[5] Muskellunge closely resemble other esocids such as the northern pike (Esox lucius) and American pickerel (E. americanus) in both appearance and behavior.

[7] Martin Arthur Williamson caught a muskellunge with a weight of 27.8 kg (61.25 pounds) in November 2000 on Georgian Bay.

[8] The fish are a light silver, brown, or green, with dark vertical stripes on the flank, which may tend to break up into spots.

The lobes of the caudal (tail) fin in muskellunge come to a sharper point, while those of northern pike are more generally rounded.

Muskie were introduced to western Saint John River in the late 1960s and have now spread to many connecting waterways in northern Maine.

[citation needed] They prefer clear waters where they lurk along weed edges, rock outcrops, or other structures to rest.

Muskellunge are the top predator in any body of water where they occur and they will eat larger prey than most other freshwater fish.

[12] They eat all varieties of fish present in their ecosystem (including other muskellunge), along with the occasional insect,[12] muskrat, rat, mouse,[12] frog, or duck.

Only humans and (rarely) large birds of prey such as bald eagles (Haliaeetus leucocephalus) pose a threat to an adult.

The muskellunge's low reproductive rate and slow growth render populations highly vulnerable to overfishing.

This has prompted some jurisdictions to institute artificial propagation programs in an attempt to maintain otherwise unsustainably high rates of angling effort and habitat destruction.

[citation needed] Though interbreeding with other pike species can complicate the classification of some individuals, zoologists usually recognize up to three subspecies of muskellunge.