Over the years scientists have discovered that many animals feel pain including some "surprises". I put the word "surprises" in quotes because solid evolutionary theory and "good biology" strongly support the notion that a large number of animals should in fact feel pain. For example, fish were long excluded from the "pain club" but we know that they do indeed feel pain and are highly sentient beings (see also).
Now we know that crabs also feel pain. In a recent study by Barry Magee and Robert W. Elwood published in the prestigious peer-reviewed journal The Journal of Experimental Biology called "Shock avoidance by discrimination learning in the shore crab (Carcinus maenas) is consistent with a key criterion for pain" these researchers "allowed shore crabs ... to choose between one of two dark shelters in a brightly lit tank. One shelter came with a mild shock. After just two trials, crabs that initially chose the shocking shelter began opting for the zapless shelter, suggesting they learned to discriminate between the two options and headed for the less painful one." Previous research had shown that "prawns whose antennae were doused with caustic soda vigorously groomed their antennae, as if trying to ameliorate pain. Importantly, this behavior didn't occur if Elwood treated the antennae with an anesthetic first." (my emphasis)
Eliminating pain on the menu
We are continually expanding the circle of sentence and consciousness and the Treaty of Lisbon, passed by member states of the European Union that went into force on December 1, 2009, recognizes that "In formulating and implementing the Union's agriculture, fisheries, transport, internal market, research and technological development and space policies, the Union and the Member States shall, since animals are sentient beings, pay full regard to the welfare requirements of animals, while respecting the legislative or administrative provisions and customs of the Member States relating in particular to religious rites, cultural traditions and regional heritage."
Crabs and many other invertebrates who supposedly don't feel pain are served up as food in the countless billions and Professor Elwood notes that it's time to reconsider how these animals are treated in the food industry. I couldn't agree more.
Please stay tuned in as more "surprises" are revealed about sentience in other animal beings and how they really do not live pain-free lives.