This chapter reveals that there are significant complexities in the Trinidadian guppy system that make the investigation of the evolutionary ecology of the guppy both more challenging than it initially appears. The particular configuration of the river systems in Trinidad and distribution of fish species, including guppies, amongst them has resulted in marked, rapid, and interpretable population differentiation in a range of adaptive traits. Key differences between populations are summarized, Trinidadian freshwater habitats are introduced, and the importance of predators in driving population differentiation is highlighted. Complexities in predator-guppy interactions are discussed and their implications assessed. The covariance in predation regime and productivity levels as well as the direct and indirect consequences of this covariance for guppy evolution are reviewed. Other factors that shape the evolutionary ecology of the guppy include history, water quality, water temperature, and human intervention. The chapter concludes by drawing attention to the extensive background data on Trinidad, which makes it one of the better-known tropical systems. The level of documentation is such that it is possible to visit Trinidad for the first time and complete a publishable study within a few weeks.
Keywords: predators, productivity, feeding behaviour, parasites, density, sex ratio, geographic variation