Vision-mediated courtship in a nocturnal arthropod

Visual signals are widely used by animals in foraging, mating and predator avoidance. Body coloration plays an important role in the reproductive behavioural interactions of many diurnal animal species; however, its role in the courtship of nocturnal species has received little attention. We investigated the role of conspicuous body coloration, a white stripe on the forehead region, in the reproductive interactions of the nocturnal brown huntsman spider, Heteropoda venatoria. We performed a series of mating trials in which we manipulated the body coloration of males and the vision of females and determined the probabilities of mating success of males in different treatments. Results showed that males that courted females with intact vision had a significantly lower probability of mating success than males that courted females whose vision was blocked. Females with intact vision were also more likely to choose males with a white stripe than those whose stripe was removed. Therefore, we have unambiguously demonstrated for the first time that body coloration plays an important role as a visual signal in the mating of nocturnal spiders.