EFFECT OF STREAM MICROHABITAT CHARACTERISTICS ON RATE OF NET ENERGY GAIN BY JUVENILE SMALLMOUTH BASS, MICROPTERUS-DOLOMIEU

We estimated the rate of energy consumed and expended by 43 juvenile s mallmouth bass, Micropterus dolomieu, videotaped in the North Anna Riv er during 1991. Habitat data were also collected in the areas where ea ch individual was videotaped. The net rate of energy gained (J . min(- 1)) increased as water depths decreased and mean water-column velociti es increased. This relationship remained statistically significant eve n when we assumed that consumption was as little as 40% of our origina l estimates, and that respiratory costs were three times higher than w e suspected. The net rate of energy gained by juvenile smallmouth bass was only affected by the characteristics of the area that they search ed and not the foraging tactics they employed.