Gretchen Goodbody-Gringley

The capacity for self-fertilization is a recurring reproductive strategy for numerous invertebrate species despite potential drawbacks associated with inbreeding depression and reduced heterozygosity. Scleractinian corals are an ideal group in which to study life history strategies as they exhibit a great degree of variation in mating systems including hermaproditic broadcasting and brooding species. Using brooding species enables direct comparisons of parent and progeny, allowing for accurate estimations of selfing. This study aims to determine the extent of self-fertilization for population maintenance as well as the effects of population demography on rates of self-fertilization in the Mediterranean coral Balanophyllia europaea. Using microsatellites, baseline population diversity will be determined and rates of self-fertilization compared among reefs based on population density. It is hypothesized that as habitat destruction and deterioration increases and population density declines, rates of self-fertilization will increase as distances between individuals increases. Given the documented inverse correlation between temperature and population density, the effects of global climate change will likely result in decreased population density and thus increased rates of self-fertilization as sea-surface temperatures rise. Increased self-fertilization and local recruitment could potentially lead to closed populations allowing for the possibility of parapatric speciation. Additionally, the resulting locally homogenous populations could be more vulnerable to environmental change. Therefore, understanding how rates of self-fertilization vary with population demography and environmental parameters will assist in efforts to predict future changes to coral populations associated with global climate change.