Population Structure, Larval Dispersal, and Gene Flow in the Queen Conch,Strombus gigas, of the Caribbean

Genetic variation from 8 polymorphic enzyme loci among 17 population samples of queen conch, Strombus gigas, exhibits similarity of allelic frequencies throughout the species distribution. Analyses of standardized variances of allelic frequencies and of the frequencies of private alleles indicate that gene flow among populations in the Caribbean must be high. However, analyses of allelic frequencies clearly demonstrate that the populations are not panmictic. Bermuda is isolated from Caribbean populations, and there are numerous further examples of heterogeneity of allelic frequencies among populations within island groups. Limited data suggest that normal conch and samba, a slower growing, melanic form, are genetically differentiated.