QUANTITATIVE CHARACTERIZATION, CLASSIFICATION AND RECONSTRUCTION OF OOCYST SHAPES OF EIMERIA SPECIES FROM CATTLE

This study reports on morphological variability of Eimeria species, wh ich may be given either by drawings or as quantitative data. The drawi ngs may be used to facilitate identification by eye of 'unknown' Eimer ia specimens, whereas quantitative data may serve as a reference set f or identification by multivariate statistical techniques. The morpholo gy of 810 Eimeria specimens was defined in binary (b/w) digital images by pixels of their oocyst outline. A Fourier transform of pixel posit ions yielded size and shape features. To classify coccidia, the quanti tative data were employed in an agglomerative clustering by average li nkage algorithm with equal weight assigned to size and shape. An inver se Fourier transform served to reconstruct oocyst outlines, i.e. outli nes of average shape and size, from mean values of features in resulti ng clusters. Clusters were subsequently identified based on their aver age morphology by comparison with drawings of species in an earlier ta xonomical work. Five hundred oocyst outlines were simulated for each c luster representing a species, and shape/size variability was presente d in contour diagrams. Differences in species shapes, and corresponden ce in length and width, were seen after reconstruction by inverse Four ier transform and comparison with earlier studies.