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.....Arthropods are the most diverse phylum of the animal kingdom, and include insects, crustaceans and spiders. The basis for proposed legislation to protect the more complex decapod crustaceans, is that they may be capable of pain and suffering. Decapod nervous systemsCrabs and lobsters have about 100,000 neurons, compared with 100bn in people and other mammals. While this allows them to react to threatening stimuli, there is no current evidence that they feel pain. Their nerves are more primitive, lacking the myelin coating which allows fast conduction of signals (pain signals in humans travel exclusively through ‘fast’ fibres). The nerves of decapods therefore conduct at around 1ms-1, compared with 100ms-1 at which pain is conducted in mammals. There is good evidence to suggest that decapods don't experience sensation the way we do. Their small number of neurons means they may not be able to be able to sense much at all. Additionally the organisation of their nervous system is very different from that of vertebrates: rather than having a spinal cord and brain where inputs from the sensory system are integrated, lobsters have a simple, system consisting of several discrete paired clusters of nerve cell bodies which are fused to a nerve cord which runs the length of the body. The largest of these ganglia control the mouthparts. In crabs, which have short bodies, the ganglia which would run through the thorax are fused into a single mass and there are fewer abdominal ganglia.Do decapods feel pain?This question is often debated by policy makers responsible for regulation of the food industry and science. It is important that animals are killed in a humane way and do not suffer, but the differences between decapod and human nervous systems complicate the issue. Some recent research has focused on this debate. For example a study shows that crabs respond to and move away from an electric shock stimulus1. However, observations in humans with injured spinal cords and the experiments on animals tell us that you cannot infer that a vertebrate can "feel" anything simply by observing that it responds with movement to a stimulus. Invertebrates use opioids as chemical transmitters, and this has also been cited...
…in northern Taiwan and other areas, they are common at seaside restaurants, served boiled and bisected with a clean lateral slice. The white meat, similar to crab or lobster in texture, is then easily removed. The species are noted for resemblance to the common woodlouse or pill bug, to which they are related. The few specimens caught in the Americas with baited traps are sometimes seen in public aquaria
