Parental acclimation to future ocean conditions increases development rates but decreases survival in sea urchin larvae

Abstract

Environmental conditions experienced by parents can have lasting effects on offspring. For some marine organisms, parental acclimation may attenuate the negative effects observed in offspring exposed to the same conditions. Here, development of the coral reef sea urchin Echinometra sp. A was examined in larvae derived from parents acclimated for 20 months in either present-day conditions or those predicted for the year 2100 (+ 2 °C/pH 7.8). Egg size was measured, and larval morphology, survival and respiration were quantified in larvae raised in present-day (26 °C/pH 8.1) and 2100 (28 °C/pH 7.8) treatments to near settlement to determine whether parental acclimation promotes greater resilience to climate change stressors. Although there was no difference in egg size, larvae from 2100 parents were generally larger and more developmentally advanced than those derived from present-day parents. However, negative carryover effects reduced survival in offspring of parents acclimated to 2100 conditions. At 15 days post-fertilization, survival of offspring derived from 2100 parents was 50.6% and 43.7% when raised in present-day and 2100 conditions, respectively, compared to 59.9% and 64.6% in offspring derived from present-day parents. When raised in 2100 conditions, respiration declined by 36.8% in larvae derived from present-day parents, while respiration rates of larvae from 2100 parents increased by 109%, suggesting that carryover effects may be associated with higher energy consumption and physiological stress in larvae from 2100 parents. Although parental acclimation enhanced growth of larvae in early development, overall, negative carryover effects outweighed potential benefits of parental acclimation to ocean warming and acidification in this species.