Intraspecific life history variation in a pond snail: the roles of population divergence and phenotypic plasticity.
Juvenile Lymnaea elodes were reciprocally transferred between ponds differing in permanence and productivity, and the resulting variation in life history traits was recorded. In a 2nd experiment, parents and their offspring from both a vernal and a permanent pond population were reared in the same pond. Proximal factors had by far the greatest effects on life history traits in the transfer experiment, with snails reared in a more productive pond showing earlier reproduction at a larger size, higher fecundity, and longer life cycle length. Snails from the more uncertain pond in terms of drying date did reproduce at an earlier age and smaller size and grew less in each pond. However, these population differences, for the most part, disappeared when snails were reared for 2 generations in the same environment. Much of the intraspecific variation in life histories seen in this species must therefore be considered the result of phenotypic plasticity. -from Author
Brown, K. (1985). Intraspecific life history variation in a pond snail: the roles of population divergence and phenotypic plasticity.. Evolution. Retrieved from https://ir.una.edu/eng_facpub/62