This research was designed to determine if a metabolic energy deficit was a cause of mortality in larval largemouth bass (Micropterus salmoides). An energy budget was established which compared the energy available in the yolk to the energy utilized in catabolism for 24 hr intervals from the time of fertilization to complete yolk absorption. The energy available to an embryo or larva was calculated from the caloric value of the yolk present at a given time. Catabolic expenditures of energy were determined by two different methods. The first was to establish the day‐to‐day dry weight loss of the larvae and convert this to an energy expenditure value. The second method used oxygen consumption at a constant temperature as a measure of catabolism. The dry weight method revealed that the average larva had enough energy remaining in the yolk to meet developmental and catabolic requirements until a slight deficit occurred in the late stages of yolk absorption (288 hr after fertilization). This deficit did not occur at a critical time in larval development, however, since observations indicated that over 50% of the larvae were capable of feeding by 288 hr. The oxygen consumption method showed that the average larva did not incur an energy deficit at any time prior to complete yolk absorption.