dug out for the eggs to be laid in, the eggs can number in the 1000’s. The Male will guard the eggs and initially the fry but will start to ignore them. The males protection includes keeping the female away. Juveniles will grow rapidly and will resort to cannibalism as they grow. An example of the breeding can be found here.

Availability: Has been in the hobby for some time now and is commonly available and relatively cheap to purchase. It is by far the most commonly kept species. Hoplias malabaricus is illegal to keep in California USA.

Additional info: Because of the enormous range of distribution there is a remote possibility that there may be multiple species under the name malabaricus, until further work is carried out this is an unknown. A good example of this being the Pantanal malabaricus that has a different physical appearance being a slimmer more pointed profile.

Small juveniles are often found in muddy puddles on the forest floor left by the drained forests . This may be a factor in the canablism of young as there would be limited food in these types of environments. Meaning they would grab what they can when they can.

Author: Stephen Cousins 2011