Fins - D1 - VI(V-VII); D2 - 14-16 (13-17); pectoral - 18-19 (17-20); anal - 11-13 (11-14)
Head - Head is as wide or wider than deep;angle of jaw is below the anterior quarter of eye. Lower jaw not prominent. Upper lip narrows slightly to rear
Color - Body brownish gray with dark brown lateral spots. Mature males completely black during spawning and nest guarding, with yellowish spots on the body and median fins fringed yellow. A large, oblong, black spot is usually present at the end of the first dorsal fin, beginning at the 5th ray. Round gobies without this spot have been found in Lake Erie. Juveniles have a light border around the black spot.
Distribution - Native to Sea of Azov, Caspian Sea, Black Sea, and Sea of Marmara. Now found in parts of Lakes Erie, Michigan, Huron, Superior, Ontario, as will as some rivers.
Habitat - Found in association with large cobble and occasionally in sand