Morphological analysis of the Eurasian perch Perca fluviatilis L., 1758 from Vlasinsko jezero reservoir

Abstract

Descriptive, bivariate and multivariate statistical analysis of 21 morphometric traits of Eurasian perch Perca fluviatilis L., 1758 from the Vlasinsko Jezero reservoir revealed complex changes in its morphology in the examined age classes (2+ - 8+). These changes comprised mostly the anterior part of the body, head included, on both dorsal and ventral sides. No allometry was detected. The two subsamples diverged at the size of approximately 15 cm in total length, at which the perch shifts to piscivory. It is most probable that morphological changes enabled that shift to piscivorous feeding. This strongly suggests that changes in morphology coincide with particular life-history stages. Sexual dimorphism of shape was negligible, although it was strong considering the size component. This was especially prominent in older age classes, thus confirming the different growth rate in sexes.