Flathead catfish

What it is

This species belongs to the family Ictaluridae and stands as the only living member of the genus Pylodictis. Adults display an olive upper body that fades to white or yellow on the belly. Younger fish often show dark mottling. The head is broad and flattened, with small eyes and a lower jaw that sticks out past the upper one. The tail fin is slightly notched, and the anal fin features fourteen to seventeen rays. They are among the largest catfish in North America, trailing only the blue catfish in maximum size.

Where it lives

Native populations inhabit waters west of the Appalachian Mountains. The range covers major drainage systems including the Mississippi, Missouri, and Ohio basins. Northern limits reach into Canada, while southern boundaries extend through Texas to the Gulf of Mexico and northeastern Mexico. The fish thrives in medium to large rivers with stable, slow-moving currents. It requires specific habitat features such as vertical banks and submerged woody debris at least three metres deep for shelter. It cannot survive in full-strength seawater but tolerates low salinity levels.

How it lives

These fish are bottom-dwellers that remain within a home range smaller than two kilometres. They do not migrate long distances. Diet shifts significantly with age. Juveniles under ten centimetres eat insect larvae. Between two and six years old, they consume crayfish before switching entirely to fish. Adults are voracious predators targeting shad, herring, sunfish, carp, and other catfish. Feeding activity peaks between nineteen and thirty-two degrees Celsius. Appetite drops below sixteen degrees Celsius and stops completely at seven degrees Celsius.

Breeding and life cycle

Reproduction occurs from late June to early July when water temperatures reach nineteen to twenty-four degrees Celsius. Males construct nests in natural depressions created by river erosion, often near submerged logs. They fiercely defend these sites and fan the eggs to supply oxygen. Females produce roughly one hundred thousand eggs per spawning event. Sexual maturity arrives between three and six years of age. Fry feed on insects and worms in shallow rocky areas. Cannibalism among young individuals is common.

Fish and people

The species is targeted by sport anglers for its size and fighting ability. A record catch weighed over sixty-three kilograms. It is also valued as food fish. However, its tendency to cannibalize juveniles makes it unsuitable for commercial aquaculture. Human activities have led to its introduction outside its native range. In several new locations, it has become an invasive species that disrupts local ecosystems.

Status and threats

The International Union for Conservation of Nature lists this species as Least Concern. Populations remain stable across most of their native range. Threats include habitat degradation from river modification and pollution. Introduction into non-native waters poses ecological risks to indigenous fish communities. Management strategies focus on controlling spread in invaded areas while maintaining sustainable harvest in native ranges.

Relatives and look-alikes

The closest living relative is the widemouth blindcat, a cave-dwelling species. Fossil evidence suggests the lineage existed for nearly twenty million years since the Middle Miocene. It is often confused with other large catfish like the blue catfish due to similar predatory habits and habitat preferences.

Questions people ask about Flathead catfish

Good reading and sources

• Flathead catfish on WikipediaEncyclopedia
• More photos on Wikimedia CommonsPhotos
• Wikidata recordOpen data