Institute of Vertebrate Biology, Academy of Sciences of the Czech Republic, Květná 8 60365, Brno, Czech Republic.
Evodevo. 2013 Sep 4;4(1):24. doi: 10.1186/2041-9139-4-24.
Extreme environmental conditions can give rise to extreme adaptations. We document growth, sexual maturation and fecundity in two species of African annual fish inhabiting temporary savanna pools.
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. All four study populations demonstrated rapid growth rates of up to 2.72 mm/day (23.4% of their total length). Both species may produce diapausing embryos or embryos that are able to hatch in as few as 15 days, resulting in a minimum generation time as short as only one month. Incubation on the surface of damp peat moss results in high embryo survival (73%) and a high proportion of rapidly developing embryos (58%) that skip diapauses and hatch in less than 30 days. We further demonstrated that rapid growth and maturation do not compromise subsequent fecundity.
Our data suggest that both species have the most rapid sexual maturation and minimum generation time of any vertebrate species, and that rapid maturity does not involve paedogenesis.
极端的环境条件会导致极端的适应。我们记录了两种栖息在季节性稀树草原池塘中的非洲一年生鱼类的生长、性成熟和繁殖力。
Nothobranchius kadleci 在 17 天大、31 毫米长时开始繁殖，Nothobranchius furzeri 在 18 天大、32 毫米长时开始繁殖。所有四个研究种群都表现出高达 2.72 毫米/天的快速生长率（占其总长度的 23.4%）。这两个物种都可能产生休眠胚胎或能够在短短 15 天内孵化的胚胎，从而使最短的世代时间短至仅一个月。在潮湿的泥炭藓表面孵化可使胚胎存活率达到 73%，并且有很大比例的快速发育胚胎（58%）跳过休眠期，在 30 天内孵化。我们进一步证明，快速生长和成熟不会影响随后的繁殖力。
我们的数据表明，这两个物种的性成熟和最小世代时间是任何脊椎动物中最快的，而且快速成熟并不涉及幼态发生。
