Osteoglossidae

Black arowana

Osteoglossum ferreirai

Mouthbrooding eggs within the Negro River basin

• Black
• Gray
• Red
• Tropical
• Regional distribution
• Freshwater fish
• South America
• Elongated
• Large
• Tropical fish

Cloaked in deep velvet tones during youth and metallic steel-blue in maturity, the black arowana is an extraordinary ancient osteoglossid endemic to the acidic blackwater tributaries of the Amazon and Orinoco basins. Its slender, elongated ribbon-like body features continuous dorsal and anal fins that run along the rear half of the torso to merge almost completely with the rounded caudal fin. Juveniles display a dramatic jet-black base highlighted by a bright yellowish-white lateral stripe, transforming as adults into iridescent dark steel-grey with fiery yellow and crimson fringes lining the fin margins. Two conspicuous, forward-projecting sensory barbels sit on the upturned chin, probing the water surface. Indigenous to the Rio Negro in Brazil and the upper Orinoco in Colombia and Venezuela, it thrives in warm, highly acidic, tannin-stained blackwater channels and flooded igapó forests down to five meters depth. A surface ambush hunter, it leaps to catch low-hanging beetles, spiders, frogs, and small fishes. Males practice devoted mouthbrooding for up to two months. Maximum recorded total length reaches sixty centimetres.

Sources: FishBase — Black Arowana, Osteoglossum ferreirai