FACTORS AFFECTING PREY CAPTURE AND OPTIMAL HOLDING VELOCITY OF WILD SOUTHERN AND HATCHERY NORTHERN BROOK CHARR (SALVELINUS FONTINALIS)

Identification of the factors affecting habitat selection is necessary for scientific management and conservation of at-risk fish populations. We tested the effects of 1) water velocity, 2) fish size, 3) days in captivity, 4) dominance, and 5) size rank, on prey capture success, holding velocity, and reactive distance of both hatchery Northern and wild Southern Brook Charr (Salvelinus fontinalis) using an experimental stream flume. In all experiments, prey capture success was negatively correlated with water velocity, holding velocity was positively

correlated with water velocity, and dominant fish had greater prey capture success than did subordinate fish. None of the variables we measured had a strong, consistent effect on reactive distance. There were few behavioral differences between Southern Brook Charr and Northern Brook Charr. The Grossman et al. (2002) optimal foraging model successfully predicted the holding velocity of wild Southern Brook Charr in Lynn Camp Prong, Tennessee.