Biogenic amines as mediators of spider behavior

Biogenic amines, such as serotonin and octopamine, are important mediators of behavior in both vertebrates and invertebrates, with remarkably consistent patterns apparent over vast taxonomic ranges. Spiders are popular model systems for behavior research, but little is known about physiological mediators of spider behavior, especially about the role of biogenic amines. We quantified base-line levels of biogenic amines at different life stages of the jumping spider Servaea incana, and considered the role of biogenic amines as mediators of intraspecfic interactions. Base-line levels of biogenic amines might be linked to resource holding potential such that winners and losers tend to differ in base-line levels at the beginning of contests. Alternatively, the winning or losing of contests might induce changes in base-line levels such that winners and losers might be similar in levels of biogenic amines at the beginning of a contest but differ at the end. To address this, we staged contests between size-matched S. incana males and measured levels of biogenic amines either immediately after the contest or three days later as well as in control groups that did not experience contests.