Gerreid fishes are largely thought to not exhibit sexual dimorphism or dichromatism. I describe differences in coloration that may distinguish sexes of Eugerres plumieri (Striped Mojarra) based on observations of an aggregation of smaller, more darkly colored males courting a single, larger, less boldly colored female during spawning, This record highlights the potential for sex-specific external appearances to be more widespread within the family than previously recognized.