Red Spot Arowana (Scleropages leichardti)

Arowanas are a fascinating and ancient group of fishes, with just six species today spread across the planet. In the Americas we have the Silver and Black Arowanas (Osteoglossum), while the remainder are classified in Scleropages. These four fishes are restricted to various regions in the West Pacific. The most famous, the Asian Arowana (S. formosa) is widespread in parts of Southeast Asia and Indonesia and often sells for large sums in the Asian aquarium trade, but, alas, due to conservation concerns, this species is not allowed to be sold in the US. The recently described S. inscriptus is an even rarer fish known from Myanmar, and it too is unavailable.

When we move down to Australia, we find S. jardinii in the northern portions of the continent, patchily distributed around the Gulf of Carpentaria and west towards the Adelaide River. It also occurs in nearby portions of New Guinea. This species has been available to aquarists for quite some time, always as captive-bred specimens. But there’s one last species (presently far rarer in captivity) which occurs here, Scleropages leichardti, found only in the Fitzroy River system of Western Australia.

The differences between these two Aussie arowanas are simple enough to observe. The red spots that give the Red Spot Arowana its name are the most obvious feature to look for, as S. jardinii is a solid bronzy affair. Other minor differences can be observed in the forward-pointing barbels, the relatively unsloped head profile and the unpatterned gill cover.

Aquarium care is more or less the same for all arowanas. A (very) large aquarium is needed for this beast, as the maximum size approaches three feet. Three feet! And a tight lid is called… arowanas like to jump. Tankmates need to be chosen with care, with larger cichlids, datnoids and rays being some of the more popular choices. A mix of large meaty foods and pellets makes for an adequate diet, though feeder fish are generally discouraged due to the risk of disease and parasites being introduced. In general, though, arowanas are immensely robust creatures with a preternatural ability to survive. This is presumably why they still swim around to this day when so many of their relatives have gone extinct.