Abstract:Aiming to improve the accuracy of water temperature prediction in industrial Cephalopholis sonnerati aquaculture, a multi-step prediction model, IHO-Mamba-MHSA, which integrated the improved hippopotamus optimization algorithm (IHO), the Mamba model, and the multi-head self-attention (MHSA) mechanism was proposed. The interquartile range (IQR) method identified outliers, and linear interpolation imputed missing values to reduce noise impact. Key feature selection was performed by using extreme gradient boosting (XGBoost). To enhance the global and local search capabilities of the hippopotamus optimization algorithm (HO) and improve its convergence speed, an IHO was proposed by incorporating differential mutation, Levy flight, and cauchy mutation to optimize a multi-objective algorithm. To further strengthen the model’s ability to capture nonlinear relationships in water temperature, handle multi-step dependencies, and extract global information, a predictive framework combining the Mamba model and MHSA was introduced. The IHO was used to optimize the hyperparameters of the Mamba-MHSA model, forming the IHO-Mamba-MHSA multi-step prediction model for industrial Cephalopholis sonnerati aquaculture water temperature. The proposed model was validated by using water temperature data from an industrial aquaculture facility in Laizhou, Shandong. Compared with genetic algorithm (GA), particle swarm optimization (PSO), and the standard HO, the IHO achieved the highest reductions in MAE, MSE, and MAPE by 33.33%, 21.74%, and 18.37%, respectively, while increasing R2 by up to 4.42%, demonstrating its superior multi-parameter optimization performance. Furthermore, compared with long short-term memory (LSTM), gated recurrent unit (GRU), backpropagation neural network (BPNN), and temporal convolutional network (TCN), the proposed model consistently outperformed across different forecasting horizons, maintaining an R2 as high as 0.888 even at a 24-step horizon. The experimental results indicated that the proposed model met the requirements for precise water temperature prediction and refined management in industrial aquaculture, providing valuable insights for water quality regulation in intensive fish farming systems.