Head to head
Arowana vs Arapaima
The arowana and the arapaima are the two best-known members of an ancient group of fish called the bonytongues, they share the Amazon, and both are surface-oriented air-breathers. But one is a slender jumper the length of your arm and the other is one of the largest freshwater fish in the world.
| Arowana | Arapaima | |
|---|---|---|
| Family | Osteoglossidae (bonytongues) | Osteoglossidae (bonytongues) |
| Length | Silver arowana ~90 cm; Asian ~1 m | 2 to 3 m, historically to 4.5 m |
| Weight | A few kilograms | Commonly 100 to 200 kg |
| Air breathing | Facultative; helps in low-oxygen water | Obligate; must surface every 10 to 20 min |
| Feeding | Surface hunter; leaps for insects and birds | Ambush predator of fish and invertebrates |
| Parental care | Male mouthbroods the eggs and fry | Male guards the young in and near the mouth |
| Human use | Prized aquarium fish, especially in Asia | Major Amazon food fish; also farmed |
| Status | Asian arowana Endangered; others less so | Data Deficient; recovering with community management |
Arowana vs Arapaima: common questions
Are arowana and arapaima the same fish?
No, but they are close cousins. Both belong to the bonytongue family, Osteoglossidae, and both live in the Amazon, but they are different genera and wildly different in size. The arowana, genus Osteoglossum in South America, is a slim, elongated fish up to about a metre long that hunts at the surface. The arapaima, genus Arapaima, is a massive, deep-bodied fish that reaches two to three metres and over 100 kilograms and is among the largest freshwater fish in the world. Think of them as a small, agile relative and a giant, heavy one within the same old family.
Do both arowana and arapaima breathe air?
Yes, but to different degrees. The arapaima is an obligate air-breather: its swim bladder is modified into a lung-like organ, and the fish must come to the surface to gulp air every 10 to 20 minutes or it will drown, an adaptation to the warm, oxygen-poor floodplain waters it lives in. The arowana is a facultative air-breather: it breathes with its gills normally but can also take air at the surface when oxygen levels drop, which lets it survive in stagnant backwaters. Both habits mean the fish spend a lot of time near the surface, where the arapaima's rolling breaths give away its position to fishers.
Why is the Asian arowana so much more expensive than an arapaima?
Because of cultural demand and legal scarcity rather than biology. The Asian arowana, or dragon fish, is regarded across parts of East and Southeast Asia as a bringer of luck and wealth, so a fine specimen is a status symbol, and top red and gold individuals have sold for tens of thousands of dollars. The species is also listed on CITES Appendix I, so the only legal fish are captive-bred at licensed farms and come microchipped and certified, which keeps supply tight. The arapaima, by contrast, is farmed and fished as food in South America, grows enormous, and is sold by the kilogram, so despite its size it is not a luxury pet.