Assessing chemical communication in the invasive crayfish Orconectes rusticus

Oral Presentations - Hoover 212

Orconectes rusticus is an invasive crayfish species that has disrupted ecosystems in the Northern Eastern United States. Eradication methods have been ineffective. Because crayfish communicate chemically by secreting pheromones, understanding what information these pheromones carry can help develop baited traps that will improve trapping efficiency. The aim of this study was to determine how Orconectes rusticus respond to chemical signals produced by conspecifics of the same and opposite sex. Previous studies in our lab have shown that female O. rusticus are attracted to pheromones produced by males, but don’t exhibit avoidance or attraction to signals produced by females. Males, on the other hand, avoid signals produced by conspecific males, but do not exhibit a differential response towards female signals. However, in these studies, all individuals were presented with a same or opposite sex pheromone vs. a no pheromone control using a Y-maze. In our study, we examine how O. rusticus respond to same and opposite-sex pheromones when presented with these signals simultaneously. We collected pheromones by socially isolating male and female O. rustiducus for 7-9 days in small 1.5 liter containers. At the end of isolation period, the water in the containers was filtered and combined with water from other same-sex individuals to create a pheromone stock. The resulting pheromone stocks were pumped through the arms of the Y-maze. The pheromone assignment to a given arm of the maze was randomized. The behavior of the crayfish at the base of the Y-maze was videotaped and individuals were believed to make a choice when they moved towards or away from one of the arms. In this study we present our preliminary findings.