Fish Feel Pain.

Found this article here about how fish feel pain.  I knew that Birds, Cats and Dogs feel pain but there has long been a myth that fish don't feel pain.  Poor Earth.  Everything suffers.  Next they will say grass suffers.  Have a read.

Ila France Porcher is a self-taught, published ethologist and the author of "The Shark Sessions." A wildlife artist who recorded the behavior of animals she painted, Porcher was intrigued by sharks in Tahiti and launched an intensive study to systematically observe them following the precepts of cognitive ethology. Credited with the discovery of a way to study sharks without killing them, Porcher has been called "the Jane Goodall of sharks" for her documentation of their intelligence in the wild. She contributed this article to Live Science's Expert Voices: Op-Ed & Insights.

Researchers at Yale Law School made headlines recently, when they suggested that people often fail to question their political beliefs in the face of scientific discoveries that contradict them. The study showed how people reason selectively, and interpret data in such a way that it conforms with their political vantage point.

This phenomenon is evident in the pseudoscience related to fisheries, a multi-billion dollar industry that has taken control of the planet's wild fish populations and the public's perceptions of these animals. Despite available facts, industry conclusions are always in favor of fishermen, not fish.

Though rigorous scientific research has established beyond all doubt that the pain system in fish is virtually identical to that of mammals, the fishing industry has maintained that fish are too simple-minded to feel pain. As a result, most people seem to believe the old fishermen's tale that no matter how you brutalize fish and sharks, they won't suffer, and the abuse continues with almost no public outcry or protest.

Yet no evidence has ever been produced to support the idea that an animal could live successfully, and survive, without the ability to feel pain, an important warning sensation. It would result in inappropriate behavior, and the fish would go straight into evolution's garbage can. Only a small percentage of fish who come into the world live to adulthood, and any weakness would doom them. [Do Fish Feel Pain? The Debate Continues ]

Neither do observations of fish behavior support the idea. Fish appear cautious and careful, and display cognitive behavior in their efforts to eat food, such as sea urchins, that could sting them. Indeed, the evolution of urchin defenses, as well as a host of other oceanic stingers, seem to have depended on the ability of fish to feel pain.

The subjective idea of fish feeling no pain has persisted, even though it fails to fit in with established science.

The study of pain in fish

Since animals cannot tell us how they feel, scientists have searched indirectly for evidence about their subjective experiences, in the studies of neuroanatomy, neurophysiology and behavior. Researchers have developed strict criteria, all of which need to be met, before they can conclude that an animal can feel pain .

First, there must be nociceptors — sensory neurons that respond to tissue damage by sending nerve signals to the spinal cord and brain. There must be neural pathways from the nociceptors to higher brain regions, and the signal from the nociceptor must be processed in the higher brain, not in the reflex centers in the hindbrain or spinal cord.

There must be opioid receptors within the nervous system, and opioid substances produced internally. Painkilling drugs should relieve the symptoms of pain that the animal displays, and the animal should be able to learn to avoid a painful stimulus. This should be so important to the animal that it avoids the threat of pain right away. The painful event should strongly interfere with normal behavior — it should not be an instantaneous withdrawal response, but long-term distress.

Fish meet all of those criteria, as has been shown in a wide variety of experiments. Their nociceptors are nearly identical to those found in mammals and humans, and the nociceptors are connected to the brain through neurons. There are also connections between the different structures of the brain, including those that are considered crucial to the experience of pain. The whole brain of the fish is active during painful events.

In addition to neural activity, certain genes that are crucial to the experience of pain in humans are also found in fish, and they are active throughout the fish's brain during painful events. This activity of the brain, at both the molecular and the physiological level, indicates that these are not reflex reactions. If they were, such activity would not be seen in the higher brain.

How fish react to pain

Fish have displayed a variety of adverse changes in their behavior after the infliction of pain, such as an extreme increase in their ventilation (respiratory) rate, rubbing damaged body parts on the surrounding environment, rocking on their pectoral fins, trying to stay upright and no longer feeding. These, and other symptoms of distress, are relieved by the administration of morphine, which completes the circle and identifies pain as the cause of the change in behavior.

Like other animals tested in laboratory settings, fish have been shown to self-administer painkillers if they can — even if that means going into a location that they do not like — to bathe in water that medicates them. This is another clue that the fish were suffering, and found relief in the undesirable location.

Fish swiftly learn to avoid painful events, which researchers think indicates that they are conscious — they experience the pain so severely that they are strongly motivated to avoid feeling it again, even after just one exposure.

Though humans can override pain, at times, in certain heightened mental states — particularly when in danger — it seems that fish cannot do so. Studies have shown that after being hurt, fish become far less alert to danger, as if their pain is too overwhelming for them to ignore it, even to escape a predator. It is thought that due to their simpler neural design and mental states, fish lack the ability to think about their pain and put it in perspective as humans can. Pain for fish seems always to be an intense experience, which suggests that they may actually feel pain more intensely than humans.

When Rebecca Dunlop of Queensland University discovered that fish learn to avoid painful experiences, she wrote, "Pain avoidance in fish doesn't seem to be a reflex response, but rather one that is learned, remembered and is changed according to different circumstances. Therefore, if fish can perceive pain, then angling [fishing] cannot continue to be considered a noncruel sport."

Because of such findings, there has been meticulous research into the best way to relieve pain in fish during surgery. Because the pain system in fish appears to be the same as that in birds and mammals, veterinarians systematically use pain relief while performing surgery on fish. Given that they are conscious, and may suffer on an emotional level, fish welfare emerges as an important issue.

Yet while amphibians, reptiles, birds and mammals have been protected from cruel treatment, fish and sharks have not, thanks to the domination of those who profit from killing them.



There was more to the article so check it out on the website if your interested.


Darcy Lee