Predictive Modeling of Climate Change Impact on Hatchability and Embryonic Development of Clarias gariepinus Under Simulated Thermal Scenarios

Increased climate warming is predicted to impact the reproductive performance of aquatic species, especially during sensitive early life stages. This study investigated the effects of varying incubation temperatures on the hatchability and developmental dynamics of Clarias gariepinus embryos, and projected the implications under future climate change scenarios. Fertilized eggs were incubated at five different temperatures: 24, 26, 28, 30, and 32 °C. Key developmental milestones and hatchability rates were observed, and a logistic regression model was applied to predict future outcomes. Results showed that hatchability peaked at 81.0 ± 1.5% at 28°C and declined significantly to 62.7 ± 3.0% at 32°C. Developmental rate increased from 0.0377 h⁻¹ at 24°C to 0.0588 h⁻¹ at 32°C, while Q₁₀ values declined from 2.15 to 1.84 across the thermal gradient. The logistic model predicted hatchability with high accuracy (R² = 0.93), and climate projections indicated potential declines in hatchability to 59.0% under RCP 8.5 and 70.5% under RCP 4.5 by 2100. In conclusion, Clarias gariepinus embryos are thermally sensitive, and future warming may reduce hatchery efficiency. It is recommended that hatchery managers adopt dynamic temperature control systems to buffer against climate-induced thermal stress.