Analysis of differences in physiochemical properties of water in which different groups of Symphysodon occur. Data were taken from Tables 3 and 4 of Bleher et al. [16]. Data are in online supplement 1. The abacaxi and Xingu phenotypes were not included in analyses due to small sample sizes. Because of linear separation of the independent variables (pH and conductivity) in tests involving the Heckel phenotype, it was not possible to include both variables in the same model, and therefore, variables were analyzed separately. Linear separation also occurred in pH due to nonoverlapping pH values for the Heckel and blue phenotypes.