Lobsters, octopuses, and squid, welcome to the sentient beings club (if you’re in the UK, at least).

The UK government has officially included decapod crustaceans — including crabs, lobsters, and crayfish — and cephalopod mollusks — including octopuses, squid, and cuttlefish — in its Animal Welfare (Sentience) Bill. This means they are now recognized as "sentient beings" in the UK. 

The move comes off the back of an independent review carried out by a team led by Dr Jonathan Birch, an associate professor in the London School of Economic's Department of Philosophy, Logic, and Scientific Method. They looked at over 300 studies and found “strong scientific evidence decapod crustaceans and cephalopod mollusks are sentient”. Sentience is a subjective concept that’s been batted about for centuries, but it generally refers to the capacity to consciously perceive feelings and sensations like pain.

Vertebrates (animals with a backbone) are already covered by the bill, but octopuses and other invertebrate animals have previously had a hard time being recognized as being sentient due to their lack of backbone. The central nervous system of invertebrates is immensely different from that of vertebrates — for instance, octopuses have a donut-shaped brain in their head and eight other “mini-brains" in each tentacle. However, this doesn't necessarily mean their central nervous system is any less complicated than certain mammals considered sentient by humans. If you’ve watched the documentary My Octopus Teacher, you’ll know that cephalopods can be incredibly intelligent, capable of some remarkably complex behavior, including potentially physical and emotional pain. There's also some solid evidence that some crustaceans feel a sense of pain.

“The amendment will... help remove a major inconsistency: octopuses and other cephalopods have been protected in science for years, but have not received any protection outside science until now. One way the UK can lead on animal welfare is by protecting these invertebrate animals that humans have often completely disregarded,” Dr Birch said in a statement.

The review recommends against using a variety of current commercial practices involving these animals, including live boiling without stunning, extreme slaughter methods, transporting the animals in icy water, and the sale of live decapod crustaceans to untrained handlers. 

The UK government has promoted this as “leading the way on animal welfare,” although its news statement points out that the change won't immediately affect existing legislation or industry practices regarding how these animals are treated in kitchens and pet stores. For now, it remains legal for a chef to toss a live lobster into a cooking pot. It will, however, be taken into account when shaping the legalization of animal welfare in the future.

A number of other countries have taken similar steps in recent years. For example, the practice of boiling lobsters alive without stunning them first is illegal in Switzerland, Norway, Austria, and New Zealand.

While boiling lobsters alive has technically been outlawed in the US since at least 1999, other rights for cephalopods and decapod crustaceans aren't quite as progressive. Octopuses aren't recognized as “animals” when it comes to federally funded research in the US so don't have to receive the same humane treatment standards given to other lab animals. This legal loophole is recognized by the Animal Welfare Act and National Institutes of Health and means that octopuses are not protected in nature or science.