Female mating preferences, lighting environment, and a test of the sensory bias hypothesis in the bluefin killifish

Sensory drive proposes that environmental conditions affect signalling dynamics and the evolution of signals and receivers. For visual systems, delineating the effects of lighting on mating preferences is difficult because lighting conditions can affect preferences via three mechanisms: (1) genetic differentiation in mating preferences can result from selection under different lighting conditions, (2) development under different lighting conditions can alter the visual system and presumably female mating preferences and (3) lighting conditions can immediately alter colour perception by filtering wavelengths and altering visual backgrounds. We teased apart these effects by crossing bluefin killifish within and between a spring population and a swamp population that differed in lighting environment. We divided offspring between clear and tea-stained rearing environments (developmental plasticity) and measured preference under tea and clear conditions (immediate effects). We found genetic differentiation: spring offspring showed a strong preference for red males. We also found a three-way interaction between genetics, developmental plasticity and immediate effects on preference for blue males: swamp offspring had the highest levels of preference for blue males when raised and tested under tea-stained conditions. Thus, the environment experienced during development and the immediate conditions during mate selection interact with genetics to determine preference. We also tested the sensory bias hypothesis, which predicts that mating preferences evolve as a correlated response to selection on nonmating behaviours such as foraging. The relationship between mating and foraging preferences was weak and provided little support for sensory bias.