Several species within the terrestrial salamander genus Plethodon exhibit color polymorphisms consisting of individuals with a dorsal stripe (striped) and individuals lacking this feature (unstriped). The ecological and physiological differences between these color morphs have been extensively studied within the ubiquitous and widespread species Plethodon cinereus. We chose to determine whether physiological differences exist between striped and unstriped morphs within the ecologically and morphologically similar Plethodon angusticlavius. We explored energy assimilation at two ecologically relevant temperatures and determined that thermal sensitivity of energy assimilation did not differ between the two color morphs. We found that energy assimilation increased with increasing temperature. Additional studies should examine whether the same ecological and physiological differences that exist between P. cinereus color morphs exist in P. angusticlavius and other polymorphic species of Plethodon.