When the type series was collected the Sungai Asinua contained clear, slow to fast-moving water with a temperature of 26 °C.

The substrate was composed of mud, sand an…

The type locality is a karst pool around 30-40 m in length, 10m in width and up to 4 m deep.

It contains still, transparent water, has a single inflow and outflow, is surrounded by rainforest and in September 2010 the water temperature was 21.5°C/70.7°F.

The habitat is used by locals as a bathing pool and sympatric species included a nat…

This species was discovered in 2009 and as far as we know it has only been collected for the aquarium hobby on a single occasion to date, by Jeffrey Christian of Maju Aquarium, Frank Evers and Hans-Georg Evers.

Prior to description it was referred to as O. sp. ‘Kendari’, O. sp. ‘neon’ or O. sp. ‘Sulawesi’.

Utilises a strategy which has become known as ‘pelvic brooding’. Spawning tends to occur in the early morning, with dominant males darkening in colouration and defending their space by driving away potential competitors, while approaching ripe females in a rigid ‘head-down’ position.

The eggs normally number 8-12 and are expelled as a single mass while being fertilised simultaneously, after which they continue to hang from th…

Commonly known as ‘Japanese rice fish’ or simply ‘rice fish’, O. latipes is well-known to science having been widely used as a model organism in genomic and experimental biology for well over a century and was the first vertebrate animal to mate in space during the mid-1990s.

It’s also been a popular aquarium fish for many years, though is less widely-available than it once was, with the ornamental ‘gold’ vari…

Best maintained in a heavily planted set-up, ideally with a dark substrate, patches of dense vegetation, and some open areas. Other décor can consist of twisted roots and pieces of bogwood, while surface vegetation is also appreciated by the fish. When maintained under such conditions they’re more likely to display their best colours, and planted aquaria also offer fry a more favourable chance of survival alongside the adults.

An exclusive inhabitant of fresh, normally standing, waters including shallow pools, ditches, rice paddies and clear water swamps. The type locality is a small ditch measuring just 3 – 6 metres in width and 0.5 – 2 metres deep. The water was clear and the substrate composed of sand, detritus and mud with growths of the macrophytes Nymphaea lotus, Jussiaea repens and Hydrilla verticillata.

This species continues to be mislabelled as O. melastigma, a name currently considered invalid by the majority of recent workers, or O. javanicus, a valid but distinct taxon. Roberts (1998) demonstrated that MClelland’s description of Aplocheilus melastigmus, later renamed O. melastigma, does not correspond with any known Oryzias species from the Indian subcontinent or Myanmar since it’s said to have a dark spot in the dorsal-fin and an excessively slim body, among other anomalies.

It can be further distinguished from congeners by the following combination of characters: small adult size; bright orange-red marginal bands on caudal-fin lobes in males; caudal-fin rounded and elongate; 5-7 dorsal-fin rays; relatively few (13-18) anal-fin rays without bony contact organs, the last ray branched; 6-8 pectoral-fin rays.

Members of the family Adrianichthyidae are…

The type locality is a karstic freshwater stream flowing under 80% forest cover with a mixed substrate of mud and sand plus patches of leaf litter.

O. woworae was collected from a still pool around 3-4 m deep, opposite an affluent spring, where it was schooling with a species of Nomorhamphus which may turn out to be a form of N. ebrardtii but has subsequently appeared in the aquarium trad…