Exposure to exogenous egg cortisol does not rescue juvenile Chinook salmon body size, condition, or survival from the effects of elevated water temperatures

Climate change is leading to altered temperature regimes which are impacting aquatic life, particularly for ectothermic fish. The impacts of environmental stress can be translated across generations through maternally-derived glucocorticoids, leading to altered offspring phenotypes. Although these maternal stress effects are often considered negative, recent studies suggest this maternal stress signal may prepare offspring for a similarly stressful environment (environmental match). We applied the environmental match hypothesis to examine whether a prenatal stress signal can dampen the effects of elevated water temperatures on body size, condition, and survival during early development in Chinook salmon Oncorhynchus tshawytscha from Lake Ontario, Canada. We exposed fertilized eggs to prenatal exogenous egg cortisol (1000ng*mL-1 cortisol or 0ng*mL-1 control) and then reared these dosed groups at temperatures indicative of current (+0°C) and future (+3°C) temperature conditions. Offspring...气候变化正引发水温格局发生改变，进而对水生生物造成冲击，尤以变温鱼类（ectothermic fish）为甚。环境胁迫的影响可通过母体源性糖皮质激素（glucocorticoids）实现跨代传递，最终改变子代的表型（phenotypes）。尽管这类母体胁迫效应常被认为是不利的，但近期研究表明，母体的胁迫信号或可帮助子代提前适应同类胁迫环境（即环境匹配（environmental match））。本研究基于环境匹配假说（environmental match hypothesis），以加拿大安大略湖的奇努克鲑（*Oncorhynchus tshawytscha*）为实验材料，旨在探究产前胁迫信号能否缓解水温升高对其早期发育阶段的体型、身体状况与存活率所产生的影响。我们将受精鱼卵暴露于产前外源皮质醇（cortisol）环境中，设置1000ng·mL⁻¹皮质醇处理组与0ng·mL⁻¹对照组，随后将经处理的鱼群分别饲养于代表当前（+0℃）与未来（+3℃）水温条件的环境中。子代……