Fine-spotted Brown Trout (Salmo trutta): Its Phenotypic Description and Biochemical Genetic Variation

Abstract

Initial studies on a small population of brown trout (Salmo trutta) in the Hardangervidda area in Norway revealed specimens with remarkable morphological characteristics. About one third of the population was classified as "fine-spotted trout" due to the occurrence of small black spots on the body and fins. These individuals also have from four to seven black spots located around the pupil of the eye. Genetic data, obtained by electrophoresis of tissue enzymes, demonstrated large differences compared with other brown trout populations. According to the information available, the abundance of fine-spotted trout has decreased during the last eight decades, which focuses on the need for preservation of the population and its habitat.