An electrophoretic investigation of populations of Atherina boyeri Risso, 1810 and A. presbyter Cuvier, 1829 (Teleostei: Atherinidae): genetic evidence in support of the two species

The data obtained using electrophoresis strongly support the specific status of Atherina boyeri Risso, 1810 and A. presbyfer Cuvier, 1829, and thuscontradict the recently proposedsynonymyof the two species. Four populations of A. boyeri and six populations of A. presbyter were assayed for 11 enzymes and general protein using muscle and liver extracts. Eight of the 11 enzymes were shown to be polymorphic at the 95% level. Sixteen loci, encoding 40 putative alleles were consistently resolved in all 10 populations. The two species were fixed for different alleles at the EST‐3 locus. At the G3PDH locus. with the exception of two heterozygotes, all individuals of each species were also homozygous for different alleles. At the PGM locus the common allele was unique to each species. The mean Nei's genetic distance ( D̄ ), over all loci, calculated between populations of A. boyeri (D̄= 0.10 ± 0.06); between populations of A. presbyter ( D̄ = 0.02 D̄ 0.02) and between populations of A. boyeri and A. presbyter ( D̄ = 0.42 D̄ 0.09) indicated the separateness of the two species. UPGMA cluster analysis based on genetic distances produced a dendrogram whose principal dichotomy resulted in the formation of two clusters. The ordination of populations in the UPGMA cluster analysis strongly reflected the geographic distribution of populations in both species.