Family Erythrinidae - Trahiras
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The information shared here is a collaborative effort, obtained from various web sources as well as information shared on MFK. Data shared is freely circulated and presented here in an attempt to provide better understanding of the Family Erythrinidae and to provide guidance of successfully maintaining these species in captivity.
Bibliography
http://www.fishbase.org/summary/FamilySummary.php?ID=103
http://www.monsterfishkeepers.com/forums/showthread.php?t=152940
Species summary
Species of this family occurs in South America. Body cylindrical. Gape reaching beyond anterior margin of orbit. Branchiostegal rays 5. Pectoral fin rays 9-14. Dorsal fin rays 8-15 and 3 vestigial rays. Dorsal fin origin anterior to anal fin and usually above pelvic fins. Anal fin rays 10-12. No adipose fin. Rounded caudal fin. Relatively large scales. Lateral line with 32-47 scales. Palatine teeth numerous. Some predaceous. Some capable of air-breathing and moving to other ponds by land. Nest-builders. About 1 m maximum length attained in Hoplias macrophthalmus of the Guianas.
16 individual species so far identified (fish base link);
Sp. Macrophthalminus discredited*
Origin and Habitat
Erythrinidae species are found in freshwater environments across South America ranging from Argentina to Guyana and Venezuela. Notable source locations include Rio Xingu, Rio Orinoco though their coverage is great.
A diverse and adaptable species, Erithrinidae are capable of inhabiting most fresh water environments from fast flowing streams and rivers to near stagnant pools and drainage ditches. Thanks to their adaptability, most Erythrinidae species will survive in a wide range of water conditions and temperatures though avoid extremes.
Habit
All Erythrinidae are predacious, though specifics diets vary from species to species. Some are dedicated Peiscovores, others feeding on insects and larvae through to small rodents and amphibians. Generally a solitary species, they are nocturnal ambush predators, choosing to rest in foliage during the day and hunt actively during the night. Sizes range from relatively small at just over 6 or 15cm through to over 100cm or 39.
General Aquaria information
Erythrinidae are predacious and as such, are generally unsuitable for the community aquaria. That said, examples do present themselves on a somewhat regular basis where specimens are kept in relative harmony with other large, robust species. However, it is widely accepted that this is generally down to the individual specimen rather than the species in general. Water chemistry is generally of secondary importance however water quality should be high. Due to their predacious nature, they are generally a messy eater, producing large quantities of waste.
When housing any Erythrinidae ensure the general rule of fish keeping is followed- 2x length = width, 4-6x length = length. Water depth is of secondary importance however overall footprint is most important. When housing large species, the above rules may seem unfeasible- Aimara for instance would require a tank of 18X6 so use common sense- you can never have a big enough aquarium.
Common traded species profile
Hoplias Malabaricus
Max size in captivity - 20"+
Locale Central to Northern South America
Minimum tank size - 120g 48" x 24" x 24"
Diet -piscivores - generally accept dead and live food
General information
The common Wolf fish is one of the more readily available members of the Wolf fish family. They are ambush predators, relying on their mottled coloration to camouflage themselves. They are very adaptive and can survive in varying water qualities.
The Malabaricus is a solitary species and incredibly aggressive towards all other fish regardless of size. It is generally a bad idea to try and mix a Common Wolf with any other fish. However, a number of people have tried with relative success to keep the Malabaricus with other fish of similar size or larger and even other Common wolves though success is rare. Breeding has been achieved in captivity, given enough space. The Male Malabaricus has a more slender body than the female.
In the aquarium, the Wolf should be provided with cover and relatively low lighting. Whilst PH and general water quality isn't important, ensure efficient filtration. The aquarium should have a secure fitting hood due to the Wolf being a notorious jumper.
Hoplerythrinus unitaeniatus
Max size in captivity - 16"
Locale - South America
Minimum tank size - 120g/ 48" x 24" x 24"
feeding - piscivores- readily accept dead due to voracious appetite
General info -
The Gold Wolf is one of the most unusual of the Wolf fish family. Unlike Hoplias Sp. or Ery. the Gold Wolf readily shoals with others of it's species. When others of its type are not available they happily shoal with characins of similar body shape (personal experience) such as Chalceus. Whilst small, they are fin nippers and generally very brave during feeding time.
