Meeting Abstract
Use of medication by humans has had unintended consequences for aquatic organisms. Excreted metabolites end up in the water, where they are absorbed by various organisms, altering their physiology. Currently, it is unclear how exposure to these pharmaceuticals alters behavior. Sertraline, a selective serotonin re-uptake inhibitor (SSRI), is a widely prescribed antidepressant that has been shown to enter aquatic environments. In crayfish, increased serotonin levels increase aggression by decreasing individual willingness to retreat. Serotonin levels increase in winners of agonistic interactions, and decrease in subordinates. However, increased serotonin levels via SSRI exposure, might increase the animal’s willingness to re-engage in agonistic interactions, ultimately altering social hierarchy and decreasing survival. In this study we examined the effect of sertraline on agonistic behavior of subordinate crayfish Orconectes rusticus. Same sex O. rusticus were paired in a status establishment fight. Following status establishment, the subordinate individual was injected with either 1) sertraline, 2) serotonin, or 3) saline control. The dominant individual was injected with a saline control. Following pharmacological treatment, the dominant and subordinate individuals were re-paired, and their interaction was compared to the status establishment fight. All agonistic interactions were recorded and the quantity of offensive and defensive behaviors was used to determine which animal was dominant. Aggression intensity was compared within dyads and between pharmacologic treatments. Our preliminary findings show that serotonin and sertraline, but not saline, increase aggressive behaviors of subordinate crayfish. However, exposure to either chemical does not cause status reversal.
