Variations in DDT concentration in muscle tissue of channel catfish, Ictalurus punctatus, from the Des Moines River, 1971.

Concentrations of DDT in muscle tissue of channel catfish, Ictalurus punctatus, from the Des Moines River, Iowa, were compared in relation to length, age, sex, and fat content. Residue concentrations were not correlated with sex. Although residue concentrations were significantly correlated with size-related factors and fat content, they varied widely. Therefore, predictions of DDT concentrations in individual catfish on the basis of length, age, or muscle fat content may be grossly inaccurate.