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Electric Eel

Electrophorus electricus

The 800-Volt Biological Weapon (200-250 cm / 6-8 feet). The Electrophorus electricus is one of the most terrifying, dangerous, and fascinating freshwater creatures on Earth. Despite its snake-like appearance, it is not an eel; it is actually a colossal, air-breathing South American Knifefish. It possesses three massive internal electric organs that make up four-fifths of its massive body, capable of discharging a catastrophic 860 Volts—enough to stun a crocodile, drop a horse, or cause cardiac arrest and fatal drowning in an adult human. Mostly blind as adults and breathing atmospheric air to survive in stagnant, oxygen-starved mud pits, keeping this apex predator is an immense physical and lethal risk strictly reserved for professional aquarists and public zoos.

Taxonomy

Class:Actinopteri

Order:Gymnotiformes

Family:Gymnotidae

Genus:Electrophorus

Species:Electrophorus electricus

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Water Temperature

23 - 28 °C

pH Value

5.5 - 7

Water type

Freshwater

Adult size

250 cm

Minimum tank volume

>= 500 L

Minimum group

>= 1

1 - 10 dGH

1 - 5 dKH

TDS

25 - 200 ppm

Conductivity

39 - 313 uS/cm

Species description

Geographical Origin and Habitat: Dark rivers of the Amazon and Orinoco basins. Prefers very slow or stagnant and murky waters, poor in dissolved oxygen, on whose bottom it lies in wait, camouflaging itself.

Taxonomy and Morphology: Electric Eel (Electrophorus electricus). In reality it is not an eel (Anguilliformes), but belongs to the Gymnotiformes (knifefish). 90% of its immense 2-meter (6.5 ft) body consists of muscle masses transformed into electrogenic plates capable of generating discharges of hundreds of volts.

Social Behavior: Solitary and apex predator, and nocturnal. In the aquarium it spends 95% of its time motionless on the bottom, emerging to the surface to gulp air (obligate air breathing).

Coloration and Sexual Dimorphism: Heavy muscular tube of gray/anthracite black or muddy brown color. In large specimens the throat and belly take on a dark orange or dirty red color. No known visual sexual dimorphism.

Care, breeding and tankmates

Aquarium Setup: Not a fish for home aquariums. Requires monumental tanks (300+ cm / 120 inches, over 2,500 liters / 660 gallons). Powerful chemical filtration given the diet, low lights and zero decor except PVC pipes to allow it to rest. MASSIVE lid, the animal can destroy it and get out.

Diet and Feeding: Fleshy carnivore. Accepts thawed fish, squid and giant mussels presented with long PLASTIC TONGS. Hunts by paralyzing the prey before swallowing it whole. One meal a week is often sufficient for large specimens.

Water Quality: Extremely robust; breathes atmospheric air so it is insensitive to the oxygen in the tank (it is sufficient that there is no toxic ammonia for the skin). Warning, if you prevent it from emerging it will drown.

Compatibility and Cohabitation: Strictly ZERO tankmates, unless you have indoor ponds. Will kill by electrocution or swallow anything placed next to it, even large Pacus or giant Cichlids.

Aquarium Breeding: Unknown in captivity. In nature the male builds a nest of salivary foam during the dry season.

Risks and Diseases: MORTAL DANGER! A discharge (up to 800V) can cause cardiac fibrillation in humans, especially in aquatic immersion. Any operation in the tank requires industrial high-voltage rubber insulating gloves and preferably moving the animal with double nets without a metal frame. Under no circumstances to be kept if inexperienced.

Geographic Origin and Distribution

Dark rivers of the Amazon and Orinoco basins. Prefers very slow or stagnant and murky waters, poor in dissolved oxygen, on whose bottom it lies in wait, camouflaging itself.

Origin

Amazon, Orinoco, and GuianasEast Asia

Fish profile

Temperament: No verified data available
Diet: No verified data available
Life expectancy: No verified data available
Adult size: 250 cm
Sex ratio: No verified data available
Feeding frequency: No verified data available
Bioload: Extreme
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

FishBase

Window to the official scientific data of the species

Data synced on: 06/15/2026

Scientific Parameters & Models

Trophic level: 3.9 ± 0.52 se
Resilience: Medium (1.4 - 4.4 years)
Phylogenetic uniqueness (PD50): 0.625
Bayesian Length-Weight: a = 0.00389, b = 3.12

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.

Variants and close relatives

Same atlas type, nearby scientific identity, genus, or family.

Recommended companions

Compatible cards from coherent ecosystems with matching parameters.

Similar care

Cards with similar requirements, difficulty, habitat, and husbandry profile.

Species description

Care, breeding and tankmates

Geographic Origin and Distribution

Origin

Fish profile

Scientific Parameters & Models

Image gallery

Related species

Variants and close relatives

Banded Knifefish

Recommended companions

Blyxa alternifolia

Blyxa cf. vietii

Alternanthera reineckii "rosaefolia minor"

Copeland's Tetra

Similar care

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Flag Acara (Smiling Cichlid)

Severum (Banded Cichlid)

Cryptic Corydoras