|A cyst on the fish's brain http://happycleananimals.wikispaces.com/Euhaplorchis+Californiensis|
Initially, there aren't any consequences since the predator in this host-parasite interaction benefits by acquiring food easily. According to Claude Combes, "Based on outdoor experiments, Lafferty and Morris estimated that after twenty days about 80% of the fish that were infected by more than 1400 metacercariae were eaten, versus approximately 20% of those infected by fewer than only 2% of those that were ininfected. " According to Lafferty's observation on the performance of a population of unparasitized snails in the absence of infected snails, he found that they released more eggs and became densely populated . Also if there weren't any parasitized snails in the natural environment the snail population will nearly double the amount .