Field Guide/Freshwater Fishes

Genus Esox is home to Northern Pike, Muskellunge, Chain Pickerel and the American Pickerel. Pike have the elongated, torpedo-like shape typical of predatory fishes, with sharply pointed heads and sharp teeth. Their coloration is typically grey-green with a mottled or spotted appearance with stripes along their backs, providing camouflage among underwater weeds, and each individual pike marking patterns are unique like fingerprints. Pikes can grow to a maximum recorded length of 1.50 m (5 ft), reaching a maximum recorded weight of 55 lb, 1 oz.

• Northern Pike (Esox lucius)
  • Their average length is about 40–55 cm (16–22 in), with maximum recorded lengths of up to 150 cm (59 in) and maximum weights of 28.4 kg (63 lb).
  • Northern pike are most often olive green, shading from yellow to white along the belly. The flank is marked with short, light bar-like spots and a few to many dark spots on the fins. Sometimes, the fins are reddish.
  • Younger pike have yellow stripes along a green body; later, the stripes divide into light spots and the body turns from green to olive green.
  • The lower half of the gill cover lacks scales, and it has large sensory pores on its head and on the underside of its lower jaw which are part of the lateral line system.
  • Unlike the similar-looking and closely related muskellunge, the northern pike has light markings on a dark body background and fewer than six sensory pores on the underside of each side of the lower jaw.
• Muskellunge (Esox masquinongy)
  • Like the northern pike and other aggressive pikes, the body plan is typical of ambush predators with an elongated body, flat head, and dorsal, pelvic, and anal fins set far back on the body.
  • Muskellunge are typically 70–120 cm (28–48 inches) long and weigh 7–16.5 kg (15–36 lb), though some have reached up to 1.8 m (6 ft) and almost 30 kg (70 lb)
  • The fish are a light silver, brown, or green, with dark vertical stripes on the flank, which may tend to break up into spots. In some cases, markings may be absent altogether, especially in fish from turbid waters. This is in contrast to northern pike, which have dark bodies with light markings.
  • A reliable method to distinguish the two similar species is by counting the sensory pores on the underside of the mandible. A muskie will have seven or more per side, while the northern pike never has more than six.
  • The lobes of the caudal (tail) fin in muskellunge come to a sharper point, while those of northern pike are more generally rounded. In addition, unlike pike, muskies have no scales on the lower half of their opercula.