Apparent Specific Dynamic Action of Largemouth Bass, Micropterus salmoides

Abstract

Oxygen consumption attributable to apparent specific dynamic action (SDA) was measured in relation to feeding level and body weight in largemouth bass, Micropterus salmoides, forced to swim at 1.7 body lengths/s (BL/s). Apparent SDA rose curvilinearly with ration size, the coefficient increasing with weight of bass. For a ration of fixed percent body weight/day, apparent SDA increased curvilinearly with weight of bass, the rate being most pronounced at higher levels of food intake. Apparent SDA expressed in energy units as a percent of ration ingested did not differ significantly with weight of fish or meal size. The overall mean apparent SDA ± SD was 14.19 ± 4.19% of the energy ingested. Time required for oxygen consumption to subside to pre-feeding levels increased with ration size and weight of bass.Over the range of swimming speeds from 1.4 to 2.5 BL/s, there were no differences in apparent SDA of similar size bass fed a ration of 4% body weight/day. Similarly, time for elevated levels of oxygen consumption to return to prefeeding rates was independent of swimming speed.