Broodstock Selection Strategies to Control Blackspot Blotches Inheritance in Hybrid Red Tilapia (Oreochromis spp) for Sustainable Fingerling Production

Red tilapia is an increasingly important aquaculture species due to its rapid growth and high consumer preference. However, variation in pigmentation, particularly blotched phenotypes, reduces market value and uniformity of fingerlings. This study assessed the effects of broodstock pigmentation phenotype on progeny survival, growth performance, reproductive success and pigmentation inheritance. Four broodstock cross combinations were established: Cross A (plain red × plain red), Cross B (blotched male × plain red female), Cross C (blotched × blotched) and Cross D (plain red male × blotched female). Broodstocks were stocked in hapas and reared under standardised conditions in a ratio of 1 male to 3 females. Each treatment group was done in triplicate hapas. Data were collected on hatching success, survival, growth performance and pigmentation phenotype distribution. Survival, hatching success and growth performance did not differ significantly amongst the four crosses (p > 0.05), with survival averaging 85.6%–86.9% and weight gains 7.1–7.4 g. In contrast, pigmentation segregation showed significant differences (p < 0.05). Cross A produced significantly higher plain red progeny (94.6% [18.2:1 ratio]), while Cross C recorded markedly higher blotched offspring (73.4% [1:2.7 ratio]). Crosses B and D yielded intermediate distributions (40%–43% blotched; 1.3–1.4:1 ratio). Maternal versus paternal blotched origin did not significantly alter body pigmentation outcomes. The study concludes that pigmentation inheritance in red tilapia is heritable and consistent with a polygenic model with major-effect alleles. Plain red male × plain red female crosses are the most effective for producing uniform progeny with high market value. Hatchery managers are advised to prioritise plain red broodstock and avoid blotched parents when the goal is consistent pigmentation. Future research should integrate molecular tools to refine selective breeding strategies and strengthen sustainable seed production systems.