Meeting Abstract
Performance in early life is predictive of individual survival and reproductive success. Here we take advantage of the broad geographical range inhabited by the threespine stickleback, Gasterosteus aculeatus, to consider how ecological factors might shape early life characteristics over evolutionary time. Additionally, with the application of maternal stressors, we investigate the extent to which offspring growth and behavior are plastically influenced by maternal condition. Both lab-reared and wild-caught parents were studied, representing populations in British Columbia and Alaska. Lab-reared mothers received one of four treatments: acute stressor at ovulation, chronic stressor throughout clutch production, post-ovulatory egg retention (an ecologically relevant challenge) or minimal handling time at ovulation (control). Wild-caught mothers were subjected to either an acute stressor or the control treatment. Fry were reared under identical conditions and assayed for growth and feeding performance during the first three weeks post yolk absorption. Geographic region had the largest effect on these traits; relative to individuals from British Columbia, fry from Alaskan populations grew faster and were able to consume a greater number of food items per unit time. Our results suggest that there is selection for these distinct regional patterns due to differences in climate, particularly in the severity and length of the winter seasons, which favors high consumption rates and fast growth to reach a critical size for successful over-wintering. We discuss how early life traits are affected by maternal stressors, ecological conditions, including predation presence and salinity, parental rearing environment, and interactions between these factors.
