Oryzias is a genus of ricefishes native to fresh and brackish water in east and south Asia. 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. They are small, up to long, and most are relatively plain in colour.
The genus name Oryzias is a reference to the scientific name for rice, Oryza.
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.
Species
These are the currently recognized species in this genus: Oryzias asinua Parenti, Hadiaty, Lumbantobing & Herder, 2013 Oryzias bonneorum Parenti, 2008 Oryzias carnaticus Jerdon, 1849 Chen, Yeh & Lai, 2025 Oryzias celebensis Weber, 1894 (Celebes medaka) Oryzias curvinotus Nichols & Pope, 1927 Oryzias dancena Hamilton, 1822 Oryzias dopingdopingensis Mandagi, Mokodongan, Tanaka & Yamahira, 2018 Oryzias eversi Herder, Hadiaty & Nolte, 2012 Oryzias hadiatyae Herder & Chapuis, 2010 (Renny's ricefish) Oryzias haugiangensis Roberts, 1998 Oryzias hubbsi Roberts, 1998 Oryzias javanicus Bleeker, 1854 (Javanese ricefish) Oryzias kalimpaaensis Gani, Suhendra, Herder, Schwarzer, Möhring, Montenegro, Herjayanto & Mokodongan, 2022 Oryzias landangiensis Utama, Mandagi, Lawelle, Masengi, Watanabe, Sawada, Nagano, Kusumi & Yamahira, 2022 Oryzias latipes Temminck & Schlegel, 1846 (Japanese ricefish) Oryzias loxolepis Kobayashi, Mokodongan, Horoiwa, Fujimoto, Tanaka, Masengi & Yamahira, 2023 Oryzias luzonensis Herre & Ablan, 1934 Oryzias marmoratus Aurich, 1935 (Marmorated medaka) Oryzias matanensis Aurich, 1935 (Matano medaka) Oryzias mekongensis Uwa & Magtoon, 1986 Oryzias melastigma McClelland, 1839 Oryzias minutillus Smith, 1945 (Dwarf medaka) Oryzias moramoensis Utama, Mokodongan, Lawelle, Masengi & Yamahira, 2024 Oryzias nebulosus Parenti & Soeroto, 2004 Oryzias nigrimas Kottelat, 1990 (black buntingi) Oryzias orthognathus Kottelat, 1990 (Sharp-jawed buntingi) Oryzias pectoralis Roberts, 1998 Oryzias polylepis Möhring, Mokodongan, Gani, Wowor, Annawaty, Böhne & Herder, 2025 Oryzias profundicola Kottelat, 1990 (Yellow finned medaka) Oryzias sakaizumii Asai, Senou & Hosoya, 2012 (Northern medaka) Oryzias sarasinorum Popta, 1905 (Sarasins minnow) Oryzias setnai Kulkarni, 1940 (Malabar ricefish) Oryzias sinensis Chen, Uwa & Chu, 1989 Oryzias soerotoi Mokodongan, Tanaka & Yamahira, 2014 Oryzias songkhramensis Magtoon, 2010 Oryzias timorensis Weber & de Beaufort, 1922 Oryzias uwai Roberts, 1998 Oryzias wolasi Parenti, Hadiaty, Lumbantobing & Herder, 2013 Oryzias woworae Parenti & Hadiaty, 2010
References