Detour-task performance in color polymorphic male mosquitofish

Conspicuous polymorphisms provide natural tests of mechanisms maintaining behavioral and underlying genetic variation. Cognition has received relatively little attention in color-polymorphic systems. We used a melanin-based polymorphism in the eastern mosquitofish (Gambusia holbrooki) to ask whether performance in a detour task differs between morphs. Melanic males (N = 38) solved the task more often than silver males (N = 37) and had a 1.59-fold higher estimated solution rate, although effect sizes were modest and statistical support was limited. These results suggest that processes associated with detour-task performance may represent an underappreciated axis of morph divergence with a potential role in the maintenance of melanin-based polymorphism.