RELATING METABOLIC PHENOTYPES TO MOVEMENT BEHAVIOR IN BROOK TROUT

Brook trout movement-related life history strategies vary considerably and range from individuals that stay within the same 100 meters their entire life to individuals that are potamodromous or anadromous. Potential drivers of movement life histories have been the subject of much research in fish, with genetic subpopulation explanations often failing to explain the phenomenon. Metabolic phenotypes have been suggested as a possible driver for expression of different movement life histories. I investigated if metabolic phenotypes are related to movement strategies within a population of brook trout (Salvelinus fontinalis) in Unnamed Creek, a tributary to the Rock River, Alger County, MI. Intermittent flow respirometry was used in the field using ambient stream water to determine metabolic phenotypes of wild trout. Individuals were then tagged with passive integrated transponders (PIT) and tracked with stationary readers and a backpack reader during the summer. Brook trout that moved over 250m displayed a significantly larger aerobic scope than individuals that moved less than 250m. Temperature effects on metabolic measures were not detected among the brook trout in this study, but this could be due to wild acclimation to a range of temperatures rather than a single value.. This study suggests that brook trout metabolic phenotypes are variable between individuals and likely relate to movement phenotype under natural field conditions