Fecundity of the bloater (Coregonus hoyi) in Lake Michigan

Using ovaries sampled seasonally from Lake Michigan bloaters in 1968-1969, we determined that one complement or modal group of eggs is produced each year and spawned mainly during January, February, and March. Fecundities estimated for 65 fish taken in October ranged from 3,230 eggs in one medium-size bloater (241 mm long) to 18,768 in the longest (305 mm). We regressed these estimates on lengths and weights of the parental fish to provide a quantitative basis for later evaluating long-term changes in reproductive potential. The resulting rectilinear regression on weight accounted for 75% of the total variation in fecundity.