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Aimara (Giant Wolf Fish)

Hoplias aimara

The Fearless Amazonian Assassin (100-120 cm / 40-47 inches). The Hoplias aimara is not a community fish; it is a solitary, hyper-aggressive, armored dinosaur. It is the absolute apex predator of its genus, heavily built like a torpedo and armed with terrifying, thick canine teeth that proudly protrude even when its mouth is fully closed. Unlike skittish predators that hide, the Aimara is infamously fearless: it will actively attack and charge anything that enters its territory, including massive tankmates and the owner's bare hands. It demands massive, heavily armored 'solitary confinement' tanks and poses a genuine physical bite risk to careless owners.

Taxonomy
Class:Actinopteri
Order:Characiformes
Family:Erythrinidae
Genus:Hoplias
Species:Hoplias aimara

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Water Temperature

24 - 30 °C

pH Value

6 - 7.5

Water type

Freshwater

Adult size

100 cm

Minimum tank volume

>= 500 L

Minimum group

>= 1

GH

4 - 15 dGH

KH

2 - 7 dKH

TDS

80 - 295 ppm

Conductivity

125 - 461 uS/cm

Species description

Geographical Origin and Habitat: Amazon River basin (Brazil, Guyana, Venezuela). Inhabits deep river beds, where it waits for prey, but does not disdain strong oxygen-rich rapids.
Taxonomy and Morphology: Aimara Wolf Fish (Hoplias aimara). The apex of wolf fish. Monstrous (reaches one meter / 3.3 feet and 40kg / 88 lbs). It has an armored head, huge projecting canines visible from jaws designed to shear and an immense tail for lightning accelerations.
Social Behavior: The asocial and hyper-aggressive killer. It is an ambush predator that lives strictly isolated (Strictly Solitary). It will attack anything that moves, often breaking tanks and hurling its snout against fingers on the glass.
Coloration and Sexual Dimorphism: Pure camouflage for the Amazonian seabed: a mix of mud brown, black and olive-silver, with a typical opaque black "mark" in the shape of an inverted V (or bar) behind the brachial operculum. No dimorphism.

Care, breeding and tankmates

Aquarium Setup: Tank for MONSTERS. An indoor pool of at least 250 cm (100 inches) (3000 liters / 800 gallons) equipped with CEMENTED LIDS. It will smash thin glass and jump out easily breaking plastic lids if frightened. Irremovable massive woods.
Diet and Feeding: Extreme carnivore (Piscivore). Can shear large fish in half. Must be fed (using LONG TONGS) with salmon steaks, whole trout, mussels and prawns. DO NOT put hands in the tank during meals or you risk stitches at the ER.
Water Quality: Requires strong currents to reproduce the rapids it comes from (essential for oxygenation) and industrial filters to support the colossal meals. Resists pH variations but cannot stand prolonged cold.
Compatibility and Cohabitation: None. It will kill and eat (or dismember) any tankmate sooner or later, including sharks, pacus and arowanas. Keep it STRICTLY as the only animal in the tank (Species-only).
Aquarium Breeding: Impossible in home aquariums. Forming a pair invariably leads to the death of one of the two partners in the confined aquarium spaces.
Risks and Diseases: PHYSICAL risk for the keeper! This is a dangerous fish. Its bites cause amputations or deep lacerations. Tank maintenance must be done by interposing plastic separators (dividers).

Geographic Origin and Distribution

Amazon River basin (Brazil, Guyana, Venezuela). Inhabits deep river beds, where it waits for prey, but does not disdain strong oxygen-rich rapids.

Origin

Amazon, Orinoco, and Guianas

Fish profile

Temperament
No verified data available
Diet
No verified data available
Life expectancy
No verified data available
Adult size
100 cm
The catalog's scalar value is 100 cm. The FishBase SPECIES table (v25.04 snapshot) source reports a maximum adult measurement of 100 cm for this species, recorded as standard length (SL). The taxonomic record consulted is Hoplias aimara (v25.04); male or unsexed record. These figures are not interchangeable: the first is the profile's editorial reference, whereas the second is a published maximum under a specific measurement convention; differences among sources can reflect sex, population, life stage and measuring method.
Sex ratio
No verified data available
Feeding frequency
No verified data available
Bioload
Extreme
The single-adult profile is classified as extreme bioload. The bioload-v2 rubric deterministically assigns this class from the verified maximum length of 100 cm; it is a catalog management category, not a direct measurement of waste output.
Flow
No verified data available
Jump risk
No verified data available
Reproduction
No verified data available
Compatibility & tankmates
No verified data available
Tank level
No verified data available

Window to the official scientific data of the species

Data synced on: 06/15/2026

Scientific Parameters & Models

Trophic level
3.7 ± 0.55 se
Resilience
Medium (1.4 - 4.4 years)
Phylogenetic uniqueness (PD50)
0.5
Bayesian Length-Weight
a = 0.00741, b = 3.13
VulnerabilityHigh to very high vulnerability (73 / 100)

Image gallery

Licensed images linked to the species or, when marked, to the closest representative taxon.

Related species

Recommendations grouped by close relatives, companion choices, and similar care.

Last updated: 08/10/2026
Aimara (Giant Wolf Fish) (Hoplias aimara) Care Guide & Tank Setup | Atlarium