Convergence of life history phenotypes in a Trinidadian killifish (Rivulus hartii)

Convergent evolution is characterized by the independent evolution of similar phenotypes within similar selective environments. Previous work on Trinidadian killifish, Rivulus hartii, demonstrated repeatable life history differences across communities that differ in predation intensity. These studies were performed in rivers located on the south slope of Trinidad’s Northern Range Mountains. There exists a parallel series of rivers on the north slope of these mountains. As on the south slope, Rivulus is found across a gradient of fish predation. However, the predatory fish species in north-slope rivers are derived from marine families, whereas south-slope rivers contain a predatory fish fauna characteristic of the South American mainland. If predator-induced mortality and the associated indirect effects are the causal factors selecting for life history patterns in Rivulus, and these are similar in north and south-slope rivers, then the specific predatory species should be interchangeable...