Photographs of three species of calanoid copepods were digitized, bina
rized and edited to remove the debris present in the images and to sim
ulate different degrees of segmentation. Twenty-eight segmented images
of the three species were generated after pre-processing to obtain th
eir digital Fourier transform or diffraction pattern. Cluster analysis
was carried out for the images of the copepods and for their diffract
ion patterns to determine which set of images discriminated genus, spe
cies and sex of the selected organisms. The dendrograms of the diffrac
tion patterns had more power of discrimination and 50% less variabilit
y. This method is promising, but more research is necessary in order t
o implement an automated system for plankton identification in the nea
r future.