Morphometric separation of Diplostomum spathaceum (Rud.) and D-mergi (Dubois) metacercariae (Digenea)

The variability and diagnostic usefulness of morphological features of meta cercariae of two Diplostomum species, D. spathaceum and D. mergi, were stud ied on 104 and 85 specimens, respectively. Metacercariae were experimentall y raised from cercariae in carp fry, Cyprinus carpio. Fourteen morphometric features and eight indices have been analysed. While no single variable co uld provide a classification with a reasonably small percentage of error, D . spathaceum and D. mergi have been separated with a misclassification rate less than 1% by applying a logistic regression model based on six signific ant variables (five metrical features and one index).