Overview
The Banded Water Cobra (Naja annulata), formerly classified within the distinct aquatic genus Boulengerina, is a formidable semi-aquatic elapid native to the ancient Great Lakes and river basins of Central Africa. Reaching lengths exceeding seven feet, this muscular, aquatic cobra spends much of its life submerged in the crystal-clear waters of Lake Tanganyika, hunting endemic cichlids among submerged granite boulder piles with astonishing aquatic speed.
Biology and Physical Characteristics
Naja annulata displays a robust, heavy-bodied form with smooth, glossy scales. Its dorsal coloration is a rich yellowish-brown or glossy olive, marked by a series of broad, prominent jet-black rings (annuli) encircling the body. Its small, rounded head houses large dark eyes with round pupils suited for underwater vision. While it can spread a narrow, elongated defensive hood on land, in water it transforms into a torpedo-like swimmer. Its venom is a potent neurotoxin that rapidly immobilizes energetic fish prey in cold aquatic depths.
Behavior and Ecology
Banded Water Cobras are skilled swimmers and divers capable of holding their breath for over ten minutes and descending to depths of 25 meters along rocky underwater drop-offs. When foraging, they actively probe deep crevices between boulders to corner cichlids, striking with lightning speed underwater. On land, they bask along wave-splashed rocks, quickly retreating into deep water or shoreline caverns if disturbed. Females are oviparous, laying clutches of up to 20 eggs in humid rock crevices.
Conservation and Human Impact
Evaluated as Least Concern by the IUCN, the Banded Water Cobra is common and widespread throughout the Lake Tanganyika littoral basin. While occasionally killed by local fishermen who encounter them along rocky beaches, they are non-aggressive in water and rarely bite humans. Potential threats stem from shoreline urban expansion, agricultural siltation that reduces lake water clarity, and intensive gillnetting. Protecting clean shoreline buffer zones preserves its specialized foraging grounds.
Interesting Factoid
Unlike terrestrial cobras that strike forward from an upright posture, the Banded Water Cobra can strike, seize, and swallow thrashing fish entirely underwater while swimming at high speed.
Last updated: October 2026