For short development species, like the sea urchin Heliocidaris erythrogramma, the entire planktonic duration can be impacted by marine heatwaves (MHW). Developmental thermal tolerance of this species through metamorphosis was investigated over a broad range (7.6–28.0 °C), including temperatures across its distribution and MHW conditions. In controls (19.5–21.0 °C), 80% of individuals developed to metamorphosis at day 5, doubling to 10 days at 14.0 °C. The thermal range (14.4–21.2 °C) of metamorphosis on day 7 reflected the realised thermal niche with 25.9 °C the upper temperature for success (T₄₀). By day 10, juvenile tolerance narrowed to the local range (16.2–19.0 °C), similar to levels tolerated by adults, indicating negative carryover effects across the metamorphic transition. Without phenotypic adjustment or adaptation, regional warming will be detrimental, although populations may be sustained by thermotolerant offspring. Our results show the importance of the metamorphic transition in understanding the cumulative sensitivity of species to MHW.

对于短发物种，例如海胆Heliocidaris erythrogramma，整个浮游持续时间会受到海洋热波（MHW）的影响。在广泛的范围内（7.6–28.0°C），包括整个分布范围和MHW条件下的温度，研究了该物种通过变态形成的发育热耐受性。在对照（19.5–21.0°C）中，80％的个体在第5天发展为变态，在14.0°C时变为10天。在第7天，变态的热范围（14.4–21.2°C）反映了已实现的热生态位，最高成功温度为25.9°C（T ₄₀）。到第10天，少年的耐受性已缩小到局部范围（16.2–19.0°C），与成年人所能忍受的水平相似，表明在整个变质期中残留的负面影响。如果不进行表型调节或适应，区域性变暖将是有害的，尽管耐高温后代可能会维持种群的生长。我们的结果表明，变质转变对于理解物种对MHW的累积敏感性至关重要。