Observed growth in weight of an individual fish is the result of an interaction between the environment and the fish's bioenergetic system. A species-specific model is presented which simulates the bioenergetics and growth of largemouth bass (Micropterus salmoides). The model is used to simulate individual growth with changes in the annual temperature regime and relative levels of prey availability. Interaction among temperature, prey availability, and individual size are examined with the model in terms of their influence on growth. Preliminary tests with the model produced an exponential long term growth pattern which is contrary to the conceptualized trend of individual fish growth. Larger weights are produced by a southern temperature regime because of a longer growing season. Variations in the relative abundance and state of availability suggests an unstable system at limiting levels. Analysis of the interaction between temperature and prey availability indicates a stable maximum growth temperature above limiting levels of prey availability while the temperature range for positive growth narrowed as prey availability declined. At limiting prey levels, the temperature range for positive growth narrowed and maximum growth temperatures declined as individual size increased in the temperature-individual size interaction. The model is tested against observed growth data for the 1975 year class of largemouth bass inhabiting West Point Reservoir, Alabama-Georgia. Simulated weights underestimate the observed weights for the first and second years by 25% and 21%, respectively. An alternative equation for caloric density is developed and employed to improve the model's reality and accuracy. / M.S.