The Layman Lab    aquatic ecology • food webs • predator-prey interactions • outreach and education

Predator-driven Phenotypic Variation in Mosquitofish

Much of my work has focused on examining predator-prey interactions in a food web context, but this framework also provides a direct link to areas of research in evolutionary biology. For example, in work headed by Brian Langerhans (Harvard University), I am studying how prey morphologies may vary across natural and human-altered predation regimes. This work began in Texas, where we demonstrated distinct morphologies in mosquitofish (Gambusia affinis) among predator- and predator-free ponds. The same general shifts in morphology appear to characterize populations of the Bahamas mosquitofish (Gambusia hubbsi).

In the long-term, Brian is seeking to link mosquitofish morphology to performance (e.g. burst speed), sexual selection (e.g. morphology-based mate choice), and natural selection (ability to evade predators), providing insights into ecological mechanisms of diversification and speciation. I am collaborating with Brian to examine morphological differences of mosquitofish among blocked and unblocked creeks on Andros Island, Bahamas, as human fragmentation of these systems affects assemblage composition (e.g. fewer piscivores are found in blocked systems) and other environmental gradients (such as flow regime). This work is placed within a context of how human impacts may drive rapid evolution of species.