An apex predator native to the fast-flowing rivers of South America. The Aimara is notorious for its incredible jaw strength, massive teeth, and unmatched aggression. It is arguably the most aggressive freshwater aquarium fish and will violently attack tankmates, equipment, and even the keeper's hands. It must be housed completely alone in a highly secure, massive aquarium with heavily weighted or lockable lids to prevent them from jumping or shattering the glass during feeding strikes.
Monster Wolf Fish (Aimara) At a Glance
Monster Wolf Fish (Aimara) Tank Requirements
Will Monster Wolf Fish (Aimara) fit in your tank?
Care guides tell you what Monster Wolf Fish (Aimara) needs, the next question is whether your tank can safely provide it. Test Monster Wolf Fish (Aimara) against your tank size, maintenance needs, and the fish you already keep before you buy.
Useful setup supplies
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Monster Wolf Fish (Aimara) Water Parameters
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Monster Wolf Fish (Aimara) Temperament & Compatibility
Monster Wolf Fish (Aimara) Varieties
Each variety inherits the species defaults above. Only differences are highlighted.
Standard (Adult)
The fully grown adult form. A solitary apex predator requiring a massive, dedicated enclosure. They are incredibly powerful and require thick acrylic or glass and absolutely secure tops.
Same care requirements as the base species
Also known as: Adult Aimara, Monster
Juvenile (Grow-out)
Juvenile stage. While much smaller, they are still highly aggressive and possess a voracious appetite. They pack on size and muscle very rapidly. A grow-out tank is acceptable but must be upgraded quickly.
Differs in 3 traits from base species
Also known as: Baby Aimara, Pup
Monster Wolf Fish (Aimara) Care Guide Summary
The Monster Wolf Fish (Aimara), scientifically known as Hoplias aimara, belongs to the Oddballs family group. Adults reach a maximum size of approximately 100 cm and have a fusiform body shape with a fast growth rate. Classified as highly aggressive, this species primarily occupies the mid-level and bottom zones of the aquarium and produces a extreme level of biological waste.
To thrive, the Monster Wolf Fish (Aimara) requires a freshwater only aquarium with a minimum volume of 1500 litres and a tank length of at least 240 cm. Water temperature should be maintained between 23°C and 28°C, with a pH range of 6–7.5 and a general hardness of 2–15 dGH. A high water flow is preferred.
Due to its specialist needs, the Monster Wolf Fish (Aimara) is best suited for fishkeepers who can provide a carefully planned setup. This species is available in 2 varieties: Standard (Adult) and Juvenile (Grow-out). Each may differ slightly in size, temperament, or care needs, so it is worth checking the specific requirements of the variety you plan to keep.
Monster Wolf Fish (Aimara) Habitat Setup
When setting up an aquarium for the Monster Wolf Fish (Aimara), a high water flow best suits their natural preferences. Because this species occupies the mid-level and bottom zones, the aquarium layout should prioritise open swimming space in the centre of the tank for free movement and sufficient floor space with hiding spots among rocks, wood, or dense planting. Useful additions include smooth gravel or rounded substrate to protect their sensitive barbels and driftwood, which can serve as both a hiding place and a dietary supplement. Keepers should note that a tight-fitting lid is essential, as this species is a known jumper.
Monster Wolf Fish (Aimara) Compatibility Notes
Classified as highly aggressive, the Monster Wolf Fish (Aimara) is best housed alone, as they do not tolerate others of their kind in confined spaces. When choosing tankmates, any fish small enough to fit in its mouth will likely be eaten, conspecific aggression can be intense, especially in smaller tanks, territorial behaviour may cause issues if hiding spots or floor space are limited, and their energetic swimming style may stress more sedentary or timid species. Selecting tankmates that favour different water layers from the mid-level and bottom zones can help reduce competition and territorial overlap.
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Frequently Asked Questions About Monster Wolf Fish (Aimara)
How big does Monster Wolf Fish (Aimara) get?
Monster Wolf Fish (Aimara) (Hoplias aimara) typically reaches a maximum adult size of approximately 100 cm. They have a fusiform body shape and a fast growth rate.
What tank size does Monster Wolf Fish (Aimara) need?
A minimum aquarium volume of 1500 litres and a tank length of at least 240 cm are recommended for Monster Wolf Fish (Aimara). This ensures enough swimming space and helps maintain stable water conditions.
What water parameters does Monster Wolf Fish (Aimara) need?
Monster Wolf Fish (Aimara) thrives in freshwater only conditions with a temperature range of 23–28°C, a pH between 6 and 7.5, and a general hardness of 2–15 dGH. A high water flow is preferred.
Is Monster Wolf Fish (Aimara) peaceful or aggressive?
Monster Wolf Fish (Aimara) is classified as highly aggressive with an aggression score of 10 out of 10. Careful tankmate selection is essential to avoid conflict.
Can Monster Wolf Fish (Aimara) live with others of its kind?
No. Only one Monster Wolf Fish (Aimara) should be kept per tank. Keeping multiples in the same aquarium typically results in aggression and stress.
Does Monster Wolf Fish (Aimara) have any special tank requirements?
Yes. Monster Wolf Fish (Aimara) benefits from smooth gravel (sensitive barbels) and driftwood (digestion/hiding) in the aquarium. These features help replicate their natural habitat and promote overall health and well-being.
Does Monster Wolf Fish (Aimara) need a lid on the tank?
Yes. Monster Wolf Fish (Aimara) is a known jumper, and a tight-fitting lid or cover is essential to prevent escape. Even a small gap can be enough for a determined fish to leap out.
Plants That Suit Monster Wolf Fish (Aimara)
These plants pair well with Monster Wolf Fish (Aimara) based on shared water preferences, layout fit, and how likely they are to hold up in the same aquarium.
African Water Fern
Bolbitis heudelotii
Boivin's Aponogeton
Aponogeton boivinianus
Capuron's Aponogeton
Aponogeton capuronii
Madagascar Lace Plant
Aponogeton madagascariensis
African Onion Plant
Crinum calamistratum
Afzel's Anubias
Anubias afzelii
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