Do Crabs Have Rights

Do crabs have rights?   

12 July 2009 by Peter Fraser Magazine issue 2716. Subscribe and get 4 free issues. For similar stories, visit the Comment and Analysis Topic Guide

ANIMAL welfare legislation generally applies only to vertebrates. There are, however, moves to include invertebrates. Proposed changes to European law, for example, would extend welfare laws to crabs and lobsters. Up to now the only invertebrate protected is the common octopus. "Invertebrate rights" has become a campaigning issue. Advocates for Animals recently produced a report which concludes that there is "potential for experiencing pain and suffering" in crustaceans. The group is particularly concerned about boiling lobsters alive. The wider public is also showing interest. Research supposedly demonstrating that hermit crabs feel and remember pain received worldwide news coverage (Animal Behaviour, vol 77, p 1243). I find the evidence unconvincing. One key argument put forward for protecting crustaceans hinges on similarities between their nervous systems and our own. Such similarities are taken as prima facie evidence that mammals feel pain. Surely this applies to invertebrates too? It is true that crustaceans have neural systems similar in some respects to those involved in human pain, but there are also important differences. The brains of lobsters and crabs have only 100,000 neurons compared with 100 billion in mammals. Their nerves conduct signals 100 times more slowly, and their brains lack the higher centres necessary for a mammal to suffer pain. Crustaceans have neural systems similar to those involved in human pain, but there are differences too Just because the components of a complex system are there does not mean that the system itself is in place. Crabs can hear, but are unlikely to appreciate opera. The superficial similarity between crustacean and mammalian brains does not necessarily mean that crabs experience pain. As for lobsters in boiling water, sensory nerves from crabs living in temperate waters fail irreversibly at 25 °C, about the temperature of tepid bath water. This procedure is not inhumane. Extending welfare to crustaceans would be a mistake. They are useful animals for research on nervous systems. Hopefully common sense and the basic scientific facts should dictate that invertebrates remain outside the legislation.