NUTRIENT-REQUIREMENTS OF CATFISHES (SILUROIDEI)

The channel catfish (Ictalurus punctatus) is the most widely cultured foodfish in the U.S., thus most of the nutrient requirement data are a vailable for this species. Qualitatively, about 40 nutrients have been identified as necessary for the normal metabolic function of the chan nel catfish with quantitative requirement values available for about 3 0 nutrients including amino acids, fatty acids, minerals and vitamins. Additional information is available on protein and energy requirement s, digestible protein and energy coefficients as well as amino acid av ailability values. Thus adequate nutritional information is available to formulate high quality practical channel catfish feeds. Only limite d nutrient requirement data are available for the other Siluroidei spe cies. Some requirement data have been reported for a few species from Africa (Clarias gariepinus, C. isheriensis, Heterobranchus longifilis and H, bidorsalis), Asia (Clarias batrachus, C. macrocephalus, C. fusc us and Heteropneustes fossilis) and Europe (Silurus glanis). The avail able requirement data will be summarized and compared with the require ment data for the channel catfish. Some variation does appear to exist in optimum dietary protein levels, essential fatty acid requirements, and lipid vs carbohydrate utilization.