Meeting Abstract
Organisms across the animal kingdom exhibit compensatory growth (CG), a form of phenotypic plasticity exhibited as faster than normal growth following a period of low nutrient levels. However, certain long-term impacts of CG, such as those on reproductive output remain poorly understood. We assessed reproductive costs of CG by exposing juvenile threespine stickleback (Gasterosteus aculeatus) to maintenance diet rations (ad libitum diet cut in half) across three different periods early in life, at one month (DPR1), two months (DPR2) and three months (DPR3) of age. Following one-month nutrient deprivation periods, the fish were returned to ad libitum diet levels and we enumerated the impact on female body weight and reproductive output (clutch and egg size) within the first spawning season, at one year of age. We hypothesized that DPR1 juveniles, due to their younger age, would show reduced body sizes and reproductive output upon reaching adulthood, in comparison to fish exposed to low nutrients at three and four months of age. Recent CG studies suggest potential trade-offs between maternal growth investment and offspring size as a response to undernourishment. Our results suggest that three-month old fish (DPR3) exposed to low nutrients, then returned to ad libitum diet levels, attained higher female body weights at one year of age, in contrast to the other dietary groups. Our work also suggest little variation in clutch size adjusted to female body weight among the dietary groups, however, fish from DPR2 and DPR3 groups yielded larger egg sizes in proportion to clutch size.
