In 1998, Edward P. Levri from Indiana University studied the how effects the parasite Microphallus has on the behavior of New Zealand mud snails impacts the New Zealand fish, Potamopyrgus antipodavun. The design of his experiment included collecting fish samples from various hours of the day, particularly morning versus evening, and counting the number of infected snails compared to non infected snails. He was able to count the snails present in the fish by first killing them and then examining the guts. Levri found that the fish guts tended to have a significantly higher amount of uninfected snails than infected. These results showed that the behavioral changes the parasite caused the snail made the fish less likely to be in the water during times where the fish population was feeding. These findings show that the parasite does not have a secondary impact on the New Zealand fish.
Oikos 81, 531-537 (1998).
So if they aren’t in the water, where are they?
On the rocks around the perimeter of the lake. They also are mud snail so they will bury themselves in sediment.
This raises good question about how dangerous some aquatic invasive species really are? Is it really necessary to tackle every problem or just the ones that are effecting us the most? It shows that some battles are more worth fighting than others.