Meeting Abstract
Temperature is a key factor in determining the physiology and distribution of marine species. The planktonic larvae of benthic marine species are likely to experience different thermal environments than adults and may also exhibit stage-dependent tolerance to thermal stress, but few studies have looked at thermal stress responses in larvae. We examined larval temperature acclimation and transgenerational effects on thermal performance in larvae of the tube-dwelling polychaete Hydroides elegans. To examine transgenerational effects, we raised offspring of four parental cohorts from settlement to reproductive maturity under two different constant temperature regimes, 20 and 25°C. Larvae from both parental temperatures were split and reared at 20 or 25°C. We measured LT50 of larvae from all four groups on Day 1 and Day 4 of development. To measure LT50, larvae were exposed to a range of 12 temperatures between 21-40°C. We found that only some cohorts of Hydroides elegans exhibit larval temperature acclimation, but transgenerational effects were seen in every cohort; larvae produced by parents reared at higher temperatures had higher thermal tolerance in all four experiments. For a more powerful and nuanced view of the capacity for larval acclimation and transgenerational effects to buffer larval thermal performance, we are currently using a similar experimental design at a wider range of temperatures (20, 25, and 29°C) to investigate the temperature limits to performance and oxygen consumption in addition to LT50. Results from these experiments will shed light on the physiological capacity of larvae of tropical marine species to coping with rapid environmental changes.
