The American lobster (Homarus americanus) is one of the most iconic and economically valuable fishery species in the Northwestern Atlantic. Surface ocean temperatures are rapidly increasing across much of the species' range, raising concern about resiliency in the face of environmental change. Warmer temperatures accelerate rates of larval development and enhance survival to the postlarval stage, but the potential costs at the molecular level have rarely been addressed. We explored how exposure to current summer temperatures (16 °C) or temperature regimes mimicking projected moderate or extreme warming scenarios (18 °C and 22 °C, respectively) for the Gulf of Maine during development influences the postlarval lobster transcriptome. After de novo assembling the transcriptome, we identified 2542 differentially expressed (DE; adjusted p < 0.05) transcripts in postlarvae exposed to 16 °C vs. 22 °C, and 422 DE transcripts in postlarvae reared at 16 °C vs. 18 °C. Lobsters reared at 16 °C significantly over-expressed transcripts related to cuticle formation and the immune response up to 14.4- and 8.5-fold respectively, relative to those reared at both 18 °C and 22 °C. In contrast, the expression of transcripts affiliated with metabolism increased up to 7.1-fold as treatment temperature increased. These results suggest that lobsters exposed to projected warming scenarios during development experience a shift in the transcriptome that reflects a potential trade-off between maintaining immune defenses and sustaining increased physiological rates under a warming environment. This could have major implications for post-settlement survival through increased risk of mortality due to disease and/or starvation if energetic demands cannot be met.

美国龙虾（龙虾美洲）是西北大西洋地区最具标志性和经济价值的渔业物种之一。在整个物种的大部分范围内，地表海洋温度都在迅速升高，这引起了人们对面对环境变化的弹性的担忧。较暖的温度加快了幼虫发育的速度并提高了到幼虫后阶段的存活率，但很少解决分子水平的潜在成本。我们研究了缅因湾在开发过程中暴露于当前夏季温度（16°C）或模仿预计的中等或极端变暖情景（分别为18°C和22°C）的温度如何影响幼虫后龙虾转录组。从头组装了转录组后，我们鉴定了2542个差异表达（DE；调整后的p <0.05）暴露于16°C与22°C的幼虫中的转录本，以及在16°C与18°C的条件下饲养的幼虫中的422 DE转录本。与在18°C和22°C饲养的龙虾相比，在16°C饲养的龙虾与表皮形成和免疫应答有关的转录本明显过量表达，分别高达14.4和8.5倍。相反，随着处理温度的升高，与代谢相关的转录本的表达增加至7.1倍。这些结果表明，在发育过程中暴露于预计的变暖情景的龙虾经历了转录组的转变，这反映了在变暖环境下维持免疫防御和维持增加的生理速率之间的潜在权衡。