Madtom Identification Guide

Key identification features

• Small size, usually only 2-5 inches long as an adult
• Adipose fin fused directly to the caudal fin, forming one continuous fin margin, a trait unique among North American catfish
• Mottled brown to tan body coloring that helps it blend with gravel and rock
• Four pairs of barbels around the mouth used to feel for prey at night
• Has venomous pectoral spines used defensively when threatened
• Stocky, rounded body that narrows toward the tail
• Broad, flattened head relative to body size, with small eyes and a wide mouth

Common look-alikes

• Juvenile bullhead catfish: the adipose fin is clearly separated from the tail fin, unlike the fused fin of a madtom
• Stonecat: larger overall and shows less distinct mottling than most madtom species

Where you'll see one

Madtoms inhabit small streams and rivers with rocky or gravel bottoms across eastern and central North America, often hiding under rocks, logs, or debris during the day and becoming active at night to forage along the bottom.