Hermaphroditism is relatively rare among the Salmonidae (See Atz, 1964 for a comprehensive review) and has never been reported for coregonine fishes. Recent examination of a collection of coregonines at the Great Lakes Fishery Laboratory disclosed a hermaphroditic bloater(Coregonus hoyi). The fish was captured in a gill net set at 50 fathoms on the bottom of Lake Michigan approximately 7.5 miles NNW of Frankfort, Michigan, on November 2, 1955. The fish had a normal rate of growth and was 234 mm long and in its 5th year of life; it was normal in external appearance but was easily identified as a hermaphrodite by gross examination of its gonads