Prey selection by sauger (Stizostedion canadense) was monitored from November 1976 through April 1977 in the portion of Watts Bar Reservoir, Tennessee, near the Kingston Steam Plant. Threadfin shad (Dorsoma petenense) provided the entire forage base for sauger until the population of threadfin was almost completely eliminated by low temperatures in December and January. Some sauger switched to alternate prey, but food consumption was greatly reduced in February-March as > 75% of stomachs were empty. Food consumption of sauger smaller than 30 em was restricted earlier in the year by the lack of threadfin less than 8.0 em. Digestive rate studies in the laboratory indicated digestion continued at a reduced, but effective, rate at temperatures < 10 C.