We often think about environmental stress as a constant pressure, but in nature, stressors often fluctuate. In our new study published in Functional Ecology, we asked whether early-life exposure to stable vs fluctuating salinity stress affects future reproductive allocation in eastern mosquitofish (Gambusia holbrooki). By quantifying protein, lipids, and glycogen in eggs and ejaculates, we provide a mechanistic understanding of how environmental variability during the developmental period can shape future reproduction investment. 🌊 🐟
We found that-
1. Females reared under fluctuating salinity produced eggs with lower protein content.
2. Both developmental history and age played important roles in male ejaculate investment. For instance, older males raised in fluctuating salinity showed higher ejaculate glycogen than both young males and males from freshwater treatments.
Our findings highlight that the pattern of stress (fluctuating vs stable salinity) can matter as much as the mean level of stressor, with sex and age both playing important roles for animal reproductive investment. Read the lay summary below:
Upama Aich 