To assess the impact of long-term starvation on nutrient stores, Procambarus clarkii (Girard) and Procambarus zonangulus (Hobbs) were starved for 5 mo with 1-mo feeding recovery. This starvation period reflects the period of time a nonfeeding crayfish might reside in a burrow during summer. P. clarkii mobilized more dry matter and energy from tissue stores than P. zonangulus. Female P. clarkii mobilized more dry matter and energy than males of either species. At the end of 5 mo of starvation P. zonangulus survival was greater than P. clarkii. Initially, lipid, carbohydrate, and protein were mobilized from all tissues in both species. However, lipid and carbohydrate mobilization decreased in the abdominal muscle and carcass after the first month. After 1-mo recovery (feeding) following starvation there was greater than 50% recovery in the mass and proximate composition of all tissues in both species. In the southeastern USA where their ranges overlap, the nutrient-rich waters and stable environmental conditions favor the survival of P. clarkii. Based on these data, we hypothesize that P. zonangulus may have an advantage over P. clarkii when environmental conditions delay emergence from the burrows in the early fall. © Copyright by the World Aquaculture Society 2010.