Walleye S ander vitreus ( M itchill) are relatively resistant to experimental infection with VHSV IVb and extant walleye strains vary in susceptibility

Compared to fathead minnow, walleye demonstrate low susceptibility to experimental infection with VHSV IVb, regardless of route of exposure or water temperature at time of infection. In triplicate and duplicate groups, walleye were intraperitoneally (i.p.) injected (10 2 –10 8 pfu/fish) or waterborne‐exposed (w; 1.4 × 10 7 pfu mL −1 ) with VHSV IVb. High cumulative mortality (64–100%) and severe gross lesions associated with VHSV IVb infection were evident only in fish i.p. injected with 10 8 pfu at 12 °C. These fish had multifocal necrosis of several tissues including the gill and heart. There was no difference in mortality between walleye infected (w or i.p.) at 12 °C (spring stocking) compared with a declining temperature profile from 18 to 12 °C (fall stocking). There were significant differences ( P