Towards ‘humane’ shrimp slaughter: A review of current knowledge gaps and methodological challenges for Penaeus vannamei

Constance Blary, Lola Reverchon-Billot, Julien Bacqué-Cazenave , Aurelia Warin

Penaeus vannamei has become the most widely farmed aquatic species worldwide, yet the methods used for its stunning and slaughter remain poorly documented and largely unvalidated scientifically. Growing regulatory attention to decapod sentience calls for a critical assessment of current slaughter practices and of the indicators available to evaluate them. This review is based on a systematic search of the scientific literature covering the last three decades, focused on sentience, pain, stress indicators, stunning and slaughter methods in shrimp P. vannamei and other decapod crustaceans. The body of literature identified in this review is composed predominantly of review papers, reports, and non-peer-reviewed documents, with only a limited number of primary experimental studies. These primary studies, together with the available reports, highlight a substantial lack of validated information on indicators of pain, consciousness, and insensibility in Penaeide. This gap is further acknowledged within the review papers identified. Consequently, the four available experimental primary articles on stunning and slaughter methods of P. vannamei remain difficult to interpret in welfare terms. Establishing whether current slaughter methods of P. vannamei are humane would require sequentially validating shrimp sentience, identifying reliable pain markers, translating them into field-applicable indicators, and then evaluating slaughter methods against these criteria. A chain of evidence that remains largely incomplete for shrimps.