Oryzias is a genus of ricefishes native to fresh and brackish water in east and south Asia.

[4] Some species are widespread and the Japanese rice fish (O. latipes) is commonly used in science as a model organism, while others have very small ranges and are threatened.

[4] They are small, up to 8 cm (3.1 in) long, and most are relatively plain in colour.

[5] The genus name Oryzias is a reference to the scientific name for rice, Oryza.

[4] They have an unusual reproductive behavior where the female facultatively (optionally) carries the eggs in a cluster at the pelvic or anal fins for a period after they have been fertilized.