Five adult or subadult muskellunge, Esox masquinongy (Salmoniformes: Esocoidei), were tracked over periods of 6–11 days by means of ultrasonic (74 ± 1 Khz) transmitters, surgically implanted in the body cavity. One of these fish demonstrated that survival and well-being for over a year is probable. There was no apparent effect on equilibrium, swimming, or feeding. There was also no apparent abnormally high amount of movement immediately after release.
Signal range was at times no greater than 10 m (in contrast to a potential of 1 km) as a result of the air in the dense aquatic vegetation.
Area occupied by a single individual for a protracted period could be described as a linear distance of 300–800 m in the stream, or a circle 300 m in diameter in the lake. Displaced individuals returned to a specific locality. Following spawning they do so over a distance as great as 6.4 km in a maximum of two days. There was evidence that two individuals used the same general area simultaneously.
Subsequent results with some of the same individuals indicated that radio transmitters are more practical and yield better results in the situation under study.