Home / Fishes / Knifefish and electric eels / Electric eel
No federal permit to keepElectric eel
Electrophorus electricus
Fishes › Knifefish and electric eels (Gymnotiformes) › Gymnotidae (Electric eels and knifefish)
Electrophorus electricus is the best-known species of electric eel.
Care at a glance
Species-specific aquarium care
- Tank: An adult reaches about 98.4 in (250 cm). That needs a pond or public-aquarium-scale system, far beyond a home aquarium.
- Water: Freshwater.
- Temperature: 73–82°F (range recorded for this species).
- Layout: Uses both the bottom and open water: give open swimming space plus cover near the substrate.
- Diet: A predator: feed meaty foods sized to its mouth (frozen fish, shrimp, worms); it will eat tankmates that fit in its mouth. FishBase classes it as a carnivore.
- Availability: Mostly kept by public aquariums; private keeping is uncommon.
Calculated from this species' own FishBase record: tank size from its typical adult length and swimming zone, water values from its recorded ranges. The group guide below fills in general care.
Care guide
Species care notes
- Water: soft, acidic water, 73–82 °F, pH 5.5–7, 1–12 dGH.
- Behaviour: a shoaling fish best kept in a group of six or more.
- Difficulty: Moderate (Seriously Fish rating).
Short excerpts from the species profile:
- Setup: “Water movement in the aquarium should be kept to a minimum.”
- Diet: “Carnivorous and is easily weaned onto dead food in captivity.”
- Tankmates: “Best kept singly and alone.”
- Breeding: “It's not been bred in captivity.”
From the Seriously Fish profile for this species, which has the full habitat, maintenance, diet, behaviour and breeding write-up 167
South American knifefish
Applies to most species in this group. Habitat: Murky tropical rivers. Individual species can differ, so compare with the species numbers above and the linked sources.
Housing & setup
- Large, dim tanks with tubes or caves; electric eels need specialist setups and are dangerous.
Diet
- Live and frozen meaty foods.
Health watch
- Black ghost knifefish are shy and sensitive to water quality.
Understanding the animal
About this animal
About this animal
It is a South American electric fish. Until the discovery of two additional species in 2019, the genus was classified as the monotypic, with this species the only one in the genus.
Quoted from the Wikipedia article “Electrophorus electricus” (CC BY-SA 4.0) 174
In the wild
In the wild
From this species’ own FishBase record (habitat, bottom type, water and breeding data), not its family. Good care copies these conditions.1
| Where it lives | Lives in freshwater, in rivers and streams, marshes and swamps, estuaries. Uses both the bottom and open water. Prefer muddy bottoms and calm waters; frequently found in coastal plains, swamps and creeks but is also found inland where a favorable biotope exist. Juveniles feed on invertebrates, adults feed on fish and small mammals. |
| Water it lives in | Freshwater, 73–82 °F (23–28 °C). |
| Climate | Tropical climate. |
| Wild diet | Hunting macrofauna (predator). |
| Behavior to plan for | Breeding: nesters. |
What this means for care
- Keep water within its wild range, 73–82 °F.
Native climate (measured)
Native climate (measured)
| Warm-season highs | about 90°F (up to 94°F in the hottest sampled areas) |
| Cool-season lows | about 70°F (down to 65°F in the coldest sampled areas) |
| Average temperature | 78–81°F across sampled records |
| Relative humidity | 77–83% on average (driest month about 74%) |
| Rainfall | about 2332 mm a year |
Measured at 226 wild occurrence records sampled against WorldClim 2.1 climate data (1970–2000 averages). Air conditions in the range are ecological context, not enclosure settings: microhabitats such as burrows, leaf litter or basking rocks can be cooler, warmer or more humid.
From the sources
From the sources
Quoted from the matching sections of reputable sources for this exact species. Specialist databases are used first; Wikipedia (community-edited, CC BY-SA 4.0) only fills gaps. Other sources are short credited quotes.
