Growth of Known‐Age Muskellunge Stocked into Northwestern Wisconsin Lakes.

Growth information from known‐age Muskellunge Esox masquinongy is relatively rare in the published literature. We tagged all extended‐growth Muskellunge fingerlings stocked into 10 northwestern Wisconsin lakes during 2009–2019 with PIT tags and later recaptured these fish to establish known age and growth. Our objective was to use known age, and length upon recapture of each stocked Muskellunge, to determine sex‐specific asymptotic length (L∞), Brody's growth coefficient (K), and mean length at age using Wang's parameterization of the von Bertalanffy growth function. Our results showed rapid juvenile growth with Muskellunge reaching lengths of about 67 cm by age 3, after which sexually dimorphic growth patterns were displayed and growth rates slowed. For example, the Wisconsin statewide minimum length limit for harvest (102 cm) was not achieved until age 9 for females, with males taking much longer or never achieving this length. Values of L∞ ± SE were 128.5 ± 7.6 cm for females and 102.0 ± 3.3 cm for males. Our study provides a method for managers to collect known age and length data for Muskellunge without sacrificing fish and validates current age and growth of northwestern Wisconsin stocked Muskellunge. [ABSTRACT FROM AUTHOR]