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Osteoglossids are carnivorous, often being specialized surface feeders. They are excellent jumpers; Osteoglossum species have been seen leaping more than 6 ft (almost 2 m) from the water surface to pick off insects and birds from overhanging branches in South America, hence the nickname "water monkeys".

Classification / Names 
Actinopterygii (ray-finned fishes) > Osteoglossiformes (Bony tongues) > Osteoglossidae(Arowanas)


Size / Weight / Age
Max length : 90.0 cm TL male/unsexed; max. published weight: 6,000 g.


Freshwater; benthopelagic.


Climate / Range
Tropical; 24°C - 30°C


South America: Amazon River basin, Rupununi and Oyapock Rivers.


Short description
Body covered with very big scales; dorsal and anal fins almost fused with the caudal fin; and 2 barbels at the extremity of the lower jaw. Adults are silvery, juvenile with blue glints and a yellow-orange bar.


These fish are omnivores with a tendency to feed on fish at the surface. The superior position of the mouth allows it to capture its prey while swimming from below. It also jumps out of the water to feed on large insects (Coleoptera). It is capable of adapting to environments with low oxygen levels.




Capt Marc will take his groups during the prime fishing season and not just to fill a week, we have prime weeks reserved for the most possible productive trips to the Amazon, contact us for full details and dates. Trips fill up fast and early.

River Monsters

in the Rio Negro River

The Mouthbreeding Fish

Osteoglossids are basal (primitive) fish from the lower Tertiary and are placed in the actinopterygiid order Osteoglossiformes. As traditionally defined, the family includes several extant species from South America, one from Africa, several from Asia, and two from Australia. Today Arapaimidae is often regarded as a separate family, which includes the arapaimas and the African arowana.  Consequently, the South American genus Osteoglossum, and the Asian and Australian genus Scleropages are the only extant general that remain in the osteoglossid family. Arapaimidae and Osteoglossidae split about 220 million years ago (Mya), during the Late Triassic.


Within Osteoglossidae, the South America Osteoglossum arowanas diverged from the Asian and Australian Scleropages arowanas about 170 Mya, during the Middle Jurassic.


The Osteoglossidae are the only exclusively freshwater fish family found on both sides of the Wallace Line.[6] This may be explained by the theory that Asian arowanas (S. formosus) diverged from the Australian Scleropages, S. jardiniiand S. leichardti, about 140 Mya, making it likely that Asian arowanas were carried to Asia on the Indian subcontinent


Several species of osteoglossids exhibit parental care. They build nests and protect their young after they hatch. All species are mouthbrooders, the parents holding sometimes hundreds of eggs in their mouths. The young may make several tentative trips outside the parent's mouth to investigate the surroundings before leaving permanently.

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