Predator-driven Phenotypic Variation in Mosquitofish

The rapid and dramatic changes in biotic and abiotic characteristics following tidal creek fragmentation is predicted to generate substantially different selection pressures for organisms inhabiting the system than were naturally present before anthropogenic impacts.  We (with Brian Langerhans and Sean Giery) are testing predictions of phenotypic differentiation based on explicit hypotheses of divergent natural selection between fragmentation regimes. Our model organism is a small endemic, livebearing fish species, Bahamas mosquitofish (Gambusia hubbsi).  Recent papers deal with topics such as sexual selection and water color, linking body morphology to fitness, and regional patterns of life history divergence.