How to Identify a Flathead Catfish (Pylodictis olivaris)
Quick answer
Flathead Catfish, Pylodictis olivaris: the 6 field marks to check, size, habitat and North American range, with sources. How to tell it from Channel Catfish.
Updated 2026-09-10 · Sources: Missouri Dept. of Conservation, nas.er.usgs.gov
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Download on the App StoreWhat are the key facts?
- Scientific name: Pylodictis olivaris
- Family: Ictaluridae (Catfish and bullheads)
- Adult size: Adult length is commonly 15-45 inches, with weight commonly 1-45 pounds (the source page's weight field literally reads "width," apparently a typo on the original site; reproduced verbatim here without correction); the maximum recorded is about 100 pounds.
- Habitat: It inhabits a variety of stream types but avoids those with high gradients or intermittent flow. It is never found in headwater creeks. It reaches its greatest abundance in large rivers.
- Range in North America: Native to the Mississippi River basin from western Pennsylvania to the White-Little Missouri River system in North Dakota, south to Louisiana; also found on the Gulf Slope from the Mobile Bay drainage in Georgia and Alabama to Mexico.
Key marks to check on a Flathead Catfish
- Head shape: The flathead catfish has a broad, flattened head with small eyes on top.
- Jaw: The lower jaw projects beyond the upper jaw.
- Tail shape: The tail fin is mostly squared off, with a slight notch (it is not deeply forked), and the anal fin is rounded, with 14-17 rays.
- Adipose fin: The adipose fin is a free lobe, widely separate from the tail fin.
- Body markings: The back and sides are pale yellow to light brown or olive, mottled with dark brown or black.
- Tail color: The upper tip of the tail fin is lighter in color than the rest of the fin.
Flathead Catfish vs Channel Catfish
The flathead catfish is the only Missouri catfish with all three of these traits together: an adipose fin that is a free lobe separate from the tail fin, a tail fin that is not forked, and a lower jaw that projects far beyond the upper jaw (except in the smallest young); the channel and blue catfish both have deeply forked tails. See the Channel Catfish page for its full mark list.
Where it lives
It inhabits a variety of stream types but avoids those with high gradients or intermittent flow. It is never found in headwater creeks. It reaches its greatest abundance in large rivers. Native to the Mississippi River basin from western Pennsylvania to the White-Little Missouri River system in North Dakota, south to Louisiana; also found on the Gulf Slope from the Mobile Bay drainage in Georgia and Alabama to Mexico.
How to photograph it for identification
Lay the fish flat on its side in even light and photograph the whole body first, then the details below. Spread the tail fin so its shape (forked, rounded or square) is clear. Get a close, sharp frame of the head: mouth, jaw length and any barbels. Shoot the side of the body before the fish dries; spots and stripes fade fast out of water. The app reads the photo and names the likely species; use the marks on this page to confirm it.
Before you keep it
Size and daily limits for this species differ by state and by water, and some waters are catch-and-release only. Check the current regulations for where you are fishing before keeping any fish; if you are unsure of the species, release it.
FAQ
What does a Flathead Catfish look like?
The flathead catfish has a broad, flattened head with small eyes on top. The lower jaw projects beyond the upper jaw.
How big does a Flathead Catfish get?
Adult length is commonly 15-45 inches, with weight commonly 1-45 pounds (the source page's weight field literally reads "width," apparently a typo on the original site; reproduced verbatim here without correction); the maximum recorded is about 100 pounds.
How do I tell a Flathead Catfish from a Channel Catfish?
The flathead catfish is the only Missouri catfish with all three of these traits together: an adipose fin that is a free lobe separate from the tail fin, a tail fin that is not forked, and a lower jaw that projects far beyond the upper jaw (except in the smallest young); the channel and blue catfish both have deeply forked tails.
Where are Flathead Catfish found?
Native to the Mississippi River basin from western Pennsylvania to the White-Little Missouri River system in North Dakota, south to Louisiana; also found on the Gulf Slope from the Mobile Bay drainage in Georgia and Alabama to Mexico.
More in North American Fish Identification
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Sources
- Missouri Dept. of Conservationmdc.mo.gov/discover-nature/field-guide/flathead-catfish
- nas.er.usgs.govnas.er.usgs.gov/queries/factsheet.aspx?SpeciesID=750
Compiled by the FishLens editorial team
Every fact on this page is taken from the sources listed above; numbers and prices are copied from the source, and prices name the guide or auction and its date. Research and drafting were assisted by AI, and each claim was then checked against the cited sources. Checked 2026-09-10. We do not buy, sell or grade items; the app identifies what you photograph and points you to these references.