Taxonomy & naming
Jerdon described the species in 1849 in a different genus, and it now sits in Oryzias; the authority is therefore in parentheses. The name refers to the Carnatic, the historical region of southern India. The Indian ricefishes have been revised several times, and records from outside peninsular India should be checked against recent literature.
Morphology
A small, translucent ricefish with the usual Oryzias body: a short, upturned mouth, a dorsal fin set far back and a long anal fin. FishBase gives a maximum of 1 in SL.
Habitat
Freshwater streams, canals, ponds and rice paddies in peninsular India, including the type river near Vaniyambadi in Tamil Nadu. FishBase says it usually occurs near the coast but also lives in fresh water and in brackish habitats.
Feeding
Takes small invertebrates and algae from the surface and upper water, as other Oryzias do.
Mating
Not described in detail for this species.
Breeding
Eggs of the genus are carried briefly by the female on filaments at the vent and then deposited on plants. Detailed accounts for O. carnaticus itself have not been published.
In the aquarium
Occasionally kept in India. A planted tank with fine live and frozen foods suits a fish of this kind, and a lid is advisable because Oryzias jump.
Conservation
The IUCN Red List assessed Oryzias carnaticus as Least Concern in 2019.