Population differentiation in Haemulon plumieri juveniles across the northern coast of the Yucatan Peninsula

Abstract

The white grunt Haemulon plumieri is an important local artisanal fishery resource along the northern coast of the Yucatan Peninsula. In the present study, the population structure of recently post-settled H. plumieri was assessed in 4 locations (Celestun, Dzilam, Yalahau and Chacmochuch) from the northern coast of the Yucatan Peninsula by using a phenotypic approach based on otolith shape analysis and by a genotypic approach using 4 microsatellite DNA markers. Both approaches indicated that the 4 location samples were different from each other: significant differences in otolith mean shapes were observed (PERMANOVA, F3,196 = 10.9879, p = 0.0001), and significant genetic differentiation was also observed (global FST = 0.0560, p < 0.001). The isolation-by-distance test revealed a significant correlation between the FST values and the geographic distance in the subpopulations (Z = 98.1407, R2= 0.8680, p = 0.001). The greatest genetic differences were observed between the Celestun and Chacmochuch samples (FST = 0.069, p < 0.001), and the lowest genetic differences were observed between the Yalahau and Chacmochuch samples (FST = 0.029, p < 0.001). Our data indicate that dispersal may be limited in this species, and this could make white grunts vulnerable to local overfishing.