Extraordinary life history in African annual fishes

0426814 - ÚBO 2014 BI eng A - Abstrakt
Blažek, Radim - Polačik, Matej - Reichard, Martin
Extraordinary life history in African annual fishes.
African Fish and Fisheries: Diversity, Conservation and Sustainable Management. Book of abstracts. Bujumbura: University of Burundi, 2013. s. 52-53.
[International Conference of the Pan African Fish and Fisheries Association (PAFFA) /5./. 16.09.2013-20.09.2013, Bujumbura]
Institucionální podpora: RVO:68081766
Klíčová slova: Nothobranchius * Mozambique
Kód oboru RIV: EG - Zoologie

Extreme environmental conditions can give rise to extreme adaptations and associated trade-offs in life history traits. We document extremely rapid growth and maturation, high fecundity and possibly extremely short generation time in two related species of African annual fish inhabiting temporary savanna pools in Mozambique (Eastern Africa). Experimental fish were kept in low densities and fed with highly nutrient-rich food. Nothobranchius kadleci started to reproduce at the age of 17 days and size of 31 mm and Nothobranchius furzeri at 18 days and 32 mm, which is clearly the fastest maturation ever observed among vertebrates. All four study populations demonstrated rapid growth rates of up to 2.72 mm (23.4% of their total length) per day. Both species may produce diapausing embryos or embryos that are able to hatch in as few as 15 days, resulting in a plausible generation time of only 1 month. Incubation on the surface of damp peat moss results in high embryo survival (73%) and high proportion of rapidly developing embryos (60%) that skip the diapauses and hatch in less than 30 days. We further demonstrated that rapid growth and maturation is not compromised by low fecundity. Our experimental fish commonly produced several hundreds eggs in a 2.5 hour spawning cycle with maximum of 583 eggs laid by a single female of N. kadleci. Our data suggest that both species have the most rapid sexual maturation and minimum generation time of any vertebrate species, and their rapid maturity is not compromised by paedogenesis.
Trvalý link: http://hdl.handle.net/11104/0232447