Like lobsters, crabs are often thrown into pots of scalding-hot water and boiled alive. The crabs will fight so hard against a clearly painful death that their claws often break off in their struggle to escape.
According to Science Focus, crustaceans naturally possess a harmful bacteria called vibrio present in their flesh that can multiply rapidly in the decaying lobster once it's dead — and it can't be eliminated by cooking either. So, to minimize the risk of food poisoning, crustaceans are often cooked alive.
Crabs can be killed by rapid destruction of both nerve centres by piercing both ganglia from the underside of the crab with a pointed spike (e.g. a thick, pointed pithing instrument, an awl or a sharp-pointed knife). Spiking must not be performed on lobsters because they have a long chain of nerve centres.
A report, commissioned by the United Kingdom government, evaluated evidence from 300 studies to conclude that cephalopods — such as octopuses, squid and cuttlefish — and decapods — crabs, lobsters and crayfish — are capable of experiencing pain and, therefore, shouldn't be boiled alive.
Kill the crab humanely before you remove the shell.
Use a knife or ice pick to stab the crab through its shell 1 inch (2.5 cm) below its mouth. You can also boil the crab for 1 minute to kill it. Numb the live crab in the freezer for 15 minutes before boiling.
Thus, crabs pass the bar scientists set for showing that an animal feels pain.
Some say the hiss that sounds when crustaceans hit the boiling water is a scream (it's not, they don't have vocal cords). But lobsters and crabs may want to since a new report suggests that they could feel pain.
Many people have heard that boiling crustaceans alive is a painful and inhumane way to kill a crab or lobster and this is backed up by many convincing studies as well as physical evidence such as animals dropping their limbs and writhing around before dying.
Lobsters and other shellfish have harmful bacteria naturally present in their flesh. Once the lobster is dead, these bacteria can rapidly multiply and release toxins that may not be destroyed by cooking. You therefore minimise the chance of food poisoning by cooking the lobster alive.
Like lobsters, crabs are often thrown into pots of scalding-hot water and boiled alive. The crabs will fight so hard against a clearly painful death that their claws often break off in their struggle to escape.
If you want to keep your crab fresh for longer than three months, it's recommended to separate the meat, legs and freeze them, which may last more than three months. Freeze them separately that would become more beneficial for you because if any parts are spoiled, it will not spoil the whole crab because it's separate.
If they feel nothing as they are boiled or carved alive, then ethical qualms about these practices seem as misplaced as they would be for vegetables. But if they do feel – if they are sentient – then they are cruel and inhumane.
So, first you keep the live creature in chilled water, then you grab it by the rear end and throw it face first into boiling water, then “gently” boil it for between 8 – 20 minutes depending on its' size.
The practice of eating live seafood, such as fish, crab, oysters, baby shrimp, or baby octopus, is widespread. Oysters are typically eaten live.
Plunging them into boiling water, freezing them or 'drowning' them in fresh water are not humane.
Crabs quickly learn to avoid painful experiences
The sentience of these creatures has long been a source of debate but we now know that crustaceans and cephalopods exhibit lots of abilities and behaviours which are accepted as evidence of sentience in other animals.
The Lacey Act
But it also eventually made it a federal crime to boil a live lobster. The Lacey Act reads it is a federal crime “to possess any fish or wildlife taken, possessed, transported, or sold in violation of any law or regulation of any State or in violation of any foreign law or Indian tribal law.”
Whether it is believed the lobsters experience pain or not, killing the lobster just before cooking is the preferred method.
Lobsters don't have vocal cords, and even if in agony, they cannot vocalise. The high pitched sound made by an overheating lobster is caused by expanding air rushing out of small holes in lobsters' bodies, like a whistle being blown. A dead lobster will “scream” just as loudly as if it was living.
In Elwood and Adam's 2015 paper, they found that a painful situation triggers a stress response in crabs. They reported that this, combined with other findings, such as decapods changing their behaviour long-term after a painful incident, demonstrates that decapods are capable of experiencing pain (2).
Researchers from York University argue that octopuses, crabs, lobsters, crayfish, and other invertebrates are indeed sentient and can feel pain, anger, fear, and happiness.
The nervous system of a crab differs from that of vertebrates (mammals, birds, fish, etc.) in that it has a dorsal ganglion (brain) and a ventral ganglion.