Predation of the Federally Endangered Roanoke Logperch (Percina rex) by the Invasive Ozark Crayfish (Faxonius ozarkae)

Abstract - An observed predation of a federally endangered Percina rex (Roanoke Logperch), by an invasive Faxonius ozarkae (Ozark Crayfish), is detailed herein. We observed the predation on 11 August 2021 in the Roanoke River near downtown Roanoke, Roanoke County, VA. The crayfish had recently captured a sub-adult Roanoke Logperch and was dragging it under a cluster of cobbles. Upon observing this behavior, we retrieved the fish, positively identified it, and confirmed it as dead. The initial state of the Roanoke Logperch was nearly undamaged apart from indentations from the crayfish's chelae behind the operculum and near the caudal peduncle. Coloration of the Roanoke Logperch at time of observation indicated the fish had likely recently been captured. A camera was not readily available, so we returned the fish to the cobble cluster until a photograph could be captured. Upon returning approximately one-half hour later, coloration of the fish had begun to fade, and the ventral portion of the fish was partially consumed by the crayfish. Herein we discuss the significance of this observation and the gravity of the continued expansion for this invasive crayfish species, both within the confines of Virginia's waters as well as throughout the eastern United States.