There are 3 strains of Lymnaea in regard to their cognitive abilities: smart, average, and dumb. The strains are defined operationally as to how easy or difficult it is to make memory and how long the memory persists. As a population each strain’s off-spring possess similar cognitive ability. Ecologically important and relevant stressors (e.g. thermal, food availability) differentially alter the ability of the strains to make or retrieve memory. We have recently been able, by selective alteration of the environment to transform a dumb snail into a smart snail. We are attempting to determine how this occurs.

There are also two classes of Lymnaea as regards their response to a crayfish predator: predator-naive and predator-experienced. The detection of crayfish in predator-experienced Lymnaea causes memory to be formed better, faster and persist longer. Feeding is also inhibited. However, in predator-naive snails this does not happen.

We are monitoring the invasion of crayfish into a now cray-fish free lake (Margo Lake, ML) where the snails are presently predator-naive. However, past history tells us that soon the ML snails will be predator-experienced. We are attempting to find out how this transformation occurs at both the behavioural and neuronal levels.

Foods such as green-tea that contain high levels of epicatechin enhance memory formation when snails are trained in that substance; whereas, foods such as black tea block memory formation. Finally, trauma occurring in juvenile snails not only changes juvenile behaviour but also changes the behaviour expressed in them when they become adults. All this in a relatively simple, tractable model system.