Boiled alive and torn limb from limb – it's time we took seriously the question of whether animals like squid, octopus and lobsters suffer
A SCIENTIST and a seafood chef walk into a bar. "We have a mutual interest," says the scientist. "I study crustaceans and you cook them." But the chef wanted to know just one thing. Do they feel pain?
Robert Elwood had been working with crabs and prawns for the best part of three decades when he bumped into TV chef Rick Stein in a local pub on the coast of Northern Ireland. Yet he was stumped. "It was the first time I ever considered the question," he says.
Although some people are horrified by the idea of cooking lobsters alive, or the practice of tearing claws from live crabs before tossing them back into the sea, such views are based on a hunch. We know next to nothing about whether or not these animals – or invertebrates in general – actually suffer. In Elwood's experience, researchers are either certain they feel pain or certain they don't. "Very few people say we need to know," he says.
The global food industry farms or catches invertebrates in their billions every year, from shrimp and squid to wasps and worms. But unlike their vertebrate cousins – pigs, chickens, fish, and so on – they enjoy virtually no legal protection (see "Outside the law"). "Early on in my career I realised that when the law speaks of animals, it does not mean invertebrates," says Antoine Goetschel, an international animal law and ethics consultant based in Zurich, Switzerland. "As long as the common opinion is that invertebrates do not suffer, they are out of the game."
But the game is changing. Relatively complex yet free of red tape, invertebrates have become the lab animal of choice for many researchers. Meanwhile, plans are afoot in the European Union and elsewhere to farm insects on an industrial scale. And Elwood and others are finding evidence that could have implications for all of these developments. The more we find out, the more we need to rethink a distinction based on backbone alone.
Pain is an awkward thing to test, though. It can't be measured directly or pointed at – it's not even easy to define. We know it when we feel it, of course. But when we are in pain, others just have to take our word for it. How can we tell when an animal is suffering? We have come a long way since Descartes, who argued that all non-human animals were merely automata, without self-awareness and incapable of feeling. But much of what we think we know still involves a lot of guesswork.
We have an empathy for animals that are familiar to us, especially other mammals. Many respond in the same ways we do when we are in pain, by nursing a wound, for example. Anatomical similarities give further clues. Since we feel pain, it seems logical to think that animals with a similarly organised central nervous system feel pain too. That covers vertebrates, from mammals to birds and, at a stretch, fish. But when it comes to a crab, a squid or a wasp, analogies break down. These are strange, alien creatures.
So how do we answer Stein's question? Elwood has been looking for ways to do so since running into Stein eight years ago. For a start, arguments by analogy are silly, he says. "Denying that crabs feel pain because they don't have the same biology is like denying they can see because they don't have a visual cortex."
Elwood and colleagues at Queen's University Belfast in the UK are instead tackling the question by looking at how these animals behave. Most organisms can respond to a stimulus that signals a potentially harmful event. Special receptors called nociceptors – which sense excessive temperatures, noxious chemicals, or mechanical injuries like crushing or tearing – are found throughout the animal world, from humans to fruit flies. When a parasitic wasp jabs its egg-laying ovipositor into a fruit fly larva, for example, the larva senses the needle and curls up, which can make the wasp pull out.
Beyond reflex
But when an animal responds to something we would consider painful, it does not necessarily mean the animal is in pain. The response might be a simple reflex, where signals do not travel all the way to the brain, bypassing the parts of the nervous system connected with the conscious perception of pain. When we scald our hand, for example, we immediately – and involuntarily – pull it away. Pain is the conscious experience that follows, once the signals have reached the brain. The key for Elwood was thus to look for responses that went beyond reflex – the crustacean equivalents of limping or nursing a wound.
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