Differentiation and allozyme variability of shads genus alosa (Clupeiformes, Alosiinae) from Azov-Black Sea basin

Abstract

Biochemical genetic marking of Sea of Azov-Black Sea shads (Alosa immaculata, A. caspia, and A. maeotica) of three local stocks—Danube, Dnepr, and Azov—was performed based on an analysis of 19 enzyme loci and a series of loci coding muscle structural proteins. The high degree of monomorphism and the absence of any differences in the allele pools are shown, thus confirming their conspecificity. It seems that Caspian, Brazhnikov, and Pontic shads are only morphologically discrete forms and their species rank is unjustified. In truth, they are local and migratory ecomorphs that are almost always present in anadromous fish species.