Alien Flathead
Pylodictis olivaris - flathead catfish. Image from Texas Parks & Wildlife.
DB: This is Earth and Sky, with a story about alien catfish.
JB: The flathead catfish grows huge – it’s prized as a trophy fish by anglers in the U.S. This fish is native to the Mississippi River drainage area. But, since the 1950s, the flathead has been introduced as a sportfish to over a dozen states in the U.S. Tom Kwak, a researcher at North Carolina State University, told us the downside of that idea.
Tom Kwak: If you look at this fish, it’s all a big mouth and then a big stomach. And there’s really not much else to the fish. And fishes in the Mississippi River drainage area, they’ve evolved with this fish. And there’s a combination of factors between the habitat, and the way other fishes evolve in that system that keep the fish assemblage there very diverse and very healthy. But when all of a sudden you introduce this eating machine into another river, the consequences are bad. We start to see other species suffering, and we get a less complex fishery, the diversity goes down, and that’s just an unhealthy system overall.
DB: More about studying the flathead catfish – and a way to stop its spread – tomorrow. Thanks today to the U.S. Forest Service and to the National Fish and Wildlife Foundation – supporting the conservation of native fish, wildlife, plants, and their habitats. I’m Deborah Byrd, with Joel Block, for Earth and Sky.
The following individual was interviewed for today’s show. Our thanks to:
Tom Kwak
Unit Leader and Associate Professor
U.S. Geological Survey
North Carolina Cooperative Fish & Wildlife Research
North Carolina State University
Raleigh, North Carolina
Additional Teacher Resources
U.S. National Oceanic and Atmospheric Administration, ACE Basin Species Gallery: Flathead Catfish
This site provides a brief natural history of the flathead catfish including information on a general description, habitat, biology, species significance, and links to more information.
U.S. Fish & Wildlife Service, New Jersey Field Office: The Insidious Flathead Catfish
This article discusses how fishery biologists are dealing with the “alien flathead” an insidious fish that was introduced to the Deleware River watershed. Although historically, the distribution of the flathead was limited to the Mississippi, Missouri, and Ohio River watersheds, it has now been released into watershed throughout North America. The article explains the implications of these catfish in various ecosystems.
Invasivespecies.gov, A Gateway to Federal and State Invasive Species Activities and Programs: Flathead Catfish
This site provides a variety of links to pages and information related to the flathead catfish as an invasive species. It includes images and recent news from the Federal Government, State Governments, Universities, and International Organizations.
