Protein requirements of smallmouth bass and largemouth bass

Protein requirements of young smallmouth and largemouth bass reared near ideal water temperatures were estimated as an initial step in quantifying specific nutrients essential to these fishes. Test fish were conditioned to accept pelleted rations, reared in small circular tanks and fed all they would easily consume at each feeding. Six levels of dietary protein were evaluated and gross energy of test diets ranged from 4,219 to 4,793 kcal per kilogram dry diet. Almquist-type plots were used to identify minimum protein requirements and maximum rates of growth. Minimum protein requirements of age 0 and 1 smallmouth bass were 45.3 and 45.2% of the dry diet and maximum rates of growth were 2.85 and 0.99% per day. In age 0 and 1 largemouth bass minimum protein requirements were not greater than 39.9 and 40.8% of the dry diet and maximum rates of growth were 2.36 and 0.76% per day. Protein utilization was measured in age 0 smallmouth and largemouth bass and dietary efficiency was measured in each group of bass. These statistics corroborate the estimated minimum protein requirements.