Oriental river prawns are widely farmed in China and Japan in pond systems, with welfare concerns around aggression, moulting vulnerability, and slaughter practices for this commercially important freshwater crustacean.
Territorial aggression in crowded M. nipponense ponds causes antenna, eye, and claw damage in subordinate individuals. Moulting prawns lacking hard shells are killed and eaten by tank-mates if no refuge is provided. Suboptimal water quality causes hypoxic stress and disease susceptibility. Evidence for nociception in freshwater prawns supports welfare consideration at slaughter. The scale of production — hundreds of thousands of tonnes annually — means small welfare improvements per individual translate to massive aggregate welfare gains.