Evaluation of Northern Snakehead Diets in Virginia’s Tidal Rivers and Lakes
Mike W. Isel and John S. Odenkirk
Abstract.—The nonnative Northern Snakehead Channa argus was first documented in the Potomac River system in 2004. Since then, their range in Virginia has expanded to include other rivers and numerous lakes as a result of dispersal and illegal introductions. Most Northern Snakehead lake populations were discovered after 2012. Through 2017, nearly 4,000 Northern Snakehead were collected via Virginia Department of Game and Inland Fisheries (VDGIF) electrofishing surveys, resulting in a robust dataset. These collections provided an opportunity to investigate food habits of Northern Snakehead in both lotic and lentic systems which may assist with management and a better understanding of potential community effects. Incidence of identifiable prey items (n = 677) was evaluated since 2004, however wet weights (n = 370) were not recorded until 2014. A total of 30 prey types were identified from Northern Snakehead stomachs taken from rivers, whereas 7 prey types were identified from lakes. Banded Killifish, Bluegill, and crayfish were the most abundant prey types (in order) based on frequency of occurrence for Northern Snakehead collected from rivers; whereas Bluegill, frogs, and Yellow Perch were most common in Northern Snakehead collected from lakes. Most important food types (in order) based on % wet weight for Northern Snakehead collected from rivers were Bluegill, Gizzard Shad, and Banded Killifish; whereas Bluegill, Yellow Perch, and frogs contributed the most mass for Northern Snakehead from lakes.