Fish
Flathead Catfish
Pylodictis olivaris · also called yellow cat, mudcat, shovelhead
Reach into a hollow log on the bottom of a big southern river in June and something the size of a dog may clamp down on your arm. Flathead catfish are the reason hand-fishing exists — a solitary, heavy-bodied predator that spends its days jammed into cover and its nights hunting live fish in the shallows.
Overview
Pylodictis olivaris is a large North American catfish, second in size only to the blue catfish. It has a broad, flattened head, a protruding lower jaw, small eyes, and mottled yellow-to-olive skin that earns it the names yellow cat, mudcat, and shovelhead. The tail is nearly square rather than forked. Big fish exceed 45 kg, and the rod-and-reel record is 55.8 kg.
A live-prey hunter
Young flatheads eat insects and crayfish, but adults switch almost entirely to live fish — sunfish, shad, carp, drum, and other catfish — caught at night in a wide, engulfing bite. Unlike the scavenging channel catfish, a flathead rarely touches carrion, which is why anglers fish for it with live bait. Each adult keeps a single daytime lair under a log jam or undercut bank and returns to it after every hunt.
Out of place
Within the Mississippi, Missouri, and Ohio basins the flathead is a native top predator in balance with its prey. Moved into Atlantic-slope rivers like the Susquehanna, Cape Fear, and Savannah, it has become a destructive invader, growing huge and stripping out native sunfish and bullheads. Agencies now run removal programmes and ask anglers to kill every flathead caught outside its native range.
Status
The flathead catfish is Least Concern, abundant where it belongs and expanding where it does not. The conservation concern runs the other way — the damage this fish does as a non-native predator — rather than any threat to its survival.
Flathead Catfish: common questions
How big do flathead catfish get?
They are among the largest freshwater fish in North America. The rod-and-reel world record is 55.8 kg, caught in Kansas in 1998, and fish of 9 to 23 kg are routine in good rivers and reservoirs. Only the blue catfish grows larger among North American catfish. Flatheads are long-lived, reaching more than 20 years and sometimes over 30, and they keep growing throughout life, so the biggest individuals are old females in large, productive river systems with plenty of prey and little fishing pressure.
What is noodling and why does it target flatheads?
Noodling, also called hand-fishing, grabbling, or hogging, is the practice of catching large catfish by hand. In late spring and early summer a male flathead clears a nest cavity in a hollow log, a hole in a bank, or a gap in rock or debris, then stays to guard the eggs and bites hard at anything that enters. A noodler wades or dives to these holes, reaches in, lets the fish clamp onto a hand or forearm, and hauls it out by the lower jaw. It is legal only in certain states and carries a real risk of injury, drowning, and encounters with snapping turtles and beavers.
Why are introduced flathead catfish a problem?
In their native Mississippi basin, flatheads are one predator among many and native prey species have evolved alongside them. When flatheads are stocked or released into rivers on the Atlantic slope and in the west, they arrive as a large, efficient, novel predator that hunts live fish almost exclusively. Populations of native sunfish, bullhead catfish, and river herring have collapsed in some invaded rivers, and because a mature flathead has essentially no predators and grows very large, there is no natural check on its numbers. Wildlife agencies now run removal programmes and encourage anglers to keep every flathead caught outside the native range.
How is a flathead catfish different from a channel catfish?
Several ways. The flathead has a broad, flattened head and a lower jaw that sticks out past the upper, while the channel catfish has a rounded head and an overbite. The flathead's tail is nearly square; the channel catfish's is deeply forked. Adult flatheads are plain mottled yellow-brown with no spots; young channel catfish are silvery with dark spots. Behaviourally the channel catfish is an opportunist that will eat almost anything, including stinkbait and cut bait, whereas the flathead strongly prefers live fish, so anglers after flatheads fish with live sunfish or shad.