Crustaceans know more than you think

Crustaceans know more than you think

Lobsters don’t scream. They don’t have the necessary apparatus to vocalize.

The high-pitched sound sometimes heard when they are dropped into a pot of boiling water is a whistle, the result of expanding air rushing out of small holes in lobsters’ bodies. If doesn’t matter whether the lobster is dead or alive. If the water is hot enough, you’ll hear the sound.

For years, it was believed that lobsters did not feel pain. Since 1987, the Lobster Institute at the University of Maine insists that’s so because invertebrates have such primitive nervous systems (they have no brain and 100,000 neurons versus a human’s 100 billion). A 2005 study financed by the Norwegian government reinforced this view.

But now a review commissioned by the UK government is disputing this long-held and convenient idea. Lobsters–and octopuses and crabs and other crustaceans–do experience pain and suffering, the study says.

Well, duh. Why wouldn’t they?

CNN reports that the creatures are included on a list of sentient beings to be given protection under new animal welfare laws.

The London School of Economics looked at 300 scientific studies to evaluate evidence of sentience in cephalopods (squid, octopus) and decapods (crabs, lobsters, crayfish, shrimp, prawns).

Vertebrates (fish, amphibians, reptiles, mammals, birds) are already classified as sentient in legislation under debate in the United Kingdom.

The school says that lobsters and crabs shouldn’t be boiled alive and includes best practices for the transport, stunning and slaughter of decapods and cephalopods.

According to, scientists have also discovered that crustaceans can learn to anticipate and avoid pain–a reasoning historically thought of as a trait unique to vertebrates.

The London School of Economics report used measures such as learning ability, possession of pain receptors, connections between pain receptors and certain brain regions, response to anesthetics or analgesics, and behaviors including balancing threat against opportunity for reward and protection against injury or threat.

Researchers say that crustaceans may experience anxiety–considered a complex emotion–in much the same way humans do. And they react to it like many of us, by seeking out a safe space.

There’s no way I’d ever toss a live lobster into a pot of boiling water, so this research isn’t a game-changer for me. Yet I always wondered about the alleged humanity of catch-and-release fishing, often practiced with virtue-signaling displays of moral superiority by those who enjoy this activity.

It turns out my concern is legitimate.

“Catch-and-release fishing is cruelty disguised as sport,” says PETA. “Studies show that fish who are caught and then returned to the water suffer such severe physiological stress that they often die of shock.” That’s not much different than being hooked, bashed in the head, and dying in order to wind up in a frying pan.

It’s astonishing that there are some who think that animals–even mammals and other vertebrates–don’t feel pain, or joy, or frustration, or anger. Anyone who’s spent time around dogs and cats knows better.

Plenty of other animals are capable of expressing themselves; I worked weekends over the course of a recent summer at a west Little Rock barn for hunter-jumper and dressage horses who spent the hottest hours of the day in their spacious stalls and were released into pastures when the sun started to go down.

Leading those 24 tall, elegant, temperamental equines into and out of grassy spaces is a slow process that allows for observation of behavior. I recall one black gelding, said to have had a role in the first “Pirates of the Caribbean” film, who loved to corner me in his box stall when I was there cleaning up after him (horse owners know that this is a nonstop event).

He’d block me from getting around him to leave the stall–not in an aggressive or bossy manner, but to amuse himself watching my efforts to move his sizable backside out of the way.

Another horse at the barn, irritated at the manner in which I was leading him, pulled his head up so high that it was an effort to hang onto him. I (stupidly) jerked the lead, which caused him to take revenge by lowering his head, then swiftly lurching it upward, banging the bottom of my chin in the process. I would have been knocked backward if I’d been a couple of inches closer. I swear he was laughing at the look on my face.

Luckily most of us–especially those who have been outwitted by a clever creature–realize that mammals are sentient. If evidence does point towards sentience being widespread among invertebrates, what does that mean? Would we end up with absurd laws banning us from stepping on insects?

No, reports the Guardian. Laws are limited by what is enforceable and reasonable.

The ambiguity of the issue, says the Guardian, suggests the need for a scientific approach to animal sentience that goes beyond intuitive reactions, which are often anthropomorphic and mammal-centric. Instead the approach should be based on examining what feelings, emotions, and pain do for us, and then looking for markers of similar brain processes in other animals.

According to, life forms that don’t have centralized nervous systems are not sentient. This includes bacteria, fungi, and plants, which don’t have nerves. Boil them if you want to. But leave the lobsters alone.

Karen Martin is senior editor of Perspective.


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