Preference of Biomphalaria tenagophila among macrophytes and their periphytons determined through the degree of attractiveness

In presence of extracts of six flowering plants the Biomphalaria tenagophila was more attracted to four them in the following sequence: Nasturtium pumilum > Polygonum acre > Commelina sp. = Echinochloa crusgalli. The periphyton of these flowering plants attracted in the same way the B. tenagophila but without no preference for either of them. Reporting the results that behavior may be evaluated as a co-evolution between snail and plants.