Length–weight relationship of brown trout in selected rivers of the West Morava River system (Serbia)

Abstract

This study investigates the length–weight relationships of brown trout from five rivers in the Golija Nature Park within the West Morava River system in Serbia. The calculated b values ranged from 2.881 to 3.947, indicating a spectrum of growth types: negative allometric, isometric, and positive allometric, while all coefficients of determination exceeded 0.9, confirming strong model fits. These differences in growth types likely reflect local habitat conditions, food availability, and density-dependent factors. Notably, the analysis revealed that certain populations exhibit slower weight gain relative to length, which may be a sign of environmental stress or reduced food availability. In light of recent assessments showing that a significant portion of trout populations in this region are of low or critically low sustainability, our findings underscore the urgency of site-specific monitoring. The results contribute to establishing a reference framework for future conservation efforts.