Joseph E. Flotemersch. SBI, Inc., 3411 Church Street, Cincinnati, OH 45244

Louis R. D'Abramo, and Donald C. Jackson, Department of Wildlife and Fisheries, Mississippi State University, Mississippi State, MS 39762

Two taxa of crayfish were evaluated relative to their potential value as a dietary source of essential amino acids and essential fatty acids for channel catfish (Ictalurus punctatus) of the Yockanookany Floodplain-River Ecosystem. One crayfish taxon was a terrestrially burrowing crayfish (Cambarus (Lacunicambarus) sp.) and the other a stream dwelling non-burrowing crayfish (Procambarus (Ortmannicus) acutus). Comparative analyses of tissue levels and nutrient requirements revealed that both taxa of crayfish are excellent sources of essential amino acids and essential fatty acids for channel catfish. Peak foraging on crayfish by Yockanookany River channel catfish was documented to be prior to peak occurrence of eggs in channel catfish. Therefore, crayfish probably serve as a significant nutrient source of essential amino acids and essential fatty acids for vitellogenesis in channel catfish of this ecosystem.