From the shallow to the mesophotic: a characterization of Symbiodiniaceae diversity in the Red Sea NEOM region

In this work, we use high throughput ITS2 gene sequencing to characterizeSymbiodiniaceae communities associated with three depth generalists and one depth specialist coral species in the NEOM region across three depth ranges, spanning the northern Saudi Arabian Red Sea and Gulf of Aqaba. We recovered different patterns of host-algal associations with the majority appearing host- and environment-specific, whilst others were more widely distributed. At large, coral specimens, were overwhelmingly associated with symbionts from the genus Cladocopium, with discovery of many previously undescribed genotypes. Interestingly, we found association with Durusdinium sp. and other known tolerant taxa in mesophotic corals in the northern Red Sea, but not in the Gulf of Aqaba.