Genomic characterization reveals high clonal redundancy in two Acropora cervicornis nurseries in the Dominican Republic

Abstract

Acropora cervicornis is often propagated through fragmentation (i.e., clonal propagation), a common practice implemented by restoration projects. Known as asexual propagation, this strategy may rapidly increase coral cover but reduces genetic variation. We used 2b-RAD sequencing to characterize multilocus genotypic variation among 45 A. cervicornis colonies maintained in two in-situ nurseries (Cap Cana, Acuario) in Punta Cana, Dominican Republic. After reference-based SNP discovery and filtering, 2,515 high-quality SNPs were retained in the dataset. Principal coordinate analysis (PCoA), hierarchical clustering, identity-by-state (IBS) distances, and relatedness estimates identified only three multilocus genets among the 45 colonies (AC1, AC2, and AC3). Of these, AC2 was the most abundant (n = 23; 51.1%), followed by AC3 (n = 14; 31.1%) and lastly AC1 (n = 8; 17.8%). Within-genet IBS distances (0.153-0.227) did not overlap with between-genet distances (0.406-0.497). AC1 and AC2 were detected in both nurseries, whereas AC3 was limited to Acuario. These results reveal substantial clonal redundancy among sampled nursery colonies that determines local reef conservation efforts. These data highlight the value of incorporating genotype identification in nursery-based coral restoration projects.