Large-scale biogeographic patterns are reflected in the genetic structure of a broadcast spawning stony coral

Abstract Countries in the Western Indian Ocean (WIO) and along Red Sea are particularly vulnerable to coral reef degradation, understanding degree of connectivity among reefs is a first step toward efficient conservation. The aim this study investigate genetic diversity, population structure patterns broadcast spawning Acropora tenuis, at large scale comparing WIO, second smaller sites within WIO. In total 689 individual A. tenuis colonies were sampled on 28 locations Saudi Arabia, Kenya, Tanzania, Mozambique Madagascar analysed with seven microsatellite markers. sample site was found be differentiated from all other which confirms hypothesised break. High differentiation between African mainland Madagascar. However, there evidence for long-distance larval dispersal North Channel region, exchange northern southwest show mixing Madagascar, as well Tanzania. Southern forms separate group Bayesian clustering. most East coast, no indication strict barriers. These results support biophysical modelling studies, propose Tanzania seeding source larvae downstream Kenya. high combined contemporary barriers can explained by long duration prevailing northbound Coast Current that facilitates higher Coast, while eddies causing retention southern