The effect of turbidity on female mate choice in the guppy

Guppies are a widespread species with a broad tolerance of polluted environments, and females rely heavily on visual cues when making mate choice decisions. We manipulated turbidity by adding suspended solids to water and tested how this affected female preference for males with more orange coloration. We found that females spent more time near males with a greater area of orange colouration in low turbidity water, but that this preference disappeared in both the mid and high turbid water treatments.

Moreover, female preferences were highly repeatable in low turbidity water and high turbidity water but not in mid turbidity water. Together, our results suggest that water turbidity impairs the ability of females to discern male colouration and affects the consistency of mate preferences. This could have consequences for the evolution of male colouration in turbid waters.