Morphometric study of Navicula morphospecies (Bacillariophyta) with respect to diatom life cycle

Abstract

Quantitative and qualitative variation in valve morphology in strains of Navicula cryptocephala and N. trivialis were examined using conventional valve measurements (length, width, striae density) and landmarkbased geometric morphometric method. The ability of morphometric techniques to distinguish individual strains on the basis of postinitial and/or sexually competent cells was assessed by multivariate analyses and permutation tests. The data showed that each strain had unique valve characters, which were shared by both large postinitial and small sexually competent cells. Landmarks representing central area and apical ends of the valves were primarily the most useful for discrimination between strains. The geometric morphometric techniques appeared to be enough sensitive to distinguish subtle morphological differences between Navicula morphospecies clonal cultures withouth any interference of diatom life cycle stage. © Czech Phycological Society.