The role of among-individual behavioural variation in the mating outcome of the spider Pisaura mirabilis

Assortative mating - preferential mating with partners of similar phenotypes - may be based on personality varia- tion if it contributes to fitness. Animal personality is defined as consistent among-individual behavioural differences across time and contexts, typically examined through trait repeatability and correlations. Such individual variation can play an important role in mating outcome, yet it is seldom examined simultaneously in interacting sexes. Here, we tested whether adult males and females of Pisaura mirabilis, a spider known for male nuptial gifts and female pre-copulatory sexual can- nibalism, exhibit consistent individual differences in aggressiveness and exploration, whether these traits correlate forming behavioural syndromes, and influence mating decisions. If more aggressive and exploratory individuals are better at gift provision (i.e., prey capture), females should prefer these traits in mates, conversely, female aggressiveness might reduce mating success, potentially promoting disassortative mating (i.e., lowly-aggressive, exploratory females pairing with highly- aggressive, exploratory males). We found that both sexes exhibited consistent individual differences in aggressiveness and exploration, with exploration being highly repeatable. Strong aggressiveness-exploration associations were lacking. Sex- specific differences in behaviour were reported at the population level: females were on average more aggressive, while males were more exploratory. Overall, among-individual behavioural variation did not predict mating success, but tended to affect mating outcomes, as less explorative females and more exploratory males showed longer copulations, suggesting potential reproductive advantages that may potentially promote disassortative pairings.