Abstract
We assessed genetic polymorphism of a bi-allelic anonymous DNA locus in otherwise highly homogeneous Turbinaria ornata populations in French Polynesia, Hawaii, Solomon, Wallis and La Réunion Islands. Large heterozygote deficiencies occurred in almost all populations, which may be related to possible self-fertilisation and short dispersal distance of zygotes. There was a high genetic differentiation among samples (Fst=0.5269***) and this was correlated with a gradient of hydrodynamic conditions prevailing on French Polynesian coral reefs. This correlation is tentatively associated with balancing selection acting on, or on the vicinity of, this anonymous DNA locus.