FLATHEAD CATFISH

(Pylodictis olivaris)

The flathead catfish is at the top of many “least wanted” invasive species lists because of its ferocious feeding habits, large size, and ability to swim long distances in a short time. Under ideal conditions, flatheads can grow to more than 55 kg (124 pounds is the record).

ORIGIN
This flathead catfish is an example of a species native to the Mississippi and Ohio River watersheds, has caused problems when people released them into new locations.

HABITAT
Flathead catfish are found in large rivers, streams and lakes; they prefer deep, sluggish pools, with logs and submerged debris cover. Males set up housekeeping in nest cavities dug into the bank where females then lay their eggs. Young flatheads live in rocky or sandy runs in the river and in the riffles.

IDENTIFICATION
As the name suggests, flatheads are most easily recognized by their flat broad flat head and lower jaw which projects beyond the upper jaw. The flathead catfish also has a distinctive tail fin outline that is square or slightly notched. While the coloration can vary, most adults have an olive cast to their back and sides with dark-brown to yellow-brown mottling. Their belly is yellowish-white, and their eyes are relatively small.

SPREAD
The earliest record of flatheads in the Delaware River Watershed was a 1991 sighting at Blue Marsh Reservoir. Since then, populations have been found in Springton Reservoir, below Blackrock Dam as well as in the main stem of the Delaware River near Robling, New Jersey; reproducing populations of flathead catfish have been documented in the Schuylkill River basin, and several hundred flathead catfish have been captured in the Fairmont Dam fishway on the Schuylkill River.

2010 Distribution Map of Flathead Catfish

IMPACT
The flathead catfish is a highly desired game fish; however its release into new watersheds has created problems for other fish species. There are several impacts such as:

• Threats to biodiversity. Flatheads compete with native fish populations for food and habitat. Flatheads introduced in Georgia and North Carolina rivers have eliminated native catfish populations and were found to prey heavily on crayfish, crabs, and shad.
• Human health risks. Flathead meat tends to accumulate toxins such as PCBs. For this reason, The Commonwealth of Pennsylvania advises eating no more than one meal a month of flatheads caught in the lower Schuylkill.
• Economic impacts. Flathead catfish may have an economic impact on the blue crab industry as well as shad, sturgeon, and striped bass.

PREVENTION AND CONTROL
Anglers are urged not to release flathead catfish caught in the Delaware or Susquehanna river watersheds.

To read more, view the Pennsylvania Sea Grant Flathead catfish fact sheet.

FOR MORE INFOMRAITON ON FLATHEAD CATFISH

• So What's the Big Deal about Flathead Catfish?
• Introduced Flathead Catfish Pilot Study
• Flathead catfish in Eastern Pennsylvania
• Pennsylvania Fish and Boat Commission: Flathead Catfish

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