Low genetic differentiation among sardine populations, Sardinella aurita, from eastern Venezuela

Abstract

In view of the great importance of Sardinella aurita as a fisheries resource in the Caribbean region, we studied the genetic differentiation among the populations from Mochima, Gulf of Cariaco and Morro de Puerto Santo, eastern Venezuela, and compared the levels of variation and population subdivision with populations from the Mediterranean and Atlantic coast of Africa (previously reported). For this, we extracted DNA from 15 muscle samples for each population. A fragment containing the control region of the mitochondrial DNA was amplified and the restriction patterns were determined using restriction fragment length polymorphism (RFLP) analysis with the enzymes Taq I, Eco RI, Hae III and Alu I. The amplification of this region produced a fragment approximately 1000 bp long or, rarely, one of approximately 1100 bp long. No further difference was found through the RFLP analysis. The comparison of the Venezuelan populations produced FST values under 0.06 and the analysis of molecular variance showed no significant differences between them. This is an indication of very low genetic differentiation among these populations, so it is not possible to discard the presence of a panmictic population in this region. The comparison of the Venezuelan and Mediterranean populations produced very low F_ST values, while the comparison of the former with African populations from Mauritania, Senegal, Ivory Coast and Ghana produced F_ST values ten times larger.