Accurate age estimates are critical for understanding life histories of fishes and developing management strategies for fish populations. However, validation of age estimates requires known-age fish, which are often lacking. We used known-age (ages 1–25) muskellunge (Esox masquinongy) to determine the precision and accuracy of age estimates from fin rays. We also determined whether fin location (anal or pelvic), fin ray number, and preparation methods affected accuracy and precision. Lastly, we determined whether von Bertalanffy growth parameters estimated from fin ray ages were similar to parameters estimated from known ages. Precision and accuracy of age estimates from anal and pelvic rays were similar and estimates were relatively precise (coefficient of variation = 8.5%) and accurate (mean absolute difference from known age = 0.85 years) for ages 4–15, but ages were overestimated for younger fish and underestimated for older fish. Growth models based on estimated age were similar to models based on known age. Anal and pelvic rays offer a nonlethal alternative for age estimation of muskellunge ages 4–15 and for producing reliable estimates of growth.

Muskellunge Esox masquinongy fisheries have increased in abundance and popularity in numerous southern and mid-Atlantic rivers. However, the paucity of information for these fisheries has limited biologists' ability to effectively manage these resources. We utilized data from simultaneously conducted fishery-dependent tag return and fisheryindependent capture-recapture studies to estimate catch-and-release exploitation and abundance of Muskellunge in the James River, Virginia. During winter electrofishing surveys in 2016-2019, we tagged 747 individual Muskellunge with dart tags and PIT tags. Thirty-seven percent of tags were returned by anglers, and 33% of tagged Muskellunge were recaptured at least once during subsequent electrofishing surveys. Eighty-eight percent of angled fish were caught by individuals targeting Muskellunge, and only 1.1% of returned tags were from fish that were harvested. Catch-andrelease exploitation (u) estimates obtained using a Brownie dead recovery model differed between the upriver (mean u AE SE = 0.57 AE 0.09) and downriver (1.00 AE 0.10) reaches of our study area. Similarly, densities of adult (≥762-mm) Muskellunge differed between the two areas (upriver: 0.80 fish/ha; downriver: 0.50 fish/ha) but were comparable to densities observed in lakes and at least one other river. The greatest site-specific density (4.69 fish/ha) was observed at a 1.6-km reach below the lowest dam, which concentrated fish and restricted upstream movement. Given the high values of u in the James River and the growing popularity of Muskellunge angling in southern waters, investigations into the effects of this level of angling on Muskellunge populations (e.g., trophy potential, abundance) will provide managers with the information needed to develop comprehensive Muskellunge management strategies.

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