Abstract:
Dactylogyrus vastator Nybelin, 1924 is a common economically significant pathogenic gill
parasite ofCyprinus carpio. D. vastator attaches to gills by means of an attachment organ,
the opisthaptor, which carries two large hamuli, a connecting bar and fourteen marginal hooks. Principal component analysis (PCA) is a multivariate analysis using morphometric data used to separate morphologically close species on the basis of considering all the measured variables simultaneously and loading for differences between the specimens. Principal component analysis was used to investigate the effects of temperature on sclerite measurements.This study was carried out to stress the morphological variation or discrimination from the measured variables of D. vastator reared at three different water temperatures using PCA.The measured variables such as spike length of the hamuli, outer root length of the right hamuli, and internal root length are major factors which clusters more than 75.0% within the eclipse by which the population of the parasite reared at different temperature regimes will be discriminated. The length measurements clusters and fall within the eclipse, the eclipse of different temperature will be separated off very'clearly for the 12°C reared specimens than those reared at 14°C and 19°C.
