Size at Stocking, Growth and Short-Term Survival of Muskellunge Reared Using Two Different Methods

Muskellunge (Esox masquinongy) are commonly reared on natural prey in hatcheries. This method is expensive and introduces biosecurity risks. Some agencies rear muskellunge on pelleted diets; however, concerns exist regarding comparative size, condition and post-stocking survival of pellet versus minnow-reared muskellunge. Nevertheless, continued biosecurity and fiscal concerns have led the State of Wisconsin to investigate the use of pellet-rearing with minnow finishing as a means of muskellunge propagation. Our objectives were to determine if differences in total length, weight, and short-term survival existed between muskellunge reared solely on natural prey (minnow only; MO) and pellet-reared muskellunge finished on minnows (minnow finished; MF). Fingerling muskellunge (N ≈ 6,000/treatment) were reared, marked, and stocked into 23 lakes throughout Wisconsin. Minnow only fish (306.12 mm, 166.62 g) were significantly larger at stocking than MF fish (272.27 mm, 107.33 g) (t_TL = -16.73, df = 198, p < 0.001; t_Weight = -17.53, df = 198, p < 0.001). Nighttime boat electrofishing catch rates were used to assess short-term (2-6 weeks) post-stocking survival. Catch rates were higher for MO fish (7.2%) that MF fish (5.2%) although fish from both treatments were captured in most lakes. Post-stocking growth was similar between treatments (≈ 20 mm).