Carolina Smok; Mariana Rojas & Mariano del Sol

This study addresses gill filament calcification in Atlantic salmon (Salmo salar) fry, a process that could erroneously be interpreted as pathological. Using various anatomical and histochemical techniques, the gills of 10 clinically healthy fry from the fish farming industry in Chi- le were analyzed. Our results show that the calcification process begins at the base of insertion of the gill filaments, advancing towards the apices of these structures. Histologically, calcification was identified in the perichondrium and in the cartilaginous matrix. This process, also observed in the gill rakers and bones of the gill arches, is directly related to the gills’ morphological plasticity, highlighting the importance of differentiating between biological responses of adaptive remodeling and certain pathologies of Salmo salar at the time productive diagnoses are made. The findings reported in this work contribute toward improving the understanding of the physiological processes in salmon and their impact on productive quality.

KEY WORDS: Gills; Gill filaments; Plasticity; Calcification.

SMOK, C.; ROJAS, M. & DEL SOL, M. Calcificación de filamentos branquiales en Salmo salar: Perspectivas sobre plasticidad y función. Int. J. Morphol., 43(1):244-249, 2025.