Theoretical Development and Empirical Validation of a Dynamic Energy Budget Model for African Catfish under Variable Temperature and Feeding Conditions in Nigeria

Dynamic energy budget theory provides a mechanistic framework for predicting how individual fish allocate ingested energy among maintenance, growth, and reproduction as a function of environmental conditions, yet no dynamic energy budget model has been parameterised for Clarias gariepinus under the temperature and nutritional regimes characteristic of Nigerian aquaculture systems. This study develops and empirically validates a dynamic energy budget model for African catfish by conducting a comprehensive set of standardised experiments at the National Institute for Freshwater Fisheries Research, Niger State, designed to estimate the full set of dynamic energy budget parameters. Experiments included starvation trials to estimate maintenance energy costs at six temperatures between 22 and 36 degrees Celsius, assimilation efficiency measurement across three diet types, reproduction output quantification across female size classes, and growth trajectories under three feeding levels and four temperature regimes. The dynamic energy budget parameter set was estimated by simultaneous fitting to all experimental datasets using a likelihood-based framework implemented in custom R code. Model validation was conducted against independent growth and reproduction data from commercial catfish farms in Ogun, Anambra, and Kano States. The validated model accurately predicted growth trajectories across all validation farm environments (mean absolute percentage error of 8.4%). Scenario analysis using the model demonstrated that optimising temperature management in recirculating aquaculture systems to maintain 30 degrees Celsius rather than ambient could reduce the time to market weight by 22 days on average in Nigerian catfish production. The dynamic energy budget model provides a mechanistic foundation for optimising feed management, temperature control, and breeding cycle planning in Nigerian catfish aquaculture.

Keywords: dynamic energy budget, bioenergetics, Clarias gariepinus, temperature, growth model