Smaller adult fish size in warmer water is not explained by elevated metabolism.

Fish and other ectotherms living in warmer waters often grow faster as juveniles, mature earlier, but become smaller adults. Known as the temperature-size rule (TSR), this pattern is commonly attributed to higher metabolism in warmer waters, leaving fewer resources for growth. An alternative explanation focuses on growth and reproduction trade-offs across temperatures.

Multigenerational exposure to warming and fishing causes recruitment collapse, but size diversity and periodic cooling can aid recovery.

Global warming and fisheries harvest are significantly impacting wild fish stocks, yet their interactive influence on population resilience to stress remains unclear. We explored these interactive effects on early-life development and survival by experimentally manipulating the thermal and harvest regimes in 18 zebrafish () populations over six consecutive generations. Warming advanced development rates across generations, but after three generations, it caused a sudden and large (30-50%) decline in recruitment.