Blue Catfish Identification Guide
Identify blue catfish by their slate-blue color, deeply forked tail, and long straight-edged anal fin.
Read the full Blue Catfish encyclopedia entry →
Key identification features
- Slate blue-gray to silvery body without spots, even in juveniles
- Deeply forked tail, more pronounced than in other North American catfish
- Long, straight-edged anal fin with 30-35 rays, giving it a rectangular rather than rounded outline
- Upper jaw slightly longer than the lower jaw
- Capable of reaching very large sizes, with mature fish regularly topping 50 pounds and trophy specimens over 100 pounds
Common look-alikes
- Channel catfish: shorter, rounded anal fin with fewer rays (24-29) and often dark spots scattered along the sides in smaller individuals
- Flathead catfish: flattened head with a protruding lower jaw and a nearly square, unforked tail
Where you'll see one
Blue catfish inhabit large rivers, deep reservoir channels, and areas with strong current where they feed on fish and invertebrates near the bottom. They are native to the Mississippi, Missouri, and Ohio River basins as well as major Gulf Coast drainages, and have been widely introduced into Atlantic Coast river systems such as Chesapeake Bay tributaries, where they now form some of the largest freshwater populations in the country.
Frequently asked questions
How do I tell a blue catfish from a channel catfish?
Blue catfish have a long, straight-edged anal fin with 30 or more rays, while channel catfish have a shorter, rounded anal fin with fewer rays and often show dark spots along the sides that blue catfish lack.
What's the easiest way to separate a blue catfish from a flathead catfish?
Blue catfish have a deeply forked tail and an upper jaw slightly longer than the lower, whereas flatheads have a nearly square tail and a lower jaw that juts out past the upper.