http://www.dnr.state.md.us/fisheries/education/tigermuskie/tigermuskie.html

The tiger muskie is a sterile hybrid cross between the muskellunge and the northern pike. The hybrid gets its name from its distinct, dark vertical bars, although some large individuals display very little barring. Whereas the hybrid can occur in the wild where both species coexist, the vast majority of hybrids are produced in the hatchery. The female muskie is usually preferred due to its greater egg production than the female northern pike. However, the northern pike and muskellunge cross is often used when suitable numbers of female muskie are not available. Maryland obtains its tiger muskie fingerlings from the Pennsylvania Fish and Boat Commission in exchange for fingerling striped bass.

It probably was a hatchery mistake and stocked as a Northern Pike.