Transgenerational inheritance of shuffled symbiont communities in the coral Montipora digitata

To evaluate the effects of El Nino driven mass thermal stress on the coral Monitpora digitata during spawning in a severe bleaching year (2016).32 colonies were collected, from a minimum of 5 - 10 metres apart laterally along the shore. Spawning occurred on 23rd April 2015, where egg-sperm bundles were collected from spawning colonies, total of 9. 27 of these colonies were re-collected from Hazard Bay in April 2016 and 5 remaining colonies were presumed dead. Colony colouration was assessed using the CoralWatch Color Chart, with photographs alongside each colony at the time of collection. Spawning occurred on 24th April 2016, and a total of 4 were spawning colonies.To determine the effects of thermal stress and the presence of bleaching in 2016, the health of coral colonies were measured using methods of effective quantum yield of photosystem II (YII), colony coloration, and Symbiodiniaceae cell density. YII was measured using Pulse Amplitude Modulated fluorometry (PAM) with a fibre optic cable (diving-PAM, Waltz).Samples from all spawning adults and 10 – 12 eggs from each colony were genotyped in both 2015 and 2016 through ITS2 amplicon sequencing. Analysis of community composition was achieved through sequence variations, evidence of shuffling of Symbiodiniaceae communities and differences in Symbiont densities and photochemical efficiencies.