Morphometric Characterization, Heterosis Expression, and Growth Performance of Genetically Improved Farmed Tilapia and Red Tilapia Hybrids for Sustainable Aquaculture Development

Aquaculture is the practice of developing aquatic animals and plants under artificial environmental conditions, either in a controlled or semi-controlled environment. Tilapia stands out as one of the most extensively farmed and consumed fish species globally, valued for its ease of preparation and relative affordability. This study investigated the morphometric characteristics, growth performance, feed utilization, and heterosis expression of hybrids derived from crosses between Genetically Improved Farmed Tilapia (GIFT) and Red Tilapia. Controlled breeding trials were conducted to produce F₁ hybrids alongside purebred GIFT and Red Tilapia groups. A 12-week growth experiment was carried out under standardized aquaculture conditions, during which growth indices, feed conversion ratio (FCR), and survival were assessed. Morphometric and meristic traits were measured and analyzed through Principal Component Analysis (PCA) and Discriminant Function Analysis (DFA) to evaluate hybrid distinctiveness. Results showed that hybrids significantly outperformed parental strains in final body weight, weight gain, and specific growth rate, while recording a lower FCR, thereby confirming the expression of heterosis in growth and feed efficiency traits. Survival rates were high and comparable across groups, indicating that enhanced performance did not compromise viability. Morphometric assessment revealed intermediate phenotypes in hybrids, with DFA achieving over 90% classification accuracy, while meristic traits remained stable across groups. PCA highlighted body size descriptors as key contributors to hybrid distinctiveness. The findings demonstrate the potential of GIFT × Red Tilapia hybrids as valuable genetic resources for sustainable aquaculture improvement, combining superior biological performance with market appeal.