Meeting Abstract
Crayfish communicate chemically. The crayfish Orconectes rusticus is an invasive species that has taken over most watersheds in the country. Traditional eradication methods have not been successful. Understanding how O. rusticus respond to pheromones from different sources can be helpful in developing species-specific chemical traps. In this study we assessed how O. rusticus respond to chemical signals generated by conspecifics of different sexes. We constructed a Y-maze with each arm receiving different chemical signals. To ensure that individuals don’t exhibit side bias, water was pumped through both arms. In the absence of a chemical signals in the water, individuals did not show preference for a particular arm of the maze. However, when a food signal was pumped through one of the arms, individuals consistently moved towards the arm containing the food signal (n=16, p< 0.01). We then created same-sex male and female pheromone solutions by combining water from 18 males and 20 females that have been isolated for 7 days. We assessed the minimum concentration of stock pheromones needed to elicit selective movement by the receiver. Male and female O. rusticus were exposed to 10%, 25%, and 50% same-sex pheromone stock that was pumped down one randomly chosen arm of the maze, while water was pumped through the other arm. Individuals were believed to make a choice when they moved towards or away from an arm containing the chemical signal. Our preliminary data show that at higher concentrations, males spent more time away from the same-sex pheromone, while females spent more time in the arm containing the chemical signal. These findings suggest that O. rusticus exhibit sexually dimorphic behavior strategies towards same-sex pheromones. These findings would be an important consideration when designing traps to limit invasion spread by O. rusticus.
