The Wolf Pack


Scientific Name:
  Hoplias curupira - Black Wolf fish

Known Common or Trade Names: Black Wolf fish, Hoplias Sp. Black.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:  Oyakawa & Mattox 2009, Holotype - Tocantins

Distribution and environment: A wide distribution across the north of South America, Venezuela, Guyana, Surinam and Brazil across the Orinoco, Amazon and its tributaries, Tocantins, Xingu and Negro Rivers, Know to live in a mixture of environments and lives in areas of flowing water.

Description:  In comparison to most Hoplias, Hoplias curupira are quite bulky in build with a blunt head and broad body. The colours vary greatly depending on mood from a light brown patterning to an almost solid black colouring hence the name ‘Black Wolf fish’. There also seems to be some colouration difference between capture locations in regards to the upper colouration of the fish. From almost an orange colouration to a much darker brown.

The defining characteristics of Hoplias curupira is four patches of small pores along each side of the underside of the jaw. All other Hoplias apart from Hoplias aimara have singular pores along the jaw. This can be seen in the image below. In addition to this they have between 34 and 39 scales along the lateral line. The patch of pores can be seen in the red circle in the image below. Images can be found on Hoplias curupira gallery

Size: A medium sized Hoplias rumored to reach close to 30”. Usually reaches 40cm – 15 – 16 inches in captivity.

Juvenile Description: The juveniles have a slimmer profile than adults but generally look similar. They develop the patch of pores by 6cm so should be easy to differentiate from other Hoplias species from an early age.

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. 150cm x 60cm x 60cm – 60” x 24” x 24” and upwards will be good for this fish. The bigger the tank the more active the fish will be and the more likely you will be able to get away with tank mates..

Tank Setup:  Hoplias curupira come from relatively open waters with some flow. The y will enjoy some open space as they will often hover and swim in mid water the bigger the tank the more likely they are to swim rather than hover. Some cover should be provided a large piece of bogwood to hide behind or a large pipe will be suitable. Curupira are diurnal so will be out in the open during the day.

Compatibility: Although known to exist as pairs in the wild it seems to be hit and miss as to keeping multiples together, usually a miss. This is also the case when kept with other Hoplias species, it has been done but this is the exception rather than the rule. Lots of communities with other species have been successful, as long as the fish is too large to be eaten, e.g. Brycon. There is an example of one being kept with the shoaling Gold wolf, hoplerythrinus unitaeniatus. Open water swimmers will encourage the wolf to swim openly as well.

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

Preferred diet: curupira 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. Curupira also consume a small amount of fruit in the wild.

Breeding: Breeding is unknown in captivity.

Availability: Has been in the hobby for some time now, it was rarely kept mostly due to the price as it is still expensive for the average fish keeper. It has now become fairly common now is probably the second most kept species after Hoplias malabaricus.

Additional info: Only recently described in 2009 and was previously known as Hoplias sp. Black. It was and still is sold under a number of names including Hoplias macrophthalmus. It has been described as a member of the Lacerdae group.

Within the “Revision of the Neotropical trahiras of the Hoplias lacerdae species-group” writen by Oyakawa & Mattox while describing the Lacerdae group there is a statement

"Hoplias curupira has a wide distribution in the Amazon basin, and variation of the color pattern was detected from different localities. It is not possible to define if this is due to ecological variation or indicative of a second species in the basin."

This suggests that there may be a further species or subspecies, this may be the colour variant shown above in the description, I have found this example to be very shy and only active at night time also extremely aggressive.

Author: Stephen Cousins 2011