Dr Heok Hee Ng has described three Nandus species - half of all known species in the world - and here explains how to keep them.
There are currently six recognised species of Nandus: N. nandus, N. nebulosus, N. oxyrhynchus, N. mercatus, N. andrewi, N. prolixus. Only two — N. nandus and N. nebulosus — are commonly available in the aquarium trade, with N. andrewi, the Slaty blue nandus being a rare import.
Nandus nandus comes from India and the latter from Sundaic South-East Asia (the greater Sunda Islands and the Malay Peninsula). Nandus nandus and Nandus nebulosus have slightly different water requirements, since they are not generally found in the same kind of habitats.
Nandus nandus is generally found in slower-flowing streams as well as backwaters of streams with a moderate flow, while N. nebulosus can either be found in slow-flowing forested streams or in swamps.
Nandus nandus does best in slightly acidic to slightly alkaline (pH 6.5-7.5) water at 22-26°C/72-79°F, while N. nebulosus does best in soft, acidic water (pH 4-6) at 24-28°C/75-82°F.
Although some aquarium literature recommends the addition of salt, this is not necessary and may even be detrimental for both species since they live in pure freshwater.
For both species, a tank with little current and furnished with ample submerged vegetation and driftwood is the ideal set-up. A substrate consisting of leaf litter is highly desirable, especially for N. nebulosus.If you’re not sure of what leaves can be used, beech and oak are excellent candidates.
Nandus are fairly shy fish, so do not expect to see them out and about much. They are ambush predators that should be fed only live food. Numerous reports corroborate the extreme difficulty in getting them to eat anything but live food.
This item was first published in the September 2009 issue of Practical Fishkeeping magazine. It may not be reproduced without written permission.