An Integrated Assessment of Life-History Traits and Biological Reference Points of Oreochromis niloticus in Lake Nubia, Sudan

Contemporary biological information on Nile tilapia in Lake Nubia, Sudan, remains limited, which constrains evidence-based fishery management. This study provides an integrated assessment of life-history traits and biological reference points for Oreochromis niloticus, based on 369 specimens collected from commercial gill-net catches at Wadi Halfa in 2021. The analyses included examining length–weight relationships, absolute condition factor, and determining age using otoliths (ear stones). Growth was studied using multiple models (von Bertalanffy, Gompertz, and logistic functions), while maturity stages were estimated using logistic regression and bootstrapping. The population exhibited predominantly negative allometric growth, while the condition factor indicated generally favorable physiological status with clear seasonal variation. Aging precision was high, and the von Bertalanffy growth model provided the best fit to the length-at-age data. Additionally, 50% maturity for both sexes occurs at approximately 2.4 years and 29.2 cm in total length, with only minor sex-related differences. These findings offer the first integrated and uncertainty-aware biological reference points for O. niloticus in Lake Nubia and establish a robust baseline to support size-based management of this data-limited fishery.