The bowfin or dogfish is the only surviving member of this primitive family of fishes. Like the gars, bowfins' swim bladders serve as primitive lungs, allowing them to gulp air from the surface and survive in waters with low oxygen levels. They are widely distributed in Minnesota lakes and rivers. Though attaining a large size and putting up a good fight when hooked, most anglers do not consider them a desirable species. The Minnesota state record for bowfin is 12 pounds, 9 ounces (Minnesota DNR, 2014).The fine specimen pictured below (the fish, not the fisherman!) weighed about 8 pounds. It was released immediately after being photographed!
Photos courtesy of Jay T. Hatch, Natural History of Minnesota Fishes. Reprinted with permission.
Bottom photo courtesy of Gary Becker.