Tadpole madtoms, Noturus gyrinus. Madtoms comprise a group of approximately 25 or 26 species of distinctive small catfishes native to North America. The tadpole madtom is the most widely distributed species, being found over a large portion of the eastern US west to eastern North Dakota south to central TX. It is also one of the larger madtoms, reaching a length of 5 inches. The name "madtom" refers to the painful sting that can be inflicted by their pectoral fin spines.