The African knifefish (Gymnarchus niloticus), also known as aba aba, is an electric fish native to rivers and lakes in Africa. It has a long, slender body with no pelvic or anal fins, and uses its elongated dorsal fin for unique, wave-like propulsion. It generates a weak electric field to sense its surroundings and find prey, compensating for its poor vision.
Scientific Name
Gymnarchus niloticus
Habitat
Bottoms of freshwater rivers and lakes in Africa
Conservation
Not endangered; no major threats identified in natural habitat
Lifespan
Estimated 10–15 years in the wild
Fun Fact
Its undulating dorsal fin inspired a robotic swimming prototype called RoboGnilos!
Diet
Carnivorous; primarily feeds on smaller fish
Average Size
Up to 1.6 meters (5.2 feet) and 19 kg (42 lbs)
Location / Placement info
Displayed in the Coastal Reef Exhibit, near the Ocean-View Tunnel
FAQ
Is the African knifefish electric?
Yes, it produces a weak electric field for navigation and hunting.
Can African knifefish live in an aquarium?
It is possible, but requires a very large tank due to its size and behavior.
Is African knifefish aggressive?
It is not aggressive toward humans but may prey on smaller tankmates.
How does African knifefish swim?
It uses its long dorsal fin to move in wave-like motions while keeping its body straight.
What inspired RoboGnilos?
Scientists used the knifefish's swimming method to develop a biomimetic robotic fin.
)