Infectivity and parasite-host influence of feeding behavior of Diplostomum flexicaudum in Notropis hudsonius.

Abstract

The two host parasite interactions were examined between Diplostomum flexicaudum, a fluke in the eyes of fish, and Notropis hudsonius (spottail shiner): infectivity and impact on fish vision. Previous investigations suggest that Diplostomiasis does not impact fish populations (kennedy, 1983); however, when studied individually, fish often display an increased susceptibility to predators (Lafferty and Morris, 1996). Different levels of exposure to parasites were set up to test the influence of D. flexicaudum on reaction time using the feeding behavior. Similarly, the various levels of exposure were compared to the quantity of metacercariae in the lenses of fish to evaluate the infectivity. Two hypothesis were confirmed: increased exposure to the cercariae of D. flexicaudum will result in a larger quantity of metacercariae in the lenses of N. hudsonius (p = 0.0107, F = 17.32, df = 2,4) and fish with greater exposure to cercariae will have a diminished ability to recognize food sources (p = 0.0472, F = 19.69, df = 1,2).