A Morphometric Study on Two Groups of Brown Trout (Salmo trutta) Population, 1758 in Northern Region of Albania

Abstract

This study was carried out to determine morphological differences between two brown trout (Salmo trutta Fario) populations of two Alpine rivers in Northern Albania: Cem River and Valbona River. Fifty five single individuals of brown trout were collected from two different rivers samples included two different age groups: (2)-year-old fish, and (3)-year-old fish; and compared their morphology in order to assess intra- variation in morphometric characteristics. Nine morphometric characteristics (total length of the fish, body height, head length, head height, snout length, eye diameter, pectoral fin length, anterodorsal length, and anteroanal length) were analyzed using PCA, and the best descriptive features of populations were determined. Among the morphometric characteristics, seven factors accounted for about 80% of variation within individuals of the two populations including, head length, eye diameter, pectoral fin length, head height. The trout populations of Cem River were easily differentiated from the ones of Valbona River according to their anterodorsal length, head height and length, and pectoral fin length.The most visible differences of the measured characteristics of the two populations were head height and pectoral fin length. It is suggested that the observed differences in the body shapes reflect the adaptation of the population in their native environmental condition of their habitats.