Lipid composition of coral propagules and reproductive material in coral restoration nurseries

Coral restoration efforts have rapidly increased worldwide, with many restoration programs utilising in-water nurseries to accelerate coral biomass yields. However, the impact of nursery environments on propagule quality has not been examined despite the importance of coral fitness for ensuring resistant populations. Here we investigated lipid profiles of Acropora millepora adults and eggs grown on coral nurseries versus native reef on the GBR, with adults assessed at two sites (Blue Lagoon and Rayban) and eggs assessed at one site (Blue Lagoon). Lipid profiles of adult colonies varied by site and origin (nursery versus wild reef), with adult nursery corals exhibiting an elevated relative abundance of storage lipids (diacylglycerols and triacylglycerols) and lipid classes responsible for regulating membrane structure (phosphatidylcholines and sterol esters), while wild corals were characterised by a greater relative abundance of fatty acids and classes involved in immunoregulation. Comparing eggs from different origins, nursery offspring were richer in energy-storing triacylglycerols, as well as ceramides and phosphatidylcholines essential for membrane structure, while wild eggs had a greater relative abundance of wax ester species also important for energy storage. Importantly, these findings demonstrate that the lipid classes with the highest relative abundance in A. millepora nursery and wild eggs differed from those in adults from the same origin, suggesting propagation origin is more important for driving lipid profiles in coral eggs compared to parental effects.