A growing body of evidence is challenging the long-held belief that crustaceans are incapable of feeling pain. New neurological data from a research team at the University of Gothenburg has added weight to calls for legal and industry reforms surrounding the treatment of animals such as crabs, lobsters, and prawns.
The study focuses on how shore crabs react to both physical and chemical stressors, recording significant neural activity that indicates the presence of pain-processing mechanisms. These findings suggest that decapod crustaceans, widely used in global seafood industries, may experience suffering when subjected to common preparation methods like boiling.
Practices still legally permitted in many countries, including immersing live lobsters in boiling water, are now under growing ethical and regulatory pressure. Researchers say these animals are more neurologically complex than previously assumed, prompting legislative reviews in several jurisdictions.
In the United Kingdom, the Animal Welfare (Sentience) Act 2022 formally recognised crustaceans as sentient beings. While the law has paved the way for future protections, it has not yet prohibited specific methods of preparation such as boiling without stunning.
Brain Recordings Reveal Active Pain Signalling in Crustaceans
A peer-reviewed study published in Biology examined how shore crabs respond to potentially painful stimuli by using surface electrodes to monitor brain activity. Researchers applied mechanical pressure and a mild acid (acetic vinegar) to the animals’ soft tissues, recording measurable spikes in neural signals in both cases.
“We could see that the crab has some kind of pain receptors in its soft tissues,” said lead author Eleftherios Kasiouras. “We recorded an increase in brain activity when we applied a potentially painful chemical.” These signals were not brief or random. The team noted fast, intense responses to pressure and slower, sustained activation after chemical exposure.
The study concluded that these responses indicate the presence of nociceptors—specialised neurons that detect harmful stimuli—and a central mechanism capable of processing those signals, supporting the view that crabs have the capacity to experience pain.
The findings align with earlier observational research suggesting that crustaceans can learn to avoid harmful environments, a behaviour not explained by reflex alone. This growing body of evidence is reshaping scientific consensus on crustacean sentience and its ethical implications.
Lobsters and Prawns May Share Similar Pain Mechanisms
Though the Gothenburg study focused on shore crabs (Carcinus maenas), the researchers suggested that similar responses are likely present in other decapod crustaceans due to their shared anatomy and neurobiology. This includes lobsters, crayfish, and shrimps.
Kasiouras stated that “we can assume that shrimps, crayfish, and lobsters can also send external signals about painful stimuli to their brain which will process this information.” This perspective is consistent with prior research on related species and supports broader concerns over current seafood handling practices.
The most common cooking method—placing lobsters directly into boiling water—remains legal in most regions, despite scientific findings suggesting it may cause significant distress. This has placed pressure on both legislators and industry to consider more humane alternatives.
UK Law Acknowledges Crustacean Sentience but Stops Short of Reform
In 2022, the UK Parliament passed the Animal Welfare (Sentience) Act, which officially recognised decapod crustaceans and cephalopod molluscs as sentient. The act established an Animal Sentience Committee, tasked with reviewing government policy decisions that could impact the welfare of sentient animals.
Under the legislation, the committee can issue reports on whether the government has shown “due regard” for animal welfare in its policy formulation. However, the law does not impose binding requirements on how sentient species must be treated during commercial processes, including slaughter or food preparation.
The act’s recognition of animal sentience is considered a foundational step, but enforcement remains limited. Campaigners and scientists have argued that meaningful protections for invertebrates will depend on how the law is interpreted and applied by policymakers going forward.
Other countries have implemented more prescriptive rules. Since 2018, Switzerland has required lobsters to be stunned before boiling, using electrical or mechanical methods. In New Zealand and parts of Australia, food safety agencies recommend placing crustaceans in a salt-ice slurry to induce a torpid state before cooking, reducing the likelihood of conscious suffering.
Humane Slaughter Methods Remain Underutilised
Researchers involved in the Gothenburg project highlighted alternative methods already available to minimise animal suffering. One approach involves chilling crabs at low temperatures (around 0°C or 32°F), which induces a state of reduced neural activity. Another technique uses electrical stunning, such as with the CrustaStun device, to render crustaceans unconscious almost instantly.
These practices are accepted by veterinary authorities in several regions but are not widely adopted in commercial seafood operations. Implementation remains uneven due to perceived cost barriers, lack of training, or absence of legal mandates.
Dr Lynne Sneddon, a researcher in animal physiology at the University of Gothenburg, stated: “We need to find less painful ways to kill shellfish if we are to continue eating them. Because now we have scientific evidence that they both experience and react to pain.”
Consumers and regulators may play an increasing role in shaping future standards. Initiatives such as sourcing transparency, humane certification schemes, and public awareness efforts have already influenced supply chain practices in other sectors, such as poultry and egg production.