Taxonomy & naming
Chen, Uwa and Chu described the species in 1989 from Kunming, Yunnan Province. It is one of the East Asian medaka group, with O. latipes and O. sakaizumii. Chinese authors have used the name for medaka from a wide area of eastern China, and the range should be taken as approximate.
Morphology
A small, slender ricefish; FishBase gives a maximum of 1 in SL. Males have the notched dorsal fin and longer anal fin typical of medaka.
Habitat
Paddies, ponds, ditches and slow streams in China, including the plateau lake region around Kunming. FishBase also reports introduced populations in Kazakhstan, the lower Kuban and the Azov basin.
Feeding
Small invertebrates and algae, as in other medaka.
Mating
Courtship is similar to that of other Oryzias.
Breeding
Eggs are carried briefly at the vent and then deposited on plants.
In the aquarium
Seldom kept outside China and research collections. It would suit the same unheated, planted setup as the Japanese medaka.
Conservation
The IUCN Red List assessed Oryzias sinensis as Least Concern in 2011.