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In a sample of 73 females of winter steelhead, Salmo gairdneri Richardson, from the 1965–66 spawning run in the Alsea River, Oregon, egg size and egg number were correlated with body length. Alsea steelhead produced approximately 32% fewer eggs than females from Trinity River, California, and 51% less than fish of similar size from Scott Creek, California.

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Gonadal development, time of spawning, and fecundity of black bullheads were examined in 1969 and 1970 for insight into the reproductive potential of this species in a warm-water lake. Maturity indexes peaked around 1 June in both years. Spawning was evidently triggered by rising water temperatures during June. Fecundity seemed unrelated to body length because ovaries of fish of similar length varied more than 100% in number of mature ova present. INTRODUCTION The black bullhead, Ictalurus melas, is an extremely abundant species in Clear Lake, a shallo.w, eutrophic lake in western Cerro Gordo County, Iowa. Bullheads compete for food with many other fishes present (Ridenhour, 1960; Welker, 1963) and probably considerably deplete food otherwise available to more desirable species (Baur, 1970). Bullheads also are forage fish for piscivorous species, such as the walleye (Jernejcic, 1969). Thus, variations in bullhead reproductive potential can provide valuable insight into the ability of this species to maintain itself in the lake. This study was initiated in May 1969 to obtain knowledge concerning the normal reproductive cycle of the black bullhead and variations in fecundity that might be related to water temperature, to body len•h and to body weight. MATERIAL AND METHODS Black bullheads larger than young-of-theyear were collected at various sites in Clear Lake by gillnet or electrofishing from 15 May to 29 September 1969, and from 19 May to 23 June 1970. Most fish were frozen soon after capture. Total length of thawed fish was measured to the nearest millimeter. The abdomen and stomach were opened, and the stomach Conservation Commission, cooperating. ß o ß ß o ß o o oo ß ooo ß ß ß ß ß 180 230 280 TOTAL LENGTH (ram) Flctmz &--Relationship of egg number to total body length for Clear Lake black bullheads captured