Acanthamoeba are free-living amoebae which can differentiate from vegetative, trophozoite forms into dormant cysts upon encountering unfavorable conditions. Acanthamoeba isolates FLA9, BP, and FLA22 are known to have unusual tolerance to environmental conditions which would promote encystment in the type strain, Neff. To facilitate further research into the behavior of these isolates, the phenotypic variables of instantaneous growth rate (μ), mean exponential encystment rate (Ԑ), and overall encystment success are calculated for the study isolates a variety of environmental conditions. Results indicate that BP and FLA22 may prefer growth conditions that are intolerable to the Neff strain. Findings suggest genomic alterations may be present which grant increased tolerance to otherwise stressful environmental conditions after several generations.