Adaptive coexistence of distinct ...

Adaptive coexistence of distinct life history strategies in fish of the genus Nothobranchius

Investigator: Mgr. Matej Polačik, Ph.D.
Number of Project: P505/11/P646
Agency: Czech Science Foundation
Duration: 01. 01. 2011 - 31. 12. 2013

In this project, I tested the hypothesis that there are coexisting alternative life history strategies in Nothobranchius furzeri, an African annual killifish. Annual killifish live in temporary pools and survive dry season exclusively as an egg buried in the bottom substrate of the pool. The duration of embryonic development is extremely variable and asynchronous even under constant conditions. The embryo may develop into pre-hatching stage within about three weeks but it may also take several years. I hypothesized that the individuals with the short incubation period were adapted to exploit an

alternative niche – a pool which desiccates during the rainy season, but refills again within the same season (secondary pool). Its shortened duration is assumed to create a selective pressure, reflected in a distinct life history strategy of fast developing embryos. In contrast, the slow-developing embryos are supposed to persist through the whole dry season and hatch into a pool with prospect of a relatively longer duration. Laboratory experiments confirmed the existence of alternative life history strategies, and further tested the mechanism of heritability (genetic VS epigenetic) and

adaptiveness of the developmental heterochrony in relation to environment.