Individual differences are consistent across changes in mating status and mediated by biogenic amines

摘要

Although aspects of an individual's state are well-known to influence the expression of behavior, it is still unclear how elements of state affect consistent among-individual differences in behavior. With binary, irreversible elements of state, such as mating status, there may be optimal behavioral phenotypes before and after mating, with individuals often prioritizing mate acquisition before and resource acquisition after. Yet, limited plasticity may prevent optimal behavior in both contexts. Additionally, it remains largely unknown if some consistencies in neural or physiological traits may limit the ability of the organism to respond to state changes. In this study, we investigated how changes in a binary state variable, mating status, affected both the mean expression and amongindividual variation in behavior and web structure of the redback spider, Latrodectus hasselti. Furthermore, we explored the role of biogenic amines in potentially mediating individual differences in behavior and web structure. We found that mated females were overall more aggressive than virgin females and also built webs structured primarily for capturing prey rather than safety. We also found that individual differences in behavior and web structure were maintained across mating statuses, which indicates the stability of these traits and may drive personality-specific state-dependent fitness trade-offs. Finally, we found that aggressive spiders had higher central nervous system dopamine levels. Interestingly, web structure was often correlated with a catabolite of tyramine (N-acetyltyramine), suggesting that variation in amine catabolism, and not the concentrations of the amines themselves, may drive individual differences in some traits.