Environmental temperature plays an important role in shaping the distribution and abundance of marine ectothermic organisms. As a general rule, larvae and juveniles are more sensitive to thermal stress than adults and, as a consequence, represent key life stages that determine in part the geographic range of a species. Identifying critical thermal limits during ontogeny allows for the prediction of the potential impacts of climate warming on the distribution of marine ectotherms. However, thermal tolerance - and therefore the potential to meet the challenge of warming- is known to vary at population scale for many species. In order to fully appreciate a species' future under climate warming, multiple populations studies from different thermal environments are necessary. In this study, we compared the thermal tolerance response during the intracapsular development of the marine gastropod Ocenebra erinaceus between two geographically separated populations: one from the middle (Solent, UK) and another from the south of the species' geographic range (Arcachon, France). The results show that the thermal tolerance response was influenced by geographic origin. Embryos from the relatively warm-water southern population (France) show a warm-eurythermal tolerance window with optimal temperatures between 12 and 18 °C. On the contrary, embryos from the cold-water northern population (UK) exhibit a narrow, warm-stenothermal, thermal tolerance window with optimal temperatures between 14 and 16 °C. In both populations, temperatures outside of the thermal range cause lethal and sub-lethal effects. Importantly, previously observed dispersal polymorphism was not observed at hatching time in either population in our study. Our study demonstrates that during early developmental stages, embryos are adapted to local thermal conditions and that they live very close to their upper thermal limits. Temperatures outside this range cause detrimental and contrasting effects on embryonic development of O. erinaceus, implying that the effects of future warming will depend on the population response to local environmental history. Our results suggest that global warming could shift the geographical distribution range of O. erinaceus poleward.

环境温度在塑造海洋变温生物的分布和丰度方面起着重要作用。一般来说，幼虫和幼虫比成虫对热应激更敏感，因此，它们代表了部分决定物种地理范围的关键生命阶段。确定个体发育过程中的关键热极限可以预测气候变暖对海洋变温分布的潜在影响。然而，众所周知，耐热性——以及应对变暖挑战的潜力——因许多物种的种群规模而异。为了充分认识一个物种在气候变暖下的未来，来自不同热环境的多个种群研究是必要的。在这项研究中，我们比较了海洋腹足动物Ocenebra erinaceus囊内发育过程中的热耐受反应在两个地理上分开的种群之间：一个来自中部（索伦特，英国），另一个来自该物种地理范围的南部（阿卡雄，法国）。结果表明，热耐受响应受地理起源的影响。来自相对温暖水域的南部种群（法国）的胚胎显示出一个温暖的广温耐受窗口，最佳温度在 12 到 18 °C 之间。相反，来自北方冷水种群（英国）的胚胎表现出狭窄的、温暖的慢热、耐热窗口，最佳温度在 14 到 16 °C 之间。在这两个种群中，温度范围之外的温度都会导致致命和亚致死效应。重要的是，先前观察到的分散多态性在我们研究的任一种群的孵化时间均未观察到。我们的研究表明，在早期发育阶段，胚胎适应当地的热条件，并且它们的生活非常接近其热上限。超出此范围的温度会对胚胎的胚胎发育造成不利和相反的影响。O. erinaceus ，暗示未来变暖的影响将取决于人口对当地环境历史的反应。我们的研究结果表明，全球变暖可能会将O. erinaceus的地理分布范围向极地转移。