Genetic population structure of the commercially most important demersal fish in the Southwest Atlantic: The whitemouth croaker (Micropogonias furnieri)

The whitemouth croaker (Micropogonias furnieri) is the main fish species of the demersal fisheries along the Atlantic coast of South America. There has been much debate regarding the number of stocks of this heavily exploited fish off the Brazilian coast between latitudes 23 degrees S and 33 degrees S. Analyses of morphometric and meristic data suggest that two stocks exist in that area, but this conclusion was not supported by genetic studies. Here, we used polymorphic nuclear loci (microsatellite and intron size polymorphisms) to compare samples of M. furnieri collected between Rio de Janeiro (23 degrees 02' S) and Chui (33 degrees 41'S), as well as samples from much further north, along the coast of Braganca at Para' State (1 degrees 03'S). Our data demonstrate the existence of three distinct stocks of the species in Brazil: one in North Brazil (Braganca - Pare State), as previously suggested; and two previously not detected genetically: one between 23 degrees S and 29 degrees S; and another south of parallel 29 degrees S. These findings indicate that the fisheries of the three areas should be managed as distinct stocks. (C) 2015 Elsevier B.V. All rights reserved.