Biologists have confirmed that crustaceans are sensitive to pain.

Lobsters, shrimp, and crabs are typically processed and cooked alive. However, it’s unlikely that anyone would want to continue this practice now, as researchers from the University of Gothenburg in Sweden have recorded heightened brain activity and central nervous system responses in the shore crab (Carcinus maenas) when exposed to pain, using electrophysiological methods. This discovery could alter the conditions in which crustaceans are kept and how they are treated.

2024-11-29 10:00:32https://naked-science.ru/article/biology/biologi-podtverdili-vospr

In 2015, researchers placed 40 crabs in separate aquariums and observed their reactions to external stimuli. Every 10 seconds for two minutes, the animals in the experimental group were subjected to electric shocks. As a result, 16 out of 20 crabs began to move rapidly within the aquariums, and four attempted to escape. Meanwhile, their counterparts in the control group were under no threat. It was at this moment that researchers first proved that crustaceans can feel pain.

Prior to this, it was believed that these invertebrates simply lacked brain regions responsible for pain response. Consequently, their brain anatomy is significantly different from that of higher animals, despite having important functional areas that process information.

Biologists from Sweden and Portugal clarified the situation in an article that appeared in the journal Biology. The team conducted a unique experiment, measuring and recording the brain and central nervous system activity of the shore crab in response to mechanical and chemical stimuli using an electrophysiological method similar to electroencephalography (EEG).

The soft tissues of the animals—antennae, claws, and walking legs—were subjected to mechanical pressure using von Frey filaments (nylon monofilaments for sensitivity diagnosis), and acetic acid was applied to them in various concentrations.

As a result, the scientists recorded an increase in activity in the crustaceans' brains in response to both the application of acetic acid and physical pressure on the soft tissues. This reaction indicates the presence of so-called nociceptors in the animals, which are responsible for the perception of pain. Since the crab's body can transmit pain signals to the brain, similar mechanisms are likely present in other crustaceans, such as lobsters and shrimp.

The researchers noted that mechanical stimuli caused a shorter but more intense activity in the brain, while the response to acetic acid lasted longer. Additionally, the crabs' antennae reacted exclusively to chemical stimuli.

Although the clear brain activity of crustaceans during mechanical and/or chemical stimulation does not mean that these animals perceive pain in the same way humans do, this discovery is important for understanding their ability to perceive harmful stimuli. The study's results raise questions about the treatment of crustaceans in fields such as the food industry, science, and aquaculture.

Biologists concluded that the crabs' sensitivity to pain should lead to more humane treatment. They urged their colleagues to consider this new data when developing regulations and standards for the care of crustaceans. Further research will help achieve a complete understanding of how nociceptors function.

“We need to find less painful methods of killing crustaceans if we want to continue consuming them, as there is now scientific evidence that they feel pain and react to it,” summed up one of the authors of the scientific paper, Lynne Sneddon.