Dietary partitioning of six co‐occurring Ponto‐Caspian gobies in the Dnieper River basin

AbstractThe diets and resource partitioning of six co‐occurring gobiids (Caucasian dwarf goby Knipowitschia caucasica; monkey goby, Neogobius fluviatilis; racer goby, Babka gymnotrachelus; round goby, Neogobius melanostomus; bighead goby, Ponticola kessleri; and western tubenose goby, Proterorhinus semilunaris) have been investigated in freshwater of the Dnieper River basin. The studied gobies were characterised by relatively similar generalised feeding strategies with the dominance of chironomid larvae in their diets, except Caucasian dwarf goby, the diet of which was dominated by copepods and cladocerans. The ontogenetic diet shift was clearly observed in all studied gobiids, except Caucasian dwarf gobies, adults of which had almost the same food spectrum as their juveniles. The highest diet overlaps were observed between monkey and racer gobies, and between monkey and round gobies. The lowest values of the diet overlap indices were recorded between Caucasian dwarf and round gobies, and between Caucasian dwarf and bighead gobies. Each studied goby species can be characterised by a unique set of features resulting in dietary partitioning such as consuming prey organisms inhabiting different microhabitats, different sizes, different spawning periods and ontogenetic diet shifts.