Although S. jardinii superficially resembles its Asian cousins, it is not considered as desirable an aquarium inhabitant, nor is it classed as being at risk in nature. It can be easily distinguished from the asian species by its much smaller scale size, greater lateral scale count (32-35 as opposed to 21-25 in the asian aros) and duller patterning. It differs from its Australian relative S. leichardtii by its more sloping head, downward-pointing barbels and patterned gill covers. The base colour…

This species is distinguished from its Australian congeners S. jardinii and S. leichardti by possessing a lower number of lateral line scales (21-26 vs 32-36).

It occurs naturally in a number of colour forms of which three were elevated to distinct species status in 2003, but the current majority view is that all represent S. formosus pending a detailed review. Kottelat (2013) mentions that the red form may…

A bizarre and very recent addition to the genus, O. exodon is infrequently imported to the hobby, but has been seen occasionally. It has specially adapted mouthparts whereby it has greatly enlarged teeth. An extra set of teeth can also be seen growing in concentric bands on the outer lips! These are used in nature to literally 'pick' fruit from overhanging branches, with the fish often leaping from the water to grab a particularly juicy fig or other fruit. When the mouth of the fish is…

Still relatively rare in the hobby, this fish was only described to science in the early 1990s. It's not yet being mass-produced in any great numbers, and demand is high, so it's quite pricey when it is available. It's a stunning fish when adult, developing bright red fin edges with filamentous extensions, and a body colour varying between blue-green and almost black. It makes a great pet as it can develop real personality and learn to recognise its owner….

This species is also referred to as ‘Asian knifefish’ or ‘ghost knifefish’ in the aquarium trade in the aquarium trade but arguably has no place in the ornamental hobby given its adult size and specialised requirements.

It is sometimes confused with the African species Xenomystus nigri but is easily told apart by its larger adult size and presence (vs. absence) of a dorsal fin.

Also known as the common catopra, this is still quite a rare species in the hobby, although it's becoming more readily available due to captive breeding efforts. It makes an interesting addition to the larger community or oddball tank….

M. trifasciata exhibits a wide variation in colour and patterning depending on locality, and it's very important that the different morphs are not mixed in the aquarium, as they will hybridise freely. These different forms are often distinguished by the addition of the name of collection locality being added to the scientific name of the fish. It's thought that several species may in fact be in evidence here, and a reclassification will probably occur at some point

As with many othe…

This species was formerly classified as part of the Melanotaenia splendida complex, but more recent research into the genetics of the species has shown that not only is M. australis genetically dissimilar to the splendida group, but also that there are 2 clear lineages within australis This may yet result in another official member of the genus.

M. australis exhibits a wide variation in colour and patterning depending on locality, and is probably the commonest rainbowfish species in Australi…

There are currently 4 described subspecies of Melanotaenia splendida. The principle differences are generally in colour, pattern and fin counts, although even these vary depending on the locality of the fish. M s. splendida in particular also exhibits a wide variation in colour and patterning depending on locality within the subspecies, and the species name is often suffixed with a place name when the fish are seen for sale. The different forms and subspecies should not be mixed in the aquarium,…