On intraspecific differentiation of Black Sea sprat (Sprattus sprattus phalericus) near the Crimean coast (preliminary report)

Variability of structural and functional characteristics of Black Sea sprat Sprattus sprattus phalericus, inhabiting the south-western Crimean (Ukraine) shelf is studied. Differentiation of this fish species into three local isolated groups coinciding with the centers of mezoscale cyclonic eddies is revealed. Differences of main population parameters of sprat and infestation with parasitic nematode, Hysterothylacium aduncum are indicators of such levels groups.