Apparent specific dynamic action (SDA), fish weight and level of caloric intake in largemouth bass, Micropterus salmoides Lacepede

Apparent SDA (specific dynamic action) in largemouth bass (Micropterus salmoides) was equated to the oxygen uptake associated with a meal of a dry pelleted diet (35.8% protein). Apparent SDA, maximum rate of oxygen uptake, and the length of time that the rate of oxygen uptake remained elevated above the prefeeding level were measured in relation to energy ingested (5-150 cal g^-1) and fish weight (5-250 g). Apparent SDA was positively related to energy intake, but for a given energy intake it was negatively related to bass weight. When expressed relative to energy intake, the mean apparent SDA of the dry pelleted diet represented 11.3% ± 1.32 (95% confidence limits). Maximum oxygen uptake following a meal was positively related to energy ingested and to fish weight. In bass smaller than 100 g and fed to satiation, oxygen uptake equalled the active rate. The length of time (12 to 76 h) that the rate of oxygen uptake remained elevated was positively related to energy ingested and negatively related to bass weight. The observations in the present study are discussed with reference to natural diets and to other studies where growth and food conversion efficiency were measured.