Collections for histopathology in corals require holding of samples in seawater for a time before they are fixed for histopathology processing. This could adversely affect interpretation of morphologic changes during histopathology examinations. We evaluated microscopic morphology of Porites evermanni and Montipora capitata, held (0-120 min) in seawater prior to fixation in Z-Fix formulated with raw or artificial seawater. We saw no evident effects of treatments on microscopic morphology. However, among 88 statistical comparisons, and after accounting for false discovery rate, holding time prior to fixation was associated with a significant increase in degree of mucosity of basal body wall.