Thermal tolerance in the amphipod Sunamphitoe parmerong from a global warming hotspot, acclimatory carryover effects within generation

摘要

The thermal response of the amphipod Sunamphitoe parmerong was contrasted between unacclimated 'wild' and acclimated populations. Brooding females were allocated to 17 degrees C or 23 degrees C treatments and their progeny developed to adulthood at the same temperature. Tolerance to acute thermal challenge (26-36 degrees C) was determined. The 17 degrees C and 23 degrees C acclimated S. parmerong had a 0.45 and 0.64 risk of death compared to the unacclimated individuals. The upper lethal temperature (LT50) was 27.4 degrees C for the unacclimated group and 29.6 degrees C and 30.4 degrees C for the 17 degrees C and 23 degrees C acclimated groups, respectively. Acclimation shifted their LT50 by 2.2 degrees C and 3 degrees C, respectively. The wild population exhibited high variability in thermal tolerance, potentially due to their environmental history and greater diversity of genotypes. After acclimation S. parmerong had decreased variability in thermal tolerance and that of the 23 degrees C group shifted by 1 degrees C compared with the 17 degrees C group. These results indicate developmental phenotypic plasticity or differential survival of resilient progeny as potential mechanisms to facilitate persistence in a warming ocean.