Discrimination between Acartia (Copepoda: Calanoida) species using their diffraction pattern in a position, rotation invariant digital correlation

Digital images of Acartia discaudata, A. clausi, A. margalefi and A. tonsa were processed to obtain their diffraction pattern. To discriminate between species and sex all diffraction patterns were correlated with a spatial filter, invariant to position and rotation, for each Acartia male and female. This filter was made up using a combination of different images of each species and sex. Considering the great similarity between the copepod species used in this work and between the male and female of each species the results obtained are very good. It is concluded that the method used to discriminate between species of this congeneric group can be very useful for the development of an automated system for the identification of copepods.