Genetic variability and fine-scale population structure in the threatened species Acropora palmata and Acropora cervicornis around Puerto Rico

The population genetic structure of the zooxanthellate corals Acropora palmata and A. cervicornis were used as a proxy to understand connectivity between reefs. Sequences of the mitochondrial control region were recovered from geographically adjacent and distant populations of A. palmata and A. cervicornis around Puerto Rico. AMOVA results from 220 A. palmata and 124 A. cervicornis colonies collected from 26 reefs of six localities suggest that significant population structure exists (phiST=0.0863, P<0.00098; phiST=0.1237, P<0.00587, for A. palmata and A. cervicornis, respectively). Significant phi ST's between reefs of Puerto Rico suggest that there is fine scale population structure. Although these species displayed significant population structure, both species exhibited low levels of nucleotide diversity which is common for scleractinian corals. Recovery of reefs in southwestern Puerto Rico might rely on the survival and sexual reproduction of local populations rather than replenishment from distant reefs because of the high levels of population subdivision.