Reduced condition factor of two native fish species Irons, K. S., Sass, G. G., McClelland, M. A., and Stafford, J. D., 2007, Reduced condition factor of two native fish species coincident with invasion of non-native Asian carps in the Illinois River, U.S.A. Is this evidence for competition and reduced fitness?: Journal of Fish Biology, v. 71, p. 258-273. ABSTRACT KEYWORDS