Meeting Abstract
Past research has shown that Physa snails change their shell morphology, life history, and behavior based on the type of predators in their environment. The snails also exhibit transgenerational plasticity with individuals exposed to crayfish cues producing more crush resistant offspring. One explanation for this is that predator-exposed snails invest more in current offspring than control snails, at the expense of growth, life expectancy, and future reproduction. To test this hypothesis, we raised snails in one of four treatments: early-life predator exposure in which snails were exposed to crayfish cues for the first five weeks of life, late life predator exposure in which snails were exposed to crayfish cues for the second five weeks of life, continuous predator exposure in which snails were exposed to crayfish cues for both the first and second five weeks of life, or no predator exposure. We measured growth rate, age at first reproduction, egg production, and lifespan in the F1 snails. We then raised the F2 offspring of the F1 snails that produced at least 8 viable offspring at the end of the early and late life periods, and measured their size, shape, and crush resistance. In the F1 snails, we determined that early life predator exposure led to delayed reproduction, decreased egg production, and reduced lifespan, but had no effect on growth. Exposure to predator cue late in life had no effect on survival, growth, or egg production. Data analysis is ongoing for the effects of early and late life exposure on the size of eggs produced by F1 individuals and F2 phenotypes.
