Lately, I’ve been thinking about the moral status of invertebrates. In her book Speciesism, animal rights activist Joan Dunayer argues that a spider has as much right to life as a person. Dunayer is the exception to the general rule that most Americans, including most animal protectionists, don’t lose sleep over the suffering of invertebrates. Spineless creatures are not covered under any federal or state animal welfare guidelines in the United States. This is not the case, however, in Great Britain where octopuses used in research are covered by animal protection statutes. Animal rights philosopher Peter Singer argued that at least some invertebrates merit moral concern when he drew the ethical bright line “somewhere between a shrimp and an oyster.” Adolf Hitler was also concerned with pain and suffering in invertebrates; he had procedures for the humane killing of crabs and lobsters in German restaurants included in the 1936 Nazi animal welfare regulations. (See here.)

Lucky Crabs and Unlucky Crabs

My interest in the moral status of invertebrates was sparked during a sunset tour boat cruise my wife and I recently took through the 10,000 Islands section of the Everglades National Park. The evening was magical – dolphins galore, flocks of giant white pelicans, more ospreys than you could count, the quiet only interrupted by a commercial fishing boat headed full tilt back to port with its catch of crabs. Our boat’s captain explained to us that there were two varieties of crabs harvested in the waters of Florida’s Gulf coast – he called them the “lucky crabs” and the “unlucky crabs.”

The unlucky crabs, he said, are blue crabs. They will be killed quickly in pots of boiling water and wind up on dinner plates at expensive South Beach supper clubs. The lucky crabs are a different species -- stone crabs (Menippe mercenaria). These creatures are endowed with huge claws which can regenerate. So instead of killing them, the crabbers simply rip one or both claws off these “lucky” fellows and toss the amputees back into the Gulf, where they will presumably grow another claw -- which will be ripped off the next time the crab is caught.

How Big a Moral Problem?

I was a bit skeptical about whether an animal that has its arms torn off is “lucky” so I did some research on the effects of traumatic amputation on crustaceans. In an early study (here), Everglades National Park Service scientists studied the survival rates of declawed stone crabs. “Using commercially accepted techniques,” the researchers pulled the claws off 201 adult stone crabs. The results were not pretty. When both claws were removed, half of the crabs died, usually within 24 hours. When one claw was removed, about 25% of the crabs died. A more recent study by Robert Elwood at Queens University in Belfast reported that declawed crabs in the UK -- where it is also common practice to amputate crabs and return them to the ocean -- suffered high levels of physiological stress as well as increased mortality rates.

Crabs that survive the trauma of declawing still have a rough go of it (here). Declawed crabs have trouble foraging for food and defending themselves from predators. They also tend to lose fights with other crabs and have decreased reproductive success. Even if everything goes right, and a declawed crab survives the trauma of amputation and is able to ward off enemies, it will take about 18 months for a “lucky” stone crab to regenerate a new claw of harvestable size.

How big is the stone crab welfare problem? In Florida alone, crab claws bring in about $10 million annually to commercial fisherman. In a typical year, about three million pounds of claws are harvested off the Florida Gulf coast. Crab claws typically range from three to six ounces and are sorted according to size – “medium,” “large,” “jumbo,” and “colossal.” (Jumbo claws were going for $24 a pound at sea food shops in Fort Myers last week.) Claws must be at least 2 and 3/4 inches long to be legally harvested.(See here.) Fishermen can amputate both claws if both make the size limit (uncommon). If we assume the average claw weighs between 4 and 5 ounces, about 10 million claws are ripped off Florida stone crabs annually.

Granted, in sheer numbers of animals, this is small potatoes compare to the nine billion broilers raised in the dark fetid atmosphere of America’s chicken grow-out houses. But, then, the chickens don’t have their legs ripped off. I admit that I have no qualms about killing the fleas on my cat, the ants in my kitchen, or the bugs on my windshield, but stone crab claws are off the menu in the Herzog household.


For a discussion of the issues raised by pain and suffering in invertebrates, see this article by animal behaviorist and octopus researcher Jennifer Mather. For an elegant essay on moralilty of eating lobster, see “Consider the Lobster” by the late David Foster Wallace.

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Hal Herzog is professor of psychology at Western Carolina University and author of Some We Love, Some We Hate, Some We Eat, Why It's So Hard To Think Straight About Animals.

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