Agonistic behavior of an invasive crayfish (Orconectes palmeri) toward the Muckalee crayfish (Procambarus gibbus): effects of residence, size, and cover

Abstract Invasive Creole Painted Crayfish (Orconectes palmeri) have spread throughout the Flint River and are currently moving from there into a tributary, Muckalee Creek. The negative behavioral impact of the invasive is a concern for the endemic Muckalee Crayfish (Procambarus gibbus). Tests examining residence, size, and cover effects on aggression demonstrated that O. palmeri is a dominant species in these encounters. This may explain the success of O. palmeri in the Flint River with Procambarus spiculifer, which is a close relative of P. gibbus, and it may also mean the endemic P. gibbus is in danger of extirpation. A survey of the Muckalee showed O. palmeri has already entered the tributary and are likely spreading upstream