Overview
The Barred Bichir (Polypterus delhezi), also called the Armored Bichir, is a living fossil belonging to the ancient basal ray-finned fish family Polypteridae. Endemic strictly to the Congo River basin of Central Africa, this prehistoric freshwater predator boasts a row of independent dorsal finlets, diamond-shaped interlocking ganoid scales, and primitive paired lungs that allow it to breathe atmospheric oxygen in stagnant, oxygen-depleted backwaters.
Biology and Physical Characteristics
Polypterus delhezi features an elongated, eel-like body coated in an impenetrable armor of multi-layered ganoid scales. Its coloration is striking: an olive-gray to yellowish-tan dorsal field intersected by 7 to 8 bold, black vertical bars spanning the flanks. Its dorsal fin is divided into 10 to 13 separate spine-supported finlets, each capable of independent erection. Uniquely, its paired lungs connect directly to the esophageal floor, allowing it to survive prolonged terrestrial exposure in moist mud.
Behavior and Ecology
Bichirs are nocturnal bottom-dwellers that move with serpentine grace across river substrates. Utilizing muscular, lobed pectoral fins that resemble primitive terrestrial limbs, the Barred Bichir ‘walks’ along the river bottom among fallen logs and roots. They rely primarily on keen chemoreception and lateral-line electroreceptors rather than vision to ambush sleeping fish, crustacean prey, and aquatic insects.
Conservation and Human Impact
Assessed as Least Concern by the IUCN, Polypterus delhezi maintains healthy, stable wild populations throughout the extensive waterways of the Congo River basin. Because it is highly sought after in the international freshwater aquarium trade for its distinctive barred markings and hardy constitution, sustainably managed collection and captive breeding represent its primary commercial touchpoints.
Interesting Factoid
Thanks to their vascularized swim-bladder lungs, bichirs are obligate air-breathers that will actually drown if prevented from periodically rising to the water’s surface for a gulp of atmospheric air.
Last updated: October 2026