This study provides the first assessment of the morphometry, length–weight relationship, and condition factor of Sarpa salpa in the Bizerte Lagoon, northern Tunisia, to enhance understanding of its population structure and growth dynamics. Morphometric traits, including body shape, fin dimensions, and eye and orbital measurements, were analyzed to provide a detailed description of the species’ morphology. The length-weight relationship indicated negative limitations in food availability, although the satisfactory condition index suggests that allometric growth, suggesting that fish grow more in length than in weight, whereas the Fulton condition factor reflected an overall good physiological state. The observed negative allometry may indicate potential the lagoon environment remains generally suitable for the species. These contrasting results emphasize the complex interaction between growth patterns and environmental conditions. The findings offer valuable baseline data on the biology and health of S. salpa populations, contributing to the sustainable management and future ecological monitoring of lagoonal ecosystems.
