Nothobranchius


Nothobranchius, known as nothobranchs or simply nothos, is a genus of small, freshwater killifish, classified in the family Nothobranchiidae in the order Cyprinodontiformes. There are about a hundred species in the genus, many with very small distributions. They are primarily native to East Africa from Sudan to northern South Africa, whereas a dozen species are found in the upper Congo River Basin, with the greatest species richness being in Tanzania.
Nothobranchius typically inhabit ephemeral pools that are filled only during the monsoon season, and show extreme life-history adaptations to survive the dry season. When their habitats dry up, the adult fish die and the eggs survive encased in the clay during the dry season. The embryos survive the dry season by entering diapause, facilitated by their specialized eggs that have a very hard chorion and are resistant to desiccation and hypoxia. These species reach maturity very quickly once diapause is broken and have a very short life span; one species, Nothobranchius furzeri, reaches maturity in 17 days and seldom lives beyond 6 months.

Etymology

The genus name Nothobranchius comes from Ancient Greek νόθος, meaning 'crossbred', and βράγχιος, meaning 'with gills'.

Species

There are 96 recognized species in this genus:Nothobranchius albertinensis Nagy, Watters & Bellstedt, 2020Nothobranchius albimarginatus Watters, Wildekamp & Cooper, 1998Nothobranchius angelae Watters, Nagy & Bellstedt, 2019Nothobranchius annectens Watters, Wildekamp & Cooper, 1998Nothobranchius attenboroughi Nagy, Watters & Bellstedt, 2020Nothobranchius balamaensis Bragança & Chakona, 2022Nothobranchius bellemansi Valdesalici, 2014Nothobranchius bojiensis Wildekamp & Haas, 1992 Nothobranchius boklundi Valdesalici, 2010Nothobranchius brieni Poll, 1938Nothobranchius capriviensis Watters, Wildekamp & Shidlovskiy, 2015 Nothobranchius cardinalis Watters, Cooper & Wildekamp, 2008 Nothobranchius chochamandai Nagy, 2014Nothobranchius cooperi Nagy, Watters & Bellstedt, 2017Nothobranchius derhami Valdesalici & Amato, 2019Nothobranchius ditte Nagy, 2018Nothobranchius eggersi Seegers, 1982Nothobranchius elongatus Wildekamp, 1982