Meeting Abstract
Many organisms across the animal kingdom have been shown to utilize plants to self-medicate against parasite infection. Often organisms change their feeding preference based on the degree of parasite infection or impact of parasitism on their physiology. Changes in feeding preference can have large scale ecological impacts if the organism being studied is an ecosystem engineer. Crayfish, an established keystone species and ecosystem engineer, were placed in feeding trials with four different species of macrophytes. After feeding trials, the crayfish were dissected and parasite loads within the hepatopancreas were quantified by image-processing techniques. The percent of the hepatopancreas that was comprised of metacercariae of the parasite Microphallus sp. as well as the percentage that was melanized, the crayfish immune response to infection, were correlated to foraging choices and amounts. Crayfish did alter their feeding preferences and amount of consumption as a result of parasite load. In addition, different macrophyte consumption was correlated with the amount of melanization of the parasites. These results indicate that crayfish seem to be able to determine when they are parasitized by Microphallus sp. and make feeding decisions based on parasite presence. Establishing a change in feeding preference is the first step to determining if crayfish self-medicate when infected with Microphallus sp.
