How to Identify a Sauger (Sander canadensis)

• Body shape: A slender, spiny-rayed fish with two separate dorsal fins and a large mouth.
• Jaw length: The upper jaw extends to about the hind edge of the eye.
• Dorsal fin: There are rows of dark spots on the first dorsal fin, unlike the walleye, which has only one large black blotch.
• Body markings: Distinct dark blotches, or "saddle marks," on the sides.

Look for the defining traits: dark spots on the leading dorsal fin, irregular dark blotches on the body, and the lack of a white tip on the lower tail. See the Walleye page for its full mark list.

A freshwater fish found principally in large, free-flowing streams, favoring water with some current, often swift. Native to much of the eastern United States and southern Canada, mostly in riverine habitats.

Lay the fish flat on its side in even light and photograph the whole body first, then the details below. Get a close, sharp frame of the head: mouth, jaw length and any barbels. Raise the dorsal and anal fins fully; ray counts and fin edges only read when the fin is spread. Shoot the side of the body before the fish dries; spots and stripes fade fast out of water. The app reads the photo and names the likely species; use the marks on this page to confirm it.

Size and daily limits for this species differ by state and by water, and some waters are catch-and-release only. Check the current regulations for where you are fishing before keeping any fish; if you are unsure of the species, release it.