Naupliar exposure to acute warming does not affect ontogenetic patterns in respiration, body size, or development time in the cosmopolitan copepod Acartia tonsa.

Short-term, acute warming events are increasing in frequency across the world's oceans. For short-lived species like most copepods, these extreme events can occur over both within- and between-generational time scales. Yet, it is unclear whether exposure to acute warming during early life stages of copepods can cause lingering effects on metabolism through development, even after the event has ended. These lingering effects would reduce the amount of energy devoted to growth and affect copepod population dynamics. We exposed nauplii of an ecologically important coastal species, Acartia tonsa, to a 24-hour warming event (control: 18°C; treatment: 28°C), and then tracked individual respiration rate, body length, and stage duration through development. As expected, we observed a decrease in mass-specific respiration rates as individuals developed. However, exposure to acute warming had no effect on the ontogenetic patterns in per-capita or mass-specific respiration rates, body length, or development time. The lack of these carryover effects through ontogeny suggests within-generational resilience to acute warming in this copepod species.