Reproductive Potential of Two Lake Whitefish (<i>Coregonus clupeaformis</i>) Populations

The reproductive potential of two lake whitefish (Coregonus clupeaformis) populations with dissimilar growth rates was studied and compared. The smaller-sized Pigeon Lake females and the larger-sized Buck Lake females had similar ratios of gonad weight to body weight during the gonad development period, but the Pigeon Lake fish produced fewer but larger eggs. Spawning occurred in both lakes for a period approaching 4 mo in both open water and under ice cover in a wide range of water temperatures. Concentrated spawning occurred in shallow water over a boulder, gravel, and sand surficial lake sediment of both lakes. The incubation of whitefish eggs was retarded under ice cover but accelerated to hatching as the water warmed and the ice left the lakes in the spring. The length of the egg incubation period, not the size of the egg under incubation, governed the size of the hatching lake whitefish.