Visual ecology of Neotropical reef fishes
The dazzling coloration of reef fishes is one of the most attractive natural phenomena. People have long been puzzled by the evolutionary history and adaptive significance of these conspicuous pattern. As an important intra- and interspecific signal, coloration of a reef fish is likely under both natural and sexual selection. Natural selection could favor decreased conspicuousness (i.e. contrast with the background) to minimize detection by predators. On the other hand, if colors serve as important interspecific signals, natural selection could favor increased conspicuousness, as in cleaner wrasses (genus Labroides). Alternatively, sexual selection might favor higher detectability. The argument about the function of reef-fish colors dates back to Darwin and Wallace, but there is still surprisingly little known about the signal function of these remarkable patterns.
The reef fish of the Neotropics provide a unique model for studying color-pattern evolution. While the Caribbean has brightly colored coral reefs and clear water, the Eastern pacific is characterized by rocky shoals and murky water. Multiple clades of reef-associated fishes have taxa in both oceans, providing a rare opportunity to conduct replicated, comparative studies of the effects of broad differences in environmental factors (turbidity, wavelength-specific attenuation, scattering, background features) on divergence in spectral and spatiotemporal components of reef-fish visual signals.