The effect of biogenic amines on female mate preference in the brush-legged wolf spider

Abstract

By Prince Charles Achaw, Neuroscience

Advisor: George Uetz

Presentation ID: AM_ATRIUM25

Abstract: Biogenic amines are neuromodulators that have actions beyond the nervous system, affecting an array of behaviors. For example, serotonin (5-HT) and octopamine (OA) play important roles in modulating aggressive and submissive behaviors in various arthropods. In spidersthe modulation of aggression is particularly important, as females often decide whether to mate with or cannibalize a male. Initial evidence in the wolf spider Schizocosa ocreata suggests that when females are treated with OA or 5-HT, mating success decreases or increases, respectively. The current study focuses on whether OA and 5-HT affect mate preferences of female S. ocreata. Because females prefer to mate with large-tufted males, we specifically examined the effect of 5-HT and OA on mate preferences for males of varying tuft size (small or large) using a two-choice test. The females were randomly assigned into one of four treatment groups: 5HT, OA, DMSO (dimethyl sulfoxide), or CO2 (carbon dioxide), with DMSO and CO2 groups being the control groups. The DMSO, 5-HT, and OA solutions were administered to the spiders via topical application. One hour later, females were presented with video playback of small- and large- tufted males via iPods. We then counted the total number of receptivity displays towards each video of the small- and large- tufted males and compared these displays across the four treatment groups. The results of this study will be presented and will provide insight as to the potential roles of 5-HT and OA in modulating mate preferences of S. ocreata.