When it comes to consuming animals, we often focus on animal welfare for species that are anatomically similar to us. As evidence grows that invertebrates also experience pain, humane killing methods are suggested to extend to crustaceans. In response, several countries have already banned boiling lobsters alive, with others likely to follow.
But what is a better way to do the deed? To understand which methods are best, researchers study how crustaceans react to potentially painful triggers.
A research team from the University of Gothenburg recorded how Norway lobsters reacted to electric shocks, a proposed alternative to live boiling, and how the painkillers aspirin and lidocaine affected the animals’ stress responses. The study, published in Scientific Reports, suggests that lobsters’ responses to human painkillers provide further evidence that they experience pain.
“The fact that painkillers developed for humans also work on Norway lobsters shows how similar we function,” said study co-author Lynne Sneddon, professor of zoophysiology at the University of Gothenburg, in a press statement. “That's why it's important to care about how we treat and kill crustaceans, just as we do with chickens and cows.”
Studying Pain Leads to Better Animal Welfare
The past century has seen a surge in animal welfare based on scientific insights into animal biology and its similarities to humans. Today, most experts agree that vertebrates can experience pain, an ability that evolved for good reason. Although uncomfortable, pain is a crucial mechanism that protects us from harm by encouraging us to stop its source.
Explore All OptionsThe question is which life forms share this ability, as determining it is challenging. Animals can’t communicate their experiences directly, so researchers rely on behavior and physiological changes associated with known pain processes.
Current research focuses on several groups of invertebrates, including crustaceans, with findings already shaping welfare practices. Parts of Australia, Austria, New Zealand, Norway, and Switzerland have banned live boiling, and in 2021, the U.K. recognized lobsters, octopus, and crabs as sentient beings to guide future welfare decisions.
“There is already evidence that decapod crustaceans exhibit signs of discomfort and stress when exposed to injuries such as forced removal of a claw,” said Sneddon. “Our latest experiments show that Norway lobsters react adversely to electric shocks which are painful to humans.”
Human Painkillers Also Work on Lobsters
The Gothenburg team studied Norway lobsters (Nephrops norvegicus) caught in the wild and transported to an experimental aquarium. They divided the animals into seven groups under different conditions, including exposure to shocks with or without aspirin or lidocaine.
Alongside behavior, the scientists analyzed hemolymph (the invertebrate equivalent of blood) and nervous tissue for physiological markers of stress. Molecules like lactate, glucose, and certain gene expressions shift during pain-related stress responses.
Both painkillers had significant effects, but in different ways. After aspirin injection, the animals groomed their legs and claws — a common stress behavior — but tail flipping in response to shocks declined. On the other hand, lidocaine also reduced tail flipping during shocks, but with fewer side effects.
Finding the Most Humane Way to Kill Crustaceans Continues
Because lobsters remained relatively calm under normal conditions but reacted strongly to electric shocks by rapidly flipping their tails and escaping, researchers suggest they respond acutely to harmful stimuli. Their responses to aspirin and lidocaine, which affect neural pain pathways, further support the hypothesis that lobsters may experience pain.
Interestingly, aspirin caused additional signs of discomfort while reducing sensitivity to shocks, indicating side effects that could complicate its use. Insights like these are valuable for future procedures involving invertebrates, including in laboratory settings.
“Our results [emphasize] the importance of ethical responsibility for the welfare of crustaceans not only in the food industry,” said Sneddon. “There are campaigns to include these crustaceans in science laws where we must reduce pain in laboratory animals. This study can help inform how to make experiments gentler for the animal with the use of pain-relieving drugs. We need to do further experiments to find out the most humane way to treat and kill crustaceans if we still want them as food in the future.”
Read more: Gentle Handling Improves Baby Chick Welfare by Triggering Positive Emotions
Article Sources
Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:
- This article references information from a study published in Scientific Reports: Effects of analgesia on the response to a noxious stimulus in Norway lobsters (Nephrops norvegicus)