| Overview | Electrophorus electricus is the best-known species of electric eel. It is a South American electric fish. Until the discovery of two additional species in 2019, the genus was classified as the monotypic, with this species the only one in the genus. Despite the name, it is not an eel, but rather a knifefish. — Wikipedia (community-edited) |
| Where it lives | Home ranges Population dynamics Growth parameters Max. ages / sizes Length-weight rel. Length-frequencies Mass conversion Recruitment Abundance Life cycle Reproduction Maturity Maturity/Gills rel. — FishBase |
| Social life and communication | The Sachs organ is the primary source of communication among E. electricus. — Animal Diversity Web |
| Wild diet | To find prey E. electricus uses its weak electric organ, also known as the Sachs organ. — Animal Diversity Web |
| Behavior | Although electric eels have the potential to be fairly aggressive animals, they are not. — Animal Diversity Web |
| Reproduction | Males construct foam nests and guard the growing larvae until mid-January when the first seasonal rains flood the breeding area, causing the about 10 cm long young eels to disperse. Males outnumber females (3:1) and are considerably larger than females. There are three successive batches of eggs deposited in a spawning period. — FishBase |
| Lifespan | The lifespan of electric eels in the wild is unknown. — Animal Diversity Web |
| Appearance and size | Electric eels are not really eels, they are actually ostariophysians, but have a strong physical resemblance to true eels. — Animal Diversity Web |
| Biology | Prefer muddy bottoms and calm waters; frequently found in coastal plains, swamps and creeks but is also found inland where a favorable biotope exist. Juveniles feed on invertebrates, adults feed on fish and small mammals, first-born larvae prey on other eggs and embryos coming from late spawning batches. — FishBase |
| History and naming | The species has been reclassified several times. When originally described by Carl Linnaeus in 1766, he used the name Gymnotus electricus, placing it in the same genus as Gymnotus carapo (banded knifefish) which he had described several years earlier. It was only about a century later, in 1864, that the electric eel was moved to its own genus Electrophorus by Theodore Gill. — Wikipedia (community-edited) |
| Conservation | IUCN Red List Least Concern More information Additional Links Encyclopedia of Life Contributors William Fink (editor), University of Michigan-Ann Arbor. — Animal Diversity Web |
Data and studies
The numbers
The numbers
Each bar is what one source reports. Where several sources weigh in, the dashed gold band marks their average.
Maximum recorded lifespan
Longest recorded lifespan reported by each database; typical lifespans are usually shorter. The AnAge record comes from an animal in human care.
Typical adult weight
Average adult body mass in each database (FishBase gives the maximum recorded weight).
Adult length
Maximum recorded length. Measured as standard length (snout to the base of the tail, not counting the tail fin). Fish in home aquariums often stay smaller than wild records.
Water temperature
Range the species tolerates in nature; aim for the middle.
pH
Water hardness
Veterinary & husbandry research
Veterinary & husbandry research
- Neuronal embryonal tumors in fish Kagan RA et al., Veterinary pathology 2010
Peer-reviewed papers that mention this species alongside captivity, zoos, veterinary care or aquaculture. Some cover several species or mention it only in passing, so check the abstract. 170
Sources for this sheet
- AnAge: The Animal Ageing and Longevity Database (Human Ageing Genomic Resources) Peer-reviewed researchCurated, referenced longevity and life-history records for thousands of species; maximum lifespans are often from zoo animals.
- FishBase (Froese & Pauly, eds.), version 24.07 Peer-reviewed researchThe global scientific database on fishes, maintained by a consortium of research institutions; every value is referenced.
- Seriously Fish species profiles Experienced keeper or breederLong-running aquarium reference written and peer-checked by experienced fishkeepers and ichthyologists; each profile covers habitat, tank size, water, diet, behaviour and breeding.
- Merck Veterinary Manual: Management of aquarium fish Zoo, university or veterinaryThe Merck Veterinary Manual: a standard veterinary reference written and reviewed by veterinary specialists.
- Merck Veterinary Manual: Types and features of aquatic systems Zoo, university or veterinaryThe Merck Veterinary Manual: a standard veterinary reference written and reviewed by veterinary specialists.
- Merck Veterinary Manual: Nutritional diseases of fish Zoo, university or veterinaryThe Merck Veterinary Manual: a standard veterinary reference written and reviewed by veterinary specialists.
- Wikipedia (species article) Community referenceFree encyclopedia; useful overviews with their own citations. Intro text is quoted under CC BY-SA 4.0.
- PubMed (U.S. National Library of Medicine) Peer-reviewed researchIndex of peer-reviewed veterinary, zoo and husbandry research.
- iNaturalist (captive observations) Community referenceCommunity observation platform run by the California Academy of Sciences and National Geographic; observations marked captive show animals living in homes, zoos and aquariums.
