Coral larval settlement preferences linked to crustose coralline algae with distinct chemical and microbial signatures

Abstract The resilience of coral reefs is dependent on the ability corals to settle after disturbances. While crustose coralline algae (CCA) are considered important substrates for settlement, it remains unclear whether larvae respond CCA metabolites and microbial cues when selecting sites attachment metamorphosis. This study tested settlement preferences an abundant species ( Acropora cytherea ) against six different from three habitats (exposed, subcryptic cryptic), compared these with metabolome microbiome characterizing CCA. all induced only one Titanoderma prototypum significantly promoted surface, rather than nearby dead or plastic surfaces. had a very distinct bacterial community metabolomic fingerprint. Furthermore, rates were specific preferred habitat, suggesting that microbes and/or chemicals serve as environmental indicators larvae. Several amplicon sequence variants two lipid classes—glycoglycerolipids betaine lipids—present in T. identified potential omic influencing settlement. These results support may promote