Diet Analysis of Flathead Catfish in the Lower Channelized Missouri River Bordering Nebraska

Flathead Catfish Pylodictis olivaris are often considered apex predators, yet little information exists regarding the influence of predation by native Flathead Catfish on game fish and species of concern. Furthermore, modifications to rivers (e.g., channelization, revetment, and construction of dams) have likely increased the amount of suitable habitat available for Flathead Catfish, ultimately leading to greater abundances of this predator.  To determine the influence Flathead Catfish have on the trophic dynamics of the lower channelized Missouri River, we posed two overarching research questions: 1) what is the diet composition of Flathead Catfish, and 2) is there a difference in mean stomach fullness of Flathead Catfish among seasons?  We used pulsed gastric lavage to remove stomach contents across three distinct seasons; May-June (spring), July-August (summer), and September-October (fall).  We collected 463 diet samples from 784 Flathead Catfish.  The four most common diet items by weight include: Siluriformes, Decapoda, Ephemeroptera, and Unidentified fish.  The proportion of full stomachs was similar in spring (74%) and summer (72%) but lower in fall (37%).  Ultimately, this research will help us gain a better understanding of the role Flathead Catfish play in the Missouri River food web, and the bioenergetics of this predator.