They will co-habit with larger Characins and Cichlids, though ensure Cichlid species are not too aggressive or territorial. Whilst the Gold Wolf is not as aggressive as other wolf species, they are still capable of a fairly damaging bite. Catfish and Pleco's are also ideal choices.
Ensure plenty of open swimming space as these are among the most active of all Wolf Fish. Cover in not necessary due to the active nature of the species. As with most other Wolf variants, ensure a tight fitting lid due to their tendency to jump when gulping air.
Hoplias Curupira
Distribution- Rio Xingu, Brazil and Rio Orinoco are notable locations but generally distributed through most of the Amazon Basin
Max size in captivity Full size in captivity unknown, expect 24+
Locale Distribution- Rio Xingu, Brazil and Rio Orinoco are notable locations but generally distributed through most of the Amazon Basin
Minimum tank size 72 x 24 x 30 as a bare minimum.
Diet -piscivores - generally accept dead and live food
General information
Hoplias Curupira or the Black Wolf Fish is a newly described species, regularly traded as Hoplias Macrophthalminus, a now defunct name. As the name suggests they are near Jet black in coloration as an adult, with deep brown/black patterns on their flanks. As juveniles they are more mottled in color, possessing more browns than blacks, gradually darkening to the recognizable black as they mature. They are deeper set than most common Hoplias species, giving the Black Wolf an opposing presence even at small sizes. Growth rates are slow in captivity once over 16.
As with most other Hoplias Sp. the Curupira is an ambush predator and will regularly patrol the tank searching for a suitable ambush location. Tank mates are very risky- do not expect anything to survive in order to stave off disappointment. I am currently keeping my Curupira with a pair of large Geophagus Brasiliensis and Gold Wolves (H. Unitaenatus) but that is by no means a safe combination. Sleepy cichlids such as Oscars or Geophagus of most varieties do not have the temperament to see off such a large predator and an aggressive cichlid could run the risk of fatal damage should it attempt to confront the Black. Large, armored catfish such as Plecos could be fine but ensure they are significantly larger. A small catfish could be considered food and with their sharp spines, could lead to fatal damage to the Curupira. Ultimately, the safest solution is to keep the Black alone.
Hoplias Aimara
Distribution- Rio Xingu, Brazil and Rio Orinoco are notable locations but generally distributed through most of the Amazon Basin
Max size in captivity Up to 39
Locale Distribution- Rio Xingu, Brazil and Rio Orinoco and Guyana
Minimum tank size 120x 36 x 48 bare minimum for a full grown fish
Diet -piscivores - generally accept dead and live food
General information
Aimara are generally identifiable by a black spot behind the gill plate, a flatter snout with eyes positioned high up on the head. Size is also a giveaway though expect a relatively slow growth rate about 18.
The holy grail of Charciforms, the Hoplias Aimara is the largest and most ferocious of all Hoplias Species. An active and highly territorial predator capable of inflicting damaging bites at a small size. Co-habiting any species with an Aimara is considered near impossible, though there is one instance on MFK of an Aimara with Large Rays. Take great care during feeding, cleaning and general tank maintenance!
Erythrinus Erythrinus and Erythrinus Sp.
Distribution- Wide spread with numerous variants. Notable within the Amazon Basin and Peru.
Max size in captivity Up to 10
Minimum tank size 48x 15x 18
Diet -piscivores - generally accept dead and live food
General information
Erythrinus Sp are some of the smallest of the Wolf family but are by no means gentle. Pound-for-pound they are easily as aggressive as any Hoplias species and should not be kept with smaller fish. On the other hand, because of their diminutive size, it is possible to co-hab this wolf with other, larger passive species. Open water Characins are an ideal companion as well as gentle Cichlid species. Avoid overly aggressive or large species though as the small wolf will not be able to compete against much more aggressive or large species. Medium catfish and L numbers would also be suitable. Tanks should provide plenty of hiding space and cover. Avoid bright lights to see the most of your Ery.
