Esox masquinongy, commonly known as the muskellunge or muskie, is a large freshwater fish found in North America's lakes and rivers. It is known for its elongated body, pointed snout, and sharp teeth. Muskies are apex predators, usually solitary, and they play a crucial role in controlling fish populations.

Esox masquinongy, commonly known as the muskellunge or muskie, is native to North America. Its geographical distribution includes the northern United States and southern Canada, specifically in the Great Lakes region, the Hudson Bay basin, and the Upper Mississippi Valley.

Muskellunge typically inhabit freshwater environments such as clear lakes, rivers, and large streams. They prefer areas with abundant aquatic vegetation, which provides both cover for hunting and spawning grounds. The water temperature in these habitats usually ranges from 15°C to 25°C (59°F to 77°F).

As an apex predator, the muskellunge plays a critical role in maintaining the balance of its aquatic ecosystem by controlling the populations of smaller fish. It is highly adapted to ambush hunting, often lurking among submerged vegetation or structures to surprise its prey. This species is known for its solitary and territorial behavior, establishing dominance over large areas of its habitat.