MEPS 279:225-235 (2004)  -  doi:10.3354/meps279225

ABSTRACT: The genetic population structure of the Caribbean stoplight parrotfish Sparisoma viride was analysed by means of allozyme electrophoresis and randomly amplified polymorphic DNA (RAPD) using blood samples from adult fish that were collected on the reefs of 5 islands (3 sites at Bonaire, 1 each at Curaçao, Jamaica, Tobago and Saba). All allozyme loci showed a single very common allele. Allele frequency differences among the locations were mainly found for rare alleles. Genetic distances among the 7 sample sites ranged from less than 0.0001 to 0.012. The fixation index (F_ST) for the allozyme loci was 0.0188. Pairwise single enzyme locus F_ST values were small, but some F_ST values differed significantly from zero. The allozyme analysis detected significant F_ST values between Curaçao and the other sample sites. The RAPD data indicated high, but slightly restricted, gene flow among 5 geographic areas. Apparently, dispersal among islands is sufficient to maintain near-homogeneous allele frequencies. We conclude that the local S. viride sub-populations are relatively open and there is a high level of migration among them.

KEY WORDS: Reef fish · Population genetics · Gene flow · Allozymes · RAPD · Dispersal · Sparisoma viride