Noturus flavus Rafinesque 1818
Identification: The Stonecat is yellow to slate above, with a light blotch on the nape, a cream-white spot at the rear of the dorsal fin base, and a cream-white blotch on the upper edge of the caudal fin. Unlike other madtoms, the premaxillary tooth patch has a backward extension from either side. The rear edge of the pectoral fin spine has no or only a few small sawlike teeth. The Stonecat is slender, has a straight edge on the caudal fin, and 15-18 anal rays. To 12 1/4 in. (31 cm) total length.
Range: The Stonecat is found in the St. Lawrence-Great Lakes, Hudson Bay (Red River) and Mississippi River basins from Quebec to Alberta, and south to northern Alabama, northern Mississippi, and northeastern Oklahoma. On the Atlantic Slope, it is found in the Hudson R. drainage of New York. The species is common throughout much of its range.
Habitat: The Stonecat lives in rubble and boulder riffles and runs of creeks and small to large rivers, and on gravel shoals of lakes.
Similar species: No other madtom has a backward extension from each side of the premaxillary tooth patch or exceeds 7 in. (18 cm) in total length.