P3.199 Friday, Jan. 6 Evolution of male coloration during a post-Pleistocene radiation of Bahamas mosquitofish (Gambusia hubbsi) MARTIN, R.A.*; RIESCH, R.; LANGERHANS, R.B.; North Carolina State Univ.; North Carolina State Univ.; North Carolina State Univ. email@example.com
Visual communication signals, such as bright colors, are a conspicuous feature of biological diversity and can vary dramatically both within and between species. In many systems male coloration serves to attract females and is therefore thought to be under strong sexual selection for conspicuousness. However, conspicuous coloration may additionally attract the notice of potential predators and thus increase risk of predation. Moreover, environmental context can strongly influence the evolution of male color, either directly (e.g., variation in light environment) or indirectly (e.g., factors affecting the relative influence of natural and sexual selection). Here we examine male coloration in Bahamas mosquitofish (Gambusia hubbsi) inhabiting ten inland blue holes that are characterized by the presence or absence of the piscivorous bigmouth sleeper (Gobiomorus dormitor), to evaluate how the predation environment, water color, and other environmental factors (i.e., population density, primary productivity, sex ratio) interact to influence the evolution of male coloration. We found clear evidence that both predation and water color drove male color divergence between blue holes. Specifically, male coloration was significantly correlated with water color across blue holes, however, individuals from low-predation environments were more conspicuous (e.g., greater orange coloration in dorsal fin, larger black shoulder patch) than those from high-predation environments. Furthermore, fish reared in a common-garden laboratory environment maintained their color differences in the lab, revealing a genetic basis to the observed divergence in male coloration.