Advisor: Dr. Peter Fong
Human pharmaceuticals or active pharmaceutical ingredients (APIs) are released into sewage treatment plants and eventually into receiving streams where they have been detected in concentrations high enough to have effects on aquatic organisms. Of these APIs, antidepressants such as fluoxetine (Prozac) have been commonly detected and have been shown to produce effects ranging from stimulation of spawning in clams to alteration of feeding behavior in striped bass. Freshwater and marine snails exposed to environmentally relevant concentrations of antidepressants detach their foot from the substrate and flip over (orifice side up). Previous experiments have shown that prior to foot detachment, some species increase crawling velocity. We hypothesize that antidepressants initially cause their toxicity by stimulating crawling which leads to foot detachment. This study tested the effect of fluoxetine on crawling velocity in three species of snail, the oyster drill Urosalpinx cinerea, the turbo snail, Lithopoma americanum, and the freshwater Physa spp. at 10-6, 10-7, and 10-8M for short periods of time. Snails were exposed to each concentration for 20 minutes, and then their velocity was measured. Results indicate a trend toward increased velocity after exposure to fluoxetine at environmentally relevant concentrations in oyster drills and in Physa.