This study investigated the post-spawning dispersal of seven species occurring in a tributary of the Římov Reservoir during the years 2000-2004. Fish were captured during spawning migration to the tributary, marked and released. The subsequent distribution of marked fish was followed in the reservoir and tributary during three successive periods 1) early summer, 2) late summer and 3) the next spawning season. Species were divided into two groups – obligatory tributary spawners (white bream Blicca bjoerkna, chub Squalius cephalus, bleak Alburnus alburnus and asp Aspius aspius) that did so predominantly in the tributary of the reservoir and generalists (bream Abramis brama, perch Perca fluviatilis and roach Rutilus rutilus) that usually spawned in the tributary as well as at different sites within the reservoir main body. We hypothesized that obligatory tributary spawners would distribute across the reservoir after spawning according to their species-specific preferences for certain feeding grounds. We expected a relatively low or erratic post-spawning dispersal for spawning generalists. The results of the study evealed that the post-spawning dispersal of obligatory tributary spawners is consistent with our hypothesis and they most likely dispersed according to their feeding ground requirements. The post-spawning dispersal of generalists revealed that the assumed low dispersal was relevant for bream and perch while erratic dispersal was observed in roach.
Keywords: distribution; feeding ground; migration; reproduction