Tropical copepod culture under climate change: live feed production and optimization

Tropical aquaculture accounts for more than a quarter of global production, yet the biomass culture of copepods as live feed has remained a major bottleneck. The demand for tropical copepods as live feed for fish, and shrimp larvae and juveniles is rapidly increasing in tropical hatcheries. However, most studies have focused on temperate to cold-adapted copepod species that may not be suitable for aquaculture in tropical regions. This paper comprehensively reviews the current development of tropical copepod culture and highlights key knowledge gaps, particularly in determining optimal food levels and rearing conditions for suitable species in five genera: Pseudodiaptomus, Acartia, Oithona, Apocyclops, and Tigriopus , especially under the interactive effects of climate change associated stressors. Across taxa, optimal food concentrations for adults generally fall within ∼400–800 μg C / L, while thermal responses are species-specific, with performance typically highest below ∼30–32 °C and declining rapidly at higher temperatures. Culture densities are often constrained to ≤400 adults/L for Pseudodiaptomus and up to ∼1000–3000 adults/L for tropical Acartia before negative density-dependent effects emerge. Climate change stressors, including warming, deoxygenation, and salinity fluctuations, can shift these thresholds, reducing biomass production and the stability of copepod harvests. Future research should focus on resolving species- and stage-specific environmental thresholds, elucidating metabolic and microbiome-mediated responses, and developing adaptive culture systems integrating real-time monitoring and predictive modelling to optimise copepod production under variable environmental conditions.