Background: One model of sexual selection posits that aspects of the environment can drive the evolution of male courtship signals indirectly, through their influence on female sensory systems.
Question: Do differences in male nuptial color correlate with differences in female visual sensitivity and the photic environment?
Methods: Male nuptial color is quantified for eighteen species of the subgenus Ulocentra (“snubnose” darters). Female visual sensitivity is determined using retinal microspectrophotometry, and differences in the photic (light) environment are quantified using spectral reflectance of background substrate at spawning sites in the stream.