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Flathead catfish (Pylodictis olivaris)
Photo credit: Eric Engbretson, U.S. Fish and Wildlife Service,

Flathead Catfish

(Pylodictis olivaris)

Report this Species!

If you believe you have found this species in its invasive range in Pennsylvania, please report your findings to iMapInvasives by submitting an observation record.

Species at a Glance

The flathead catfish is one of the largest species in the catfish family and it can live for up to 20 years. It feeds voraciously on other fish, making it a possible threat to native ecosystems. It has many nicknames, including pied cat, mud cat, Mississippi cat, shovelhead cat, yellow cat, and Opelousa cat.


Key characteristics of the flathead catfish are its flattened head, tiny eyes, squared tail, and protruding lower jaw. It can grow up to 152 cm (60 in) long and weigh on average 14 kg (30 lbs), although some have been known to reach over 45 kg (100 lbs). Coloration is usually brownish-yellow with mottled speckles on the back and a cream-colored white to yellow belly.

Similar Species

Most often confused with the channel catfish (Ictalurus punctatus), the flathead catfish is nearly double its weight. The lower jawbone of the flathead extends outward from the rest of the face, like an underbite, whereas the channel catfish’s upper jaw extends over the lower. The channel catfish also has a forked tail instead of a squared tail


Thriving in reservoirs, lakes, rivers, and large streams, the flathead catfish prefers deep, still, muddy waters with logs and other debris to use as shelters.


The most likely vector of spread is intentional stocking and release by anglers for game and food fishing.


Native to North America, including areas of the Mississippi River Basin, the Great Lakes, and the Ohio River drainage, flathead catfish are invasive in western states and throughout the entire Mid-Atlantic region, extending down to Florida.


Note: Distribution data for this species may have changed since the publication of the Mid-Atlantic Field Guide to Aquatic Invasive Species (2016), the source of information for this description.

*To learn more about the native/invasive range of the flathead catfish in Pennsylvania, check out the information available for this species on our Invasive Here but Not There page.

Environmental Impacts

Because it is fast-growing, long-lived, and feeds voraciously on other fish, the flathead catfish poses a threat to the region’s ecologic and economic resources, such as native fish populations. Species such as sunfish and native catfishes have declined heavily in some areas where flathead catfish are present.

Note: The flathead catfish poses specific management and policy challenges. It is native to the western part of Pennsylvania in the Ohio, Allegheny, and Monongahela river watersheds; however, it is considered invasive in eastern Pennsylvania.


Information for this species profile comes from the Mid-Atlantic Field Guide to Aquatic Invasive Species (2016).

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