The lower jaw has a row of 6 to 9 pores along each side. There are l6 to l9 branchiostegal rays, usually l9 rays in the dorsal fin, and l47 to l55 cycloid scales along the lateral line. The color of muskellunge varies considerably. It is usually olive to dark gray with dark over markings on the sides. When present, these markings will consist of dark spots or bars on a light background.
Muskellunge are strictly carnivorous.
They feed primarily on other fishes such as perch, suckers and shiners. The first food of young muskellunge is zooplankton, but after a few days of life fish are consumed. It also feeds extensively on frogs, crayfish and large water insects and has been known to devour ducklings, shore birds and even young aquatic mammals. An aggressive feeder, large musky have been reported attacking human appendages dangled in the water, but these incidents are indeed rare and unusual, and perhaps more lore than factual. Muskellunge spawn in early spring, several weeks later than northern pike.