Determining minimum ultimate size, setting size limits and developing trophy standards and indices of comparable size for maintaining quality muskellunge (Esox masquinongy) populations and sport fisheries

Growth and ultimate size can provide important population insights and a sound biological basis for setting length limits, which can be the best single regulation for preventing overexploitation of muskellunge (Esox masquinongy) populations. A system was developed, using cleithral age and total length at age confidence limits (CL) data, to determine reproductive and growth potential (ultimate size) for calculating and setting increased size limits based on minimum reproductive size (upper 99% CL at age at first maturity + 2 year) and minimum ultimate size (MUS) calculated from the lower 99% CL—minimum ultimate size limit (MUSL). MUS also provides a trophy standard and an index of relative size for comparing trophy potential of individuals within and among populations. Guidelines are provided for determining minimum sample size (mean ± 95% confidence interval = 12 ± 4) and minimum age (8–10 ± 2.0 year) required to produce valid von Bertalanffy growth trajectories. MUS, MUSL, and trophy standards for both length and estimated weight are provided for female and male muskellunge from 14 Ontario sources. Mean MUS, or trophy standard, for females was 115 ± 10.3 cm (MUSL range 75–135) and 11.1 ± 2.6 kg (2.5–17.5) and for males was 95 ± 7.5 cm (66–110) and 6.1 ± 1.3 kg (1.9–9.2). These indices can precisely define growth and growth potential for muskellunge populations and individuals and can be used to better manage and maintain or improve the quality of muskellunge populations and fisheries.

Growth, mortality and movements of a sanctuary population of maskinonge

A Schumacher population estimate based on 995 maskinonge taken by trap nets, between the months of May and October in the years 1951–1953, set the number of maskinonge in Nogies Creek at between 769 and 1,122 in July 1953. The mean standard length of these fish was 53.0cm. S.L. in the first year) compared favourably with that for maskinonge in other waters. Fish of age-groups II, III and IV predominated. The small number of fish over four years of age was apparently due to a 70% annual mortality rate at least after the third year of life and perhaps before age III.Recaptures of tagged maskinonge demonstrated that there was little movement of maskinonge in summer, and what movement there was, was mainly upstream. In the fall there was far more movement of fish, and this was mainly in a downstream direction.The area supports a fairly large population of maskinonge but the high mortality after three years of age limits its value for raising maskinonge to legal size. The potential for rearing fish to three years of age is such that it may be very advantageous to move hatchery fish here for one or two years before liberation. cm. The rate of growth (26.3

Growth of tiger muskellunge reared at three temperatures and fed different amounts of protein

Growth rates of tiger muskellunge (muskellunge Esox masquinongy ♀ x northern pike E. lucius ♂) fed diets containing 35, 45, or 55% crude protein for 5 weeks at 17, 20, or 23°C were compared. Fish fed diets containing 45 or 55% protein grew faster at all temperatures than those fed 35% protein. Growth of tiger muskellunge fed a diet containing either 45 or 55% protein did not increase significantly at optimum growth temperatures (20 or 23°C). At 17°C, below the optimum temperature range, growth did increase when the percentage of protein in the diet was increased.

Characteristics of trophy-sized muskellunge

An effort was made to compile a listing of trophy-sized muskellunge which have been angled from Ontario waters. A trophy-sized muskellunge in this study was defined as a fish exceeding 114 cm (45 inches) in length or 10.0 kg (22 pounds) in weight. Information was obtained for a total of 9,708 muskellunge which were angled in Ontario between 1917 and 2010. The majority of records originated from volunteer angler diaries maintained by members of Muskies Inc. and Muskies Canada Inc. Most trophy-sized muskellunge were angled early in the season and numbers decreased as the season progressed. The geographic distribution of trophy-sized muskellunge was spread well over their Ontario range. There was a significant positive trend in the maximum size of muskellunge reported annually. There was also a significant increase in the maximum size of muskellunge reported after the changes to minimum size limit regulations in 2001. An increase in the catch-and-release angling ethic in conjunction with the implementation of new minimum size limit regulations is believed to be responsible for the increased number of trophy-sized muskellunge being angled in Ontario. Based on the number of Ontario waters producing trophy-sized muskellunge and the increasing number of trophy-sized fish being reported annually, Ontario’s muskellunge management strategy appears to be achieving the objective of  providing a diversity of trophy angling opportunities.