Close genetic similarity among populations of the white croaker (Micropogonias furnieri) in the south and south-eastern Brazilian Coast. I. Allozyme studies

Micropogonias furnieri (white croaker) is a demersal sciaenid species highl y exploited along the south-eastern coast of South America. Off the Brazili an Coast some morphological and population dynamic characters suggested the presence of two partially isolated populations between 23 degrees S and 33 degrees S latitude. To study the white croaker population structure in thi s area, 17 enzyme and one protein-encoding loci were examined by starch and polyacrylamide gel electrophoresis in seven sampling sites for a total of 638 individuals. The allozyme results showed a high degree of genetic homogeneity in allele frequencies (F-st = 0.005) and also high levels of gene flow were found amo ng the sampled populations. Therefore, the results do not support the hypot hesis of the presence of two partially isolated populations of the white cr oaker in the studied area. (C) 1998 Elsevier Science B.V. All rights reserv ed.