Sex-associated differences in sclerochronology and sensitivity to thermal stress in Caribbean and eastern Pacific reef-building corals

Abstract

The density banding patterns of the skeletons of massive reef-building corals can be used as historical records of their growth, life history, and environmental conditions. By analyzing these patterns, it is possible to estimate growth parameters such as skeletal density, extension rate, and calcification rate. The responses of stony corals to environmental stress depend on the amount of energy available for high-energetic metabolic processes, including skeletal calcification and sexual reproduction. The sex of a colony may also influence its calcification rate and resistance to environmental stressors like thermal anomalies. Here, we review and summarize the literature that focuses on sex-associated differences in coral calcification rates between male and female colonies and then we examine their differential responses to changes in sea surface temperature (SST) in Porites panamensis, P. lobata, Pavona gigantea, Siderastrea siderea, Montastraea cavernosa, Dichocoenia stokesi, and Dengrogyra cylindrus from the eastern Pacific and Caribbean regions through a reanalysis of published data. Differences in the calcification rates between sexes were due to the energy available for calcification and the strategy employed for skeletal growth. Female corals exhibited lower calcification rates than male colonies in all coral species. The results reveal that overall, the calcification rate was negatively related to SST when the data of both sexes were pooled. However, when data were analyzed separately by sex, only the calcification rate of females was significantly dependent on SST. These findings highlight the implications for paleoenvironmental reconstructions using coral skeletons and the potential disparities in the populations of gonochoric corals.