Assessing growth characteristics of Nile tilapia [Oreochromis niloticus (Linnaeus, 1758)] for sustainable aquaculture and enhancing global food security

Understanding the variability in morphometric and meristic traits of Nile tilapia (Oreochromis niloticus) alongside the physicochemical quality of its aquatic environment is crucial for successful fishery management and conservation efforts. This study examined the morphometric and meristic characteristics of O. niloticus from various samples, aiming to provide insights into the species' variability and habitat conditions. The results revealed significant variation in morphometric traits, with body weight ranging from 0.4 to 2.2 grams, total length from 35.4 to 67.7 cm, and standard length from 32.5 to 64.5 cm. Other key measurements included head length, pre-dorsal length, pectoral and pelvic lengths, dorsal and anal fin lengths, peduncle length, and caudal length, all of which showed wide ranges, indicating phenotypic plasticity likely influenced by environmental factors and genetic diversity. Meristic analysis recorded dorsal fin ray counts from 24 to 34 and anal fin rays from 28 to 35, with other fin ray numbers also showing variability. Such meristic traits are valuable for distinguishing populations and assessing fish health and adaptation. The water quality assessment indicated generally favorable conditions for fish growth. Dissolved oxygen was adequate at 5.5 ± 0.5 mg/l, with a slightly acidic pH of 5.6 ± 0.2. Conductivity and total dissolved solids were low, reflecting good habitat quality. Temperature was measured at a somewhat low 2.8 ± 0.5 °C, which may warrant attention for optimal tilapia growth. Other parameters such as bicarbonate, alkalinity, and hardness were within suitable ranges, supporting aquatic health. Both biochemical and chemical oxygen demands were negligible, indicating minimal pollution stress, although total hydrocarbons detected at 0.8 ± 0.2 mg/l highlight some environmental pressure. This study provides a comprehensive morphometric and environmental profile of Nile tilapia populations, identifying significant phenotypic variation and confirming generally good habitat conditions, yet flagging slight deviations in pH and temperature that could impact sustainability. Targeted improvements in water quality and ongoing monitoring are recommended to enhance fish health, growth performance, and long-term aquaculture viability for this globally important species.