Developing reliable methods to assess pain in fish is critical for improving welfare in aquaculture, research, and recreational fishing — and the science has advanced significantly in recent years.
The scientific consensus on fish pain has shifted substantially over the past two decades. While early dismissals relied on the absence of a neocortex (the brain region associated with pain processing in mammals), fish possess functionally analogous structures that respond similarly to noxious stimuli. Assessment tools adapted from mammalian research are enabling more systematic welfare monitoring in aquaculture settings. The practical challenge is that fish behavioral responses are less legible to human observers than those of mammals — they do not cry out or adopt postures we intuitively recognize as pain-related. Validated assessment tools help bridge this interpretive gap, enabling farm managers, researchers, and veterinarians to make evidence-based decisions about pain mitigation.