Gymnarchus niloticus

fish

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June 29, 2026

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Gymnarchus niloticus, also known as the African knifefish or aba, is a species of freshwater fish belonging to the family Gymnarchidae. It is characterized by its long, eel-like body and a prominent dorsal fin that runs the length of its body, which it uses for propulsion.12

A unique feature of Gymnarchus niloticus is its ability to generate and detect weak electric fields. It uses specialized electric organs to navigate, communicate, and locate prey in its often murky aquatic environment. This species also prepares a floating nest for its eggs and guards its young for approximately 18 days.2

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osteoglossomorph
Life cycle and reproduction
In contrast, Gymnarchus niloticus (Gymnarchidae) prepares a large floating nest from the matted stems of swamp grasses, biting off the stems and fashioning them into a trough-shaped structure with an internal length of about 50 cm (20 inches). Spawning takes place in the nest, and one or…
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In contrast, Gymnarchus niloticus (Gymnarchidae) prepares a large floating nest from the matted stems of swamp grasses, biting off the stems and fashioning them into a trough-shaped structure with an internal length of about 50 cm (20 inches). Spawning takes place in the nest, and one or…
Read More

life
Photosensitivity, audiosensitivity, thermosensitivity, chemosensitivity, and magnetosensitivity
The nocturnal African freshwater fish Gymnarchus niloticus operates a dipole electrostatic field generator and a sensor to detect the amplitude and frequency of disturbances in turbulent waters.
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The nocturnal African freshwater fish Gymnarchus niloticus operates a dipole electrostatic field generator and a sensor to detect the amplitude and frequency of disturbances in turbulent waters.
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