Adult Flat Bullheads range from between 6 to 8-1/2 inches in length, making them the smallest bullhead species. Their distinct features include a stout body, depressed head and a rounded anal fin. The species is found in most freshwater sources, though it prefers warm tributaries and drainage and doesn't like rough waters. Flat Bullheads eat plants, insects and even other fish. Females mature at three years old and spawn in June and July. Flat Bullhead are considered safe to eat.
The Yellow Bullhead is the second smallest species of bullhead found in the U.S., as it ranges from about 5 inches to close to one foot in length. These catfish are distinguished by their pale chin barbels, a brown-golden body and dusky brown fins. The species prefers warm backwaters and ponds, thought it can be found in lakes, reservoirs and flowing rivers. It eats micro-crustaceans, fish and insect larvae. Yellow Bullhead are the most commonly caught catfish of bullheads.
The Black Bullhead grows from just under 6 inches to close to 1 foot in length. The species is the most adaptable of the four, as it handles low oxygen, high temperatures and turbulent waters. It's distinguishable by its dark barbells (whiskers), and a more robust body than the other three. The fish is rarely caught, though safe to eat.
The Brown Bullhead is the largest of the four species, growing up to 13 inches in length. The species preys on invertebrates, micro crustaceans, fish and even algae. It is less adaptable than the Black Bullhead as it avoids turbulent waters. The species ranges in color, gray, brown or black is most common and has what can be described as a chunky body. The Brown Bullhead is a commonly caught catfish.