We examined survival, predation mortality, growth, and prey consumption for three sizes of fingerlings of muskellunge (Esox masquinongy) after stocking. Small (100 mm total length), medium (200 mm), and large (250 mm) fingerlings were introduced into each of three reservoirs over 3 years. Fall survival, based on population estimates and electrofishing catch per unit effort, was lowest for small fingerlings and increased with fingerling size. Across all reservoirs, survival of large fingerlings was 2–3 times that of medium fingerlings. Cost‐benefit analyses showed large fingerlings to have the lowest cost per survivor. Predation by largemouth bass (Micropterus salmoides) decreased with fingerling size at stocking. Both foraging success and growth of stocked fingerlings were correlated with prey density. In contrast, prey species composition did not appear to influence foraging success or growth. Because they were stocked earlier, medium fingerlings achieved a greater size than did large fingerlings through the first fall when prey density was high but not when prey density was low. To maximize survival, growth, and cost‐effectiveness, we recommend stocking large muskellunge fingerlings in systems with high prey and low largemouth bass densities.
